Principles of Flight Test

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081 PRINCIPLES OF FLIGHT - AEROPLANE

01 Subsonic Aerodynamics

SUBSONIC AERODYNAMICS 01-01 Basics, Laws and Definitions 2625.

Airplane

ATPL

CPL

The angle between the aeroplane and the wing root chord line is the:

longitudinal

axis

A) angle of incidence. B) glide path angle. C) angle of attack. D) climb path angle. On fixed-wing aircraft, angle of incidence is the angle between the chord line of the wing where the wing is mounted to the fuselage and the longitudinal axis of the fuselage. The angle of incidence is fixed in the design of the aircraft by the mounting of the wing to the fuselage. Other terms for angle ofincidence in this context are "rigging angle" and "rigger's angle of incidence'~ It should not be confused with the angle of attack, which is the angle the wing chord presents to the airflow in flight. Note that some ambiguity in this terminology exists, as some engineering texts that focus solely on the study of airfoils and their medium may use either term when referring to angle of attack. 4202.

Airplane

ATPL

CPL

Wing loading is: A) B) C) D)

the ratio of lift to wing weight. the ratio of wing area to wing weight. the ratio of lift to aircraft weight. the ratio of aircraft weight to wing area.

In aerodynamics, WING LOADING is the loaded weight of the aircraft divided by the area of the wing. The faster an aircraft flies, the more lift is produced by each unit area of wing, so a smaller wing can carry the same weight in level flight, operating at a higher wing loading. Correspondingly, the landing and takeoff speeds will be higher. The high wing loading also decreases manoeuvrability. Wing loading is a useful measure of the general manoeuvring performance of an aircraft. Wings generate lift owing to the motion of air over the wing surface. Larger wings move more air, so an aircraft with a large wing area relative to its mass (i.e., low wing loading) will have more lift at any given speed. Therefore, an aircraft with lower wing loading will be able to takeoff and land at a lower speed (or be able to take off with a greater load). It will also be able to turn faster. Increase in wing loading means higher load factor, and hence higher stall speed; it increases by a factor of the square root of the load factor. The unit is Nlm'. Pressure is also force per area and consequently the same unit. (In SI Nlm' also has its own name, Pascal (Pa).)

4232.

Airplane

ATPL

CPL

The angle of attack of a two dimensional wing section is the angle between: A) B) C) D)

the chord line of the aerofoil and the fuselage centreline. the chord line of the aerofoil and the free stream direction. the fuselage core line and the free stream direction. the chord line and the camber line of the aerofoil.

(Refer to figure 081-£30) Terminology definition: angle between the chord line and the relative (local) airflow. Angle of attack (AOA, a - Greek letter alpha) is a term used in aerodynamics to describe the angle between the chord line of an airfoil and the vector representing the relative motion between the airfoil and the air through which

I 2625 (A) I 4202 (D) I 4232(8) I 4237(D) I 7658(A) I

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it is moving. For a two-dimensional airfoil, angle ofattack is the angle between the chord line and the direction of arrival of the incoming air. In aviation, angle of attack is used to describe the angle between the chord line of the (three dimensional) wing of a fixed-wing aircraft and the vector representing the relative motion between the aircraft and the atmosphere. Since a wing can have twist, a chord line of the whole wing may not be definable, so an alternate reference line is simply defined. Often, the chord line of the root of the wing is chosen as the reference line. The angle of attack is often confused with the pitch angle of an aircraft. Pitch angle is measured from the same reference line as angle of attack (conceptually the chord line), but to the horizon. Whereas, the angle of attack is measured from the (same) reference line to the direction of the arrival of the air to the wing (caused by the relative motion between the wing and the atmosphere).

4237.

Airplane

ATPL

CPL

The units of wing loading (i) W/S and (ii) dynamic pressure qare: A) (i) B) (i) C) (i) D) (i)

N/m 3; (i) kg/m2 kg/m; (ii) N/m2 N/m; (ii) kg N/m 2; (ii) N/m2

For explanation refer to question #4202 on this page.

7658.

Airplane

ATPL

CPL

The airfoil chord is: A) a straight line from the wing leading edge to the trailing edge. B) a line equidistant from the upper and lower wing surfaces. C) a line tangential to the wing surface at the point of maximum curvature. D) a line drawn at 15% chord from the root to the tip. (Refer to figure 081-£37) MEAN CAMBER LINE: is the line drawn halfway between the upper and lower surfaces of the airfoil. This would be the same as a line connecting the centers of all circles inscribed in the profile. This line gives us a picture of the average curvature of the airfoil section. The shape of the mean camber line is very important when determining the aerodynamic characteristics of the airfoil section. CHORD LINE: is a straight line joining the leading edge and the trailing edge. The length of the chord line is called chord. (Note: The leading edge is the point where the mean camber line intersects the front part of the airfoil section. The trailing edge is the point where the mean camber line intersects the rear part). The chord of a wing may vary greatly from root to tip. Mostly the root chord is greater than the tip chord. CAMBER: The distance between the Mean Camber Line and the Chord line is called the camber. The point where the distance between the mean camber line and the chord line is the greatest is called the maximum camber. A cambered airfoil has a camber line that is not coinciding with the chord line. If the airfoil is symmetrical (zero camber), the Mean Camber Line is a straight line between the leading and trailing edges and thus co-incident with the Chord.

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Aviationexam Test Prep Edition 2012 7691. Airplane ATPL CPL The term angle of attack in a two dimensional flow is defined as:

A) the angle for maximum lift/drag ratio. B) the angle between the aeroplane climb path and the horizon. C) the angle formed by the longitudinal axis of the aeroplane and the chord line of the wing. D) the angle between the wing chord line and the direction ofthe relative wind/airflow. For explanation refer to question #4232 on page 3.

Airplane ATPL CPL For a subsonic flow the continuity equation states that if the cross-sectional area of a tube increases, the speed of the flow: 7700.

A) first increases then decreases. B) does not change. C) increases. D) decreases.

7808. Airplane ATPL CPL The aspect ratio of the wing is the ratio between:

A) the wingspan and the root chord. B) the wingspan and the mean geometric chord. C) the tip chord and the wingspan. D) chord and root chord. (Refer to figure 081-E45) The ASPECT RATIO of a wing is defined as the ratio between wingspan and the average chord. The average chord is the same as the mean geometric chord. Wing area is wingspan multiplied by average chord. Informally, a high aspect ratio indicates long, narrow wings, whereas a low aspect ratio indicates short, stubby wings. Aspect Ratio = (wingspanj27 wing area, or Aspect Ratio = wingspan 7 mean chord. By referring to the illustration, AR = b 7 C. Hence, AB = (b x b) 7 (c x b) = b2 7 S, where S is the wing area.

7812. Airplane ATPL CPL Drag is acting in the direction of __ • Lift is perpendicular tothe ___•

In fluid dynamics, the continuity equation is a mathematical statement saying that, in any steady state process, the rate at which mass enters a system is equal to the rate at which mass leaves the system. In fluid dynamics, the continuity equation is analogous to Kirchhoff's Current Law in electric circuits. The equation of continuity says that AxpxV is constant in a stationary flow, where A is the cross-sectional area, p (rho) the air density, and V the airflow velocity. Subsonic flow is considered incompressible and in an incompressible flow the density p (rho) is constant. Therefore, any change in the area has no effect on density, but only on the velocity. The velocity (V) must decrease if the area (A) is increasing and vice versa.

7708. Airplane ATPL CPL The following unit of measurement: kgm/s2 is expressed in the 51-unit system as:

A) Pascal B) Newton C) Joule D) Watt SI unit kg signifies mass, and mis' signifies acceleration. Mass x acceleration is force, and SI unit for force is Newton (N).

7715. Airplane ATPL CPL The (subsonic) static pressure:

A) increases in a flow in a tube when the diameter decreases. B) is the total pressure plus the dynamic pressure. C) is the pressure in a point at which the velocity has become zero. D) decreases in a flow in a tube when the diameter decreases. The equation of continuity says that AxpxV is constant in a stationary flow, where A is the cross-sectional area, p the air density, and V the airflow velocity. In an incompressible flow the density is constant, which means the velocity (V) must increase if the area (A) is decreasing. Increasing velocity means higher dynamic pressure (!hpV'), and according to Bernoulli's equation the static pressure is equal to the total pressure minus the dynamic pressure. The total pressure is constant (measured where the velocity has become zero), so a higher dynamic pressure means a lower static pressure.

7752. Airplane ATPL CPL A line connecting the leading and trailing edge midway between the upper and lower surface of a aerofoil. This definition is applicable for:

A) chord line B) relative wind (airflow) C) horizon D) longitudinal axis Lift is always perpendicular to the direction of movement and drag is in the opposite direction to the movement. Relative wind/airflow is the direction of movement. 7833. Airplane ATPL CPL The true airspeed (TAS) is:

A) higher than the indicated airspeed (lAS) at altitudes below sea level, under ISA conditions. B) lower than the indicated airspeed (lAS) at altitudes below sea level, under ISA conditions. C) equal to the lAS, multiplied by the air density at sea level. D) EAS corrected for compressibility. (Refer to figure 081-EI28) lAS is actually the dynamic pressure reading (!hpTAS') but is equal to TAS in ISA conditions at 0 metres. At lower altitude the density is increased, and with the same lAS, TAS must be less.

7839. Airplane ATPL CPL Bernoulli's equation can be written as (PT P5 static pressure, q dynamic pressure):

=

=

-

= total

pressure,

A) PT = Ps-q B) PT - q =Ps C) PT+PS=q D) PT=q-PS Bernoulli's Equation states: Total Pressure = Dynamic Pressure (!hpV') + Static Pressure = Constant. Rewriting Bernoulli's equation: Pr = q + Ps (= Constant) gives:Pr-q=P,

Airplane ATPL CPL In a symmetrical airfoil the mean camber line is? 7846.

A) B) C) D)

A line joining points of mean camber along the wing. A line joining points of maximum camber along the wing. A curve co-incident with the top surface of the airfoil. A straight line co-incident with the chord line.

For explanation refer to question #7658 on page 3.

A) the Mean Aerodynamic Chord line. B) the chord line. C) the camber line. D) the upper camber line. For explanation refer to question #7658 on page 3.

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7691 (0)

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7700 (0)

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7708 (8)

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7715 (0)

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7752 (e)

I

7808 (8)

I

7812 (8)

I

7833 (8)

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7839 (8)

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7846 (0)

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01 Subsonic Aerodynamjcs 7887.

Airplane

ATPL

CPL

If the continuity equation is applicable, what will happen to the air density (rho) if the cross sectional area of a tube changes? (low speed, subsonic and incompressible flow) A) The density depends on the change of the tube area. B) rho' < rho2. e) rho' > rho2. D) rho' = rho2. For explanation refer to question #7700 on page 4.

7895.

Airplane

ATPL

A) climb path angle. B) glide path angle. e) angle of attack. D) same as the angle between chord line and fuselage axis. For explanation refer to question #4232 on page 3.

Airplane

ATPL

A) parallel to airflow. B) parallel to dynamic pressure. e) in all directions. D) downwards. Since static pressure is caused by the weight of the column of air above, it will act in all directions.

Airplane

ATPL

CPL

Which one of the following statements about Bernoulli's theorem is correct? A) The dynamic pressure is maximum in the stagnation point. B) The dynamic pressure decreases as static pressure decreases. C) The total pressure is zero when the velocity of the stream is zero. D) The dynamic pressure increases as static pressure decreases.

=

Bernoulli's Equation states: Total Pressure Dynamic Pressure (V,plf2) + Static Pressure = Constant. In the stagnation point the velocity V is zero and hence the dynamic pressure is zero. If the velocity of the stream is zero, then the total pressure is equal to the static pressure. Since the sum of static and dynamic pressure is constant, if the dynamic pressure' increases, then the static pressure must decrease.

15609.

Airplane

ATPL

15739. Airplane ATPL CPL The relative thickness of an aerofoil is expressed in:

A) degrees cross section tail angle. B) % chord. e) camber. D) meters. On an airfoil section all dimensions are expressed in percentages of the chord.

A) the chord of an equivalent untwisted, rectangular wing with the same pitching moment and lift characteristics as the actual wing. B) the chord of a large rectangular wing. C) the average chord of the actual aeroplane. D) the wing area divided by the wingspan. (Refer to figure OBI-E22) Mean Aerodynamic Chord (MAC) is the chord drawn through the geographical centre of the plan area. A rectangular wing of this chord and the same span would have identical pitching moment characteristics. Physically, MAC is the chord of a rectangular wing, which has the same area, aerodynamic force and position of the center of pressure at a given angle of attack as the given wing has. Simply stated, MAC is the width of an equivalent rectangular wing in given conditions. Therefore, not only the measure but also the position of MAC is often important. In particular, the position of center of mass (CoM) of an aircraft is usually measured relative to the MAC as the percentage of the distance from the leading edge of MAC to CoM with respect to MAC itself. Note that the attached figure implies that the MAC occurs at a point where leading or trailing edge sweep changes. In general, this is NOTthe case.

15760. Airplane ATPL CPL What is the unit of measurement for power?

CPL

Which formula or equation describes the relationship between force (F), acceleration (a) and mass (m)? A) B) e) D)

Lift and drag is always normal to each other and vary with angle of attack, but the variation is not linear. Lift and drag are the corposants of the total reaction that in turn depends on the pressure distribution about the profile.

15750. Airplane ATPL CPL The Mean Aerodynamic Chord (MAC) for a given wing of any platform is basically:

CPL

Static pressure acts:

7945.

A) vary linearly with the angle of attack. B) depend on the pressure distribution about the aerofoil. e) are normal to each other at just one angle of attack. D) are proportional. to each other, independent of angle of attack.

CPL

The angle between the direction of the undisturbed airflow (relative wind) and the chord line of an aerofoil is the:

7919.

15738. Airplane ATPL CPL The lift and drag forces, acting on an aerofoil:

m=Fxa a=Fxm F=m+a F=mxa

A) N/m B) N m/s e) kg m/s2 D) Pa/m 2 Power is defined as the rate of doing work, i.e. ForcexDistanceiTime.ln SI units that is Nmls.

Newton's second law says: Force equals mass multiplied by acceleration, i.e.F=mxa.

21017.

Airplane

ATPL

CPL

An aerofoil is cambered when: '5737. Airplane The total pressure: (note: rho = density)

ATPL

CPL

A) can be measured in a small hole in a surface, parallel to the local stream. B) is the static pressure plus the dynamic pressure. e) is the static pressure minus the dynamic pressure. D) is V2 rho V2•

A) the upper surface of the aerofoil is curved. B) the chord line is curved. C) the line, which connects the centres of all inscribed circles, is curved. D) the maximum thickness is large compared with the length of the chord. For explanation refer to question #765B on page 3.

Bernoulli's equation (theorem) states: Total Pressure =Dynamic Pressure (V2plf2) + Static Pressure = Constant.

1 7887 (0) 1 7895 (C) 1 7919 (C) 1 21017 (C) 1

1 7945 (0) 115609 (0) 1 15737 (8) 1 15738 (8) 115739 (8) 1 15750 (A) 1 15760 (8) 1

Aviationexam Test Prep Edition 2012 21037. Airplane ATPL CPL Bernoulli's equation is: (note: rho is density; PSTAT is static pressure; PDYN is dynamic pressure; PTOT is total pressure)

A) B) e) D)

PTOT + V2rho x TAS2 =constant PSTAT + V2rho x IAS2 =constant PDYN + V2rho x IAS2 = constant PSTAT + V2rho x TAS2 = constant

Bernoulli's Equation states: Total Pressure = Dynamic Pressure(!hpV') + Static Pressure = Constant. "V" in the dynamic pressure is TAS. The equation can therefore also be written: Static Pressure + Vzp(TASY = Constant. 21081.

Airplane

ATPL

CPL

In a convergent tube with an incompressible sub-sonic airflow, the following pressure changes will occur:

21133. Airplane ATPL CPL The unit of measurement for density is:

A)

kg/m3

B) psi e) kg/cm2 D) bar Density is mass per volume. In SI units mass is kg, while volume is cubic metres or m3• The 51 unit for density is therefore kg/m3 (e.g. the density of water is about 1000 kg/m~ since a 1 m3 of water weighs about 1 Tonne). Kg/m3 is sometimes equivalently written as kg m-3. 21170. Airplane ATPL CPL Which of the following statements, about a venturi in a subsonic airflow are correct?

= = =

dynamic pressures in the undisturbed and in the throat are equal. 2) The total pressures in the undisturbed and in the throat are equal.

A) Ps decreases, PDYD increases, static temperature increases. B) Ps increases, PDYD decreases, PTOT remains constant. e) P5 decreases, PDYD increases, PTOT remains constant. D) P5 decreases, PTOT increases, static temperature decreases.

A) 1 is incorrect and 2 is correct. B) 1 and 2 are correct. e) 1 is correct and 2 is incorrect. D) 1 and 2 are incorrect.

Ps static pressure PDYN dynamic pressure P TOT total pressure

1) The

flow flow

The continuity equation states that the mass flow = Axpxll, where A is the cross section area, p the air density, and V the velocity, is constant in a flow through a duct. Incompressible means a constant air density (p). In a convergent duct A is decreasing which means the velocity (V) increases. Bernoulli's equation, Pr= POYN + Ps= Constant, says, that if the velocity increases, so does the dynamic pressure (Poyn = VzpV'). For the total pressure to remain constant, the static pressure must decrease.

The continuity equation states that the mass flow = A x P x II, where A is the cross section area, p the air density, and V the velocity, is constant in a flow through a duct. Subsonic flow is considered incompressible meaning a constant air density (p). In a venturi A is decreasing to a minimum at the throat which means the velocity (V) increases. Bernoulli's equation, Pr = POYN + Ps = Constant, says, that if the velocity increases, so does the dynamic pressure (POYN = VzpV'), while the total pressure remains constant.

21116. Airplane ATPL CPL The difference between lAS and TAS will:

23202. Airplane ATPL CPL The mean camber line of an aerofoil section is:

A) increase with increasing air density. B) increase with decreasing temperature. e) decrease with decreasing altitude. D) decrease with increasing speed. (Refer to figure 081-E128) IASis actually the dynamic pressure reading (VzpTAS2) but is equal to TAS in ISA conditions at 0 metres. If the density increases (e.g. if the temperature or altitude is less) the difference between TA5 and lAS gets smaller. (If the speed is increased the compressibility correction increase and thus increasing the difference.) 21129. Airplane ATPL CPL The SI unit of measurement for pressure is:

A) Ib/gal B) kg/m3 e) N/m2 Pressure is force per area. The unit must therefore be N/m2 (also known as Pascal (Pa)).

Airplane

ATPL

CPL

The SI units of air density (i) and force (ii) are: A) B) e) D)

kg/m2; (ii) kg kg/m 3; (ii) N (i) N/m 2; (ii) N (i) (i)

(i) N/kg; (ii) kg

Density is mass per volume; in SI units that is kg/m3. Force is mass x acceleration.ln 51 units that is (kg x m)/sec2which also has the name Newton (N).

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For explanation refer to question #7658 on page 3. 23205. Airplane ATPL CPL The dynamic pressure is equal to: (note: p = density, V= speed)

A) p XV2 B) V2 p xV e) V2pXV2 D) V2 V x density2 Dynamic pressure is VzpV', where p is density and V speed.

D) bar/dm 2

21130.

A) a straight line from the leading edge to the trailing edge. B) a line from the leading to the trailing edge equidistant from the upper and lower surfaces. e) the profile of the upper surface of an aerofoil section. D) an arc of circle from the leading edge to the trailing edge.

23210. Airplane ATPL CPL The thickness to chord ratio of an aerofoil is:

A) the ratio of wing thickness at the root to the thickness at the tip. B) the ratio of the maximum thickness of an aerofoil section to its chord. e) the ratio of the wingspan to the mean chord. D) the ratio of the thickness at the quarter chord point to the chord. (Refer to figures 081-E129 and 081-E130) 'Thickness.,. chord" ratio is, as the name implies, the maximum thickness divided by the chord. The "thickness.,. chord" ratio has significant influence on the critical Mach number. The smaller the "thickness .,. chord" ratio, the higher the critical Mach number. A high ratio would therefore not be suitable for high speeds, and nar for very high altitudes, where the speed of sound is much lower and hence the Mach number higher at the same lAS.

121037 (0) 121081 (C) 1 21116 (C) 1 21129 (C) 1 21130 (8) 1 21133 (A) 1 21170 (A) 123202 (8) 123205 (C) 123210 (8) 1

01 Subsonic Aerodynamics

23237. Airplane ATPL CPL A swept wing compared to the same wing without sweep will give: A) the same lift at a given angle of attack but a lower el max. B) more lift at a given angle of attack. C) less lift at a given angle of attack. D) the same lift at a given angle of attack and a higher elmax • (Refer to figures 081-£129, 081-E730 and 081-E93) A straight wing and a swept wing with the same profile will have different Cia-curves. The curve for the swept wing is less steep than the one for the straight wing. For the same angle of attack, a swept wing will therefore produce less lift than the straight.

23248. Airplane ATPL CPL Taper ratio is the ratio of: A) the root thickness to the root chor.d. B) the span to the root chord. C) the tip chord to the root chord. D) the span to the mean chord. (Refer to figures 081-E129 and 081-E130) Taper ratio is defined as the root chord divided by the tip chord. Consequently, a tapered wing will have a smaller chord at the tip than at the root.

23250. Airplane ATPL CPL A wing would be said to be swept back if: A) the wing tips were lower than the wing roots. B) the tip chord was less than the root chord. C) the quarter chord line was inclined backwards from the lateral axis. D) the tip incidence was less than the root incidence. (Refer to figures 081-E129 and 081-E730) The sweep angle is usually measured as the angle between the line of 25% chord and a perpendicular to the root chord.

23275. Airplane ATPL CPL At a constant TAS the dynamic pressure: A) will be greater at sea level than at high altitude. S) will be less at sea level than at high altitude. e) will be the same at sea level as at high altitude. D) will be greater at altitude than at sea level.

23350. Airplane ATPL CPL Density of the atmosphere will: A) increase with increase in humidity. B) decrease with increase in humidity. e) remain unaffected by changes in humidity. D) decrease with a decrease in humidity. According to Avogardo's principle the number of molecules present in equal volumes of gasses atthe same temperature and pressure are equal.lfhumidity is increased, water molecules must replace either nitrogen (N2 ) or oxygen (02 ) molecules. The molecular weight of N2 is 28,02, of O2 32,0, while for water (HP) it is 18,02. Lighter molecules replacing heavier ones means decrease in mass, so the density will decrease.

26792. Airplane ATPL CPL Bernoulli's theorem states that in a perfect and constant airstream: A) the sum of static and dynamic pressure is constant. B) the dynamic pressure is equal to the static pressure. C) the dynamic pressure is always greater than the static pressure. D) the sum of dynamic pressure and total pressure is constant. Bernoulli's equation (theorem) states: Total Pressure = Dynamic PressureMpV2) + Static Pressure = Constant.

26793. Airplane ATPL CPL If temperature of a gas is kept constant and pressure increases, the density: A) increases. B) decreases. e) remains constant. D) has no effect. The density is proportional to the static pressure and inversely proportional to the ambient temperature; or poo PIT. If the temperature is constant and the pressure increased, the density will also increase.

26796. Airplane ATPL CPL Aspect ratio of a wing is the ratio between: A) wing span and wing root chord. B) wing root chord line and wing tip chord line. C) wing span squared and wing area. D) wing span and dihedral angle.

Dynamic pressure is ~pV2, where p is density and VTAS. The density decreases with altitude, which means that at a constant TAS, the dynamic pressure will also decrease with altitude.

For explanation refer to question #7808 on page 4.

23277. Airplane ATPL CPL The CAS is the lAS corrected for:

26821. Airplane ATPL CPL If pressure is kept constant and temperature increases, the density:

A) position and instrument error. B) position, instrument and compressibility error. e) compressibility and density error. D) position, instrument, compressibility and density error. (Refer to figure 081-E128) Indicated Air Speed (lAS) corrected for instrument and position error is Calibrated Air Speed (CAS). CAS corrected for compressibility is Equivalent Air Speed (EAS). EAS corrected for relative density (or density altitude) is True Air Speed (TAS).

23282. Airplane ATPL CPL A wing is said to be tapered if: A) it is inclined upwards from root to tip. B) the chord at the wing tip is less than the chord at the root. C) the incidence at the tip is less than at the root. D) the camber is increased at the wing tip. For explanation refer to question #23248 on this page.

A) increases. B) decreases. e) remains constant. D) has no effect. The density is proportional to the static pressure and inverse proportional to the ambient temperature; or poo PIT. If the pressure is constant and the temperature increased, the density will decrease.

26823. Airplane ATPL CPL If density is kept constant, the dynamic pressure increases proportionally with: A) velocity. B) the square of the velocity. e) the static pressure. D) inversely with the square of the velocity. Dynamic pressure (q) = vary with V2.

~pV2.lf"p" (rho)

is constant, the dynamic pressure will

I 23237 (C) I 23248 (C) I 23250 (C) I 23275 (A) I 23277 (A) I 23282 (8) I 23350 (8) I 26792 (A) I 26793 (A) I 26796 (C) I I 26821 (8) I 26823 (8) I

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Aviationexam Test Prep Edition 2012

224781. Airplane ATPL CPL Bernoulli's equation can be written as: (PT = total pressure, P5 = static pressure and q =dynamic pressure)

A) Pr=Ps+q B) Pr = PsI q C) Pr=Ps-q D) Pr=q-Ps For explanation refer to question #7839 on page 4.

224799. Airplane ATPL CPL Dihedral of the wing is: A) the angle between and the vertical axis. B) the angle between and the horizon. C) the angle between and the lateral axis. D) the angle between and the lateral axis.

the 0.25 chord line of the wing the 0.25 chord line of the wing the leading edge of the wing

As shown in the illustration, dihedral causes a stabilizing roll moment in case of a sideslip because the down going wing gets a greater angle of attack than the up going, and therefore the down going wing produces more lift than the up going. Therefore, dihedral increases the static lateral stability. Since the stability is in roll, the relevant axis is the longitudinal axis. Since increasing the dihedral will increase the stability, the control forces in roll manoeuvre will therefore be increased.

Airplane

ATPL

CPL

p=pressure rho = density T = absolute temperature The relationship between pressure, density and absolute temperature of a given mass of air can be expressed as follows: A) B) C) D)

p * rho I T = constant rho I (T * p) =constant p I (rho * T) =constant p* T I rho = constant

232032. Airplane ATPL CPL Which of these statements about weight or mass is correct? A) Weight is a force. B) Mass =weight * volume. C) The weight of an object is independent of the acceleration due to gravity. D) The mass of an object depends on the acceleration due to gravity. 232035. Airplane ATPL CPL Assuming subsonic incompressible flow, how will air density change as air flows through a tube of increasing cross-sectional area? The air density: A) decreases with increasing cross-sectional area. B) depends upon the shape of the tube alone and not its crosssectional area. C) does not vary. increases with increasing cross-sectional area.

Dr

..

airflow

through

1) The dynamic pressure in the undisturbed airflow is the same as in the throat. 2) The total pressure in the undisturbed airflow and in the throat is the same. A) B) C) D)

1) is correct, 2) is correct. 1) is correct, 2) is incorrect. 1) is incorrect, 2) is correct. 1) is incorrect, 2) is incorrect.

For explanation refer to question #21170 on page 6.

the 0.25 chord line of the wing

(Refer to figure 081-E20) DIHEDRAL Angle is the upward angle from horizontal of the wings of a fixedwing aircraft, or of any paired nominally-horizontal surfaces on any aircraft. Basically it means that the wing-tips are located higher than the wing-root (the wings slope slightly upward from root to tip). Downward angled wings have negative Dihedral Angle which is referred to as ANHEDRAL. Wings with more than one angle change along the full span are said to be POLYHEDRAL.

232030. Given:

232039. Airplane ATPL CPL Considering subsonic incompressible a Venturi, which statement is correct?

For explanation refer to question #7700 on page 4.

232040. Airplane ATPL CPL Considering subsonic incompressible a Venturi, which statement is correct?

airflow

through

1) The dynamic pressure in the undisturbed airflow is higher than in the throat. 2) The total pressure in the undisturbed airflow is higher than in the throat. A) B) C) D)

1) is correct, 2) is incorrect. 1) is incorrect, 2) is incorrect.

1) is incorrect, 2) is correct. 1) is correct, 2) is correct.

For explanation refer to question #21170 on page 6.

232042. Airplane ATPL CPL Considering subsonic incompressible a Venturi, which statement is correct?

airflow

through

1) The dynamic pressure in the undisturbed airflow is lower than in the throat. 2) The total pressure in the undisturbed airflow is lower than in the throat. A) B) C) D)

1) is correct, 2) is incorrect. 1) is incorrect, 2) is incorrect. 1) is correct, 2) is correct. 1) is incorrect, 2) is correct.

For explanation refer to question #21170 on page 6.

232043. Airplane ATPL CPL Considering subsonic incompressible a Venturi, which statement is correct?

airflow

through

1) The dynamic pressure in the undisturbed airflow is lower than in the throat. 2) The total pressure in the undisturbed airflow and in the throat is the same. A) B) C) D)

1) is correct, 2) is incorrect. 1) is incorrect, 2) is incorrect. 1) is incorrect, 2) is correct. 1) is correct, 2) is correct.

For explanation refer to question #21170 on page 6.

232044. Airplane ATPL CPL Considering subsonic incompressible a Venturi, which statement is correct?

airflow

through

1) The dynamic pressure in the undisturbed airflow is lower than in the throat. 2) The total pressure in the undisturbed airflow is higher than in the throat. A) B) C) D)

1) is incorrect, 2) is correct. 1) is correct, 2) is correct. 1) is correct, 2) is incorrect. 1) is incorrect, 2) is incorrect.

For explanation refer to question #21170 on page 6.

1224781 (A) 1224799 (C) 1232030 (C) 1232032 (A) 1232035 (C) 1232039 (C) 1232040(8) 1232042 (A) 1232043 (D) 1232044 (C) 1

01 Subsonic Aerodynamics

232045. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The dynamic pressure in the undisturbed airflow is the same as in the throat. 2) The total pressure in the undisturbed airflow is lower than in the throat. A) S) C) D)

1) is correct, 2) is correct. 1) is incorrect, 2) is correct. 1) is correct, 2) is incorrect. 1) is incorrect, 2) is incorrect.

232050. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The static pressure in the undisturbed airflow is lower than in the throat. 2) The speed in the undisturbed airflow is the same as in the throat. A) S) C) D)

1) is incorrect, 2) is correct. 1) is correct, 2) is correct. 1) is correct, 2) is incorrect. 1) is incorrect, 2) is incorrect.

For explanation refer to question #27170 on page 6.

For explanation refer to question #27170 on page 6.

232046. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The dynamic pressure in the undisturbed airflow is the same as in the throat. 2) The total pressure in the undisturbed airflow is higher than in the throat.

232051. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The static pressure in the undisturbed airflow is lower than in the throat. 2) The speed in the undisturbed airflow is higher than in the throat.

A) S) C) D)

1) is correct, 2) is correct. 1) is incorrect, 2) is correct. 1) is correct, 2) is incorrect. 1)is incorrect, 2) is incorrect.

A) S) C) D)

1) is incorrect, 2) is incorrect.

1) is correct, 2) is incorrect. 1) is incorrect, 2) is correct. 1) is correct, 2) is correct.

For explanation refer to question #27170 on page 6.

For explanation refer to question #21170 on page 6.

232047. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The dynamic pressure in the undisturbed airflow is higher than in the throat. 2) The total pressure in the undisturbed airflow is lower than in the throat.

232052. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The static pressure in the undisturbed airflow is the same as in the throat. 2) The speed in the undisturbed airflow is lower than in the throat.

A) S) C) D)

1) is incorrect, 2) is incorrect. 1) is correct, 2) is correct. 1) is incorrect, 2) is correct. 1) is correct, 2) is incorrect.

A) S) C) D)

1) is correct, 2) is incorrect. 1) is incorrect, 2) is correct. 1) is incorrect, 2) is incorrect. 1) is correct, 2) is correct.

For explanation refer to question #27170 on page 6.

For explanation refer to question #27170 on page 6.

232048. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The dynamic pressure in the undisturbed airflow is higher than in the throat. 2) The total pressure in the undisturbed airflow is the same as in the throat.

232053. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The static pressure in the undisturbed airflow is the same as in the throat. 2) The speed in the undisturbed airflow is the same as in the throat.

A) S) C) D)

1) is incorrect, 2) is correct. 1) is correct, 2) is incorrect. 1) is correct, 2) is correct. 1) is incorrect, 2) is incorrect.

A) S) C) D)

1) is incorrect, 2) is incorrect. 1) is correct, 2) is incorrect. 1) is incorrect, 2) is correct. 1) is correct, 2) is correct.

For explanation refer to question #27170 on page 6.

For explanation refer to question #21170 on page 6.

232049. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The static pressure in the undisturbed airflow is lower than in the throat. 2) The speed in the undisturbed airflow is lower than in the throat.

232054. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The static pressure in the undisturbed airflow is the same as in the throat. 2) The speed in the undisturbed airflow is higher than in the throat.

A) S) C) D)

1) is correct, 2) is correct. 1) is incorrect, 2) is incorrect. 1) is correct, 2) is incorrect. 1) is incorrect, 2) is correct.

For explanation refer to question #27170 on page 6.

A) S) C) D)

1) is correct, 2) is incorrect. 1) is correct, 2) is correct. 1) is incorrect, 2) is incorrect. 1) is incorrect, 2) is correct.

For explanation refer to question #21170 on page 6.

1232045 (0) 1232046 (0) 1232047 (A) 1232048 (A) 1232049 (0) 1232050 (0) 1232051 (A) 1232052 (8) 1232053 (A) 1232054 (C) 1

Aviationexam Test Prep Edition 2012

232055. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The static pressure in the undisturbed airflow is higher than in the throat. 2) The speed in the undisturbed airflow is lower than in the throat. A) B) C) 0)

1) is incorrect, 2) is incorrect. 1) is incorrect, 2) is correct. 1) is correct, 2) is correct. 1) is correct, 2) is incorrect.

232060. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The dynamic pressure in the throat is lower than in the undisturbed airflow. 2) The total pressure in the throat is higher than in the undisturbed airflow. A) 1) is correct, 2) is incorrect. B) 1) is incorrect, 2) is correct. C) 1) is incorrect, 2) is incorrect. 0) 1) is correct, 2) is correct.

For explanation refer to question #21170 on page 6.

For explanation refer to question #21170 on page 6.

232056. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The static pressure in the undisturbed airflow is higher than in the throat. 2) The speed in the undisturbed airflow is the same as in the throat.

232061. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The dynamic pressure in the throat is the same as in the undisturbed airflow. 2) The total pressure in the throat is lower than in the undisturbed airflow.

A) B) C) 0)

1) is incorrect, 2) is incorrect. 1) is incorrect, 2) is correct. 1) is correct, 2) is incorrect. 1) is correct, 2) is correct.

A) 1) is incorrect, 2) is correct. B) 1) is correct, 2) is correct. C) 1) is correct, 2) is incorrect. 0) 1) is incorrect, 2) is incorrect.

For explanation refer to question #21170 on page 6.

For explanation refer to question #21170 on page 6.

232057. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The static pressure in the undisturbed airflow is higher than in the throat. 2) The speed in the undisturbed airflow is higher than in the throat.

232062. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The dynamic pressure in the throat is the same as in the undisturbed airflow. 2) The total pressure in the throat is higher than in the undisturbed airflow.

A) B) C) 0)

1) is correct, 2) is incorrect. 1) is correct, 2) is correct. 1) is incorrect, 2) is incorrect. 1) is incorrect, 2) is correct.

A) 1) is incorrect, 2) is correct. B) 1) is correct, 2) is incorrect. C) 1) is correct, 2) is correct. 0) 1) is incorrect, 2) is incorrect.

For explanation refer to question #21170 on page 6.

For explanation refer to question #21170 on page 6.

232058. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which sta~ment is correct? 1) The dynamic' pressure in the throat is lower than in the undisturbed airflow. 2) The total pressure in the throat is lower than in the undisturbed airflow.

232063. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The dynamic pressure in the throat is higher than in the undisturbed airflow. 2) The total pressure in the throat is lower than in the undisturbed airflow.

A) 1) is correct, 2) is correct. B) 1) is incorrect, 2) is incorrect. C) 1) is correct, 2) is incorrect. 0) 1) is incorrect, 2) is correct.

A) B) C) 0)

1) is incorrect, 2) is incorrect. 1) is correct, 2) is incorrect. 1) is correct, 2) is correct. 1) is incorrect, 2) is correct.

For explanation refer to question #21170 on page 6.

For explanation refer to question #21170 on page 6.

232059. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The dynamic pressure in the throat is lower than in the undisturbed airflow. 2) The total pressure in the throat is the same as in the undisturbed airflow.

232064. Airplane ATPL CPL Considering subsonic incompressible airflow through a Venturi, which statement is correct? 1) The dynamic pressure in the throat is higher than in the undisturbed airflow. 2) The total pressure in the throat is the same as in the undisturbed airflow.

A) B) C) 0)

1) is incorrect, 2) is incorrect. 1) is correct, 2) is correct. 1) is correct, 2) is incorrect. 1) is incorrect, 2) is correct.

For explanation refer to question #21170 on page 6.

A) B) C) 0)

1) is incorrect, 2) is incorrect. 1) is correct, 2) is correct. 1) is correct, 2) is incorrect. 1) is incorrect, 2) is correct.

For explanation refer to question #21170 on page 6.

1232055 (C) 1232056 (C) 1232057 (A) 1232058 (8) 1232059 (0) 1232060 (C) 1232061 (0) 1232062 (0) 1232063 (8) 1232064 (8) 1

01 Subsonic Aerodynamics

232065. Airplane ATPL CPL Considering subsonic incompressible a Venturi, which statement is correct?

For explanation refer to question #21170 on page 6.

airflow

through

1) The dynamic pressure in the throat is higher than in the undisturbed airflow. 2) The total pressure in the throat is higher than in the undisturbed airflow. A) B) C) D).

1) is incorrect, 2) is incorrect. 1) is incorrect, 2) is correct. 1) is correct, 2) is correct. 1) is correct, 2) is incorrect.

through

A) 1) is correct, 2) is incorrect. B) 1) is correct, 2) is correct. C) 1) is incorrect, 2) is incorrect. D) 1) is incorrect, 2) is correct.

through

1) is correct, 2) is correct. 1) is incorrect, 2) is correct. 1) is incorrect, 2) is incorrect. 1) is correct, 2) is incorrect.

airflow

through

1) is correct, 2) is correct. 1) is incorrect, 2) is correct. 1) is incorrect, 2) is incorrect. 1) is correct, 2) is incorrect.

1) is incorrect, 2) is incorrect. 1) is correct, 2) is incorrect.

airflow

through

1) The static pressure in the throat is higher than in the undisturbed airflow. 2) The speed of the airflow in the throat is the same as in the undisturbed airflow. 1) is correct, 2) is correct. 1) is correct, 2) is incorrect. 1) is incorrect, 2) is correct. 1) is incorrect, 2) is incorrect.

232073. Airplane ATPL CPL Considering subsonic incompressible a Venturi, which statement is correct?

airflow

through

1) The static pressure in the throat is higher than in the undisturbed airflow. 2) The speed of the airflow in the throat is higher than in the undisturbed airflow. 1) is incorrect, 2) is correct. 1) is correct, 2) is incorrect. 1) is incorrect, 2) is incorrect. 1) is correct, 2) is correct.

For explanation refer to question #21170 on page 6.

airflow

through

1) The static pressure in the throat is the same as in the undisturbed airflow. 2) The speed of the airflow in the throat is lower than in the undisturbed airflow. 1) is correct, 2) is incorrect. 1) is incorrect, 2) is correct. 1) is correct, 2) is correct. 1) is incorrect, 2) is incorrect.

1) is incorrect, 2) is correct. 1) is correct, 2) is correct.

232072. Airplane ATPL CPL Considering subsonic incompressible a Venturi, which statement is correct?

A) B) C) D)

For explanation refer to question #21170 on page 6.

A) B) C) D)

through

For explanation refer to question #21170 on page 6.

1) The static pressure in the throat is lower than in the undisturbed airflow. 2) The speed of the airflow in the throat is higher than in the undisturbed airflow.

232069. Airplane ATPL CPL Considering subsonic incompressible a Venturi, which statement is correct?

airflow

1) The static pressure in the throat is higher than in the undisturbed airflow. 2) The speed of the airflow in the throat is lower than in the undisturbed airflow.

A) B) C) D)

For explanation refer to question #21170 on page 6.

A) B) C) D)

232071. Airplane ATPL CPL Considering subsonic incompressible a Venturi, which statement is correct?

For explanation refer to question #21170 on page 6.

airflow

1) The static pressure in the throat is lower than in the undisturbed airflow. 2) The speed of the airflow in the throat is the same as in the undisturbed airflow.

232068. Airplane ATPL CPL Considering subsonic incompressible a Venturi, which statement is correct?

1) The static pressure in the throat is the same as in the undisturbed airflow. 2) The speed of the airflow in the throat is higher than in the undisturbed airflow.

A) B) C) D)

For explanation refer to question #21170 on page 6.

A) B) C) D)

through

For explanation refer to question #21170 on page 6.

airflow

1) The static pressure in the throat is lower than in the undisturbed airflow. 2) The speed of the airflow in the throat is lower than in the undisturbed airflow.

232067. Airplane ATPL CPL Considering subsonic incompressible a Venturi, which statement is correct?

airflow

A) 1) is correct, 2) is incorrect. B) 1) is incorrect, 2) is incorrect. C) 1) is correct, 2) is correct. D) 1) is incorrect, 2) is correct.

For explanation refer to question #21170 on page 6.

232066. Airplane ATPL CPL Considering subsonic incompressible a Venturi, which statement is correct?

232070. Airplane ATPL CPL Considering subsonic incompressible a Venturi, which statement is correct?

232074. Airplane ATPL CPL Which of these statements about weight or mass is correct? A) The weight of an object depends on the acceleration due to gravity. B) The mass of an object depends on the acceleration due to gravity. C) Mass = weight x volume. D) In the SI system the unit of measurement for weight is the kilogram.

1232065(0) 1232066 (A) 1232067(0) 1232068 (A) 1232069(0) 1232070(0) 1232071 (C) 1232072(0) 1232073 (A) 1232074 (A) 1

Aviationexam Test Prep Edition 2012

232075. Airplane ATPL CPL Which of these statements about weight or mass is correct? A) Mass = weight x volume. B) In the SI system the unit of measurement for weight is the kilogram. e) The mass of an object is independent of the acceleration due to gravity. D) The weight of an object is independent of the acceleration due to gravity. 232076. Airplane ATPL CPL Which of these statements about weight or mass is correct? A) The mass of an object depends on the acceleration due to gravity. B) The weight of an object is independent of the acceleration due to gravity. C) In the SI system the unit of measurement for mass is the kilogram. D> In the SI system the unit of measurement for weight is the kilogram. 232077. Airplane ATPL CPL Which of these statements about weight or mass is correct? A) The mass of an object depends on the acceleration due to gravity. B) In the SI system the unit of measurement for weight is the Newton. e) The weight of an object is independent of the acceleration due to gravity. D) In the SI system the unit of measurement for weight is the kilogram. 232078. Airplane ATPL CPL Which of these statements about weight or mass is correct? A) The weight of a body can be determined by dividing its mass by the acceleration due to gravity. B) The weight of a body can be determined by dividing the acceleration due to gravity by its mass. e) The mass of a body can be determined by dividing its weight by the acceleration due to gravity. D) The mass of a body can be determined by mUltiplying its weight by the acceleration due to gravity. Airplane ATPL CPL 232079. Which of these statements about weight or mass is correct? A) The mass of a body can be determined by multiplying its weight by the acceleration due to gravity. B) The weight of a body can be determined by dividing the acceleration due to gravity by its mass. C) The weight of a body can be determined by dividing its mass by the acceleration due to gravity. D) The weight of a body can be determined by mUltiplying its mass by the acceleration due to gravity. 232080. Airplane ATPL CPL For a subsonic flow the continuity equation states that if the cross-sectional area of a tube decreases, the speed oftheflow: A) increases. B) decreases. C) does not change. D) first decreases then increases. For explanation refer to question #7700 on page 4.

232081. Airplane ATPL CPL The angle of attack of an aerofoil section is the angle between the: A) bottom surface and the relative airflow. B) bottom surface and the chord line. e) bottom surface and the horizontal. D) chord line and the relative undisturbed airflow. For explanation refer to question #4232 on page 3.

232091. Lift is the:

Airplane

ATPL

CPL

A) vertical component of the total aerodynamic force, perpendicular to the undisturbed airflow. B) component of the total aerodynamic force, perpendicular to the mean aerodynamic chord. e) component of the total aerodynamit force, perpendicular to the undisturbed airflow. D) component of the total aerodynamic force, perpendicular to the local airflow. For explanation refer to question #7872 on page 4.

232092. Airplane ATPL CPL The angle of attack of an aerofoil section is defined as the angle between the: A) local airflow and the chord line. B) undisturbed airflow and the chord line. e) local airflow and the mean camber line. D) undisturbed airflow and the mean camber line. For explanation refer to question #4232 on page 3.

232100. Airplane ATPL CPL Dihedral of a wing is the angle between: A) the wing plane and the horizontal with the aeroplane in an unbanked, level condition. B) the leading edge of the wing and the lateral axis. e) the quarter~chord line of the wing and the normal axis. D) the quarter-chord line of the wing and the lateral axis. For explanation refer to question #224799 on page 8.

232103. Airplane ATPL CPL Wing sweep angle is the angle between: A) the leading edge of the wing and the lateral axis. B) the quarter-chord line of the wing and the normal axis. e) the quarter-chord line of the wing and the lateral axis. D) the wing plane and the horizontal with the aeroplane in an unbanked, level condition. For explanation refer to question #23250 on page 7.

232104. Airplane ATPL CPL An aeroplane's angle of incidence is defined as the iln.gle between the: ' A) longitudinal axis and the horizontal plane. B) speed vector and the horizontal plane. C) longitudinal axis and the wing root chord line. D) speed vector and longitudinal axis.

\

For explanation refer to question #2625 on page 3.

232105. Airplane ATPL CPL The mean geometric chord of a wing is the: A) wing span squared divided by wing area. B) aspect ratio multiplied by the taper ratio. C) wing area divided by the wing span. D) wing area divide by mean aerodynamic chord.

1232075 (C) 1232076 (C) 1232077(8) 1232078 (C) 1232079 (D) 1232080 (A) 1232081 (D) 1232091 (C) 1232092(8) 1232100 (A) 1 1232103 (C) 1232104 (C) 1232105 (C) 1

01 Subsonic Aerodynamics

232183.

Airplane

ATPL

CPL

An aeroplane's angle of attack can be defined as the angle between its: A) B) C) D)

speed vector and longitudinal axis. longitudinal axis and the horizontal plane. lateral axis and the horizontal plane. speed vector and the horizontal plane.

For explanation refer to question #4232 on page 3.

01-02 Two-dimensional Airflow Around an Aerofoil 3963.

Airplane

ATPL

CPL

The aerodynamic centre of the wing is the point, where: A) change of lift due to variation of angle of attac.k is constant. B) pitching moment coefficient does not vary with angle of attack. C) aerodynamic forces are constant. D) the aeroplanes lateral axis intersects with the centre of gravity. The aerodynamic center of an airfoil moving through a fluid is the point at which the pitching moment coefficient for the airfoil does not vary with lift coefficient i.e. angle of attack. It is fundamental in the science of stability of aircraft in flight. Another way to define the aerodynamic centre is: 'The point where all changes in the magnitude of the lift force effectively take place': AND "the point about which the pitching moment wiJI remain constant at 'normal' angles of attack'~ For symmetric airfoils in subsonic· flight the aerodynamic center is located approximately 25% of the chord from the lea'ding edge of the airfoil. This point is described as the quarter-chord point. This result also holds true for 'thin-airfoils', For non-symmetric (cambere,d) airfoils the quarter-chord is only an approximation for the aerodynamic center. A similar concept is that of center ofpressure. The location of the center ofpressure varies with changes of lift coefficient and angle of attack. This makes the center ofpressure unsuitable for use in analysis of longitudinal static stability.

4270.

Airplane

ATPL

CPL

With increasing angle of attack, the stagnation point will move __ and the point of lowest pressure will move __• A) up; aft B) down; forward C) down; aft D) up; forward The stagnation point at the leading edge will move downwards when the angle of attack is increased because of the shape of the profile. On the upper surface the point oflowest pressure moves forward, just as the CPO

4278.

Airplane

ATPL

CPL

Consider an aerofoil with a certain camber and a positive angle of attack. At which location will the highest flow velocities occur? A) B) C) D)

Upper side. Lower side. In front of the stagnation point. In the stagnation point.

Because of the curvature of the wing the air on the top has to travel a longer distance. The speed must therefore increase on the upper side.

7905.

Airplane

ATPL

CPL

The lift force, acting on an aerofoil:

A) is mainly caused by suction on the upper side of the aerofoil. B) increases, proportional to the angle of attack until 40°. C) is mainly caused by overpressure at the underside of the aerofoil. D) is maximum at an angle of attack of 2°. (Refer to figure 081-E32) The pressure distribution around a wing profile is shown on the illustration. It is quite obvious that the low pressure (suction) on the upper side is contributing more to the lift thim the high pressure below the wing.

7925.

Airplane

ATPL

CPL

As subsonic air flows through a convergent duct, static pressure _ and velocity ___• A) increases; decreases B) increases; increases C) decreases; decreases D) decreases; increases The continuity equation states that the mass flow = AxpxV, where A is the cross section area, p the air density, and V the velocity, is constant in a flow through a duct. Subsonic flow is considered incompressible meaning a constant air density (p). In a convergent duct A is decreasing which means the velocity (V) increases. Bemoulli's equation, Pr= POYN + Ps= Constant, says, that if the velocity increases, so does the dynamic pressure (POYN = ~pV"). For the total pressure to remain constant, the static pressure must decrease.

7927.

Airplane

ATPL

CPL

On an asymmetrical, single curve aerofoil, in subsonic airflow, at Ibw angle of attack, when the angle of attack is increased, the centre of pressure will (assume a conventional transport aeroplane): A) B) C) D)

move forward. move aft. remain matching the airfoil aerodynamic centre. remain unaffected.

(Refeao figure 681-E43) As seen on the illustration CP moves forward when the angle of attack is increased.

7929.

Airplane

ATPL

CPL

The point, where the aerodynamic lift acts on a wing is: A) B) C) D)

the CG location. the centre of pressure. the point of maximum thickness of the wing. the suction point of the wing.

(Refer to figure 081-E43) The Center of Pressure (CP) is the point on a body where the total sum of the aerodynamic pressure field acts, causing a force and no moment about that point. In other words, the total aerodynamic force acts along a line whose

1232183 (A) 13963(8) 14270(8) I 4278 (A) I 7905 (A) 17925(0) I 7927(A) 17929(8) I

Aviationexam Test Prep Edition 2012 intersection with the chord line is called the centre ofpressure. The CP of an aircraft is the point where all of the aerodynamic pressure field may be represented by a single force vector with no moment. A similar idea is the aerodynamic center which is the point on an airfoil where the pitching moment produced by the aerodynamic forces is constant with angle of attack. The location of the CP varies with the angle of attack (on cambered airfoil), but in general it is located within the forward half of the chord. When considering subsonic airflows of less than M 0.4, the CP is located at the 25% chord point ("quarter-chord point") for any aerofoil regardless of camber, thickness and angle of attack. For a symmetric airfoil, as angle of attack and lift coefficient change, the center of pressure does not move. It remains around the quarter-chord point for all angles of attack and lift coefficients. On a cambered airfoil the CP does not occupy a fixed location. For a conventionally cambered airfoil, the CP lies a little behind the quarter-chord point at maximum lift coefficient (large angle of attack), but as lift coefficient reduces (angle ofattack reduces) the center ofpressure moves toward the rear.

7961. Airplane ATPL Which statement is correct?

CPL

A) The centre of pressure is the point on the wings leading edge where the airflow splits up. B) As the angle of attack increases, the stagnation point on the wing's profile moves downwards. C) The stagnation point is another name for centre of pressure. D) The stagnation point is always situated on the chord line, the centre of pressure is not. (Refer to figure 081-f53) Because of the up wash ahead of the wing the stagnation point is slightly below the chord line on the leading edge of the wing. If the angle of attack is increased the stagnation point will follow the curvature of the profile and thus move downwards (and backwards). This principle is for example used for the operation ofsome stall-warning systems (that use the "Flapper switch'?

1560S. Airplane ATPL CPL In a stationary subsonic streamline flow pattern, if the streamlines converge, in this part of the pattern, the static pressure will __ and the velocity will ___• A) B) C) D)

decrease; increase increase; increase increase; decrease decrease; decrease

20S81. Airplane ATPL CPL (Refer to figure OS1-1 0) Which one of the bodies in motion (all bodies have the same cross section area) will have the least form drag? BodyD. Bodye. Body A. BodyB.

The lowest drag will be experienced by body "C' because its form drag is reduced significantly by its streamlined shape. The next lowest drag will be experienced by body "0". Although bodies "A" and "B" might appear to experience the same significant value of drag, the body '~" will be subject to a lower drag than body "B" - this is because the airflow behind body "B" will be more turbulent than behind body '~': In summary, if we were to sort the bodies in order from the least to the highest values of drag experienced; the order would be C 0, A, B.

20882. Airplane ATPL CPL (Refer to figure OS1-0S) How are the speeds (shown in the figure) at point 1 and point 2 related to the relative wind/airflow V?

1 7961 (8)

V1 >Vz andVz V VI if the density doubles the lift will double.

232147. Airplane ATPL CPL Regarding the lift formula, if airspeed doubles, lift will:

A) be 4 times greater. B) also double. C) not change. D) halve. For explanation refer to question #232746 on this page.

232148. Airplane ATPL CPL If the lift generated by a given wing is 1.000 kN, what will be the lift if the wing area is doubled?

A) 2.000 kN B) 1.000 kN C) 500 kN D) 4.000 kN

at a positive angle of attack, it can never generate zero lift. at a negative angle of attack. at zero angle of attack.

126387 (0) 126396 (0) 126809 (0) 1232094 (0) 1232137 (C) 1232139 (C) 1232142 (0) 1232143 (8) 1232146 (A) 1232147 (A) 1 1232148 (A) 1

01 Subsonic Aerodynamics

232149. Airplane ATPL CPL If the wing area is increased, lift will: A) B) C) D)

increase with the square of the wing area. increase because it is directly proportional to wing area. not change because the lift coefficient is constant. remain constant.

For explanation refer to question #7755 on page 77.

232152. Airplane ATPL CPL The lift coefficient CL versus angle of attack curve of a negatively cambered aerofoil section intersects the vertical axis ofthe graph: A) B) C) D)

below the origin. above the origin. nowhere. at the origin.

232153. Airplane ATPL CPL The lift coefficient CL versus angle of attack curve of a positively cambered aerofoil section intersects the horizontal axis ofthe graph: A) B) C) D)

to the left of the origin. at the origin. nowhere. to the right of the origin.

Airplane ATPL CPL 232154. The lift coefficient CL versus angle of attack curve of a symmetrical aerofoil section intersects the horizontal axis ofthe graph: A) B) C) D)

at the origin. to the right of the origin. nowhere. to the left of the origin.

232155. Airplane ATPL CPL The lift coefficient CL versus angle of attack curve of a negatively cambered aerofoil section intersects the horizontal axis ofthe graph: A) B) C) D)

to the right of the origin. at the origin. to the left of the origin. nowhere.

232156. Airplane ATPL CPL Regarding a positively cambered aerofoil section, which statement is correct? I. The angle of attack has a positive value when the lift coefficient equals zero. II. A nose up pitching moment exists when the lift coefficient equals zero. A) B) C) D)

I is correct and II is incorrect. I is incorrect and II is correct. I is correct and II is correct. I is incorrect and II is incorrect.

232157. Airplane ATPL CPL Regarding a positively cambered aerofoil section, which statement is correct? _ I. The angle of attack has a negative value when the lift coefficient equals zero. II. A nose up pitching moment exists when the lift coefficient equals zero. A) B) C) D)

I is incorrect and II is incorrect. I is correct and II is correct. I is incorrect and II is correct. I is correct and II is incorrect.

Airplane ATPL CPL 232158. Regarding a positively cambered aerofoil section, which statement is correct? I. The angle of attack has a positive value when the lift coefficient equals zero. II. A nose down pitching moment exists when the lift coefficient equals zero. A) B) C) D)

I is correct and II is correct. I is incorrect and II is incorrect. I is incorrect and II is correct. I is correct and II is incorrect.

Airplane ATPL CPL 232159. Regarding a symmetric aerofoil section, which statement is correct? 1) The angle of attack is zero when the lift coefficient equals zero. 2) The pitching moment is zero when the lift coefficient equals zero. A) B) C) D)

1) is correct and 2) is incorrect. 1) is incorrect and 2) is correct. 1) is correct and 2) is correct. 1) is incorrect and 2) is incorrect.

232160. Airplane ATPL CPL Regarding a symmetric aerofoil section, which statement is correct? 1) The angle of attack has a positive value when the lift coefficient equals zero. 2) A nose down pitching moment exists when the lift coefficient equals zero. A) B) C) D)

1) is incorrect and 2) is correct. 1) is correct and 2) is incorrect. 1) is incorrect and 2) is incorrect. 1) is correct and 2) is correct.

232161. Airplane ATPL CPL Regarding a symmetric aerofoil section, which statement is correct? 1) The angle of attack has a negative value when the lift coefficient equals zero. 2) A nose up pitching moment exists when the lift coefficient equals zero. A) B) C) D)

1) is incorrect and 2) is correct. 1) is incorrect and 2) is incorrect. 1) is correct and 2) is incorrect. 1) is correct and 2) is correct.

1232149 (8) 1232152 (A) 1232153 (A) 1232154 (A) 1232155 (A) 1232156 (0) 1232157 (0) 1232158 (C) 1232159 (C) 1232160 (C) 1 1232161 (8) 1

Aviationexam Test Prep Edition 2012

232162.

Airplane

ATPL

232163.

CPL

Regarding a symmetric aerofoil section, which statement is correct? 1) The angle of attack is zero when the lift coefficient equals zero. 2) A nose up pitching moment exists when the lift coefficient equals zero. A) B) C) D)

1) is correct and 2) is correct. 1) is correct and 2) is incorrect. 1) is incorrect and 2) is correct. 1) is incorrect and 2) is incorrect.

Airplane

ATPL

CPL

Regarding a symmetric aerofoil section, which statement is correct? 1) The angle of attack has a positive value when the lift coefficient equals zero. 2) The pitching moment is zero when the lift coefficient equals zero. A) B) C) D)

1) is correct and 2) is incorrect.

1) is incorrect and 2) is incorrect. 1) is correct and 2) is correct. 1) is incorrect and 2) is correct.

01-04 Three-dimensional Airflow About an Aeroplane 4091.

Airplane

ATPL

CPL

As fuel is consumed during a level flight cruise at high level: A) B) C) D)

the angle of attack must be increased. the stalling speed will increase. the centre of pressure will move forward. induced drag will decrease.

The fuel consumed will decrease the total weight of the aircraft. To maintain level flight the angle of attack can therefore be decreased which in turn decreases the induced drag.

4192.

Airplane

ATPL

separation of the boundary layer over the wing. interference of the air stream between wing and fuselage. spanwise flow pattern resulting in the tip vortices. propeller wash blowing across the wing.

(Refer to figure 081-£30) In aerodynamics, lift-induced drag, induced drag, vortex drag, or sometimes drag due to lift, is a drag force that occurs whenever a moving object redirects the airflow coming at it. This drag force occurs in airplanes due to wings. With other parameters remaining the same, as the angle of attack increases, induced drag increases. When producing lift, air below the wing is generally at a higher than atmospheric pressure, while air above the wing is generally at a lower than atmospheric pressure. On a wing this pressure difference causes air to flow from the lower surface wing root, around the wingtip, towards the upper surface wing root. This span wise flow of air combines with chordwise flowing air, causing a change in speed and direction, which twists the airflow and produces vortices along the wing trailing edge. The vortices created are unstable, and they quickly combine to produce wingtip vortices. The resulting vortices change the speed and direction of the airflow behind the trailing edge, deflecting it downwards, and thus inducing down wash behind the wing. Wingtip vortices also modify the airflow around a wing, reducing the effectiveness of the wing to generate lift, thus requiring a higher angle of attack to compensate, and tilting the total aerodynamic force rearwards. The angular deflection is small and has little effect on the lift. However, there is an increase in the drag equal to the product of the lift force and the angle through which it is deflected. Since the deflection is itself a function of the lift, the additional drag is proportionalto the square of the lift. The total aerodynamic force is usually thought of as two components, lift and drag. By definition, the component of force parallel to the oncoming flow is called drag; and the component perpendicular to the oncoming flow is called lift. At practical angles of attack the lift greatly exceeds the drag. Unlike parasitic drag on an object (which is proportional to the square of the airspeed), for a given lift, induced drag on an airfoil is inversely proportional to the square of the airspeed. In straight and level f1ightQ(pn airc:r(J_ft,flftvaJie~oflly_ slowly because it is approximately equal to the weight of the aircraft. Conse-

1232162 (8) 1232163 (0) 1 4091 (0) 1 4192 (C)

A high aspect ratio wing will produce less induced drag than a wing of low aspect ratio because the size of the wing vortices will be much reduced on a longer, thinner wing. Induced drag can therefore be said to be inversely proportional to aspect ratio. The lift distribution may also be modified by the use of washout, a span wise twist of the wing to reduce the incidence towards the wingtips, and by changing the airfoil section near the wingtips. This allows more lift to be generated at the wing root and less towards the wingtip, which causes a reduction in the strength of the wingtip vortices. Induced drag depends on the angle of attack, and with a constant lAS in level flight the angle of attack is constant. However, if the weight changes the lift must change correspondingly by adjusting the angle of attack.

CPL

Induced drag is created by the: A) B) C) D)

quently in straight and level flight, the induced drag is inversely proportional to the square of the airspeed. At the speed for minimum drag, induced drag is equal to parasitic drag.

4196.

Airplane

ATPL

CPL

Which of the following decreases induced drag? A) B) C) D)

Wing fences. Anhedral. Winglets. Low aspect ratio plan form.

A winglet is a near-vertical extension of the wing tips. The wingtip vortex, which rotates around from below the wing, strikes the cambered surface

of the winglet, generating a force that angles inward and slightly forward. Thus the wing let converts some of the otherwise-wasted energy in the wingtip vortex to an apparent thrust. Another benefit of winglets is that they reduce the strength of wingtip vortices, and thus reduce the induced drag and decrease the risk of a wake turbulence incident for the aircraft that follows closely behind.

4204.

Airplane

ATPL

CPL

At a constant lAS, induced drag is affected by: A) B) C) D)

aircraft weight. changes in thrust. angle between chord line and longitudinal axis. wing location.

(Refer to figure 081-£30) In aerodynamics, lift-induced drag, induced drag, vortex drag, or sometimes drag due to lift, is a drag force that occurs whenever a moving object redirects the airflow coming at it. This drag force occurs in airplanes due to wings. With other parameters remaining the same, as the angle of attack increases, induced drag increases. Induced drag depends on the angle of attack, and with a constant lAS in level flight the angle of attack is constant. However, if the weight changes the lift must change correspondingly by adjusting the angle of attack.

1 4196 (C)

1 4204 (A)

1

01 Subsonic Aerodynamics

Airplane High aspect ratio: 4223.

ATPL

(Refer to figures 087-E729 and 087-E130) A high aspect ratio will give a greater vertical speed of the wing tips for a given roll rate, leading to a greater increase in effective angle of attack. The higher the effective angle of attack at the tip, the greater the resistance to roll or aero-

CPL

A) reduces parasite drag. B) reduces induced drag. C) increases stalling speed. D) reduces manoeuvrability.

dynamic damping. VMO is among other factors determined by sufficient roll control. With higher aerodynamic damping control can be maintained in roll at lower speed.

(Refer to figures 087-E729 and 087-E130) Induced drag coefficient Co; is equal to C//TTAR, where AR is aspect ratio. An increase in aspect ratio means a smaller Cor and thus less induced drag.

7669. Airplane ATPL CPL Which of the following wing planforms produces the lowest induced drag? (assume zero wing twist)

4227. Airplane ATPL CPL Which of the following descriptions most accurately describes the airflow that causes wing tip vortices?

A) From the tip to the root on the top surface and from the root to the tip on the bottom surface over the wing tip. B) From the tip to the root on the top surface and from the root to the tip on the bottom surface over the trailing edge. C) From the root to the tip on the top surface and from the tip to the root on the bottom surface over the trailing edge. D) From the root to the tip on the top surface and from the tip to the root on the bottom surface over the wing tip.

A) Rectangular. B) Elliptical. C) Tapered. D) Circular. If the lift is diminished towards the wingtips there is less pressure differential near the wingtips to create wingtip vortices. Minimum induced drag is achieved when the span wise lift distribution is elliptical. The parameter with greatest effect on lift distribution is the wing planform. Thus, a wing with elliptical planform would have low induced drag.

7671. Airplane ATPL CPL Induced drag is caused by:

The wing tip vortices form as higher pressure air below the wing spills into the area of lower pressure above the wing. The movement around the tip added to the free stream velocity creates a vortex. It is therefore a span wise flow towards the root on the upper surface and towards the tip on the lower surface that can be said to cause the wing tip vortices.

A) increased pressure at the leading edge stagnation point. B) wing mounted fuel tanks. C) wing tip vortices and downwash. D) winglets and washout. For explanation refer to question #4792 on page 22.

Airplane ATPL CPL Induced drag may be reduced by: 4233.

7701. Airplane ATPL CPL With flaps deployed, at a constant lAS in straight and level flight, the magnitude of tip vortices:

A) an increase in the taper ratio of the wing. B) an increase in aspect ratio. C) a decrease of the aspect ratio. D) the use of a wing tip with a much thinner aerofoil.

A) increases. B) increases or decreases depending upon the initial angle of attack. C) decreases. D) remains the same.

(Refer to figures 087-E729 and 087-E130) Induced drag coefficient Co; is equal to C//TTAR, where AR is aspect ratio. Increased aspect ratio thus means decreased induced drag. The higher the aspect ratio the steeper is the C/a curve. Maximum on the C/a curve corresponds with the critical angle of attack, so increased aspect ratio means decreasing critical angle of attack.

Deployment of flaps increases CL' To maintain level flight the wing angle ofattack has to be decreased. Lower angle ofattack means weaker tip vortices.

Airplane ATPL CPL Excluding constants, the coefficient of induced drag (C DI) is the ratio of:

Airplane ATPL CPL The wake vortices behind a large aircraft begin on takeoff __ _ and end on landing _ .

4249.

7712.

A) atV2; in the flare B) on rotation; as the nosewheel touches down C) at V,; when lift dump is selected D) at 80 kts; on touchdown

A) CL2 and 5 (wing surface). B) CL2 and AR (aspect ratio). C) CL and CD' D) CL and b (wing span).

Wake vortex generation begins when the nose wheel lifts off the runway on take-off and continues until the nose wheel touches down on landing.

Induced drag coefficient CoJs equal to C//TTAR, where AR is aspect ratio.

4258. Airplane The induced drag:

ATPL

CPL

7733. Airplane ATPL CPL Which location on the aeroplane has the largest effect on the induced drag?

A) increases as the lift coefficient increases. B) increases as the aspect ratio increases. C) has no relation to the lift coefficient. D) increases as the magnitude of the tip vortices decreases. Induced drag coefficient Co; is equal to C//TTAR, where AR is aspect ratio. Increased CL means increased Co; and thus induced drag. (Increased aspect ratio means less induced drag; the magnitude of the tip vortices are proportional to the induced drag.)

7662. Airplane ATPL CPL An increase in aspect ratio will:

A) have no effect on a wing or airfoil section. B) cause V1MD to be reduced. C) cause induced drag to increase. D) cause V1MD to be increased.

I I

4223 (8) 7733 (C)

I I

4227 (A)

I

4233 (8)

I

4249 (8)

I

4258 (A)

I

A) Wing root junction. B) Engine cowling. C) Wingtip. D) Landing gear. (Refer to figures 087-E729 and 087-E130) The wing tip vortices form as higher pressure air below the wing spills into the area of lower pressure above the wing causing the airflow behind the wing to be forced downwards (down wash}. The down wash causes the air flow direction at the centre of pressure to be deflected and thus tilting the total reaction on the wing backwards. Lift is the vertical component of the total reaction and the horizontal component - in opposite direction to the movement - is induced drag. Although small vortices form along the trailing edge of the wing the tip vortices are much stronger and therefore associated with the induced drag.

7662 (8)

I

7669 (8)

I

7671 (C)

I

7701 (C)

I

7712 (8)

I

EI

Aviationexam Test Prep Edition 2012 7829. Airplane ATPL CPL Which statement about induced drag and tip vortices is correct? A) Tip vortices can be diminished by vortex generators. B) The flow direction at the upper side of the wing has a component in wing root direction, the flow at the underside of the wing in wing tip direction. C) The flow direction at the upper and under side of the wing, both deviate in wing tip direction. D) The wing tip vortices and the induced drag decrease at increasing angle of attack. . On the upper side of the wing there is a lower static pressure than the ambient pressure causing the airflow to move towards the wing root whilst the higher pressure on the underside gives a movement towards the tip. At the wing tip the higher pressure under the wing has the possibility of move towards the lower pressure on top, but adding the aircraft velocity results in a swirling motion creating the tip vortex.

7858. Airplane ATPL CPL The induced drag coefficient, COi is proportional with:

A) CL2. B) CL•

A) B) C) D)

the top to beneath the wing via the wings trailing edge. beneath to the top of the wing via the wing tip. beneath to the top of the wing via the trailing edge. the top to beneath the wing via the leading edge.

On the upper side of the wing there is a lower static pressure than the ambient pressure causing the airflow to move towards the wing root whilst the higher pressure on the underside gives a movement towards the tip. At the wing tip the higher pressure under the wing has the possibility of move towards the lower pressure on top, but adding the aircraft velocity results in a swirling motion creating the tip vortex.

15708. Airplane ATPL CPL What is the effect of high aspect ratio of an aeroplanes wing on induced drag? A) It is unaffected because there is no relation between aspect ratio and induced drag. B) It is increased because high aspect ratio produces greater downwash. C) It is reduced because the effect of wing-tip vortices is reduced. D) It is increased because high aspect ratio has greater frontal area.

Induced drag coefficient Co; is equal to C/ITTAR, where AR is aspect ratio. With TT and aspect ratio constant, Co; is proportional to CL squared.

(Refer to figures 081-E129 and 081-E130) The tip vortices of a high aspect ratio wing affect a smaller proportion of the span so the overall change in down wash will be less, giving a smaller rearward tilt to the lift force. Induced drag therefore decreases as aspect ratio increases.

7861. Airplane ATPL CPL In straight and level flight, which of the following would cause induced drag to vary linearly if weight is constant:

15751. Airplane ATPL CPL What is the effect on induced drag of mass and speed changes? (Note: all other factors of importance remaining constant)

C) square root (CL).

D) CLMAX '

A) 1/v B) V C) 1/V2

A) B) C) D)

D) V2 If weight is constant, lift would be constant. Lift is L = *pIPSC" and in straight and level flight density r is constant. The lift coefficient is CL = WI(*pSIP), or since weight, density and wing area are constant, CL = ClIP, where C is a constant. A factor 1/IP would therefore give a constant C" and since the drag coefficient for induced drag is Co, = C/ITTAR, where AR is the aspect ratio, also a constant CD; From the formula for induced drag 0, = *pIPSCo;' a constant CD' would make the induced drag vary linearly with IN.

7876. Airplane ATPL CPL The relationship between induced drag and the aspect ratio is: A) B) C) D)

a decrease in the aspect ratio increases the induced drag. there is no relationship. induced drag = 1,3 aspect ratio value. an increase in the aspect ratio increases the induced drag.

(Refer to figures 081-E129 and 081-E130) Induced drag coefficient CD' is equal to C/ITTAR, where AR is aspect ratio. A decrease in aspect ratio means a larger CD' and thus more induced drag.

7904. Airplane ATPL CPL Induced drag at constant lAS is affected by: A) B) C) D)

engine thrust. aeroplane weight. aeroplane wing location. angle between wing chord and fuselage centre line.

The aeroplane weight is equal to the lift, and at a certain speed this means flying a certain angle of attack. More weight at the same speed requires a larger angle of attack, and a larger angle of attack gives more induced drag.

7946. Airplane ATPL CPL The span-wise flow is caused by the difference between the air pressure on top and beneath the wing and its direction of movement goes from:

I 7829 (8) I 7858 (A) I 7861

(C)

Increases with increasing speed and decreasing mass. Increases with increasing speed and increasing mass. Decreases with decreasing speed and decreasing mass. Decreases with increasing speed and decreasing mass.

Induced drag is proportional to angle ofattack. Increasing speed means smaller angle of attack and thus decreased induced drag. Decreased weight means less lift required and therefore smaller angle of attack and thus decreased induced drag.

15757. Airplane ATPL CPL High aspect ratio, as compared with low aspect ratio, has the effect of: A) increasing lift and drag. B) increasing induced drag and decreasing critical angle of attack. C) decreasing induced drag and critical angle of attack. D) increasing lift and critical angle of attack. Induced drag coefficient CD' is equal to C/IAR, where AR is aspect ratio. Increased aspect ratio thus means' decreased induced drag. The higher the aspect ratio the steeper is the Cia curve. Maximum on the Cia curve corresponds with the critical angle of attack, so increased aspect ratio means decreasing critical angle of attack.

15763. Winglets: A) B) C) D)

Airplane

ATPL

CPL

create an elliptical lift distribution. decrease the induced drag. decrease the static lateral stability. increase the manoeuvrability.

Winglets generate a small forward force and also block the air flowing from the bottom to the top surface of the wing, reducing the strength of the tip vortex. Both of these reduce the induced drag.

I 7876 (A) I 7904 (8) I 7946 (8) 115708 (C) 115751 (0) 115757 (C) 115763 (8) I

01 Subsonic Aerodynamics

15778. Airplane ATPL CPL The induced angle of attack is the result of: A) B) C) D)

downwash due to tip vortices. a large local angle of attack in a two dimensional flow. downwash due to flow separation. change in direction of flow due to the effective angle of attack.

(Refer to figure 087-£30) As seen on the illustration the induced angle of attack is the angle between the relative flow and the effective flow. The latter is not parallel with the relative flow because of the upwash in front of the wing and the down wash behind it. The change of direction is due to the pressure difference and the resulting tip vortex.

21131. Airplane ATPL CPL The span-wise flow on an unswept wing is from the: A) B) C) D)

lower to the upper surface via the wing tip. upper surface via the trailing edge to the lower wing surface. lower surface via the trailing edge to the upper wing surface. upper surface via the leading edge to the lower wing surface.

On the upper side of the wing there is a lower static pressure than the ambient pressure causing the airflow to move towards the wing root whilst the higher pressure on the underside gives a movement towards the tip. At the wing tip the higher pressure under the wing has the possibility of move towards the lower pressure on top.

21148. Airplane ATPL CPL What is the effect on induced drag of an increase in aspect ratio? A) Induced drag increases, because the effect of tip vortices increases. B) Induced drag increases, because a larger aspect ratio increases the frontal area. C) Induced drag decreases, because the effect of tip vortices decreases. D) Induced drag decreases, because a larger aspect ratio causes more downwash. For explanation refer to question #75708 on page 24.

21173. Airplane ATPL CPL Which statement concerning the local flow pattern around a wing is correct? A) Slat extension, at a constant angle of attack and normal extension speeds, will increase the lift coefficient, which will also increase the induced drag coefficient. B) By fitting wing lets to the wing tip, the strength of the wing tip vortices is reduced which in turn reduces induced drag. C) Sweep back reduces drag since, compared with a straight wing of equal area, the span increases. D) Vortex generators on the wing partially block the spanwise flow over the wing leading to a reduction in induced drag. For explanation refer to question #75763 on page 24.

21179. Airplane ATPL CPL Which statement is correct? A) Tip vortices and induced drag decrease with increasing angle of attack. B) Tip vortices can be diminished by vortex generators. C) The flows on the upper and lower surfaces of the wing are both in wing tip direction. D) The flow on the upper surface of the wing has a component in wing root direction. On the upper side of the wing there is a lower static pressure than the ambient pressure causing the airflow to move toWards the wing root whilst the higher pressure on the underside- gives a movement towards the tip.

23215. Airplane ATPL CPL Due to the span wise pressure gradient, on an unswept wing at a low angle of attack, producing lift, the airflow: A) on the upper surface tends to flow towards the tip, on the lower surface towards the root. B) on both upper and lower surfaces tends to flow towards the tip. C) on the upper surface tends to flow towards the root, on the lower surface towards the tip. D) on both upper and lower surfaces tends to flow equally towards the root. Air has a natural tendency to stream from higher to lower pressure. A wing under the given circumstances will have a low pressure on the top surface and a high pressure on the bottom surface. The air streaming over the wing because of the motion will therefore on the top surface tend to stream towards the wing root and on the bottom surface towards the wing tip.

23221. Airplane ATPL CPL For an aircraft in level flight, induced drag: A) B) C) D)

would be less ifthe aspect ratio was increased. would be greater if the aspect ratio was increased. would be less if the weight was increased. would be independent of aspect ratio.

(Refer to figures 087-£729 and 087-£730) Induced drag coefficient Co; is equal to C//TTAR, where AR is aspect ratio. An increase in aspect ratio means a smaller CD; and thus reduced induced drag.

23232. Airplane ATPL CPL Induced drag of an aircraft would be increased with: A) B) C) D)

increased speed. increased weight. increased aspect ratio. decreased angle of attack.

Increased weight means increased lift required. Maintaining speed the only way to increase lift is to increase the angle of attack to get a higher value of lift coefficient (C). Induced drag coefficient CD; is equal to C//TTAR, where AR is aspect ratio. If CL is increased, so is CD; and thus the induced drag. If the speed is increased at a constant angle of attack in stead to create more lift, the induced drag will increase because of the higher TAS, ref. 0; = ~pIf2SCo;'

23236. Airplane ATPL CPL For a tapered wing without twist, the effective angle of attack will be: A) B) C) D)

greatest at the tip. greatest at the root. equal across the span. greatest at the centre span.

(Refer to figures 087-£729 and 087-£730) The effective angle of attack is angle between the chord and the effective airflow at the wing. The effective airflow is deflected downwards because of the upwash in front of the wing and down wash behind it. The stronger the upwash and down wash, the steeper the effective flow and hence a smaller effective angle of attack. At the tip where the tip vortex gives the strongest upwash and down wash, the effective angle of attack is smallest..

23251. Airplane ATPL CPL For aircraft of the same weight, flying at the same lAS the angie of attack will be: A) B) C) D)

the same at altitude as at sea level. greater at altitude than at sea level because the TAS is greater. less at altitude than at sea level because the TAS is greater. less at altitude than at sea level because the density is less.

lAS is really the dynamic pressure reading (V,pTAS2). Considering the lift formula, L = ~pIf2SCL' a constant lAS (and the constant wing area 5) mean that CL' and hence the angle of attack, must remain constant to produce lift equal to the weight which is considered constant. (The TAS will of course be higher at altitude when lAS is maintained because p decreases.)

115778 (A) 1 21131 (A) 1 21148 (C) 1 21173 (8) 1 21179 (0) 123215 (C) 123221 (A) 123232 (8) 123236 (8) 1 23251 (A) 1

Aviationexam Test Prep Edition 2012

23303.

Airplane

ATPL

23324.

CPL

For a rectangular wing at constant speed and angle of attack, induced drag: A) B) C) D)

will will will will

be uniform across the wing span. be greatest at the wing tip. be greatest at the wing root. be greatest at the inboard end of the wing root.

The tip vortices generate a stronger down wash at the wing tips on a rectangular planform. The local direction of the air flow at the tip will consequently be steeper. The down wash causes the air flow direction at the centre ofpressure to be deflected and thus tilting the total reaction on the wing backwards. Lift is the vertical component of the total reaction and the horizontal component - in opposite direction to the movement - is induced drag.

23313.

Airplane

ATPL

CPL

The nose up or nose down orientation of an aircraft relative to the horizon is known as: A) B) C) D)

the angle of attack. the angle of incidence. the attitude of the aircraft. the angle between the relative airflow and the chord line of the wing.

The orientation of an aircraft will always be attitude.

23316.

Airplane

ATPL

CPL

A) B) C) D)

increased. decreased. unaltered. increased to the critical angle of attack.

The lift equation: LIFT = J.:2p\PSCL' where: • C, = coefficient of lift. This represents angle of attack of the airfoil and the shape of the airfoil. This described in terms of thicknesslchord ratio and a camber and can be altered in flight, for example, by lowering the flaps. • p = The density of the air. For any given altitude during subsonic flight, the density may be considered to be constant. • \P = The velocity of the aircraft, squared. • S =The wing area. Considering the lift equation, to maintain the lift to continue straight and level flight if density (p) is reduced only C, can be increased when V (TAS) is constant. To increase C, the angle of attack is increased.

23317.

Airplane

ATPL

A) proportional to the square of the velocity of the relative airflow. B) proportional to increases and decreases in the velocity of the relative airflow. C) inversely proportional to the air density. D) inversely proportional to the area of the wing. Considering the formulae for lift and drag, L = J.:2p\PSC, and 0 = J.:2p\PSCD , it is obvious that both are proportional to the square of the relative airflow (V).

Airplane

ATPL

CPL

The principal cause of hazardous conditions associated with the wake turbulence of large aeroplanes is the: A) B) C) D)

high speeds at which large aircraft operate. vortices generated at the wing tips. propeller or jet wash. laminar flow aerofoil.

The danger associated with wake turbulence is from the tip vortices that extend up to 9 nautical miles behind the aircraft.

I 23303 (8)

1 23313 (C)

CPL

stays at ground level. gradually descends to ground level. gradually descends to a lower level. gradually ascends to a higher level.

Trailing vortices tend to drift slowly downwards and level off between 500 and 1000 feet below the flight path of the aircraft.

23325.

Airplane

ATPL

CPL

During a takeoff made behind a departing large aircraft, the pilot can minimise the hazard of wake turbulence by: A) extend the takeoff rolland not rotating until well beyond the jet's rotation point. B) maintaining extra speed on takeoff and climb out. C) remaining below the jet's flight path until able to turn clear of its wake. D) being airborne prior to reaching the jet's rotation point and climbing above its flight path. The wake turbulence starts when the aircraft rotates, and the vortices tend to drift downwards. To avoid encountering a preceding aircraft's wake turbulence, take-off should be before the other aircraft's rotation point and climb above its flight path.

Airplane

ATPL

CPL

At positive angles of attack, a wing produces most lift at: A) B) C) D)

4° angle of attack. wings level. just before the stall. just after the stall.

(Refer to figure 081-E113) The lift equation: LIFT = J.:2p\PSC" where: • C, = coefficient of lift. This represents angle of attack of the airfoil and the shape of the airfoil. This described in terms of thicknesslchord ratio and a camber and can be altered in flight, for example, by lowering the flaps. • p = The density of the air. For any given altitude during subsonic flight, the density may be considered to be constant. • \P =The velocity of the aircraft, squared. • S = The wing area. Considering the lift equation, all other factors being equal, the wing will produce most lift at the highest value of C,. On the illustration it is obvious that C, is at it maximum value at stall and it will therefore produce most lift just before stalling. When it stalls, lift decreases dramatically.

Airplane

ATPL

CPL

Induced drag is greatest:

Both lift and drag of an aerofoil are:

23323.

A) B) C) D)

23353.

CPL

ATPL

Vortex wake behind large aircraft:

23342.

If TAS is kept constant, to maintain straight and level flight with reduced air density the angle of attack of an aircraft's wings must be:

Airplane

I 23316 (A)

A) B) C) D)

at the wing tip. at the wing root. at high speeds. at low angles of attack.

For explanation refer to question #23303 on this page.

23356.

Airplane

ATPL

CPL

Increased downwash from the wing: A) reduces the effective angle of attack of the tail plane. B) increases the effective angle of attack of the tail plane. C) reduces the effective angle of attack of the tail plane if it has a positive camber, and increases the effective angle of attack of the tail plane if it has a negative camber. D) does not affect the effective angle of attack of the tail plane. Because of the down wash the horizontal tail will experience a smaller angle of attack than the wing. Since the horizontal tail provides the greatest stabilising influence of the aircraft, a smaller angle of attack reduces the tail's contribution to longitudinal stability.

1 23317 (A) 123323 (8)

I 23324 (C) I 23325 (D)

123342 (C)

I 23353 (A) I 23356 (A)

1

01 Subsonic Aerodynamics

23535. Airplane ATPL CPL Which of the following would occur if an aircraft in level flight maintaining a constant TAS, flew into an area of lower pressure? A) B) C) D)

Total drag decrease. Parasite drag decrease. Lift increase. Induced drag increase.

Lower pressure means lower density. To maintain level flight at constant TAS, the angle of attack must be increased. The drag coefficient for parasite drag is almost constant for angles of attack up to near stall whereas the coefficient for induced drag increases exponentially. The induced drag will increase whilst parasite drag remains practically constant.

23602. Airplane ATPL CPL Wing tip vortices are caused by unequal pressure distribution on the wing which results in airflow from:

26787. Airplane ATPL CPL A high aspect ratio wing produces: A) B) C) D)

a decrease in induced drag. less sensitivity to gust effects. a decrease in stall speed. an increase in induced drag.

26790. Airplane ATPL CPL Induced drag on a wing is:

For explanation refer to question #7829 on page 24.

23701. Airplane ATPL CPL What is the cause of induced angle of attack? A) Downwash from trailing edge in the vicinity of the wing tips. B) Change in flow from effective angle of attack. C) The upward inclination of the free stream flow around the wing tips. D) Wing downwash altering the angle at which the airflow meets the tail plane. (Refer to figure 081-E30) The effective air flow over the profile is inclined to the free stream air flow because of the upwash in front of the profile and the down wash behind it. The induced angle of attack is the angle between the free air flow and the induced air flow as shown in the illustration.

23734. Airplane ATPL CPL Assuming zero wing twist, the wing planform that gives the highest local lift coefficient at the wing root is:

A) a product of lift and is always greatest at the wing root. B) greatest at the wing tip. C) a product of lift and skin friction and is greatest at the wing tip. D) a product of skin friction, profile and interference drag. Induced drag is a product of lift, that is the horizontal component of the total reaction on the profile. Near the tips the upwash and down wash are increased making the effective airflow at the profile steeper. The total reaction is perpendicular to this effective airflow, so at the tip the induced drag is greatest.

26798. Airplane ATPL CPL When are the wing tip vortices created? A) B) C) D)

When the aeroplane starts. When the wing produces lift. Only in aeroplanes with a short wing span. When the aeroplane lands.

The tip vortices are formed when the pressure difference between upper and lower surface of the wing exists, which is when lift is produced.

26801. Airplane ATPL CPL At a constant velocity airflow, a high aspect ratio wing will have (in comparison with low aspect ratio wing):

A) swept-back. B) rectangular. C) elliptical. D) tapered. (Refer to figure 081-E49) The planform determines the maximum of the local lift coefficient Cc The illustration shows the local lift coefficient in proportion to the wing lift coefficient CL for various planforms.lt is obvious that the rectangular planform has the highest CL at the root and hence will produce more of the lift.

24483. Airplane ATPL CPL On an untapered wing of constant section: induced downwash is maximum at the wing tip. induced downwash increases from tip to root. the separation point is constant throughout the span. induced downwash is constant over all the span.

forces

A) B) C) D)

increased drag, especially at a high angle of attack. decreased drag, especially at a high angle of attack. decreased drag, especially at a low angle of attack. decreased performance when climbing.

(Refer to figure 081-E111) Flying at a given speed requires a certain value ofcoefficient of lift (CJ. The illustration shows that a high aspect ratio (AR) means a smaller coefficient of drag (CJ and hence less drag. It is also evident that a high angle of attack, giving a large value of CL makes the difference between high and low aspect ratios larger.

26982. Airplane ATPL CPL Geometric washout means that:

(Refer to figures 081-E129 and 081-E130) The tip vortices generates a stronger down wash at the wing tips on a planform without taper. This down wash is called the induced down wash.

26215. Airplane ATPL CPL When considering the aerodynamic on an aerofoil section:

(Refer to figure 081-EI08) As seen in the illustration in the upper diagram the lift coefficient, and hence the lift, will increase linearly with angle of attack, whilst the lower diagram the drag coefficient, and hence the drag, increases exponentially with angle of attack.

For explanation refer to question #4223 on page 23.

A) bottom to top around the trailing edge. B) top to bottom around the trailing edge. C) bottom to top around the wingtip. D) top to bottom around the wingtip.

A) B) C) D)

of attack. C) lift and drag increase exponentially with an increase in angle of attack. D) lift increases linearly and drag increases exponentially with an increase in angle of attack.

acting

A) lift and drag increase linearly with an increase in angle of attack. B) lift and drag act normal to each other only at one angle

A) there is an airflow along the wing that keeps it clean (prevents ice accumulation in flight). B) the tip of the wing has higher angle of attack than the root. C) the tip of the wing has lower angle of attack than the root. D) the horizontal tail has lower angle of attack than the wing. Washout refers to a feature of wing design to deliberately reduce the lift distribution across the span of the wing of an aircraft. The wing is designed so that lift is strongest at the wing roots and decreases across the span, becoming weakest at the wing tip. This is usually to ensure that, at the stall, the wing root stalls before the wing tips, providing the aircraft with some resistance

123535 (D) 123602 (C) 1 23701 (A) 1 23734 (8) 124483 (A) 1 26215 (D) 1 26787 (A) 1 26790 (8) 1 26798 (8) 1 26801 (8) 1 126982 (C) 1

Aviationexam Test Prep Edition 2012 to spinning and maintaining the aileron effectiveness. Washout may also be used to modify the span wise lift distribution to reduce lift-induced drag.

The strength of the tip vortices is proportionate to the angle of attack. At takeoff the speed is very low requiring a high angle of attack to obtain lift, an angle

Washout is commonly achieved by designing the wing with a slight twist, reducing the angle of incidence from root to tip, and therefore causing a lower angle of attack at the tips than at the roots. This is sometimes referred to as structural washout, to distinguish it from aerodynamic washout.

larger than in a turn within limitations.

Washout may be accomplished by other means e.g. modified aerofoil section, vortex generators, leading edge wing fences, notches, or stall strips. This is referred to as aerodynamic washout. Its purpose is to tailor the spanwise lift distribution or reduce the probability of wing tip stall.

26990. Airplane ATPL CPL What changes in aircraft control must be made to maintain altitude while the airspeed is being decreased? A) Increase the angle of attack to compensate for the decreasing lift. B) Increase the angle of attack to produce more lift than drag. e) Decrease the angle of attack to compensate for the increasing drag. D) Maintain a constant angle of attack until the desired airspeed is reached, then increase the angle of attack. (Refer to figure 081-E113) To maintain altitude the lift must remain equal to weight. From the lift formula, L *pIPSCL' it is evident, that if the velocity (V) is decreased the lift coefficient (CL ) must be increased to maintain level flight. The lift coefficient varies with the angle of attack as shown in the illustration, so the angle of attack should be increased.

=

26994. Airplane ATPL CPL The construction feature of a wing called "wash out" is: A) an increase in the angle of incidence from root to tip. B) an increase of camber from root to tip. e) a decrease of camber from root to tip. D) a decrease in the angle of incidence from root to tip. For explanation refer to question #26982 on page 27.

27005. Airplane ATPL CPL Compared to a "high aspect ratio" wing a "low aspect ratio" wing will produce: A) less induced drag and have a higher stalling angle. B) more induced drag and have a higher stalling angle. e) more induced drag and have the same stalling angle. D) more induce.d drag and have a reduced stalling angle. For explanation refer to question #4233 on page 23.

27014. Airplane ATPL CPL At the tip of the wing in level flight, the air flows: A) from the upper surface to the lower surface. B) from the lower surface to the upper surface and then down at the trailing edge. e) from the lower surface to the upper surface and then diverges away from the fuselage. D) to produce induced drag at its lowest value. Air has a natural tendency to stream from higher to lower pressure. A wing in level flight will have a low pressure on the top surface and a high pressure on the bottom surface. Consequently, there will be a flow from the lower surface to the upper surface. The air streaming over the wing because of the motion has to be added giving the flow a swirling moment that causes a down wash behind the wing.

27033. Airplane ATPL CPL Wing tip vortices have the highest intensity during: A) takeoff. B) cruise. C) high speed. D) turns.

lID

232145. Airplane ATPL CPL Assuming standard atmospheric conditions, in order to generate the same amount of lift as altitude is increased, an aeroplane must be flown at: A) a higher TAS for any given angle of attack. B) the same TAS regardless of angle of attack. e) a lower TAS and a lower angle of attack. D) a lower TAS for any given angle of attack. 232150. Airplane ATPL CPL If the airspeed is doubled, whilst maintaining the same control surface deflection the aerodynamic force on this control surface will: A) become four times greater. B) double. e) increase by the square root of the airspeed. D) become four times smaller. 232165. Airplane ATPL CPL Assuming ISA conditions and no compressibility effects, if an aeroplane maintains straight and level flight at the same angle of attack at two different altitudes, the: A) lAS at both altitudes is the same. B) TAS at both altitudes is the same. e) lAS is higher at the higher altitude. D) TAS is lower at the higher altitude. 232166. Airplane ATPL CPL Assuming ISA conditions and no compressibility effects, if an aeroplane maintains straight and level flight at the same angle of attack at two different altitudes, the: A) TAS is lower at the lower altitude. B) TAS is higher at the lower altitude. e) lAS is lower at the lower altitude. D) lAS is higher at the lower altitude. Airplane ATPL CPL 232182. The fundamental difference between the aerodynamic characteristics of two and three-dimensional flow is that, in a three-dimensional flow about a wing: A) flow separation occurs at the stall. B) a downward component is added to the chordwise speed component of the flow behind the wing. e) a spanwise component exists in addition to the chordwise speed component. D) an upward component is added to the chordwise speed component. Airplane ATPL CPL 232187. Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices increases as the angle of attack increases. II. The strength of wing tip vortices increases as the aspect ratio decreases. A) I is correct, II is incorrect. B) I is correct, II is correct. e) I is incorrect, II is incorrect. D) I is incorrect, II is correct.

126990 (A) 126994 (0) 127005 (8) 127014 (8) 127033 (A) 1232145 (A) 1232150 (A) 1232165 (A) 1232166 (A) 1232182 (C) 1 1232187 (8) 1

01 Subsonic Aerodynamics

232188. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices decreases as the angle of attack increases. II. The strength of wing tip vortices increases as the aspect ratio increases. A) B) C) 0)

I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect. I is incorrect, II is correct.

232189. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices increases as the angle of attack increases. II. The strength of wing tip vortices increases as the aspect ratio increases. A) B) C) 0)

I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is correct. I is incorrect, II is incorrect.

232190. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices decreases as the angle of attack increases. II. The strength of wing tip vortices increases as the aspect ratio decreases. A) B) C) 0)

I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is correct, II is correct.

232191. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices is not affected by angle of attack. II. The strength of wing tip vortices increases as the aspect ratio decreases. A) B) C) 0)

I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is correct. I is correct, II is incorrect.

232192. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices decreases as the angle of attack increases. II. The strength of wing tip vortices is not affected by aspect ratio. A) B) C) 0)

I is correct, II is correct. I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect.

232193. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? . I. Assuming no flow separation, the strength of wing tip vortices is not affected by angle of attack. II. The strength of wing tip vortices increases as the aspect ratio increases. A) B) C) 0)

I is incorrect, II is correct. I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is incorrect.

232194. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices is not affected by angle of attack. II. The strength of wing tip vortices is not affected by aspect ratio. A) B) C) 0)

I is incorrect, II is incorrect. I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is correct.

232195. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices decreases as the angle of attack decreases. II. The strength of wing tip vortices increases as the aspect ratio decreases. A) B) C) 0)

I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct.

232196. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices increases as the angle of attack decreases. II. The strength of wing tip vortices increases as the aspect ratio decreases. A) B) C) 0)

I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct.

232197. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices decreases as the angle of attack decreases. II. The strength of wing tip vortices increases as the aspect ratio increases. A) B) C) 0)

I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is correct. I is incorrect, II is incorrect.

1232188 (C) 1232189 (A) 1232190 (A) 1232191 (8) 1232192 (C) 1232193 (0) 1232194 (A) 1232195 (0) 1232196 (0) 1232197 (A) 1

Aviationexam Test Prep Edition 2012 232198. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices increases as the angle of attack decreases. II. The strength of wing tip vortices increases as the aspect ratio increases. A) B) C) 0)

I is correct, II is correct. I is incorrect, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect.

232203. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices decreases as the angle of attack increases. II. The strength of wing tip vortices decreases as the aspect ratio increases. A) B) C) 0)

I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct.

232199. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect?

232204. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect?

I. Assuming no flow separation, the strength of wing tip vortices increases as the angle of attack increases. II. The strength of wing tip vortices is not affected by aspect ratio.

I. Assuming no flow separation, the strength of wing tip vortices is not affected by the angle of attack. II. The strength of wing tip vortices decreases as the aspect ratio increases.

A) I is correct, II is correct. B) I is correct, II is incorrect. C) I is incorrect, II is correct. 0) I is incorrect, II is incorrect.

A) I is incorrect, II is incorrect. B) I is correct, II is correct. C) I is correct, II is incorrect. 0) I is incorrect, II is correct.

232200. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect?

232205. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect?

I. Assuming no flow separation, the strength of wing tip vortices decreases as the angle of attack decreases. II. The strength of wing tip vortices is not affected by aspect ratio.

I. Assuming no flow separation, the strength of wing tip vortices decreases as the angle of attack decreases. II. The strength of wing tip vortices decreases as the aspect ratio increases.

A) I is correct, II is incorrect. B) I is correct, II is correct. C) I is incorrect, II is incorrect. 0) I is incorrect, II is correct.

A) I is correct, II is correct. B) I is correct, II is incorrect. C) I is incorrect, II is correct. 0) I is incorrect, II is incorrect.

232201. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices increases as the angle of attack decreases. II. The strength of wing tip vortices is not affected by aspect ratio decreases. A) I is incorrect, II is incorrect. B) I is correct, II is correct. C) I is correct, II is incorrect. 0) I is incorrect, II is correct. 232202. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices increases as the angle of attack increases. II. The strength of wing tip vortices decreases as the aspect ratio increases. A) I is incorrect, II is incorrect. B) I is incorrect, II is correct. C) I is correct, II is correct. 0) I is correct, II is incorrect.

232206. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices increases as the angle of attack decreases. II. The strength of wing tip vortices decreases as the aspect ratio increases. A) I is incorrect, II is incorrect. B) I is correct, II is incorrect. C) I is incorrect, II is correct. 0) I is correct, II is correct. 232207. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices increases as the angle of attack increases. II. The strength of wing tip vortices decreases as the aspect ratio decreases. A) I is incorrect, II is incorrect. B) I is correct, II is correct. C) I is correct, II is incorrect. 0) I is incorrect, II is correct.

1232198(0) 1232199(8) 1232200 (A) 1232201 (A) 1232202 (C) 1232203(0) 1232204(0) 1232205 (A) 1232206 (C) 1232207 (C) 1

01 Subsonic Aerodynamics

232208. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices decreases as the angle of attack increases. II. The strength of wing tip vortices decreases as the aspect ratio decreases. A) I is incorrect, II is correct. B) I is incorrect, II is incorrect. C) I is correct, II is incorrect. D) I is correct, II is correct. 232209. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices is not affected by angle of attack. II. The strength of wing tip vortices decreases as the aspect ratio decreases. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct.

232210. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices decreases as the angle of attack decreases. II. The strength of wing tip vortices decreases as the aspect ratio decreases. A) B) C) D)

I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is correct. I is incorrect, II is incorrect.

232211. Airplane ATPL CPL Which of these statements about the strength of wing tip vortices are correct or incorrect? I. Assuming no flow separation, the strength of wing tip vortices increases as the angle of attack decreases. II. The strength of wing tip vortices decreases as the aspect ratio decreases. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct.

232212. Airplane ATPL CPL What is the effect of increasing wing aspect ratio on induced drag? A) It reduces because the effect of wing-tip vortices is reduced. B) It increases because increasing aspect ratio produces greater downwash. C) It increases because increasing aspect ratio increases frontal area. D) It is unaffected because there is no relation between aspect ratio and induced drag.

232218. Airplane ATPL CPL The induced angle of attack is: A) caused by the fuselage and is greatest at the wing root. B) the angle by which the flow over the wing is deflected when landing flaps are set. C) the angle by which the relative airflow is deflected due to downwash. D) the angle between the local flow at the wing and the horizontal tail. 232220. Airplane ATPL CPL Increasing the aspect ratio of a wing: A) B) C) D)

increases stall speed. decreases induced drag. increases induced drag. decreases gust load.

232230. Airplane ATPL CPL What is the effect of wing lets on the drag of the wing? A) B) C) D)

Increase parasite drag, decrease induced drag. Increase friction drag, decrease form drag. Increase induced drag, decrease friction drag. Increase induced drag, decrease interference drag.

232233. Airplane ATPL CPL When wing lift is zero, its induced drag is: A) B) C) D)

zero. maximum. low. high.

232234. Airplane ATPL CPL Which statement, about the effects on drag of fitting external tip tanks to the wings of an aeroplane, is correct? I. Parasite drag increases. II. Induced drag increases. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct.

232235. Airplane ATPL CPL Which statement, about the effects on drag of fitting external tip tanks to the wings of an aeroplane, is correct? I. Parasite drag decreases. II. Induced drag increases. A) B) C) D)

I is incorrect, II is correct. I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect.

232236. Airplane ATPL CPL Which statement, about the effects on drag of fitting external tip tanks to the wings of an aeroplane, is correct? I. Parasite drag increases. II. Induced drag decreases. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is incorrect. I is correct, II is correct. I is incorrect, II is correct.

1232208 (B) 1232209 (A) 1232210 (A) 1232211 (A) 1232212 (A) 1232218 (C) 1232220 (B) 1232230 (A) 1232233 (A) 1232234 (B) 1 1232235 (D) 1232236 (C) 1

EI

Aviationexam Test Prep Edition 2012 232237. Airplane ATPL CPL Which statement, about the effects on drag of fitting external tip tanks to the wings of an aeroplane, is correct? I. Parasite drag decreases. II. Induced drag decreases. A) I is incorrect, II is incorrect. B) I is correct, II is incorrect. C) I is incorrect, II is correct. 0) I is correct, II is correct. 232238. Airplane ATPL CPL Which statement, about the effects on drag of removing external tip tanks from the wings of an aeroplane, is correct? I. Parasite drag increases. II. Induced drag increases. A) I is correct, II is correct. B) I is correct, II is incorrect. C) I is incorrect, II is correct. 0) I is incorrect, II is incorrect. 232239. Airplane ATPL CPL Which statement, about the effects on drag of removing external tip tanks from the wings of an aeroplane, is correct? I. Parasite drag decreases. II. Induced drag increases. A) I is incorrect, II is incorrect. B) I is incorrect, II is correct. C) I is correct, II is correct. 0) I is correct, II is incorrect. 232240. Airplane ATPL CPL Which statement, about the effects on drag of removing external tip tanks from the wings of an aeroplane, is correct? I. Parasite drag increases. II. Induced drag decreases. A) I is incorrect, II is incorrect. B) I is correct, II is incorrect. C) I is correct, II is correct. 0) I is incorrect, II is correct. Airplane ATPL CPL 232241. Which statement, about the effects on drag of removing external tip tanks from the wings of an aeroplane, is correct? I. Parasite drag decreases. II. Induced drag decreases. A) I is incorrect, II is correct. B) I is incorrect, II is incorrect. C) I is correct, II is incorrect. 0) I is correct, II is correct. Airplane ATPL CPL 232242. Which of these statements about induced drag are correct or incorrect? I. An elliptical spanwise lift distribution generates less induced drag than a rectangular lift distribution. II. Induced drag increases with decreasing aspect ratio.

Airplane ATPL CPL 232243. Which of these statements about induced drag are correct or incorrect? I. An elliptical spanwise lift distribution generates more induced drag than a rectangular lift distribution. II. Induced drag decreases with decreasing aspect ratio. A) I is incorrect, II is correct. B) I is correct, II is correct. C) I is correct, II is incorrect. 0) I is incorrect, II is incorrect. Airplane ATPL CPL 232244. Which of these· statements about induced drag are correct or incorrect? I. An elliptical spanwise lift distribution generates more induced drag than a rectangular lift distribution. II. Induced drag increases with decreasing aspect ratio. A) I is incorrect, II is correct. B) I is correct, II is incorrect. C) I is correct, II is correct. 0) I is incorrect, II is incorrect. Airplane ATPL CPL 232245. Which of these statements about induced drag are correct or incorrect? I. An elliptical spanwise lift distribution generates less induced drag than a rectangular lift distribution. II. Induced drag decreases with decreasing aspect ratio. A) I is correct, II is incorrect. B) I is incorrect, II is correct. C) I is correct, II is correct. 0) I is incorrect, II is incorrect. Airplane ATPL CPL 232246. Which of these statements about induced drag are correct or incorrect? I. An rectangular spanwise lift distribution generates less induced drag than an elliptical lift distribution. II. Induced drag increases with increasing aspect ratio. A) I is correct, II is correct. B) I is correct, II is incorrect. C) I is incorrect, II is incorrect. 0) I is incorrect, II is correct. 232247. Airplane ATPL CPL Which of these statements about induced drag are correct or incorrect? I. An rectangular spanwise lift distribution generates more induced drag than an elliptical lift distribution. II. Induced drag decreases with increasing aspect ratio. A) I is incorrect, II is correct. B) I is incorrect, II is incorrect. C) I is correct, II is correct. 0) I is correct, II is incorrect.

A) I is correct, II is incorrect. B) I is incorrect, II is incorrect. C) I is correct, II is correct. 0) I is incorrect, II is correct.

Ell

1232237 (C) 1232238 (C) 1232239 (C) 1232240 (A) 1232241 (C) 1232242 (C) 1232243 (D) 1232244 (A) 1232245 (A) 1232246 (C) 1 1232247 (C) 1

01 Subsonic Aerodynamics

232248. Airplane ATPL CPL Which of these statements about induced drag are correct or incorrect? I. An rectangular spanwise lift distribution generates less induced drag than an elliptical lift distribution. II. Induced drag decreases with increasing aspect ratio. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is correct. I is incorrect, II is correct. I is correct, II is incorrect.

232249. Airplane ATPL CPL Which of these statements about induced drag are correct or incorrect? I. An rectangular spanwise lift distribution generates more induced drag than an elliptical lift distribution. II. Induced drag increases with increasing aspect ratio. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is correct.

Airplane ATPL CPL 232250. Which of these statements about induced drag are correct or incorrect? I. Induced drag increases as angle of attack increases. II. At constant load factor, induced drag increases with increasing aeroplane mass. A) B) C) D)

I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is correct, II is correct.

232251. Airplane ATPL CPL Which of these statements about induced drag are correct or incorrect? I. Induced drag decreases as angle of attack increases. II. At constant load factor, induced drag decreases with increasing aeroplane mass. A) B) C) D)

I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is correct. I is incorrect, II is incorrect.

232252. Airplane ATPL CPL Which of these statements about induced drag are correct or incorrect? I. Induced drag decreases as angle of attack increases. II. At constant load factor, induced drag increases with increasing aeroplane mass. A) B) C) D)

I is incorrect, II is correct. I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is incorrect.

232253. Airplane ATPL CPL Which statement about induced drag is correct?

C) I is correct, II is incorrect. D) I is correct, II is correct. Airplane ATPL CPL 232255. Which of these statements about induced drag are correct or incorrect? I. Induced drag decreases as angle of attack decreases. II. At constant load factor, induced drag decreases with decreasing aeroplane mass. A) B) C) D)

I is correct, II is correct. I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect.

232256. Airplane ATPL CPL Which of these statements about induced drag are correct or incorrect? I. Induced drag increases as angle of attack decreases. II. At constant load factor, induced drag decreases with decreasing aeroplane mass. A) B) C) D)

I is incorrect, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect. I is correct, II is correct.

Airplane ATPL CPL 232257. Which of these statements about induced drag are correct or incorrect? I. Induced drag decreases as angle of attack decreases. II. At constant load factor, induced drag increases with decreasing aeroplane mass. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct.

232258. Airplane ATPL CPL Decreasing the aspect ratio of a wing: A) B) C) D)

increases induced drag. decreases stall speed. decreases induced drag. increases gust load.

232260. Airplane ATPL CPL The total drag of a three dimensional wing consists of: A) B) C) D)

pressure drag, friction drag and parasite drag. induced drag and interference drag. induced drag and parasite drag. parasite drag and pressure drag.

232273. Airplane ATPL CPL Total drag is the sum of: A) B) C) D)

parasite drag and induced drag. induced drag and friction drag. friction drag and pressure drag. parasite drag, interference drag and pressure drag.

I. Induced drag increases as angle at attack increases. II. At constant load factor, induced drag decreases with increasing aeroplane mass. A) I is incorrect, II is correct. B) I is incorrect, II is incorrect.

1232248 (C) 1232249 (C) 1232250(0) 1232251 (0) 1232252 (A) 1232253 (C) 1232255 (A) 1232256 (A) 1232257(8) 1232258 (A) 1 1232260 (C) 1232273 (A) 1

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Aviationexam Test Prep Edition 2012

232275. Airplane ATPL CPL If the airspeed reduces in level_ flight below the speed for maximum LID, the total drag of an aeroplane will: A) B) C) D)

increase because of increased parasite drag. reduce because of reduced induced drag. increase because of increased induced drag. reduce because of reduced friction drag.

Airplane ATPL CPL 232370. Wing twist (geometric and aerodynamic) is used to: 1} Improve stall characteristics. 2} Reduce induced drag. 3} Reduce interference drag. 4} IncreaseVMo' The combination that regroups all ofthe correct statements is:

232301. Airplane ATPL CPL Which statement about an aeroplane entering ground effect is correct?

A) 1,2

B) 1,3 C) 3,4 D) 2,3

I. The downwash angle remains constant. II. The induced angle of attack increases. A) B) C) D)

I is incorrect, II is correct. I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is incorrect.

01-05 Total Drag 4195. Airplane ATPL CPL (Refer to figure 081-06) Which line represents the total drag line of an aeroplane? A) B) C) D)

Line B. Line A. Line C. Line D.

(Refer to figure 087-f705) The total drag is induced drag plus parasite drag. Induced drag decreases with speed whilst parasite drag increases with speed. The total drag curve therefore has the appearance shown in the illustration. In this figure line "C'is obviously representing the total drag curve.

4222. Airplane ATPL CPL (Refer to figure 081-05) The diagram shows the parameter X against TAS. If horizontal flight is considered axis X represents:: A) the total drag. B) the induced drag. C) the lift force. D) the parasite drag.

A) B) C) D)

4256. Airplane ATPL CPL At a load factor of 1 and the aeroplane's minimum drag speed, what is the ratio between induced drag Di and parasite drag Dp? Di/Dp=l. It varies between aeroplane types. Di/Dp=2. Di I Dp = 1 12.

(Refer to figure 087-f705) The total drag is induced drag plus parasite drag. As can be seen in the illustration, the minimum of the curve for the total drag is where induced drag 0; and profile drag 0 p are equal. 0(0p is therefore 717.

Decreasing, then increasing. Decreasing. Increasing. Increasing, then decreasing.

(Refer to figure 087 -f7 05) The total drag is induced drag plus parasite drag. Induced drag decreases with speed whilst parasite drag increases with speed. The total drag curve therefore has the appearance shown in the illustration, that is decreasing, then increasing.

4262. Airplane ATPL CPL The aeroplane drag in straight and level flight is lowest when the: A) B) C) D)

The X axis on figure 087 -06 must be induced drag. If speed is increased in horizontal flight the coefficient of lift C, must be reduced to maintain the same lift. Reducing C, means reducing the angle of attack. Lower angle of attack The induced drag coefficient CD; is equal to C/ITTAR, where AR is aspect ratio. IfC, is decreased, so is CD; and thus the induced drag.

A) B) C) D)

4260. Airplane ATPL CPL How does the total drag vary as speed is increased from stalling speed (Vs) to maximum lAS (V NE) in a straight and level flight at constant weight?

parasite drag equals twice the induced drag. parasite drag is equal to the induced drag. induced drag is equal to zero. induced drag is lowest.

For explanation refer to question #4256 on this page.

7680. Airplane ATPL CPL What happens to total drag when accelerating from CLMAX to maximum speed? A) B) C) D)

Increases. Increases then decreases. Decreases. Decreases then increases.

(Refer to figure 087 -f7 05) CLMAX is not the minimum drag speed VMD. CLMAX corresponds in level flight to the minimum speed at which the airplane will fly without stalling (= close to the stall-speed) where the total drag is high. At that point, you are located at the left top of the drag curve, which has a shape of a letter "U". Accelerating to maximum speed means following the drag curve (refer to the attached figure). As you accelerate, the total drag initially decreases, due to a decrease in induced drag, but then increases as a result of an increased parasite drag.

1232275 (C) 1232301 (D) 1232370 (A) 1 4195(C) 14222(8) 1 4256 (A) 1 4260 (A) 14262(8) 1 7680 (D) 1

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01 Subsonic Aerodynamics

7682. Airplane ATPL CPL A body is placed in a certain airstream. If the density of the airstream decreases to half its original value, the parasite drag will decrease by a factor of: A) 4 B) 2

From the drag equation it is obvious that the only factor mentioned in the answers that has any influence on the drag is the air stream velocity (V).

7832. Airplane ATPL CPL How does aerodynamic drag vary when airspeed is doubled? Bya factor of: A) B) C) D)

C) 8 D) 1,4 DRAG (D) equation: 0 = *pIf2SCV' where: p =the mass density of the fluid (rho), V = the velocity of the object relative to the air, S =is the reference area, and Co = the drag coefficient - a dimensionless constant. From the drag equation it is clear that reducing the density p by a factor 2 will reduce the drag by the same value.

7736.

Airplane

ATPL

increase with increased altitude. constantly vary regardless of altitude. remain the same regardless of altitude. reduce with increased altitude.

If an aircraft is flown at a constant lAS, dynamic pressure will be constant. As density decreases with increasing altitude, TAS must be increased to maintain the constant lAS. Therefore the drag will not vary with altitude, and hence will the minimum drag speed as lAS (V,M,) also remain constant.

7738.

Airplane

ATPL

CPL

When the undercarriage is lowered in flight: A) form drag will increase and the aircraft's nose down pitching moment will be unchanged. B) induced drag will increase and the aircraft's nose down pitching moment will increase. C) form drag will increase and the aircraft's nose down pitching moment will increase. D) induced drag will decrease and the aircraft's nose down pitching moment will increase. Lowering the undercarriage changes the form of the aircraft and thus increases the form drag. Induced drag only changes when lift changes. Since the undercarriage is below the centre of gravity, the drag force will produce a nose down moment.

7799.

Airplane

ATPL

CPL

In subsonic flight, which is correct for VMO? A) B) C) D)

7834. Airplane ATPL CPL A body is placed in a certain airstream. If the airstream velocity increases by a factor of 4, the parasite drag will increase by a factor of: A) B) C) D)

8 4 16 12

DRAG (D) equation: 0 = *pIf2SCV' where: p = the mass density of the fluid (rho), V = the velocity of the object relative to the air, S =is the reference area, and Co =the drag coefficient - a dimensionless constant. From the drag equation it is clear that increasing the airstream velocity (V) by a factor 4 will increase the drag by the same factor squared, i.e. 42 = 76.

7835. Airplane ATPL CPL What does parasite drag vary with? A) Square of the speed. B) CLMAX '

C) Speed. D) Surface area. Parasite drag is Op = *pIf2SCop' CoP is more or less constant at different angles of attack, except for angles near stall, so it is not really dependant of C!MAX" The S in the formula is the wing area, not the surface area, so parasite drag varies with 1f2. Note: A pedant could argue that parasite drag varies with surface area since friction drag depends on the wetted area, although changes in wetted area only occurs using certain flap types or variable geometry wings.

Parasite drag greater than induced drag. 7840.

CL and Co are minimum. Best glide range achieved. Best endurance speed for a piston engine.

7826.

Airplane

ATPL

CPL

The aerodynamic drag of a body, placed in a certain airstream depends amongst others on: the airstream velocity. the specific mass of the body. the weight of the body. the CG location of the body.

I

7736 (C)

I

7738(C)

I

7799 (C)

ATPL

CPL

A) B) C) D)

decreases at first, then increases. decreases. increases at first, then decreases at McRlr increases as the square of the lAS.

From the formula for profile drag, 0 = *pIf2SCoP' it is clfi!ar that the drag is increased as the square of\!, which is TAS.

7922.

Airplane

ATPL

CPL

An aircraft flying straight and level; if density halves, aerodynamic drag will: A) increase by a factor of four. B) increase by a factor of two. C) decrease by a factor of two. D) decrease by a factor of four.

DRAG (D) equation: 0 = *pIf2SCV' where: p = the mass density of the fluid (rho), V = the velocity of the object relative to the air, S =is the reference area, and CD = the drag coefficient - a dimensionless constant.

17682(8)

Airplane

As the speed of an aircraft at 20.000 ft increases, profile drag:

In subsonic flight the minimum drag speed (VM ,) corresponds to the best LID ratio which is equivalent to the glide ratio. Gliding at best glide ration means the maximum horizontal distance per unit lost altitude. Alternatively, tangent of the gliding angle is OIL, and the lower the tangent, the smaller the angle.

A) B) C) D)

DRAG (D) equation: 0 = *pIf2SCV' where: p =the mass density of the fluid (rho), V = the velocity of the object relative to the air, S =is the reference area, and CD = the drag coefficient - a dimensionless constant. From the drag equation it is clear that if airspeed is doubled, drag is increased by a factor 22 = 4.

CPL

For a constant aircraft weight at constant lAS and in level flight: A) V1MO will B) V1MO will C) V1MO will D) V1MO will

2 1 16 4

From the formula for drag, 0 = *pIf2SCV' it is clear that if density is halved, the drag would also be decreased by a factor 2.

I

7826(A)

I

7832 (D)

I

7834(C)

I

7835(A)

I

7840(D)

I

7922(C)

I

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Aviationexam Test Prep Edition 2012 15706. Airplane ATPL CPL The value of the parasite drag in straight and level flight at constant weight varies linearly with the:

A) angle of attack. B) square of the angle of attack. C) square of the speed. D) speed.

21016. Airplane ATPL CPL An aeroplane, being manually flown in the speed unstable region, experiences a disturbance that causes a speed reduction.lfthe altitude is maintained and thrust remains constant, the aeroplane speed will:

A) increase. B) further decrease. C) initially increase and thereafter decrease. D) initially further decrease and thereafter increase.

(Refer to figure 081-E89) The formula for parasite drag, Dp = J7p\PSCDP ' shows that parasite drag is proportional to the speed squared (\P), because CDP is more or less constant at different angles of attack, except for angles near stall as shown in the illustration.

(Refer to figure 081-El02) In an unstable region the speed will diverge from the original speed. If the speed decreases it will decrease further.

15707. Airplane ATPL CPL An aeroplane accelerates from 80 kt to 160 kt at a load factor equal to 1. By what factors will the induced drag coefficient (i) and the induced drag (ii) change?

21031. Airplane ATPL CPL An aeroplane transitions from steady straight and level flight into a horizontal co-ordinated turn with a load factor of 2, the speed remains constant and the:

A) (i)Y2 (ii) 1116. B) (i) 1 (ii) Y2. C) (i) 1/16 (ii) lA.

A) lift increases by a factor of 4. B) angle of attack increases by a factor of 1/4. C) induced drag increases by a factor of 4.

D) total drag increases by a factor of 4.

D) (i) lA (ii) 2. Consider the lift formula L = J7p\PSCL• Doubling the speed means the lift coefficient (CL ) has to be reduced by a factor 4. The induced drag coefficient CDi is equal to C//TTAR, where AR is aspect ratio. If CL is reduce by 1/4 CD/s reduced by I/W) = 1/16. In the formula for induced drag D = J7p\PSCDi the change will be: J7r(2V)2S(CD/16) or J7p4\PS(CD/16). 4/16 is Y-i, so the induced drag is altered by a factor Y-i.

Airplane ATPL CPL Increasing air pressure will have the following effect on the drag of an aeroplane (angle of attack, OAT and TAS are constant): 15762.

A) B) C) D)

the drag is only affected by the ground speed. the drag increases. this has no effect. the drag decreases.

In the formula for drag, D = J7p\PSCD, constant angle of attack and TAS mean that it is clear that Vand CD are constant. Density (p) is proportional with pressure and inverse proportional with temperature. With increasing pressure and constant temperature, density will increase, and thus increase the drag. 15764. Airplane ATPL CPL The interference drag is created as a result of:

A) separation ofthe induced vortex. B) the addition of induced and parasite drag. C) interaction between aeroplane parts (e.g. wing/fuselage). D) downwash behind the wing. Interference drag refers to boundary layer 'interference' at wing/fuselage, wing/engine nacelle and other such junctions. The mixing of the boundary layers causes additional vortices creating extra drag. 20889. Airplane ATPL CPL In what way do (i) induced drag and (ii) parasite drag alter with increasing speed?

A) B) C) D)

(i) decreases; (ii) increases (i) increases; (ii) increases (i) decreases; (ii) decreases (i) increases; (ii) decreases

Induced drag varies inversely as the square of the Indicated Air Speed (lAS), whilst parasite drag varies directly as the square of/AS.

Load factor is defined as the actual lift divided by the normal lift, i.e. the weight. If the load factor is 2 then the actual lift is the double of the lift at straight and level flight. Consider the lift formula L = J7p\PSCc Doubling the lift while density (p) and speed (V) remains constant means the lift coefficient (C,J has to be increased by a factor 2. The induced drag coefficient CDi is equal to C//TTAR, where AR is aspect ratio. If CL is doubled CDi is increased by 22 = 4. The formula for induced drag D =J7p\PSCDi shows that with all other factors but CDi constant and CDi increased by a factor 4, the induced drag is increased by a factor 4. 21072. Airplane ATPL CPL How does the total drag change, in straight and level flight at constant mass, as speed is increased from the stall speed (Vs) to maximum lAS (V NE orVMO)?

A) B) C) D)

Initially decreases, then increases. Decreases. Increases. Initially increases, then decreases.

For explanation refer to question #4260 on page 34. 21091. Airplane ATPL CPL Increasing dynamic pressure will have the following effect on the drag of an aeroplane (all other factors of importance remaining constant):

A) B) C) D)

drag increases across the whole speed range. none. drag decreases across the whole speed range. at speeds greater than the minimum drag speed, drag increases.

A higher dynamic pressure (J7p\P) means either a lower altitude or a higher speed, or both in combination. With constant altitude a higher speed means drag decreases below minimum drag speed (VMD) and increases above VMD . With constant speed and decreased altitude the drag curve moves to the right, but the same happens to the drag. 23219. Airplane ATPL CPL If landing gear is lowered:

A) B) C) D)

total total total total

drag increases and VMD decreases. drag increases and VMD increases. drag is the same and VMD increases. drag increases and VMD is the same.

(Refer to figure 081-El05) If the gear is lowered more parasite drag is caused, which increase the total drag. Looking at the illustration, it can be seen that if the Dp curve is raised, the minimum on the total drag curve will be at a lower speed.

115706 (C) 115707 (C) 115762 (8) 115764 (C) 120889 (A) 1 21016 (8) 121031 (C) 1 21072 (A) 121091 (D) 123219 (A) 1

01 Subsonic Aerodynamics 23223. Airplane ATPL CPL The effect of changes of aspect ratio on total drag will be:

A) greatest at low speed. B) greatest at high speed. C) the same at all speeds. 0) no effect at any speed. (Refer to figure 081-£105) Higher aspect ratio means reduced induced drag. Induced drag coefficient Co; is equal to C//TTAR, where AR is aspect ratio. An increase in aspect ratio means a smaller Cor and thus less induced drag. Induced drag (D) is inversely proportional to the speed = as the speed increases, the induced drag decreases, but at the same time the parasite drag (Op) increases. Parasite drag is not affected by the aspect ratio. Therefore, the increased aspect ratio will show a positive effect on drag reduction at lower speeds.

Airplane ATPL CPL To fly at a given lAS, the thrust required at altitude: 23224.

A) will be less than at sea level.

B) will be the same as at sea level and wilJ'be given by the same

throttle position. C) will be the same as at sea level, but will require the throttle to be advanced. 0) will be greater than at sea level. Flying constant lAS means that the dynamic pressure (Y:,pV» is constant. Flying at altitude where density is lower means the TAS will be higher, but from the lift formula L = *pV>SC, it can be seen that CIf and consequently the angIe of attack, is constant. This in turn means that the drag coefficient (Co) is also unchanged, which means the drag is the same. However, at altitude the engine(s) produces less thrust because of the Idwer density, so the throttle need to be advanced to give sufficient thrust to balance the drag.

Airplane ATPL CPL An aircraft at an lAS of 150 kts at sea level, then flies at 10.000 ft, the drag will: 23225.

A) be greater at sea level than at 10.000 ft. B) be greater at 10.000 ft than at sea level. C) be the same. 0) depends on the angle of incidence. Flying constant lAS means that the dynamic pressure (*pV» is constant. Flying at altitude where density is lower means the TAS will be higher, but from the lift formula L = *pV>SC, it can be seen that C" and consequently the angle of attack, is constant. This in turn means that the drag coefficient (Co) is also unchanged, which means the drag is the same.

23226. Airplane ATPL CPL The minimum total drag of an aircraft in flight occurs:

A) B) C) 0)

at the stalling speed. at the speed where parasite drag and induced drag are equal. at the speed where induced drag is least. at the speed where parasite drag is least.

(Refer to figure 081-£105) The total drag is induced drag plus parasite drag. The total drag curve is therefore the sum of the curves for parasite drag and induced drag as shown in the illustration. The minimum on the total drag curve is where parasite drag equals induced drag.

23257. Airplane ATPL CPL The purpose of streamlining is:

A) to reduce form drag. B) to reduce induced drag. C) to increase lift. 0) to reduce skin friction drag.

23258. Airplane ATPL CPL Skin friction drag resulting from a laminar boundary layer will be:

A) more than from a turbulent boundary layer. B) less than from a turbulent boundary layer. C) the same as from a turbulent boundary layer. 0) unmeasurable. The turbulent boundary layer with its characteristic eddies exposes more air to the surface with greater mixing of the lower layers with the faster moving air further away from the surface. This mixing creates greater drag on the surface.

23259. Airplane ATPL CPL For an aircraft in level flight, as indicated air speed increases:

A) B) C) 0)

both parasite and induced drag increase. parasite drag decreases, induced drag increases. parasite drag increases, induced drag decreases. both parasite and induced drag decrease.

An increased lAS in level flight also means an increased TAS. To maintain level flight, lift must be constant. With an increases TAS, the angle of attack must be reduced. The lower angle of attack means reduced induced drag, while the increased speed means increased parasite drag.

23260. Airplane ATPL CPL If speed is reduced from 300 kts to 150 kts the form drag will be:

A) B) C) 0)

double half a quarter a third.

DRAG (D) equation: o = *pV>SCD' where: p =themass density of the fluid (rho), V = the velocity of the object relative to the air, S = is the reference area, and Co = the drag coefficient - a dimensionless constant. From the drag equation it is obvious that if the speed V is halved, the drag would be 0 = *p(V+21SCo = (*pV>SCO )+22 = (*pV>SCo)+4. The drag will be reduced to quarter value.

23261. Airplane ATPL CPL If the weight of an aircraft is increased, for a constant speed:

A) B) C) 0)

profile drag will increase; induced drag will remain the same. induced drag will increase; profile drag will remain the same. both profile drag and induced drag will remain the same. profile drag will increase, induced drag will decrease.

If the weight is increased, lift must increase. At constant speed lift can only be increased by increasing angle of attack. A higher angle of attack means increased induced drag, but at constant speed parasite drag remains the same.

23290. Airplane ATPL CPL At high speed an aircraft will have:

A) B) C) 0)

more profile drag than induced drag. more induced drag than profile drag. about the same profile drag as induced drag. only induced drag.

(Refer to figure 081-£105) The total drag is induced drag plus parasite drag. The total drag curve is shown in the illustration, where it can be seen that at speeds above minimum drag speed, the drag of an aircraft will be more parasite drag than induced drag.

Streamlining a body reduces the amount of vortices behind the body and therefore the form drag. Penalty is an increase in skin friction drag because of a larger wetted area.

I 23223 (A) I 23224 (C) I 23225 (C) I 23226 (8) I 23257 (A) I 23258 (8) I 23259 (C) I 23260 (C) I 23261

(8)

I 23290 (A) I

Aviationexam Test Prep Edition 2012

23294. Airplane ATPL CPL If the weight of an aircraft is increased, the minimum drag speed (VMO): A) B) C) D)

is the same but occurs at a higher angle of attack. is the same and occurs at the same angle of attack. is increased. is decreased.

If an aircraft is operated at a higher gross weight, more lift will be required. If more lift is generated, induced drag will be higher. The total drag will be greater, and VMD will occur at a higher lAS.

23315. Airplane ATPL CPL The drag of an aircraft will: A) increase with increase in air temperature. B) increase with decrease in air density. C) increase with increase in air pressure. D) decrease with an increase in stagnation pressure.

A) if it recovers from displacements about any of the three axes at all speeds. B) if it can be trimmed to fly at any speed between stalling speed and VNE • C) when the speed is disturbed from its trimmed value, it tends to return to the original speed. D) if it can fly a 3° glide slope without the need to adjust the thrust setting.

23332. Airplane ATPL CPL For an aircraft flying at a speed above VMO:

From the drag equation it can be seen that drag is proportional to the density (p). Density varies proportionally with pressure and inversely proportional with temperature. Increased drag is caused by higher pressure or lower temperature.

23327. Airplane ATPL CPL An aircraft is required to cruise, maintaining VMO' As the weight decreases the lAS must be: A) decreased, and the angle of attack decreased. B) decreased, and the angle of attack remain constant. C) increased, and the angle of attack decreased. D) kept the same, and the angle of attack kept the same.

A) a speed increase causes a drag increase which will cause a deceleration. B) a speed increase causes a drag decrease causing further acceleration. C) a speed increase causes a drag increase causing an acceleration. D) a speed decrease causes a drag increase causing a deceleration. (Refer to figure 087-E702) As seen in the illustration, an increase in speed causes a thrust deficiency (0 > T) which will decelerate the aircraft.

23536. Airplane ATPL CPL The minimum drag speed (TAS):

(Refer to figure 087-E723) If the weight is decreased, lift must decrease. At a given lAS lift can only be decreased by decreasing angle of attack. A smaller angle of attack means decreased induced drag, but the parasite drag remains the same. The curve for the total drag will therefore move to the left and slightly down, as shown in the illustration. Minimum drag speed will be lower. Flying VMD means flying best LID ratio, which is at an angle of attack independent of weight.

A) B) C) D)

23331. Airplane ATPL CPL An aircraft is said to have speed stability:

For explanation refer to question #23330 on this page.

DRAG (D) equation: o = Y2pIPSCD' where: p = the mass density of the fluid (rho), V = the velocity of the object relative to the air, S = is the reference area, and CD = the drag coefficient - a dimensionless constant.

23329. Airplane ATPL CPL At a ___ weight the maximum level flight speed will be _ cause of a change in ___ drag,

return to equilibrium without pilot interference. Speed stability therefore means the aircraft will return to the trimmed speed ifdisturbed. Speed stability exists above the minimum drag speed VMD as shown in the illustration. When flying at a speed corresponding to point A, a gust decelerating the aircraft will result in a thrust surplus which will accelerate the aircraft, while a gust accelerating the aircraft results in a thrust deficiency which slows the aircraft down.

be-

lower; less; parasite lower; less; induced higher; less; induced higher; less; parasite

A higher weight requires an increase in lift obtained by a higher angle ofattack. Higher angle of attack causes increased induced drag and hence increased total drag. With unchanged thrust available, the maximum speed achievable is lower.

23330. Airplane ATPL CPL Speed stability of an aircraft: A) is stable below VMD because total drag decreases as speed decreases. B) is unstable above VMD because thrust decreases as speed increases. C) is unstable below VMD because total drag decreases as speed decreases. D) is stable above VMD because total drag increases as speed increases. (Refer to figure 087-E702) Stability in general means that the aircraft disturbed from equilibrium will

A) remains constant with increasing aircraft weight. B) increases with increasing altitude. C) decreases with increasing altitude. D) .reduces with increasing aircraft weight. If altitude increases it is necessary to increase the angle of attack to compensate for lower density. This means the induced drag will be higher. The total drag will be greater, and VMD will occur at a higher TAS. (If an aircraft is operated at a higher gross weight, more lift will be required. If more lift is generated, induced drag will be higher. The total drag will be greater, and VMD will occur at a higher TAS.)

23547. Airplane ATPL CPL As altitude increases the excess thrust at a given lAS: A) decreases because drag increases and thrust decreases. B) increases because drag decreases and thrust is constant. C) decreases because thrust decreases and drag is constant. D) increases because drag decreases and thrust increases. Flying constant lAS means that the dynamic pressure (Y2pIP) is constant. Flying at altitude where density is lower means the TAS will be higher, but from the lift formula L = Y2pIPSCL it can be seen that Clf and consequently the angle ofattack, is constant. This in turn means that the drag coefficient (CJ is also unchanged, which means the drag is the same. However, at altitude the engine(s) produces less thrust because of the lower densitY. The difference between thrust and drag will therefore decrease.

24067. Airplane ATPL CPL Parasite drag is linearly proportional to: A) B) C) D)

speed. angle of attack. speed 2• weight.

(Refer to figure 087-E89)

123294 (C) 1 23315 (C) 1 23327 (8) 123329 (C) 123330 (D) 1 23331 (C) 1 23332 (A) 1 23536 (8) 123547 (C) 1 24067 (C) 1

EI

01 Subsonic Aerodynamics The formula for parasite drag, Dp = MlpIPSCop ' shows that parasite drag is proportional to the speed squared (IP), because COP is more or less constant at different angles of attack, except for angles near stall as shown in the illustration.

24547. Airplane ATPL CPL When an aircraft selects its undercarriage and flaps down in flight, its V1MD will ___ (as opposed to maintaining the clean configuration). When in clean configuration the speed stability will ___ (as opposed to configuration with gear and flaps extended). A) increase; reduce B) increase; increase e) reduce; reduce D) reduce; increase

A) induced drag, and is greatly affected by changes in airspeed. B) parasite drag, and is greatly affected by changes in airspeed. C) induced drag, and is not affected by changes in airspeed. D) profile drag, and is not affected by changes in airspeed. Induced drag is a product of lift, that is the horizontal component of the total reaction on the profile. The direction of the total reaction depends on the angle of attack, which in turn varies with speed to provide the required lift coefficient.

26813. Airplane ATPL CPL Which relationship is correct when comparing drag and airspeed?

(Refer to figures 087-f102 and 087-f722) The change in configuration (lowering of the gear and extension of the flaps) causes the parasite drag to increase and therefore the total drag curve to move up and to the left (see attached figure). Due to this movement the ~MO reduces to a slower speed. The speed moves into the more unstable region. Now when we clean up the aircraft and retract the gear and flaps, the total drag curve moves down and to the right, ~MO increases and the speed moves to the right, into a more stable region => speed stability increases (see attached figure).

26384. Airplane Parasite power:

26800. Airplane ATPL CPL That portion of the aircraft's total drag created by the production of lift is called:

ATPL

CPL

A) varies as drag2 • B) is parasite drag x velocity. e) varies as velocity2. D) is always the largest % of total power required in straight level flight. Power equals force multiplied by speed. In this case, parasite drag x velocity.

26797. Airplane ATPL CPL The resistance, or skin friction, due to the viscosity of the air as it passes along the surface of the wing is part of the: A) induced drag. B) form drag. e) parasite drag. D) interference drag.

A) If you double the airspeed you double the induced drag. B) If you double the airspeed the induced drag is halved. C) If you double the airspeed the induced drag is reduced to 1PI. D) If you double the airspeed the parasite drag is doubled. From the lift formula, L = MlpIPSCL, it is evident, that if the velocity (V) is doubled the lift coefficient (CL) must be reduced by a factor 4 (2 squared) to maintain level flight. Induced drag coefficient COj is equal to C/llTAR, where AR is aspect ratio. If CL is reduces by 4, COj will be reduced by a factor 76. In the formula for induced drag, OJ = MlpIPCOi' V means an increase of4 whilst CoJs a reduction by 7176. The total reduction is therefore 4176 = l4.

232259. Airplane ATPL CPL Which drag components make up parasite drag? 1) pressure drag. 2) friction drag. 3) induced drag. 4) interference drag. The combination that regroups all of the correct statements is:

A) 1,2,4 B) 1,2,3,4 e) 1,3,4 D) 2,3,4 232262. Airplane ATPL CPL Interference drag is the result of:

Parasite drag is made up by the skin friction drag and the form drag, and it is not associated with lift production such as induced drag.

A) downwash behind the wing. B) aerodynamic interaction between aeroplane (e.g. wing/fuselage). e) the addition of induced and parasite drag. D) separation of the induced vortex.

parts

01-06 Ground Effect 7675. Airplane ATPL CPL Ground effect is most likely to result in which problem? A) Deep stall. B) Hard landings. e) Becoming airborne before reaching recommended takeoff speed. D) Inability to get airborne even though airspeed is sufficient for normal takeoff needs. The decreased down wash in ground effect gives an increase in the effective angle of attack that makes it possible to be airborne at a lower speed. However, after leaving ground effect the aircraft would settle-back on to the runway.

7763. Airplane ATPL CPL Ground effect occurs: A) it acts like a decrease in aspect ratio. B) it is only effective up to 1 wing span from the ground. e) during the approach to landing. D) it aids landing by increasing the induced drag. (Refer to figure 087-f770) Ground effect acts like an increase in aspect ratio and reduces the induced drag, but it is only effective under one wingspan from the ground as shown in the illustration. Most of the induced drag reduction in ground effect is achieved only up to MI of the span - once above MI of the span (up to about 7 span), the induced drag reduction drops below 70% (compared to for example 50% induced drag reduction at a height of 711O'h of the span).

124547 (D) 126384 (8) 1 26797 (e) 126800 (A) 1 26813 (e) 1232259 (A) 1232262 (8) 1 7675 (e) 1 7763 (8)

1

Aviationexam Test Prep Edition 2012

7764. Airplane ATPL CPL What will happen in ground effect? A) B) C) D)

23319. Airplane ATPL CPL Floating caused by ground effect will be most realized during an approach to land when:

An increase in strength of the wing tip vortices. The wing downwash on the tail surfaces increases. The induced angle of attack and induced drag decreases. A significant increase in thrust required.

(Refer to figure 081-E30) The decreased down wash in ground effect gives an increase in the effective angle of attack and thus reduces the induced angle of attack; see illustration. A smaller induced angle of attack means a decrease in induced drag.

7777. Airplane ATPL CPL Ground effect has the following influence on the landing distance: A) B) C) D)

decreases. increases. does not change. increases, only if the landing flaps are fully extended.

Entering ground effect will increase lift and reduce induced drag. Both factors will slow the descent and hence increase the landing distance.

7790. Airplane ATPL CPL On entering ground effect, maintaining flight at the same speed: A) B) C) D)

A) B) C) D)

at a higher than normal angle of attack. at twice the length ofthe wing span above the surface. at less than the length of the wing span above the surface. at target threshold speed.

For explanation refer to question #7924 on this page.

23320. Airplane ATPL CPL It is possible to fly an aircraft just clear of the ground at a slightly slower airspeed than that required to sustain level flight at higher altitudes. This is the result of: A) a cushioning effect of the air as it is trapped between the ground and the descending aircraft. B) ground interference with the static pressure system which produces false indications on the ASI. C) interference of the ground surface with the airflow patterns about the aircraft in flight. D) the ASI giving a false reading due to lower TAS at low pressure altitudes. The decreased down wash in ground effect gives an increase in the effective angle of attack that makes it possible to be airborne at a lower speed.

23321. Airplane ATPL CPL An aeroplane leaving ground effect will:

ground effect has no effect on power. less power is required. more power is required. lift decreases.

Entering ground effect will increase lift and reduce induced drag. With less drag power required decreases, so to maintain speed, less power from the engine is needed.

7924. Airplane ATPL CPL Floating due to ground effect during an approach to land will occur: A) at a speed approaching the stall. B) when the height is less than twice the length of the wing span above the surface. C) when a higher than normal angle of attack is used. D) when the height is less than half of the length of the wing span above the surface. (Refer to figure 081-E110) In the illustration the consequence of ground effect is shown as reduction in induced drag, but other consequences such as increased lift follows this curve. It is clear, that floating will be prominent at heights below half the wingspan.

23318. Airplane ATPL CPL What must a pilot be aware of as a result of ground effect? A) Wingtip vortices increase, creating wake turbulence problems for arriving and departing aircraft. B) Induced drag decreases, and any excess speed in the flare may cause floating. C) A full stall landing will require less up elevator deflection than when free of ground effect. D) Ground effect is due to a cushion of air generated by a landing aircraft when very close to the ground. Entering ground effect will increase lift and reduce induced drag. With excess speed the increased lift will cause floating.

A) experience a decrease in the thrust required. B) experience a decrease in stability and a nose up change in moments. C) require a lower angle of attack to attain the same lift coefficient. D) experience a decrease in induced drag. When leaving ground effect the down wash behind the wing will increase. This will increase the angle of attack on the tail plane, produce more lift and give a nose-up pitch moment. Increased downwash on the tail plane decreases the static longitudinal stability.

23322. Airplane ATPL CPL An aeroplane is usually affected by ground effect at what height above the surface? A) B) C) D)

Twice the aeroplane's wing span above the surface. 3 to 4 times the aircraft's wing span. Less than halfthe aircraft's wing span above the surface. Only after the main wheels touch the ground.

(Refer to figure 081-E110) In the illustration the consequence of ground effect is shown as reduction in induced drag, but other consequences such as increased lift follows this curve. It is clear, that floating will be prominent at heights below half the wingspan. Most of the positive effect is achieved only up to 17 of the span - once above 17 of the span (up to about 1 span), the induced drag reduction due to the ground effect drops below 10% (compared to for example 50% induced drag reduction at a height of 1110th of the span).

24069. Airplane ATPL CPL When an aeroplane enters ground effect: A) B) C) D)

the effective angle of attack is decreased. the induced angle of attack is increased. the lift is increased and the drag is decreased. drag and lift are both reduced.

In ground effect there is less up- and down wash. The decreased down wash causes the air flow direction at the centre of pressure to be deflected less and thus tilting the total reaction on the wing forwards. Lift is the vertical component of the total reaction and it will increase. The horizontal component - in opposite direction to the movement - is induced drag. With a more vertical total reaction the induced drag is decreased.

I

-----------

7764 (C)

I

7777 (8)

I

7790 (8)

I

7924 (0)

- - - - ---------------

I 23318 (8) I 23319 (C) I 23320 (C) I 23321

(8)

I 23322 (C) I 24069 (C) I

01 Subsonic Aerodynamics

232278. Airplane ATPL CPL Assuming constant lAS, when an aeroplane enters ground effect: A) the induced angle of attack increases. B) induced drag increases. C) the effective angle of attack increases. 0) the effective angle of attack decreases. Airplane ATPL CPL 232279. Which statement, about an aeroplane entering ground effect at constant angle of attack, is correct? I. The lift coefficient CL increases. II. The induced drag coefficient COl decreases. A) I is incorrect, II is incorrect. B) I is correct, II is incorrect. C) I is incorrect, II is correct. 0) I is correct, II is correct. 232280. Airplane ATPL CPL Which statement, about an aeroplane entering ground effect at constant angle of attack, is correct? I. The lift coefficient CL remains constant. II. The induced drag coefficient COl decreases. A) I is incorrect, II is incorrect. B) I is correct, II is incorrect. C) I is incorrect, II is correct. 0) I is correct, II is correct. Airplane ATPL CPL 232281. Which statement, about an aeroplane entering ground effect at constant angle of attack, is correct? I. The ~ift coefficient CL decreases. II. The induced drag coefficient COl decreases. A) I is incorrect, II is correct. B) I is incorrect, II is incorrect. C) I is correct, II is incorrect. 0) I is correct, II is correct. 232282. Airplane ATPL CPL Which statement, about an aeroplane entering ground effect at constant angle of attack, is correct? I. The lift coefficient CL increases. II. The induced drag coefficient COl remains constant. A) I is incorrect, II is incorrect. B) I is correct, II is correct. C) I is incorrect, II is correct. 0) I is correct, II is incorrect. Airplane ATPL CPL 232283. Which statement, about an aeroplane entering ground effect at constant angle of attack, is correct? I. The lift coefficient CL decreases. II. The induced drag coefficient COl remains constant. A) I is incorrect, II is correct. B) I is correct, II is correct. C) I is incorrect, II is incorrect. 0) I is correct, II is incorrect.

232284. Airplane ATPL CPL Which statement, about an aeroplane entering ground effect at constant angle of attack, is correct? I. The lift coefficient CL increases. II. The induced drag coefficient COl increases. A) I is incorrect, II is correct. B) I is correct, II is incorrect. C) I is incorrect, II is incorrect. 0) I is correct, II is correct. Airplane ATPL CPL 232285. Which statement, about an aeroplane entering ground effect at constant angle of attack, is correct? I. The lift coefficient CL remains constant. II. The induced drag coefficient COl increases. A) I is incorrect, II is correct. B) I is correct, II is correct. C) I is correct, II is incorrect. 0) I is incorrect, II is incorrect. Airplane ATPL CPL 232286. Which statement, about an aeroplane entering ground effect at constant angle of attack, is correct? I. The lift coefficient CL decreases. II. The induced drag coefficient COl increases. A) I is incorrect, II is correct. B) I is correct, II is correct. C) I is incorrect, II is incorrect. 0) I is correct, II is incorrect. 232287. Airplane ATPL CPL Which statement, about an aeroplane leaving ground effect at constant angle of attack, is correct? I. The lift coefficient CL increases. II. The induced drag coefficient CD; increases. A) I is correct, II is correct. B) I is correct, II is incorrect. C) I is incorrect, II is correct. 0) I is incorrect, II is incorrect. Airplane ATPL CPL 232288. Which statement, about an aeroplane leaving ground effect at constant angle of attack, is correct? I. The lift coefficient CL remains constant. II. The induced drag coefficient COl increases. A) I is incorrect, II is incorrect. B) I is incorrect, II is correct. C) I is correct, II is correct. 0) I is correct, II is incorrect. 232289. Airplane ATPL CPL Which statement, about an aeroplane leaving ground effect at constant angle of attack, is correct? I. The lift coefficient CL decreases. II. The induced drag coefficient COl increases. A) I is correct, II is correct. B) I is incorrect, II is incorrect. C) I is correct, II is incorrect. 0) I is incorrect, II is correct.

1232278 (C) 1232279(0) 1232280 (C) 1232281 (A) 1232282 (D) 1232283 (C) 1232284(8) 1232285 (D) 1232286 (C) 1232287 (C) 1 1232288(8) 1232289 (A) 1

Aviationexam Test Prep Edition 2012

232290.

Airplane

ATPL

CPL

Which statement, about an aeroplane leaving ground effect at constant angle of attack, is correct? I. The lift coefficient CL increases. II. The induced drag coefficient CD1 remains constant. A) B) C) D)

I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is correct. I is incorrect, II is incorrect.

232291.

Airplane

ATPL

CPL

Which statement, about an aeroplane leaving ground effect at constant angle of attack, is correct? I. The lift coefficient CL decreases. II. The induced drag coefficient CD1 remains constant. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is correct.

232292.

Airplane

ATPL

CPL

Which statement, about an aeroplane leaving ground effect at constant angle of attack, is correct? I. The lift coefficient CL increases. II. The induced drag coefficient CDI decreases. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is incorrect. I is correct, II is correct. I is incorrect, II is correct.

232293.

Airplane

ATPL

CPL

Which statement, about an aeroplane leaving ground effect at constant angle of attack, is correct? I. The lift coefficient CL remains constant. II. The induced drag coefficient CD1 decreases. A) I is correct, II is correct. B) I is correct, II is incorrect. C) I is incorrect, II is correct. D) I is incorrect, II is incorrect. 232294.

Airplane

ATPL

CPL

Which statement, about an aeroplane leaving ground effect at constant angle of attack, is correct? I. The lift coefficient CL decreases. II. The induced drag coefficient CD; decreases. A) B) C) D)

I is incorrect, II is correct. I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is incorrect.

232295.

Airplane

ATPL

CPL

Which statement about an aeroplane entering ground effect is correct? I. The downwash angle increases. II. The induced angle of attack decreases. A) B) C)· D)

I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is correct. I is incorrect, II is incorrect.

232296.

Airplane

ATPL

CPL

Which statement about an aeroplane entering ground effect is correct? I. The downwash angle remains constant. II. The induced angle of attack decreases. A) I is incorrect, II is incorrect. B) I is correct, II is incorrect. C) I is incorrect, II is correct. D) I is correct, II is correct. 232297.

Airplane

ATPL

CPL

Which statement about an aeroplane entering ground effect is correct? I. The downwash angle decreases. II. The induced angle of attack decreases. A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is incorrect.

232298.

Airplane

ATPL

CPL

Which statement about an aeroplane entering ground effect is correct? I. The downwash angle increases. II. The induced angle of attack remains constant. A) I is correct, II is correct. B) I is incorrect, II is correct. C) I is incorrect, II is incorrect. D) I is correct, II is incorrect. 232299.

Airplane

ATPL

CPL

Which statement about an aeroplane entering ground effect is correct? I. The downwash angle decreases. II. The induced angle of attack remains constant. A) B) C) D)

I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct.

232300.

Airplane

ATPL

CPL

Which statement about an aeroplane entering ground effect is correct? I. The downwash angle increases. II. The induced angle of attack increases. A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct.

232302.

Airplane

ATPL

CPL

Which statement about an aeroplane entering ground effect is correct? I. The downwash angle decreases. II. The induced angle of attack increases. A) B) C) D)

I is incorrect, II is correct. I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect.

1232290 (0) 1232291 (A) 1232292 (8) 1232293 (0) 1232294 (EI) 1232295 (C) 1232296 (C) 1232297 (A) 1232298 (C) 1232299 (A) 1 1232300 (8) 1232302 (0) 1

01 Subsonic Aerodynamics

232303. Airplane ATPL CPL Which statement about an aeroplane leaving ground effect is correct?

232309. Airplane ATPL CPL Which statement about an aeroplane leaving ground effect is correct?

I. The downwash angle increases. II. The induced angle of attack increases.

I. The downwash angle remains constant. II. The induced angle of attack decreases.

A) B) C) D)

A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct. I is incorrect, II is incorrect.

232304. Airplane ATPL CPL Which statement about an aeroplane leaving ground effect is correct?

I is correct, II is correct. I is incorrect, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect.

232310. Airplane ATPL CPL Which statement about an aeroplane leaving ground effect is correct?

I. The downwash angle remains constant. II. The induced angle of attack increases.

I. The downwash angle decreases. II. The induced angle of attack decreases.

A) B) C) D)

A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is correct.

232305. Airplane ATPL CPL Which statement about an aeroplane leaving ground effect is correct? I. The downwash angle decreases. II. The induced angle of attack increases. A) B) C) D)

I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct.

232306. Airplane ATPL CPL Which statement about an aeroplane leaving ground effect is correct? I. The downwash angle increases. II. The induced angle of attack remains constant. A) B) C) D)

I is correct, II is correct. I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect.

232307. Airplane ATPL CPL Which statement about an aeroplane leaving ground effect is correct? I. The downwash angle decreases. II. The induced angle of attack remains constant. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is correct.

232308. Airplane ATPL CPL Which statement about an aeroplane leaving ground effect is correct? I. The downwash angle increases. II. The induced angle of attack decreases. A) I is incorrect, II is incorrect. B) I is correct, II is correct. C) I is correct, II is incorrect. D) I is incorrect, II is correct.

I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is correct. I is correct, II is incorrect.

232311. Airplane ATPL CPL Assuming constant lAS, when an aeroplane enters ground effect: A) induced drag increases. B) the effective angle of attack does not change. C) the effective angle of attack decreases. D) the induced angle of attack reduces. 232312. Airplane ATPL CPL Assuming constant lAS, when an aeroplane enters ground effect: A) B) C) D)

the effective angle of attack decreases. induced drag reduces. downwash does not change. the induced angle of attack increases.

232313. Airplane ATPL CPL Assuming constant lAS, when an aeroplane enters ground effect: A) B) C) D)

induced drag increases. downwash reduces. the effective angle of attack decreases. downwash does not change.

232314. Airplane ATPL CPL Assuming constant lAS, when an aeroplane leaves ground effect: A) B) C) D)

the effective angle of attack increases. the induced angle of attack decreases. induced drag decreases. the effective angle of attack decreases.

232315. Airplane ATPL CPL Assuming constant lAS, when an aeroplane leaves ground effect: A) B) C) D)

the effective angle of attack increases. the induced angle of attack increases. the effective angle of attack does not change. induced drag decreases.

1232303 (C) 1232304 (D) 1232305 (0) 1232306 (0) 1232307 (C) 1232308 (C) 1232309 (0) 1232310 (8) 1232311 (0) 1232312 (8) 1 1232313(8) 1232314(0) 1232315(8) 1

Aviationexam Test Prep Edition 2012 232316. Airplane ATPL CPL Assuming constant lAS, when an aeroplane leaves ground effect:

A) downwash does not change. B) induced drag increases. C) the induced angle of attack decreases. 0) the effective angle of attack increases.

232317. Airplane ATPL CPL Assuming constant lAS, when an aeroplane leaves ground effect:

A) B) C) 0)

downwash does not change. downwash increases. induced drag decreases. the effective angle of attack increases~

01-07 The Relationship between the Lift Coefficient and Speed in Steady, Straight and Level Flight Airplane ATPL CPL An aeroplane maintains straight and level flight while the speed is doubled. The change in lift coefficient will be: 2627.

A) B) C) 0)

xO,25 x2,0 xO,5

x4,0

The lift equation: LIFT = ~p\PSC" where: • CL = coefficient of lift. This represents angle of attack of the airfoil and the shape of the airfoil. This described in terms of thicknesslchord ratio and a camber and can be altered in flight, for example, by lowering thefJaps. • p = The density of the air. For any given altitude during subsonic flight, the density may be considered to be constant. • \P =The velocity of the aircraft, squared. • S =The wing area. From the lift equation it is evident, that if the velocity (V) is doubled the lift would increase by a factor 4 (22 = 4). To maintain level flight, the lift should be constant, so the lift coefficient CLshould be 0,25 of the former value.

7714. Airplane ATPL CPL An aeroplane performs a straight and level horizontal flight at the same angle of attack at two different altitudes: (all other factors of importance being constant, assume ISA conditions and no compressibility effects) A) B) C) 0)

the TAS at the higher altitude is higher. the TAS at both altitudes is the same. the TAS at the higher altitude cannot be determined. the TAS at the higher altitude is lower.

The lift equation: LIFT = ~p\PSCL' where: • CL = coefficient of lift. This represents angle of attack of the airfoil and the shape of the airfoil. This described in terms of thickness/chord ratio and a camber and can be altered in flight, for example, by lowering thefJaps. • p = The density of the air. For any given altitude during subsonic flight, the density may be considered to be constant. • \P = The velocity of the aircraft, squared. • S = The wing area. In the lift equation all factors except density and speed (TAS) are constant. At higher altitude p is reduced; therefore TAS (V) must be increased to maintain the same lift (= weight).

7869. Airplane ATPL CPL If TAS is doubled, by which of the following factors should the original CL be multiplied to maintain level flight? A) 0,25 B) 0,5

C) 2,0 0) 4,0 The lift equation: LIFT = ~p\PSCL' where: • CL = coefficient of lift. This represents angle of attack of the airfoil and the shape of the airfoil. This described in terms of thickness/chord ratio and a camber and can be altered in flight, for example,. by lowering thefJaps. • p = The density of the air. For any given altitude during subsonic flight, the density may be considered to be constant. • \P = The velocity of the aircraft, squared. • S = The wing area. From the lift equation it can be seen that to maintain constant lift with double the speed, CLmust be reduced to quarter value, or multiplied by a factor 0,25.

7906. Airplane ATPL CPL To maintain level flight, if the angle of attack is increased the speed must be:

A) B) C) 0)

reduced. increased in the same ratio as the lift/drag ratio decreases. kept constant. increased.

(Refer to figure 081-E113) Angle of attack governs the lift coefficient Cc From the typical curve for CL shown in the illustration, it is clear that an increase in angle of attack gives a higher value of CL' From the lift formula L = ~p\PSCL it can be seen that to maintain the same lift with an increased angle of attack - and thus CL - the speed must be reduced.

21021. Airplane ATPL CPL An aeroplane flies in straight and level flight with a lift coefficient CL=l. What will be the new value of CL after the speed has doubled, whilst still maintaining the original condition of flight?

A) B) C) 0)

1,00 0,50 0,25 2,00

The lift equation: LIFT = ~p\PSC" where: • CL = coefficient of lift. This represents angle of attack of the airfoil and the shape of the airfoil. This described in terms of thicknesslchord ratio and a camber and can be altered in flight, for example, by lowering the fJaps. • p = The density of the air. For any given altitude during subsonic flight, the density may be considered to be constant. • \P = The velocity of the aircraft, squared. • S = The wing area. From the lift equation it is obvious that if the speed V is doubled, the lift coefficient C" has to be reduced to quarter value, or multiplied by a factor 0,25

1232316 (8) 1232317 (8) 1 2627 (A)

1 7714 (A)

1 7869 (A) 1 7906 (A) 1 21021 (C) 1

01 Subsonic Aerodynamics

(i.e. CL = 1 x 0,25 =0,25).

21086. Airplane ATPL CPL In straight and level flight at a speed of 1,3 Vs' the lift coefficient, expressed as a percentage of its maximum (C LMAX )' would be: A) 169% B) 130% C) 59% D) 77% The lift is equal in both cases: L = 17pV/SCLMAX = 17p(1,3 VSJ2SCL gives V/CLMAX = (1,3 VSJ2CL, where CL is the actual lift coefficient. Eliminating Vson both sides gives CLMAX = 1,32CL orCL=(111,32)CLMAX= 0,592 CLMAX' that is 59% of CLMAX '

24537. Airplane ATPL CPL An aircraft flying at 150 kts EAS at 10.000 ft compared to the same aircraft flying at the same EAS at sea level will have: A) B) C) D)

the same angle of attack. a smaller angle of attack. a larger angle of attack. a lower lAS.

26976. Airplane ATPL CPL What changes in angle of attack must be made to maintain altitude while the airspeed is being increased? A) Decrease the angle of attack to compensate for the increasing lift. B) Increase the angle of attack to produce more lift than drag. C) Decrease the angle of attack to compensate for the increasing drag. D) Maintain a constant angle of attack until the desired airspeed is reached, then increase the angle of attack. (Refer to figure 081-E113) The lift equation: LIFT = 17p\f2SCL' where: • CL = coefficient of lift. This represents angle of attack of the airfoil and the shape of the airfoil. This described in terms of thicknesslchord ratio and a camber and can be altered in flight, for example, by lowering the flaps. • p = The density of the air. For any given altitude during subsonic flight, the density may be considered to be constant. • \f2 = The velocity of the aircraft, squared. • S = The wing area. From the lift equation it is evident, that if the velocity (V) is increased the lift coefficient (CJ must be reduced to maintain level flight. The lift coefficient varies with the angle of attack as shown in the illustration, so the angle of attack should be decreased.

Flying constant EAS means that the dynamic pressure (17p\f2) is constant. Flying at a lower altitude where density is higher means the TAS will be higher, but from the lift formula L = 17p\f2SCL it can be seen that CL' and consequently the angle of attack, is the same in both cases.

26825. Airplane ATPL CPL An increase in the speed at which an airfoil passes through the air increases lift because: A) the increased speed of air passing over the airfoil's upper surface decreases the pressure, thus creating a greater pressure differential between upper and lower surface. B) the increased speed of the airflow creates a lesser pressure differential between the upper and lower airfoil surfaces. C) the increased velocity ofthe relative wind increases the angle of attack. D) the impact pressure of the air on the lower surface of the airfoil creates less positive pressure. The air passing over the airfoil's upper surface has a higher velocity than the air speed thus decreasing the pressure. The air passing under the airfoil has a lower velocity and thus increases pressure. The pressure differences creates lift. If the air on the upper surface increases speed, the pressure differential between upper and lower surface will increase.

232323. Airplane ATPL CPL Whilst maintaining straight and level flight with a lift coefficient CL 1, what will be the new approximate value of CL after the speed is increased by 41%?

=

A) B) C) D)

0,60 0,30 0,25 0,50

232324. Airplane ATPL CPL Whilst maintaining straight and level flight with a lift coefficient CL 1 what will be the new approximate value of CL after the speed is increased by 30%?

=

A) B) C) D)

0,30 0,25 0,60 0,50

01 -08 The Stall 2628. Airplane ATPL CPL The stall speed increases, when? (all other factors of importance being constant) A) B) C) D)

Weight decreases. Pulling out of a dive. Spoilers are retracted. Minor altitude changes occur e.g. 0-10.000 ft.

The stall speed increases with the square root of the load factor. The loa~ factor increases when pulling out of a dive.

3834. Airplane ATPL CPL How does stalling speed (lAS) vary with altitude? A) It remains constant at lower altitudes but decreases at higher altitudes due to compressibility effects. B) It remains constant. C) It increases with increasing altitude, because the density decreases. D) It remains constant at lower altitudes but increases at higher altitudes due to compressibility effects. (Refer to figure 081-E95) The stalling speed as lAS is constant at lower altitudes as long as the speed is low enough for compressibility effects not to be present. Eventually, the stalling speed has increased with altitude to such an extent that these effects are important, and the stalling speed will then increase.

121086 (C) 124537 (A) 126825 (A) 126976 (A) 1232323 (D) 1232324 (C) 1 2628 (8) 1 3834 (0) 1

Aviationexam Test Prep Edition 2012 4131. Airplane ATPL CPL IfVS1g is 100 kts, the stalling speed in a 45° bank level turn will be: A) 119 kts B) 80 kts C) 141 kts D) 100 kts

4201. Airplane ATPL CPL When entering a stall, the Centre of Pressure (CP) will ___ (i) on a straight wing and __ (ii) on a strongly swept wing. (i) not move; (ii) not move (i) move aft; (ii) not move (i) move aft; (ii) move aft

(i) move aft; (ii) move forward

(Refer to figure 081-E48) A straight wing will stall from the wing root and the centre of pressure (CP) moves aft. Aswept wing will stall atthe tip first causing the CP to move forward.

4209. Airplane ATPL CPL An aircraft whose weight is 237 402 N stalls at 132 kts. At a weight of 356 103 N it would stall at: A) B) C) D)

A) B) C) D)

4214. Airplane ATPL CPL When comparing the properties of laminar and turbulent boundary layers, which of the following statements is correct? Separation point will occur earlier in the turbulent layer. Friction drag will be equal in both types of layers. Friction drag is lower in the turbulent layer. Friction drag is lower in the laminar layer.

Because the air in a laminar boundary layer moves in layers it has less friction than a turbulent boundary layer where eddies create additional friction.

4224. Airplane ATPL CPL An aeroplane has a stall speed of 100 kts at a load factor n=1. In a turn with a load factor of n=2, the stall speed is:

Low speed stall. High speed stall (shock stall). Deep stall. Accelerated stall.

(Refer to figure 081-E21) ACCELERATED STALL is a stall that occurs while the aircraft is experiencing a load factor higher than 1 (1 G), for example while turning or pulling up from a dive. In these conditions, the aircraft stalls at higher speeds than the normal stall speed (which always refers to straight and level flight). DEEP STALL is a dangerous type of stall that affects certain aircraft designs, notably those with a T-tail configuration. In these designs, the turbulent wake of a stalled main wing Hblankets Hthe horizontal stabilizer, rendering the elevators ineffective and preventing the aircraft from recovering from the stall. Deep stall is a stable stall where the angle of attack is between 40-60~

4248. Airplane ATPL CPL With increasing angle of attack the CP will reach its most forward point: A) B) C) D)

88 kts 162 kts 108 kts 172 kts

Stall occurs when angle of attack is increased above the critical angle giving the maximum lift coefficient (C!MAX). Form W = L = ~PV2SCL it is obvious that an increase in weight will increase the stall speed since CLis at the maximum value. The new stall speed will be: VSNEW = VSOLD x v(New weight + Old weight} = 132 kts x v(356 103 N + 237402 N} = 132 kts x v0,5} = 161,2 kts = approx. 162 kts.

A) B) C) D)

forward. This will cause a pitch up moment. At the same time, the down wash on the tailplane is increased because the effective lift produced is concentrated inboard on the wing. This will add to the nose up pitching movement.

4243. Airplane ATPL CPL The type of stall that has the largest associated angle of attack is:

Stalling speed in a turn is V"g x vn, where Hn His the load factor. The load factor in a turn is 1 + cos ([), where ([) is the bank angle. In this case the stalling speed is: 100 kts + vcos 45° = 100 + v0,70711 kts = 118,92 kts - 119 kts.

A) B) C) D)

A swept wing will stall at the tip first causing the centre of pressure to move

just below the stalling angle. just above the stalling angle. at the stalling angle. at various points dependent on aircraft weight.

(Refer to figure 081-E29) The centre ofpressure moves forward at increasing angle ofattack and reaches its most forward position just before the stalling angle.

4274. Airplane ATPL CPL A jet aeroplane cruises buffet free at constant high altitude. Which type of stall is most likely to occur if this aeroplane decelerates during an inadvertant increase in load factor? A) B) C) D)

Low speed stall. Accelerated stall. Shock stall. Deep stall.

Decelerating means increasing the angle of attack to maintain level flight. Turbulence could cause a momentary increase in angle of attack above the critical angle, but as the increased angle of attack also increases the load factor, this stall will be an accelerated stall. ACCELERATED STALL is a stall that occurs while the aircraft is experiencing a load factor higher than 1 (1 g), for example while turning or pulling up from a dive. In these conditions, the aircraft stalls at higher speeds than the normal stall speed (which always refers to straight and level flight). DEEP STALL is a dangerous type of stall that affects certain aircraft designs, notably those with a Hail configuration. In these designs, the turbulent wake of a stalled main wing Hblankets Hthe horizontal stabilizer, rendering the elevators ineffective and preventing the aircraft from recovering from the stall. In a deep stall the angle of attack is between 40-60°.

A) 70 kts B) 282 kts C) 141 kts D) 119 kts The stall speed increases with the square root of the load factor. The stall speed at load factor 2 is therefore: Vs= VS1gv2 = 100kts x 1,14142 = 141 kts.

4239. Airplane ATPL CPL On a swept wing aeroplane at low airspeed, the pitch up phenomenon: A) is caused by boundary layer fences mounted on the wings. B) never occurs, since a swept wing is a remedy to pitch up. C) is caused by extension of trailing edge lift augmentation devices. D) is caused by wingtip stall.

7645. Airplane ATPL CPL The sensor of a stall warning system can be activated by a change in the location of the: A) B) C) D)

stagnation point. centre of lift. transition region. centre of gravity.

(Refer to figure 081-E53) The stagnation point is the only possible item among the suggestions that is accurate for a stall warning device.

(Refer to figure 081-E48)

I

4131 (A)

I

4201 (0)

I

4209 (8)

I

4214 (0)

I

4224 (C)

I

4239 (0)

I

4243 (C)

I

4248 (A)

I

4274 (8)

I

7645 (A)

I

01 Subsonic Aerodynamics 7650. Airplane ATPL CPL The CP on a swept wing aircraft will move forward due to:

A) boundary layer fences and spanwise flow. B) tip stall of the wing. C) flow separation at the root due to spanwise flow. D) change in wing angle of incidence. (Refer to figure 087-£48) A boundary layer fence reduces the spanwise flow making movement of the CP less likely. Separation at the root will move the CP backwards. Changing the angle ofincidence requires an indication of the change to be able to say anything about the consequence on the CPO

Vs = Stall speed or minimum steady flight speed for which the aircraft is still controllable. Vso = Stall speed or minimum flight speed in landing configuration. Vs, = Stall speed or minimum steady flight speed for which the aircraft is still controllable in a specific configuration. VSR = Reference stall speed. VSRO = Reference stall speed in landing configuration. VSR , = Reference stall speed in a specific configuration. Vsw = Speed at which the stall warning will occur. 7716. Airplane ATPL CPL The pitch up effect of an aeroplane with swept wing in a stall is due to the:

7656. Airplane ATPL CPL An aeroplane has a stalling speed of 100 kts in a steady level flight. When the aeroplane is flying a level turn with a load factor of 1,5 the stalling speed is:

A) 141 kts B) 122 kts C) 82 kts D) 150 kts

A) aft movement of the centre of gravity. B) wing tip stalling first. C) forward movement of the centre of gravity. D) wing root stalling first. For explanation refer to question #4239 on page 46.

The stall speed increases with the square root of the load factor. The stall speed at load factor 7,5 is therefore: Vs =VS,g /7,5 = 700 kts x 7,2247 = 722 kts.

7718. Airplane ATPL CPL Which of the following is the speed that would activate the stick shaker:

A) 1,5 Vs B) 1,05Vs

7664. Airplane ATPL CPL Which of the following statements about stall speed is correct?

A) Use of a T-tail will decrease the stall speed. B) Increasing the angle of sweep of the wing will decrease the stall speed. C) Decreasing the angle of sweep of the wing will decrease the stall speed. D) Increasing the anhedral of the wing will decrease the stall speed. (Refer to figure 087-£93) Form the lift formula L = Jo2plPSCL it is obvious that the lowest stall speed will occur with the highest value of CL • In the illustration is shown the curves for lift coefficient for the same profile but with and without sweep. The lesser the sweep, the higher the value of CIMAJ(" 7681. Airplane ATPL CPL Stick pushers must be installed in aeroplanes with dangerous stall characteristics. Dangerous stall characteristics include:

C) 1,2 Vs

D) above Vs Certification requirements say that the stall warning must begin at a speed Vsw exceeding the speed at which the stall is identified, by not less than 5 knots or 5% CAS, whichever is the greatest. If 7.05 Vs is not mentioned, the correct answer is "greater than Vs': £ASA CS 25.207 f. ..J (c) When the speed is reduced at rates not exceeding 0.5 mls2 (one knot per second), stall warning must begin, in each normal configuration at a speed, Vsw' exceeding the speed at which the stall is identified in accordance with CS 25.207 (d) by not less than 9.3 kmlh (five knots) or five percent CAS, whichever is greater. Once initiated, stall warning must continue until the angle of attack is reduced to approximately that at which stall warning began. f. ..J 7727. Airplane ATPL CPL The wing of an aeroplane will never stall at low subsonic speeds as long as:

A) the CAS exceeds the power-on stall speed. B) the lAS exceeds the power-on stall speed. C) the angle of attack is smaller than the value at which the stall occurs. D) there is a nose-down attitude.

A) distinct aerodynamic buffet. B) pitch down and yaw. C) excessive wing drop and deep stall. D) pitch down and increase in speed. Pitch down is not a dangerous stall characteristic, whereas pitch up is that can cause the aircraft to enter deep stall.

Stall occurs when angle of attack is increased above the critical angle (giving the maximum lift coefficient (CIMAX)) irrespective of speed or aircraft attitude. 7728. Airplane ATPL CPL Which of the following is the speed in level flight that would activate the stall warning?

Airplane ATPL CPL Stall speed in a turn is proportional to: 7698.

A) the square root of the load factor.

A) VS1G + 15 kts

B) weight. C) lift.

B) 1,2 VS19 C) 1,05 VS1G D) 1,5VS1G

D) TAS squared. The stall speed always increases with the square root of the load factor. In a turn the lift is increased to provide a centripetal force for the turn thus increasing the load factor. 7699. Airplane ATPL CPL Which of the following is the correct designation of stall speed in the landing configuration:

Stall warning must begin at a speed Vsw' exceeding the speed at which the stall is identified, by not less than 5 knots or 5% CAS, whichever is the greatest. That is: Vsw = 7,05 VS'G. 7732. Airplane ATPL CPL The input to a stick shaker comes from:

A) the airspeed, and sometimes the rate of change in airspeed. B) the angle of incidence. C) angle of attack, and sometimes the rate of change in angle of attack. D) the angle of attack only.

A) VSL B) Vso C) VS1

D) VS1G

I I

7650 (8) 7732 (C)

I I

7656 (8)

I

7664 (C)

I

7681 (C)

I

7698 (A)

I

7699 (8)

I

7716 (8)

I

7718 (8)

I

7727 (C)

I

7728 (C)

I

Ell

Aviationexam Test Prep Edition 2012 Input to the stick shaker is the angle of attack as measured by an a-vane or a-probe, but to give an earlier warning, the rate of change of angle ofattack is also computed as input.

7759.

Airplane

ATPL

CPL

A) decreases; rearward B) increases; rearward C) decreases; forward D) increases; forward (Refer to figures 087-E773 and 087-ES3) When the profile stalls, the lift coefficient - and thus the lift - will decrease, whilst the centre ofpressure moves rearward to approximately mid-chord. As the angie of attack increases, the air will meet the most forward point of the profile in relation to the flow at a point further back on the lower side than before. The illustration, explaining the workings of a flapper switch, shows clearly, that the stagnation point will be further down and aft than at a lower angle of attack.

Airplane

ATPL

CPL

In recovery from a spin: A) B) C) D)

ailerons should be kept neutral. airspeed increases. ailerons used to stop the spin. rudder and ailerons used against the direction of spin rotation.

Aileron position is often a contributory factor to flat spins, or to higher rotation rates in normal spins. It is therefore recommended to neutralize ailerons in spin recovery.

7761.

Airplane

ATPL

CPL

What causes deep stall in a swept back wing? A) B) C) D)

CP moves aft. CP moves forward. Root stall. Spanwise flow from tip to root on wing upper surface.

Airplane

ATPL

CPL

The boundary layer of a wing is caused by: A) suction at the upper wing side. B) the normal shock wave at transonic speeds. C) a turbulent stream pattern around the wing. D) a layer on the wing in which the stream velocity is lower than the free stream velocity, due to friction. Surface friction will slow the air molecules in contact with the surface which will slow the neighbouring molecules, etc., until the molecules are unaffected and moves with the free stream velocity. The layer affected by the friction is termed the boundary layer.

7773.

Airplane

ATPL

CPL

Which kind of boundary layer has the strongest change in velocity close to the surface? A) B) C) D)

No difference. Laminar boundary layer. Turbulent boundary layer. The boundary layer in the transition between turbulent and laminar.

(Refer to figure 087-Ell) The turbulent boundary layer with its characteristic eddies gives a greater mixing of the slower moving layers with the faster moving air further away from the surface. This mixing increases the velocity near the surface that gives

I I

7759 (A) 7818 (A)

I I

7760 (A)

I

7761 (8)

I

7768 (0)

Airplane

ATPL

CPL

Which of the following statements about the stall of a straight wing aeroplane is correct? A) The horizontal tail will stall at a higher speed than the wing. B) Buffeting is the result of flow separation on the tail plane. C) The nose down effect is the result of increasing downwash, due to flow separation. D) Just before the stall the aeroplane will have a nose-down tendency. Just before the stall, the lift coefficient is at its maximum value and the lift will be large. As the lift acts behind the centre of gravity, this causes a nose-down moment.

7782.

Airplane

ATPL

CPL

At the point of stall: A) B) C) D)

lift decreases, drag decreases. lift constant, drag increases. lift decreases, drag increases. lift decreases, drag constant.

(Refer to figure 087-E773) When the profile stalls, the lift will decrease, and the separated boundary layer will cause an increase in drag.

7800.

Airplane

ATPL

CPL

During an erect spin recovery: A) the ailerons are held in the neutral position. B) the control stick is moved side ways, against the angle of bank. C) the control stick is moved side ways, in the direction of the angle of bank. D) the control stick is pulled to the most aft position. The normal procedure is to keep the ailerons neutral to avoid any roll that could cause the stall to develop into a spin.

(Refer to figure 087-E48) The root cause of a deep stall in a swept back wing is tip stall that causes the CP to move forward. This movement then causes the nose-up pitching moment from the tail plane to stall the wing.

7768.

Note: an EDDY is the swirling of a fluid and the reverse current created when the fluid flows past an obstacle.

7774.

If angle of attack is increased beyond the critical angle of attack, the lift coefficient _ and the stagnation point moves ___•

7760.

a greater change in velocity profile.

I

7810.

Airplane

ATPL

CPL

When a pilot makes a turn in horizontal flight, the stall speed: A) B) C) D)

increases with flap extension. increases with the square root of load factor. decreases with increasing bank angle. increases with the load factor squared.

For explanation refer to question #7698 on page 47.

7814.

Airplane

ATPL

CPL

Which of the following statements about the spin is correct? A) In the spin, airspeed continuously increases. B) An aeroplane is prone to spin when the stall starts at the wing root. C) During spin recovery the ailerons should be kept in the neutral position. D) Every aeroplane should be designed such that it can never enter a spin. The normal procedure is to keep the ailerons neutral to avoid any roll that could change the characteristics of the spin.

7818.

Airplane

ATPL

CPL

A boundary layer fence on a swept wing will: A) improve the low speed characteristics. B) improve the high speed characteristics. C) increase the critical Mach number. D) improve the lift coefficient of the trailing edge flap. Wing fences prevents the outward drift of the boundary layer and thus reduces

7773 (C)

I

7774 (0)

I

7782 (C)

I

7800 (A)

I

7810 (8)

I

7814 (C)

I

01 Subsonic Aerodynamics the tendency to tip stall. This will allow flying at higher angles of attack, i.e. fly slower.

7850. Airplane ATPL CPL The following factors increase stall speed: A) a lower weight, decreasing bank angle, a smaller flapsetting. B) a higher weight, selecting a higher flap setting, a forward CG shift. C) increasing bank angle, increasing thrust, slat extension. D) an increase in load factor, a forward CG shift, decrease in thrust.

7823. Airplane ATPL CPL Which combination of design features is known to be responsible for deep stall: A) B) C) D)

swept back wings and wing mounted engines. straight wings and aT-tail. swept back wings and aT-tail. straight wings and aft fuselage mounted engines.

(Refer to figure 087-E27) DEEP STALL is a dangerous type of stall that affects certain aircraft designs, notably those with a T-tail configuration. In these designs, the turbulent wake of a stalled main wing "blankets" the horizontal stabilizer, rendering the elevators ineffective and preventing the aircraft from recovering from the stall. In a deep stall the angle of attack is between 40-60°. Swept-back wings tends to stall first near the tips causing a pitch-up. Separated airflow from the stalled wing will immerse a high-set tailplane in low energy turbulent air, reducing elevator effectiveness.

7836. Airplane ATPL CPL What effect on stall speed do the following have? A) B) C) D)

7855. Airplane ATPL CPL If the straight and level stall speed is 100 kts, what will be the stall speed in a 1,3 g turn? A) B) C) D)

114 kts 130 kts 81 kts 100 kts

The stall speed increases with the square root of the load factor. The stall speed at load factor 7,3 is therefore: Vs = VS1Gv7,3 = 700 kts x 7,7407 = 774 kts.

Increased anhedral increases stall speed. Fitting a T tail will reduce stall speed. Increasing sweepback decreases stall speed. Decreasing sweep angle decreases stall speed.

(Refer to figure 087-E93) Anhedral and T-tail has no influence on stall speed. Sweepback causes the CL curve to have less slope and a smaller value of C!MAX than the straight wing (see the illustration). A smaller value of CLMAX means a higher stall speed.

7841. Airplane ATPL CPL Which aeroplane design has the highest probability of a super stall? A) B) C) D)

Increase in load factor increases stall speed by a factor of the square root of the load factor; a forward CG shift means the tailplane must provide a larger downforce to maintain equilibrium and thus the need for more lift; decrease in thrust means deceleration and therefore larger angle of attack.

A canard wing. AT-tail. Swept wings. A low horizontal tail.

7870. Airplane ATPL CPL By what approximate percentage will the stall speed increase in a horizontal coordinated turn with a bank angle of 45°? A) B) C) D)

19% 31% 41% 52%

In a turn the stall speed increases by a factor of 7Ncos (J), where (J) is the bank angle. Cos 45°= 0,70777, so the stall speed will increase by 7N0,70777 = 7,7892

-79%.

7878. Airplane The stall speed:

(Refer to figures 087-E27 and 087-E48) A swept wing will stall at the tip first causing the centre of pressure to move forward. This will cause a pitch up moment. At the same time, the down wash on the tailplane is increased because the effective lift produced is concentrated inboard on the wing. This will add to the nose up pitching movement. If the elevators cannot counter the nose up pitching, there is a danger of super stall. A T-tail would make this outcome likely, but it is the sweep that is the root cause.

7848. Airplane ATPL CPL The normal stall recovery procedure for a light single engined aeroplane is: A) full power and stick roll-neutral nose-down, correction for angle of bank with stick. B) full power and stick roll-neutral nose-down, correcting for angle of bank with rudder. C) idle power and stick roll-neutral nose-down and no other corrections. D) idle power and stick neutral, waiting for the natural nose-down tendency. Full power to minimise height loss; stick roll neutral to prevent risk of entering spin, and forward to lower the nose to decrease angle of attack; prevent wing drop with rudder rather than ailerons as these are reversed on a stalled wing.

A) B) C) D)

ATPL

CPL

increases with the length of the wingspan. decreases with an increased weight. does not depend on weight. increases with an increased weight.

Stall speed increases with increased weight because a higher angle of attack is required to produce an increased lift. Stall happens when the maximum CL is reached, and that will be at a higher speed when the weight is increased.

7891. Airplane ATPL CPL At the same weight, with the CG at its forward limit: A) Vs is lower, the stalling angle is unchanged. B) Vs is higher, the stalling angle is greater. C) Vs is higher, the stalling angle is unchanged. D) Vs is lower, the stalling angle is less. A forward CG shift means the tailplane must provide a larger down force

to maintain equilibrium and thus the need for more lift that is provided by a higher angle of attack. Stall happens when the maximum CL is reached, and that will be at a higher speed when the CG is forward. However, the angle of attack at stall is always the same angle.

7916. Airplane ATPL CPL What is the standard stall recovery for a light aircraft? A) B) C) D)

Pitch down, stick neutral roll, correct for bank with rudder. Pitch down, stick neutral roll, correct for bank with aileron. Pitch down, stick neutral, wait for neutral tendency. Pitch down, stick neutral roll, do not correct for bank.

Pitch down to lower the nose to decrease angle of attack; stick roll neutral to prevent risk of entering spin; prevent wing drop with rudder rather than ailerons as these are reversed on a stalled wing.

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7823 (C)

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7836 (0)

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7841 (C)

I

7848 (8)

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7850 (0)

I

7855 (A)

I

7870 (A)

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7878 (0)

I

7891 (C)

I

7916 (A)

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Aviationexam Test Prep Edition 2012

7936. Airplane ATPL CPL Which of the following aircraft designs would be most prone to super stall? A) B) C) D)

T-tail. Swept forward wing. Swept back wing. Pod mounted engines beneath the wing.

15614. Airplane ATPL CPL Low speed pitch up is caused by the: A) B) C) D)

wing tip vortex. Mach trim system. spanwise flow on a swept back wing. spanwise flow on a swept forward wing.

(Refer to figure 081-£48)

For explanation refer to question #7841 on page 49.

A swept wing has an increased tendency to stall first near the tips. Loss of lift at the tips moves the centre ofpressure forward, giving a nose up pitching mo-

7941. Airplane ATPL CPL Stalling speed in a 15° bank level turn is 60 kts. The stalling speed in a 45° bank level turn will be:

ment.

A) B) C) D)

60 kts 85 kts 70 kts 83 kts

A turn will increase the load factor and thus the stall speed by a factor of the square root of the load factor. The stall speed at 15~ VSI5 = V S1G X ,f(1 + cos 15°). From this: V S1G = V S1S X ,fcos 15°. The stall speed at 45°, V S45 = V S1G X ,f(1 + cos 45°) = (VS15 x ,fcos 15°) x ,f(1 + cos 45°) = V S1G x ,f(cos 15° + cos 45°) = 60 kts x ,f(0,96593 + 0,70711) =70,13 kts = 70 kts.

7948. Airplane ATPL CPL The stalling speed in lAS will change according to the following factors? A) Will increase during turn, increased mass and an aft CG location. B) Will decrease with a forward CG location, lower altitude and due to the slip stream from a propeller on an engine located forward of the wing. C) Will increase with increased load factor, icing conditions and more flaps. D) May increase during turbulence and will always increase when banking in a turn. A turn will increase the load factor and thus the stall speed by a factor of the square root of the load factor. Increased mass will increase stall speed. Aft CG will decrease stall speed, whereas forward CG will increase it. Altitude has no effect on stall speed in lAS. Stall speed increases with increased load factor and icing conditions, but flaps decreases stall speed. Turbulence can increase the stall speed by increasing angle of attack. The only combination with just true statements is D.

7964. Airplane ATPL CPL What causes a swept wing aircraft to pitch-up at the stall: A) B) C) D)

negative camber at the root. separated airflow at the root. spanwise flow. rearward movement of the CPo

The span wise flow builds up it to stall first.

a

slower boundary layer at the tip causing

15612. Airplane AWL CPL As angle of attack is increased on a conventional low speed aerofoil at low subsonic speeds, flow separation normally starts on the: A) upper surface near the leading edge. B) upper surface near the trailing edge. C) lower surface near the leading edge. D) lower surface near the trailing edge. (Refer to figure 081-£33) The separation on an aerofoil always starts at the trailing edge because of the adverse pressure gradient behind the point of maximum flow velocity.

15718. Airplane ATPL CPL Compared with level flight prior to the stall, the lift and drag __ in the stall change. A) B) C) D)

increases; decreases decreases; increases decreases; decreases increases; increases

For explanation refer to question #7782 on page 48.

15720. Airplane ATPL CPL The vane of a stall warning system with a flapper switch is activated by the change of the: A) B) C) D)

point of lowest pressure. stagnation point. centre of pressure. centre of gravity.

(Refer to figure 081-£53) The flapper switch is activated by movement of the stagnation point.

15721. Airplane ATPL CPL A strongly swept back wing stalls. If the wake of the wing contacts the horizontal tail, the effect on the stall behavior can be: A) B) C) D)

tendency to increase speed after initial stall. nose up tendency and/or lack of elevator response. nose down tendency. increase in sensitivity of elevator inputs.

(Refer to figure 081-£49) On a strongly swept back wing, the wingtips will stall first. This means that the aircraft will have a tendency to pitch up when stalling, and it will lead to deep stall. If the horizontal tail is in the turbulent air flowing from the stalled wing, it will lose efficiency, and the aircraft will not be able to get out of the stall.

15722. Airplane ATPL CPL The function ofthe stick pusher is: A) to activate and push the stick forward at or beyond a certain value of angle of attack. B) to activate and push the stick forward prior to stick shaker. C) to vibrate the controls. D) to pull the stick, to avoid a high speed stall. A stick pusher is a device attached to the elevator control system, which physically pushes the control column forward, reducing the angle of attack before super-stall can occur.

15742. Airplane ATPL CPL Which of the following situations leads to a decreasing stall speed (lAS)? A) Increasing air density. B) Increasing load factor. C) Decreasing weight. D) Increasing altitude. Decreasing weight means lower lift coefficient at a given lAS, and thus larger margin to stall. (Stalling speed in lAS does not change with altitude.)

1 7936 (C) 1 7941 (C) 1 15742 (C) 1

1 7948 (D) 1 7964 (C) 1 15612 (8) 115614 (C) 1 15718 (8) 115720 (8) 1 15721 (8) 115722 (A) 1

01 Subsonic Aerodynamics

15745. Airplane ATPL CPL Increase of wing loading will: A) B) C) D)

decrease the minimum gliding angle. increase CLMAX • decrease takeoff speeds. increase the stall speeds.

For explanation refer to question #4202 on page 3.

15746. Airplane ATPL CPL Compared with stalling airspeed (Vs) in a given configuration, the airspeed at which stick shaker will be triggered is: A) 1,20Vs. B) 1,30Vs. C) 1,12 Vs. D) greater than VS. For explanation refer to question #7778 on page 4Z

15748. Airplane ATPL CPL The critical angle of attack: A) B) C) D)

changes with an increase in gross weight. remains unchanged regardless of gross weight. increases if the CG is moved forward. decreases if the CG is moved aft.

The critical angle of attack is a property only determined by the profile and planform. It is entirely independent of weight and position of the centre of gravity.

15753. Airplane ATPL CPL The stall speed in a 60° banked turn increases by the following factor: A) 1,41

B) 1,07

C) 1,30 D) 2,00 In a turn the stall speed increases by a factor of 1 -;- YCOS (/), where (/) is the bank angle. Cos 60° = 0,5, so the stall speed will increase by 1 -;- yO,S = 1,41.

15758. Airplane ATPL CPL An aeroplane has a stall speed of 78 kts at its mass of 6.850 kg. What is the stall speed when the mass is 5.000 kg? A) 91 kts B) 78 kts C) 57 kts D) 67 kts The stall speed at increased weight is Vs NEW = Vs OLD x y(New Weight -;- Old Weight) = 78 kts x y(5.000 kg -;- 6.850 kg) = 78 x y0,723 kts = 66,6 kts - 67 kts.

16655. Airplane ATPL CPL With the centre of gravity on the forward limit, the stalling speed would be: A) B) C) D)

independent of the centre of gravity position. lower than with the centre of gravity on the aft limit. higher than with the centre of gravity on the aft limit. the same as with the centre of gravity on the aft limit.

A forward CG means the tailplane must provide a larger down force to maintain equilibrium and thus the need for more lift that is provided by a higher angle of attack. Stall happens when the maximum CL is reached, and that will be at a higher speed when the CG is forward.

16656. Airplane ATPL CPL When pulling out of a dive the angle of attack: A) increases. B) decreases. C) remains the same.

D) cannot be increased at all due to structural considerations. To pull out of a dive additional lift is required to act as a centripetal force to change the attitude. Consequently, it is necessary to increase the angle of attack.

16658. Airplane ATPL CPL As the centre of gravity is changed, recovery from a stall becomes progressively: A) B) C) D)

more difficult as the centre of gravity moves aft. more difficult as the centre of gravity moves forward. less difficult as the centre of gravity moves aft. is unaffected by centre of gravity position, only by all up weight.

To recover from a stall the elevator must produce an upward force to create a nose-down pitching moment. When the centre of gravity moves aft, the elevator must produce less downwards force to maintain equilibrium, and even change to an upwards force when the centre of gravity moves behind the centre of pressure. This reduces the available margin for extra upward force from the elevator.

16660. Airplane ATPL CPL A wing stalling angle is: A) B) C) D)

unaffected by a turn. increased in a hight rate of turn. decreased in a high rate of turn. decreased in any turn.

The stalling angle is a property only determined by the profile and planform. It is entirely independent of turning.

16665. Airplane ATPL CPL In a level banked turn, the stalling speed will: A) B) C) D)

decrease. increase. remain the same. vary inversely with wing loading.

(Refer to figure 081-£14) As shown in the illustration the lift provides both centripetal force and a force equal to and opposite the weight. The load factor (L-;-W) is therefore greater than 1. Stall speed in a turn is VS1g x yn, where "n" is the load factor, and since n is greater than one, the stall speed is increased.

16666. Airplane ATPL CPL A low wing loading (aircraft weight has been reduced): A) B) C) D)

increases stalling speed. increases takeoff run, stalling speed and landing speed. decreases stalling speed and landing speed. does not affect any of the above.

Stall speed decreases with decreased weight because a smaller angle of attack is required to produce the necessary lift. Stall happens when the maximum CL is reached, and that will be at a lower speed when the weight is reduced. This means the landing speed can be reduced proportionally.

16670. Airplane The load factor is:

ATPL

CPL

A) the ratio of lift to drag. B) the ratio of centripetal force to lift. C) the ratio of thrust to weight. D) the ratio of lift to weight. LOAD FACTOR is the ratio of the lift on an aircraft to the weight of the aircraft. The load factor is expressed in multiples of "g" where 1 g represents conditions in straight and level flight. In straight and level flight the lift is equal to the weight so the ratio of lift to weight is one, and the load factor is 1 g. Load factors greater than one, and less than one, are achieved by manoeuvring of the aircraft by the pilot, and by atmospheric gusts. Load factor increases the stall speed bya factor of the square root of the load factor. In the definition of load factor, lift on an aircraft is not simply the lift generated by the wing. Lift on an aircraft is the vector sum of the lift generated

115745 (0) 115746 (0) 1 15748 (8) 115753 (A) 115758 (0) 116655 (C) 116656 (A) 116658 (A) 116660 (A) 116665 (8) 1 1 16666 (C) 1 16670 (0) 1

Aviationexam Test Prep Edition 2012 by the wing and fuselage plus the lift generated by the tailplane which is almost always downwards. Lift on an aircraft is therefore almost always less than the lift generated by the wing and fuselage.

16678. Airplane ATPL CPL When an aircraft with a typical aerofoil is in level flight at low speed and high angle of attack, the normal axis is: A) B) C) D)

vertical. horizontal from side to side. horizontal from front to rear. nearly vertical.

The normal axis is perpendicular to the longitudinal axis (X-axis) of the aircraft. When flying with a high angle of attack, the longitudinal axis is around 10-12° to the flight path, and the normal axis will therefore be nearly vertical, but leaning the same amount of degrees backwards.

16684. Airplane ATPL CPL The purpose of a fixed spoiler on the leading edge of a wing at the root is to: A) B) C) D)

prevent the aircraft from exceeding its maximum speed VNE. ensure that the root of the wing stalls before the tip. prevent the wing from stalling at the root. re-energise the boundary layer thereby delaying the stall (although at a cost of increased form drag).

A fixed spoiler on the leading edge is also known as a stall strip. The sharp leading edge of the stall strip ensures a lower stalling angle than the more rounded leading edge of the wing and thus inducing stall.

21022. Airplane ATPL CPL An aeroplane hasa stall speed of100 ktsat a mass of 1.000 kg. Ifthe mass is increased to 2.000 kg, the new value of the stall speed will be: A) B) C) D)

141 kts 200 kts 150 kts 123 kts

The stall speed at increased weight is Vs NEW = Vs ow x Y(New W + Old W) 100ktsxY(2.000kg+ 1.000 kg) = 100xy2= 141,42kts-14Ikts.

=

21033. Airplane ATPL CPL As altitude is increased, the stall speed (lAS): A) remains constant regardless of altitude. B) initially remains constant and at higher altitudes decreases. C) initially remains constant and at higher altitudes increases. D) remains constant until the tropopause and at higher altitudes increases. For explanation refer to question #3834 on page 45.

21046. Airplane ATPL CPL During a steady horizontal turn, the stall speed: A) B) C) D)

increases with the square root of the load factor. increases linearly with the load factor. increases inversely with the load factor. increases with the square of the load factor.

The stall speed always increases with the square root of the load factor.

21056. Airplane ATPL CPL Given an initial condition in straight and level flight with a speed of 1,4 Vs. The maximum bank angle attainable without stalling in a steady co-ordinated turn, whilst maintaining speed and altitude, is approximately: A) B) C) D)

32° 44° 60° 30°

In a turn the stall speed increases by a factor of 1 + YCOS , where is the bank angle. This factor can in this case be 1,4, or 1,4 = 1 + YCOS . This gives YCOS = 1 + 1,4 =0,714. Cos is then (0,714/ =0,51, which corresponds to a bank angle of60,41°-60°.

21073. Airplane ATPL CPL How is stall warning presented to the pilots of a large transport aeroplane? A) Stick pusher. B) Stick shaker and/or aerodynamic buffet. C) Stall warning light only. D) Aural warning only. Of the possible options, stick shaker and/or buffeting is the most correct answer.

21077. Airplane ATPL CPL If the aspect ratio of a wing increases whilst all other relevant factors remain constant, the critical angle of attack will: A) remain constant only for a wing consisting of symmetrical aerofoils. B) increase. C) remain constant. D) decrease. The higher the aspect ratio the steeper is the Cia curve. Maximum on the Cia curve corresponds with the critical angle of attack, so increased aspect ratio means decreasing critical angle of attack.

21156. Airplane ATPL CPL When considering a swept back wing, with no corrective design features, at the stall: A) leading edge stall will occur first, which produces a nose-down pitching moment. B) wing root stall will occur first, which produces a rolling moment. C) tip stall will occur first, which produces a nose-down pitching moment. D) tip stall will occur first, which produces a nose-up pitching moment. For explanation refer to question #4239 on page 46.

23233. Airplane ATPL CPL The critical angle of attack at which a given aircraft stalls is dependent on the: A) B) C) D)

gross weight. attitude and airspeed. design ofthe wing. altitude.

The stalling angle is a property only determined by the profile and planform. It is entirely independent of weight or altitude.

23234. Airplane ATPL CPL Which action will result in a stall? A) B) C) D)

Exceeding the critical angle of attack. Flying at a low airspeed. Raising the aircraft's nose too high. Lowering the flaps during the cruise.

For explanation refer to question #7727 on page 47.

23235. Airplane ATPL CPL An aircraft is said to stall when: A) the lift force from the wings is greater than the weight. B) the airflow over the top surface of the wing separates which results in a large increase in drag and a large loss of lift. C) the angle of attack of the wings is greater than 10 degrees. D) it flies too slowly at low altitude.

116678 (0) 116684 (8) 121022 (A) 121033 (C) 121046 (A) 121056 (C) 121073 (8) 121077 (0) 1 21156 (0) 123233 (C) 1 123234 (A) 1 23235 (8) 1

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01 Subsonic Aerodynamics STALL is a condition in aerodynamics where the angle of attack increases beyond a certain point such that the lift begins to decrease. The angle at which this occurs is called the critical angle of attack. This critical angle is dependent upon the profile of the wing, its planform, its aspect ratio, and other factors, but is typically in the range of 8° to 20° relative to the incoming wind for most subsonic airfoils (often 16° quoted as the typical critical angle for most airfoils). The critical angle of attack is the angle of attack on the lift coefficient versus angle-of-attack curve at which the maximum lift coefficient occurs.

cause the stall speed to:

Flow separation over the airfoil's upper surface begins to occur at small angles of attack while attached flow over the wing is still dominant. As angle of attack increases, the separated regions on the top of the wing increase in size and hinder the wing's ability to create lift. At the critical angle of attack, separated flow is so dominant that further increases in angle ofattack produce less lift and vastly more drag.

23268. Airplane ATPL CPL The TAS of an aircraft at the stalling angle of attack at a given weight:

23254. Airplane ATPL CPL At the stalling angle of attack the lift/drag ratio will be: A) B) C) D)

higher than the optimum angle of attack. lower than at the optimum angle of attack. the same as at the optimum angle of attack. the angle of attack does not affect the lift/drag ratio.

(Refer to figure 081-E114) The LID ratio is maximum at the optimum angle ofattack (normally around 4°) and decreases at any angle beyond that. At stall it is therefore much lower than at the optimum angle of attack.

23262. Airplane ATPL What affects the indicated stall speed? A) B) C) D)

Angle of attack, weight, and air density. Load factor, angle of attack and power. Weight, load factor, CG position, power and Mach number. Humidity, air density and temperature.

Angle of attack does not directly affect indicated stall speed. Air density, which in turn is dependent on humidity and temperature, does not affect indicated stall speed.

23264. Airplane ATPL CPL With the CG on the forward limit, compared to the aft limit, the stalling speed would be: A) B) C) D)

higher. lower. the same. depends on the length of MAC.

For explanation refer to question #16655 on page 51.

23265. Airplane ATPL CPL With engine power on, an aircraft will stall: A) B) C) D)

at a higher speed than with power off. at a lower speed than with power off. at the same speed as with power off. aircraft will not stall.

A) B) C) D)

remain unaffected. decrease. increase. decrease only if turning at the same time.

For explanation refer to question #21046 on page 52.

A) B) C) D)

is constant at all altitudes. increases as altitude increases. decreases as altitude increases. increases as altitude decreases.

The lift equation: LIFT = l2pIPSCL' where: • CL = coefficient of lift. This represents angle of attack of the airfoil and the shape of the airfoil. This described in terms of thickness!chord ratio and a camber and can be altered in flight, for example, by lowering the flaps. • p = The density of the air. For any given altitude during subsonic flight, the density may be considered to be constant. • IP = The velocity of the aircraft, squared. • S = The wing area. From the lift equation the stall speed as a TAS can be expressed as Vs = veL + MpCLMAX}}.lfaltitude is increased, the density (p) decreases, which will increase the stall speed.

23286. Airplane ATPL CPL The stalling angle of an aerofoil is approximately: A) 4° B) _2° C)W D) 10° Traditionally 16° is quoted as the stalling angle.

23296. Airplane ATPL CPL If the stalling speed of an aircraft is 75 kts, the approximate stalling speed in mph is: A) B) C) D)

mUltiply 75 by 0,87. divide 75 by 0,87. dividing 75 by 0,87 and subtracting the relative density. multiplying 75 by 8,7.

1 knot is 1,1507794 miles per hour, so multiply the knots with this factor or divide by 1 + 1,1507794 = 0,868976.

23298. Airplane ATPL CPL A fixed spoiler on the leading edge of the wing at the root will: A) B) C) D)

prevent the stall commencing at the root. induce a root stall. give a shorter landing run. maintain a laminar boundary layer at the stall.

(Refer to figure 081-E08) Power on stall speed is lower because of the induced velocity behind propellers or the vertical component of thrust on jets increases the lift.

For explanation refer to question #16684 on page 52.

23266. Airplane ATPL CPL The ratio between the total air load imposed on the wing and the gross weight of an aircraft in flight is known as:

23302. Airplane ATPL CPL A rectangular wing, compared to other wing planforms, has a tendency to stall:

A) B) C) D)

load factor and directly affects stall speed. load factor and has no effect on stall speed. aspect ratio and directly affects stall speed. load factor and is inversely proportional to the square root of the stall speed.

For explanation refer to question #16670 on page 51.

23267. Airplane ATPL CPL In a rapid recovery from a dive, the effects of load factor would

A) first at the leading edge, with progression outward toward the wing root and tip. B) first at the wingtip, with the stall progression toward the wing root. C) first at the wing root, with the stall progression towards the wing tip. D) first at the semi-span centre, giving good aerodynamic stall warning. (Refer to figure 081-E49)

I 23254 (8)1 23262 (C) I 23264 (A) I 23265 (8) I 23266 (A) I 23267 (C) I 23268 (8) I 23286 (C) I 23296 (8) I 23298 (8) I 123302 (C) I

Aviationexam Test Prep Edition 2012 The fairly strong tip vortices on a rectangular wing decreases the effective angle of attack at the tips, thus delaying the stall of the tips.

23304. Airplane ATPL CPL The change in downwash along a wing without taper: A) reduces damping in roll. B) reduces the adverse yaw effect in roll. e) causes the stall to occur at the root first. D) increases the load factor at the wing tip. (Refer to figures 081-£30 and 081-E49) The tip vortices generates a stronger down wash at the wing tips on a rectangular planform. This decreases the effective angle of attack at the tip (see illustration), thus delaying the tip stalling. The stall on a wing without taper therefore begins at the root.

23334. Airplane ATPL CPL A stick shaker will operate: A) at the stall. B) before the stall. e) after the stall. D) only during the stall. A stick shaker is a stall warning device, and as such it is activated before

A) outer wing is stalled. B) outer wing is more stalled than the inner. e) inner wing is more stalled than the outer. D) outer wing is not stalled. Autorotation occurs when one wing stalls before the other. The roll will be towards the most stalled wing, or the inner wing in the roll. Consider an aircraft that has been subjected to a roll to the left at an angle of attack beyond the angle of maximum coefficient of lift. This rolling motion can be caused by a gust, induced by a sideslip, by pilot input, by unbalanced fuel distribution in the wings or by other factors. The wing moving downwards experiences a higher angle of attack, while the wing moving upwards has a lower Ao.A Since the coefficient of lift decreases when the Ao.A is higher than that which creates the maximum lift, ie. the stall AoA the downgoing wing experiences a lower coefficient of lift. Thus, we can say that the wing that moves downwards has greater flow separation than the wing that moves upwards. In addition to this, the left wing has a higher coefficient of drag than the right one since the coefficient of drag increases with the continuing increase in angle of attack. The wing that moves downwards experiences a lower coefficient of lift and a greater coefficient of drag. The difference in angles of attack reSUlting in different lift forces between the two wings, keeps the aircraft rolling. The same difference in angles of attack also causes a difference in drag forces, which keeps the aircraft in a yawing condition. The motion in yaw enhance the differences in Ao.A of the wings.

the stall.

In an autorotation, the aircraft continues to roll and yaw due to less lift but higher drag of the downgoing wing.

23335. Airplane ATPL CPL A stall warning vane on an aircraft wing is fitted:

23344. Airplane ATPL CPL A decrease in weight due to fuel consumption in flight will:

A) on the lower surface. B) on or at the leading edge. e) just above the leading edge. D) just below the leading edge.

A) reduce the stalling speed, but the stall angle remains the same. B) reduce the stalling speed and the stalling angle. e) reduce the stalling angle and increase the stalling speed. D) have no effect on the stall speed or angle.

(Refer to figure 081-£53) The stall waning vane triggers a micro switch and therefore uses the movement of the stagnation point when angle of attack changes. Near stall the stagnation point is just below the leading edge.

A lower weight means lower stalling speed, but the stalling angle is a prop-

23336. Airplane ATPL CPL Which statement is true concerning the aerodynamic conditions which occur during a spin entry?

23354. Airplane ATPL CPL The lift / drag ratio of a wing section at its stalling angle of attack is:

A) After a full stall, the wing that drops continues in a stalled condition while the rising wing regains and continues to produce some lift, causing the rotation. B) After a partial stall, the wing that drops remains in a stalled condition while the rising wing regains and continues to produce lift, causing the rotation. C) After a full stall, both wings remain in a stalled condition throughout the rotation. D) After an incipient spin, the wing that drops remains in a stalled condition while the rising wing continues un-stalled, causing the rotation. The spin is a controlled or uncontrolled manoeuvre. It is a stalled situation (both wings are stalled), with the nose usually pointed sharply downwards in which the aircraft descends in a helical path with an angle of attack greater than the angle of maximum lift. It is essential to know that a spin occurs with the wings in a stalled flight condition, and that it can develop in any attitude, at any airspeed at/or below manoeuvring speed.

23337. Airplane ATPL CPL During a spin to the left, which wing(s) is/are stalled? A) Neither. B) Only the left. e) Both. D) Only the right. For explanation refer to question #23336 on this page.

23338. Airplane ATPL CPL During autorotation the:

erty determined by the profile and planform only and thus not dependent on weight.

A) high. B) of a negative quantity. e) maximum. D) low. (Refer to figure 081-E114) The UD ratio is maximum at the optimum angle ofattack (normally around4°) and decreases at any angle beyond that. At stall it is therefore at a low value.

23363. Airplane ATPL CPL If the clean 1 G stall speed for an aircraft is 151 kts, Vs during a 45° bank turn will be: A) 151 kts B) 122 kts e) 141 kts D) 180 kts In a turn the stall speed increases by a factor of 1 + cos (J), where (J) is the bank angle. Cos 45° = 0,70711, so the stall speed will be: Vs = 151 kts x (1 + ";0,70711) = 179,57 kts - 180 kts.

23372. Airplane ATPL CPL In what flight condition must an aircraft be placed in order to spin? A) Stalled. B) Partially stalled with one wing low. e) In a steep diving spiral. D) A steep turn. A spin requires stall plus a yaw and roll in the same direction.

I 23304 (C) I 23334 (8) I 23335 (0) I 23336 (C) I 23337 (C) I 23338 (C) I 23344 (A) I 23354 (D) I 23363 (0) I 23372 (A) I

01 Subsonic Aerodynamics

23379. Airplane ATPL CPL In a turn the stalling speed will be:

A) less than in level flight. B) more than in level flight but at a lower angle of attack. C) the same as in level flight. D) more than in level and at the same angle of attack. In a turn the stall speed increases by a factor of llvcos (/), where (/) is the bank angle, but the stalling angle is a property determined by the profile and planform only and thus not dependent on turning.

23537. Airplane ATPL CPL Comparing the lAS and TAS stall speed at 5.000 ft and sea level, the lAS stalling speed will normally be:

A) B) C) D)

the same as at sea level but the lAS will be higher. higher than at sea level but the lAS will be the same. the same as at sea level and the lAS will be the same. higher than at sea level and the lAS will be higher.

The stalling speed as lAS is constant at lower altitudes as long as the speed is low enough for compressibility effects not to be present. From the lift formula the stall speed as a TAS can be expressed as Vs = v(L 7 (Y:,pCLMAX }). If altitude is increased, the density (p) decreases, which will increase the stall speed.

23611. Airplane Laminar flow has:

A) B) C) D)

ATPL

more friction than turbulent. same friction as turbulent. less friction than turbulent. can not determine only from the informatiori given.

23653. Airplane ATPL CPL Where does airflow separation begin?

Upper surface, towards the leading edge. Lower surface, towards the trailing edge. Upper surface, towards the trailing edge. Lower surface, towards the leading edge.

Airflow separation happens at the upper surface near the trailing edge of the profile because the boundary layer on the top of the wing has insufficient energy to adhere to the entire surface. The JAA has worded the answer very poor/yo What they meant was "in an area that is located close TOWARDS THE TRAILING EDGE". Be careful- the question asks where does the separation BEGIN - not in what direction it progresses.

Airplane ATPL CPL Which of the following is true? 23660.

A) B) C) D)

A turbulent boundary layer has more kinetic energy. A turbulent boundary layer is thinner. Less skin friction is generated by a turbulent layer. A laminar flow boundary layer is less likely to separate.

The turbulent boundary layer with its characteristic eddies gives a greater mixing of the slower moving layers with the faster moving air further away from the surface. This mixing increases the kinetic energy in the boundary layer.

23661. Airplane ATPL CPL Stalling speed increases when:

A) B) C) D)

recovering from a steep dive. the aircraft is subjected to minor altitude changes. the aircraft weight decreases. flaps are deployed.

The stall speed increases with the square root of the load factor. In a recovery from a steep dive, the load factor increases significantly which in turn increases the stall speed.

Increases. Decreases. Remains constant. Depends on the degree offlap deflection.

With flaps down, the lift coefficient CL is increased without any change to the angle of attack. From the lift formula the stall speed can be expressed as Vs =v(L 7 (V,pCLMAX}). If CL is increased, the stall speed will be lower.

23708. Airplane ATPL CPL If a jet aircraft is at 50° bank angle during a constant altitude turn, compared to straight and level flight the stall speed will be:

A) B) C) D)

1,6 greater. 1,41 greater. 1,25 greater. 2,0 greater.

In a turn the stall speed increases by a factor of 1 7 vcos (/), where (P is the bank angle. Cos 50° = 0,643 so the stall speed will increase by a factor 1 7 vO,643 = 1,247 - 1,25.

23713. Airplane The lAS of a stall:

CPL

Because the air in a laminar boundary layer moves in layers it has less friction than a turbulent boundary layer where eddies creates additional friction.

A) B) C) D)

A) B) C) D)

ATPL

CPL

A) increases with high altitude/more flaps; slats. B) may increase with increasing altitude, especially high altitude; forward CG; icing. C) decreases with forward CG and increasing altitude. D) altitude never affects stall speed lAS. The stalling speed as lAS is constant at lower altitudes as long as the speed is low enough for compressibility effects not to be present. Eventually, the stalling speed has increased with altitude to such an extent that these effects are important, and the stalling speed will then increase. A forward CG means the tailplane must provide a larger down force to maintain equilibrium and thus the need for more lift that is provided by a higher angle of attack. Stall happens when the maximum C, is reached, and that will be at a higher speed when the CG is forward. The build up ofice on the profile will alter itand the first effect is a reduction in the maximum lift coefficient and thus the stall speed.

23714. Airplane ATPL CPL The angle of attack at the stall:

A) B) C) D)

increases with forward CG. decreases with aft CG. decrease with decrease in weight. is not affected by changes in weight.

The stalling angle is a property only determined by the profile and planform. It is entirely independent of weight or CG.

23733. Airplane ATPL CPL Which list of configurations gives an increasing critical angle of attack?

A) B) C) D)

Clean wing => Flaps extended => slats extended Flaps extended => Clean wing => Slats extended Slats extended => Clean wing => Flaps extended Clean wing => Slat extended => Flaps extended

(Refer to figure 081-E104) Deployment of flaps decreases the critical angle of attack compared to the clean wing, whilst extending the slats only will increase it. The sequence of increasing critical angle of attack is therefore: Flaps extended - clean wing - slats extended.

24462. Airplane ATPL CPL One of the factors leading to pitch-up at the stall on swept wing aircraft is:

23684. Airplane ATPL CPL What happens to stall speed with flaps down?

A) B) C) D)

negative camber at the root. airflow separation at the root. spanwise outward flow of the boundary layer. rearward movement of the CPo

123379 (D) 123537 (A) 1 23611 (C) 123653 (C) 123660 (A) 1 23661 (A) 123684 (8) 1 23708 (C) 1 23713 (8) 1 23714 (D) 1 1 23733 (8) 1 24462 (C) 1

~~~--.----------.---------------

Aviationexam Test Prep Edition 2012 (Refer to figure 081-£48) The span wise flow builds up a slower boundary layer at the tip causing it to stall first. The tip stall causes the centre of pressure to move forward. This will create a pitch up moment. At the same time, the down wash on the tailplane is increased because the effective lift produced is concentrated inboard on the wing. This will add to the nose up pitching movement.

24463. Airplane ATPL CPL Which of the following aircraft designs would be most likely to have poor recovery characteristics from a deep stall? A) High aspect ratio straight wing. B) Straight wing, T tail turboprop. e) Swept wing, T tail. D) Low aspect ratio straight wing. (Refer to figure 081-£21) A swept wing will stall at the tip first causing the centre of pressure to move forward. This will cause a pitch up moment. At the same time, the downwash on the tailplane is increased because the effective lift produced is concentrated inboard on the wing. This will add to the nose up pitching movement. If the elevators cannot counter the nose up pitching, there is a danger of super stall. A Hail would make this outcome likely, and with the elevator immersed in the separated air flow from wings and fuselage its effectiveness is greatly reduced.

24466. Airplane ATPL CPL At an AUW of 241 030 N an aircraft stalls at 133 kts in level flight. At an AUW of 367200 N it will stall at ___ in level flight. A) 89 kts B) 163 kts e) 110 kts D) 180kts

D) retreating. For explanation refer to question #23235 on page 52.

26394. Airplane ATPL CPL The point where a laminar boundary layer becomes turbulent is called: A) the separation point. B) the transition point. e) the critical point. D) the deflection point. (Refer to figure 081-£33) In the field of fluid dynamics the point at which the boundary layer changes from laminar to turbulent is called the transition point.

26398. Airplane ATPL CPL That point where airflow leaves the surface of an aerofoil is known as: A) the critical point. B) the stagnation point. e) the separation point. D) the transition point. Definition. And the term more or less says it.

26399. Airplane ATPL CPL Which of the following are used as stall warning devices? A) Angle of attack sensor and stall strip. B) Stick shaker and angle of attack indicator. e) Angle of attack indicator and speed indicator. D) Stick shaker and stall strip.

The stall speed at increased weight is Vs NEW = Vs OLD x v(New Weight.;. Old Weight) = 133 kts x v(367 200 N.;. 241030 N) = 164,16 kts - 163 kts.

Input to the stick shaker is the angle of attack as measured by an a-vane or a-probe. Stall strip and ASI are not warning devices.

24467. Airplane ATPL CPL Assuming no compressibility effects, the correct relationship between stall speed, limit load factor (n) and VA is:

26806. Airplane ATPL CPL The aerodynamic characteristics of an aircraft in an incipient spin is that the:

VA = Vs x v(n) C) VA =Vs x1/n A)

A) inner and outer wings are completely stalled. B) outer wing is completely stalled. e) outer wing is partially stalled. D) inner wing is partially stalled.

Manoeuvre speed VA is the lowest speed where the max. allowed load factor can be obtained without stalling. VA is therefore Vs x Vn.

In the incipient spin the inner wing stalls more than the outer and starts dropping, thus making the aircraft yaw in the direction of the inner wing.

24484. Airplane ATPL CPL An aircraft with a takeoff weight of 10.000 kg has a basic stalling speed Vs of 240 kts. What is the stalling speed as the aircraft turns onto finals with landing flaps extended (C LMAX doubles) at 30° AOB at an AUW of 6.400 kg?

26811. Airplane ATPL CPL How does stalling speed vary with load factor?

A) 146 kts B) 192 kts e) 240 kts D) 292 kts

A) It decreases inversely with the square root of the load factor. B) It increases proportionally with the square root of the load factor. e) It decreases inversely with the load factor. D) It increases proportionally with the load factor. The stall speed increases with the square root of the load factor.

The stall speed at changed weight is Vs NEW = Vs OW x v(New Weight.;. Old Weight) = 240 kts x v(6.400 kg .;. 10.000 kg) = 192 kts. Flaps double the value of CL' which in turn will decrease the stall speed with a factor 1 .;. v2. The stall speed will then be 192 kts.;. v2 = 135,76 kts.ln a turn the stall speed increases by a factor of 1 .;. VCOS (]), where (]) is the bank angle. Cos 30° =0,86603, so the stall speed will increase by a factor 1 .;. vO,86603. The final stall speed is therefore Vs = 135,76 kts.;. vO,86603 = 145,9 kts - 146 kts.

26822. Airplane ATPL CPL An aerofoil at its stalling angle will have a LID ratio which is:

25460. Airplane ATPL CPL When the upper surface of an aerofoil is predominantly covered in separated airflow the aerofoil is:

(Refer to figure 081-£114) The drag at the stalling angle is very high and the lift to drag ratio is therefore relatively low.

A) high B) zero C) negative D) low

A) descending. B) climbing. C) stalled. 124463 (C) 124466 (8) 124467 (8) 124484 (A) 125460 (C) 126394 (8) 126398 (C) 126822 (D) I

I 26399 (8)

126806 (C)

I 26811

(8)

I

01 Subsonic Aerodynamics

26971. Airplane ATPL CPL The angle of attack at which an aircraft stalls:

A) decreases with an increase in engine power. B) remains constant regardless of gross weight. C) increases with an increase in engine power. D) varies with gross weight and density altitude. The stalling angle is a characteristic of the profile and planform depending on the angle of attack only.

26980. Airplane ATPL CPL Indicated stalling speed varies with varying tempe.rature.

A) TRUE

B) FALSE An aerofoi! will stall at the same angle of attack under varying conditions of altitude, weight and load factor. This implies that an aircraft will stall at the same lAS at all altitudes for a given weight in 1 G flight.

26986. Airplane ATPL CPL With increasing altitude flying at a constant lAS will result in:

A) B) C) D)

a reduction in TAS. a reduction in the stalling angle. no change in the stalling angle. an increased stalling angle.

The stalling angle is a characteristic of the profile and planform depending on the angle of attack only. It is therefore independent of altitude.

Airplane ATPL CPL It is possible to reduce the spanwise airflow over swept wings, due to adverse pressure gradients, by: 27011.

A) B) C) D)

wing fences. trailing edge vortex generators. increased anhedral. leading edge stall inducers.

(Refer to figure 081-E44) Wing fences prevent outward drift of the boundary layer as shown in the illustration.

27016. Airplane ATPL CPL When looking at the airflow over the wing, from the wing surface and up, the air is:

A) caused to tend to flow from root to tip over a straight wing. B) accelerated to the transition point. e) decelerated to the transition point. D) accelerated to the separation point. (Refer to figure 081-E33) The airflow accelerates over the first part of the upper surface of the wing and slows down again when it has passed a point near the maximum thickness. The boundary layer changes from laminar to turbulent at the transition point, and that is usually just ahead of the point of maximum thickness.

27020. Airplane ATPL CPL In a level turn with 60° lateral bank, the load factor is 2,0 and the stall speed increases by:

A) 50% B) 40% e) 10% D) 20% In a turn the stall speed increases by a factor /n, where "n" is the load factor. With a load factor of 2 the increase will be /2 = 1,4142, or an increase of about 40%.

27030. Airplane ATPL CPL Stick pusher is installed in aircraft when:

by normal category. e) the Ale has no yaw damper installed. D) the Ale is used in supersonic speeds. A stick pusher is a device attached to the elevator control system, which physically pushes the control column forward, reducing the angle of attack before super-stall can occur. This device is fitted to aircraft with swept wings and Hail that otherwise might be prone to super-stall and thus would not be certified. 27031. Airplane ATPL CPL Superstall is a condition:

A) where the wings have stalled at high speed. B) which is easily to recover from. e) which is a stable stall with almost a constant pitch attitude. D) where the Ale is in a spin. For explanation refer to question #4243 on page 46.

232328. Airplane ATPL CPL Which of these statements about the effect of wing sweep on centre of pressure location are correct or incorrect?

1) The centre of pressure on a straight wing moves aft as the angle of attack approaches and exceeds the critical angle of attack. 2) The centre of pressure on a strongly swept back wing moves forward as the angle of attack approaches and exceeds the critical angle of attack. A) 1) is correct, 2) is correct. B) 1) is incorrect, 2) is incorrect. e) 1) is correct, 2) is incorrect. D) 1) is incorrect, 2) is correct. For explanation refer to question #4201 on page 46.

232333. Airplane ATPL CPL Which statement is correct about the laminar and turbulent boundary layer:

A) friction drag will be equal in both types of layers. B) friction drag is lower in the laminar layer. e) separation point will occur earlier in the turbulent layer. D) friction drag is lower in the turbulent layer. 232337. Airplane ATPL CPL The transition point is where the boundary layer changes from:

A) separated flow into attached flow. B) laminar into turbulent. e) turbulent into laminar. D) attached flow into separated flow. 232342. Airplane ATPL CPL In a steady, level, co-ordinated turn the load factor n and the stall speed Vs will be:

A) n greater than B) n smaller than e) n greater than D) n smaller than

1, Vs lower than in straight and level flight. 1, Vs higher than in straight and level flight. 1, Vs higher than in straight and level flight. 1, Vs lower than in straight and level flight.

232346. Airplane ATPL CPL Stall speed (lAS) varies with:

A) altitude. (below approximately 10.000 ft) B) weight. e) density. D) temperature.

A) the aircraft is directional unstable. B) the Ale has failed to meet the stalling requirements 1 26971 (8) 1 26980 (8) 126986 (e) 1 27011 (A) 1 27016 (8) 1 27020 (8) 1 27030 (8) 1 27031 (e) 1232328 (A) 1232333 (8) 1 1232337(8) 1232342 (e) 1232346(8) 1

Aviationexam Test Prep Edition 2012 232357. Airplane ATPL CPL Which statement is correct? I. Stall speeds are determined with the CG at the aft limit. II. Minimum control speeds are determined with the CG at the forward limit. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct. I is incorrect, II is incorrect.

232359. Airplane ATPL CPL The stall speed decreases: (all other relevant factors are constant) A) in a horizontal turn. B) when flaps are retracted. C) when, during a manoeuvre, the aeroplane nose is suddenly pushed firmly downwards (e.g. as in a push over). D) when the CG is moved forward. 232364. Airplane ATPL CPL If the stall speed of an aeroplane is 60 kts, at what speed will the aeroplane stall if the load factor is 2? A) B) C) D)

120 kts. 66 kts. 72 kts. 85 kts.

I. Stall speeds are determined with the CG at the forward limit. II. Minimum control speeds are determined with the CG at the aft limit. I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect. I is incorrect, II is correct.

Airplane ATPL CPL 232366. Which statement is correct? I. Stall speeds are determined with the CG at the aft limit. II. Minimum control speeds are determined with the CG at the aft limit. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is incorrect. I is correct, II is correct. I is incorrect, II is correct.

232367. Airplane ATPL CPL Which statement is correct? I. Stall speeds are determined with the CG at the forward limit. II. Minimum control speeds are determined with the CG at the forward limit. A) B) C) D)

A) B) C) D)

improve the lift coefficient of the trailing edge flaps. improve the high speed handling characteristics. improve the low speed handling characteristics. increase the critical Mach number.

232376. Airplane ATPL CPL Low speed pitch up can be caused by the: A) boundary layer separation at the wing tip of a forward swept wing. B) dihedral effect. C) wing tip vortices on high aspect ratio wings. D) outward drift of the boundary layer on a swept-back wing. For explanation refer to question #15614 on page 50.

232377. Airplane ATPL CPL Which of these statements about stall speed is correct? A) B) C) D)

Increasing sweepback increases stall speed. Increasing sweepback decreases stall speed. Increasing wing anhedral decreases stall speed. Decreasing wing anhedral decreases stall speed.

Airplane 232382. A stick pusher:

Airplane ATPL CPL 232365. Which statement is correct?

A) B) C) D)

Airplane ATPL CPL 232371. The main purpose of a boundary-layer fence on a swept wing is to:

I is correct,1I is incorrect. I is correct, II is correct. I is incorrect, II is correct. I is incorrect, II is incorrect.

ATPL

CPL

A) pushes the elevator control forward prior to stick shaker activation. B) pushes the elevator control to avoid a stall at a negative load factor. C) pushes the elevator control forward when a specified value of angle of attack is exceeded. D) vibrates the elevator control. 232387. Airplane ATPL CPL Regarding deep stall characteristics, identify whether the following statements are correct or incorrect: I. The combination of a wing with sweepback and aT-tail make an aeroplane prone to deep stall. II. A stick pusher system can be fitted to an aeroplane that exhibits abnormal stall characteristics. A) B) C) D)

I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is correct. I is incorrect, II is incorrect.

232388. Airplane ATPL CPL The pitch up tendency of an aeroplane with swept back wings during a stall is caused by the: A) B) C) D)

forward movement of the centre of pressure. forward movement of the centre of gravity. aft movement of the centre of pressure. aft movement of the centre of gravity.

232391. Airplane ATPL CPL One disadvantage of wing sweepback is: A) that the critical Mach number is significantly lower. B) a severe pitch down moment when the centre of pressure shifts forward. C) the tendency of the wing root section to stall prior to the wingtip section. D) the tendency of the wingtip section to stall prior to the wing root section.

1232357(0) 1232359 (C) 1232364(0) 1232365 (A) 1232366(0) 1232367 (A) 1232371 (C) 1232376(0) 1232377 (A) 1232382 (C) 1 1232387 (A) 1232388 (A) 1232391 (0) 1

01 Subsonic Aerodynamics

232392. Airplane ATPL CPL Regarding deep stall characteristics, identify whether the following statements are correct or incorrect: I. A wing with forward sweep and a low horizontal tail makes an aeroplane prone to deep stall. II. A stick shaker system is fitted to an aeroplane to resolve deep stall problems. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is correct.

232393. Airplane ATPL CPL Regarding deep stall characteristics, identify whether the following statements are correct or incorrect: I. The combination of a wing with sweepback and aT-tail make an aeroplane prone to deep stall. II. A stick shaker system is fitted to an aeroplane to resolve deep stall problems. A) B) C) D)

I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect. I is incorrect, II is correct.

232394. Airplane ATPL CPL Regarding deep stall characteristics, identify whether the following statements are correct or incorrect: I. A wing with forward sweep and a low horizontal tail makes an aeroplane prone to deep stall. II. A stick pusher system can be fitted to an aeroplane that exhibits abnormal stall characteristics. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is correct.

232395. Airplane ATPL CPL Regarding deep stall characteristics, identify whether the following statements are correct or incorrect: I. An aeroplane with a low horizontal tail and wings with sweepback is normally prone to deep stall. II. An aeroplane with a canard is normally prone to deep stall. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is correct. I is correct, II is incorrect. I is incorrect II is correct.

232396. Airplane ATPL CPL Which statement is correct? I. A stick pusher activates at a higher angle of attack than a stick shaker. II. A stick pusher prevents the pilot from increasing the angle of attack fu rther. A) B) C) D)

I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is correct. I is incorrect II is incorrect.

232397. Airplane ATPL CPL Which statement is correct? I. A stick pusher activates at a lower angle of attack than a stick shaker.

II. A stick shaker prevents the pilot from increasing the angle of attack further. A) B) C) D)

I is correct II is correct. I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect.

232398. Airplane ATPL CPL Which statement is correct? I. A stick pusher activates at a higher angle of attack than a stick shaker. II. A stick shaker prevents the pilot from increasing the angle of attack further. . A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct.

232399. Airplane ATPL CPL Which statement is correct? I. A stick pusher activates at a lower angle of attack than a stick shaker. II. A stick pusher prevents the pilot from increasing the angle of attack further. A) B) C) D)

I is incorrect, II is correct. I is correct, II is correct. I is incorrect, II is incorrect. I is correct II is incorrect.

232400. Airplane Negative tail stall is:

ATPL

CPL

A) flow reversal on the fin leading to flow re-attachment. B) a sudden reduction in the downward aerodynamic force on the tailplane. C) a typical aerodynamic problem for canards. D) flow separation at the rear of the lower surface of the wing. 232401. Airplane ATPL CPL Which statement about negative tail stall is correct? A) Negative tail stall is a stall of the tail plane when the aerodynamic force is in upward direction. B) When negative tail stall occurs, the aeroplane will show an uncontrollable pitch-up moment. C) Negative tail stall is a stall of the fin with a negative sideslip angle (nose pointing to the right of the relative airflow). D) When negative tail stall occurs, the aeroplane will show an uncontrollable pitchdown moment. 232402. Airplane ATPL CPL Which of these statements about stall speed is correct? A) B) C) D)

Decreasing sweepback increases stall speed. Decreasing sweepback decreases stall speed. Decreasing wing anhedral decreases stall speed. Increasing wing anhedral decreases stall speed.

232403. Airplane ATPL CPL Which of these statements about stall speed is correct? A) Increasing wing anhedral decreases stall speed. B) Decreasing forward sweep decreases stall speed. C) Decreasing wing anhedral decreases stall speed. D) Decreasing forward sweep increases stall speed.

1232392(8) 1232393(8) 1232394 (C) 1232395 (A) 1232396 (A) 1232397 (C) 1232398 (C) 1232399 (A) 1232400(8) 1232401 (D) 1 1232402 (8) 1232403 (8) 1

Aviationexam Test Prep Edition 2012

232404. Airplane ATPL CPL Which of these statements about stall speed is correct? A) B) C) D)

Decreasing wing anhedral decreases stall speed. Increasing wing anhedral decreases stall speed. Increasing forward sweep decreases stall speed. Increasing forward sweep increases stall speed.

Airplane ATPL CPL 232544. What will happen if a large transport aeroplane slowly decelerates in level flight from its cruise speed in still air at high altitude? A) B) C) D)

Stick shaker activation or low speed buffeting. High speed buffet. CLMAX will increase due to shock stall. An accelerated stall.

232554. Airplane ATPL CPL When altitude increases, the stall speed (lAS) will: A) increase due to increasing compressibility effects as a result of increasing Mach number. B) decrease due to decreasing temperature and decreasing Mach number. C) decrease due to increasing McRir D) increase due to decreasing McRlr 232581. Airplane ATPL CPL The maximum cruise altitude can be limited by a 1,3 g load factor because when exceeding that altitude: A) turbulence may induce high speed or low speed buffet. B) high speed buffet will occur immediately after exceeding this maximum altitude. C) turbulence may cause the limit load factor to be exceeded. D) use of normal manoeuvring bank angles may cause the limit load factor to be exceeded. 232591. Airplane ATPL CPL Which of these statements about wing sweep back are correct or incorrect? I. Increasing wing sweepback increases MeRIT" II. Increasing wing sweepback increases the drag divergence Mach number. A) B) C) D)

I is incorrect, II is correct. I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect.

232593. Airplane ATPL CPL Which of these statements about wing sweep back are correct or incorrect? I. Increasing wing sweepback decreases MeRIT" II. Increasing wing sweepback increases the drag divergence Mach number. A) I is incorrect, II is correct. B) I is correct, II is incorrect. C) I is correct, II is correct. D) I is incorrect, II is incorrect. 232594. Airplane ATPL CPL Which of these statements about wing sweep back are correct or incorrect?

Mach number. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is correct.

232595. Airplane ATPL CPL Which of these statements about wing sweep back are correct or incorrect? I. Increasing wing sweepbackdecreases MeRIT" II. Increasing wing sweepback decreases the drag divergence Mach number. A) B) C) D)

I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is correct. I is incorrect, II is incorrect.

232596. Airplane ATPL CPL Which of these statements about wing sweep back are correct or incorrect? I. Decreasing wing sweep back increases MeRIT" II. Decreasing wing sweepback increases divergence Mach number. A) B) C) D)

the

drag

I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct. I is incorrect, II is incorrect.

Airplane ATPL CPL 232597. Which of these statements about wing sweep back are correct or incorrect? I. Decreasing wing sweepback decreases MeRIT" II. Decreasing wing sweepback increases divergence Mach number. A) B) C) D)

the

drag

I is incorrect, II is correct. I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is incorrect.

232598. Airplane ATPL CPL Which of these statements about wing sweep back are correct or incorrect? I. Decreasing wing sweepback increases MeRIT" II. Decreasing wing sweepback decreases divergence Mach number.

the

drag

A) I is correct, II is correct. B)I is incorrect, II is incorrect. C) I is incorrect, II is correct. D) I is correct, II is incorrect. 232599. Airplane ATPL CPL Which of these statements about wing sweep back are correct or incorrect? I. Decreasing wing sweepback decreases MeRIT" II. Decreasing wing sweepback decreases divergence Mach number. A) B) C) D)

the

drag

I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect. I is incorrect, II is correct.

I. Increasing wing sweepback increases MeRIT" II. Increasing wing sweepback decreases the drag divergence 1232404 (D) 1232544 (A) 1232554 (A) 1232581 (A) 1232591 (8) 1232593 (A) 1232594 (8) 1232595 (0) 1232596 (0) 1232597 (8) 1 1232598 (C) 1232599 (A) 1

01 Subsonic Aerodynamics

232730. Airplane ATPL CPL Sweep back of a wing positively influences: 1) Static longitudinal stability. 2} Static lateral stability. 3} Dynamic longitudinal stability. The combination that regroups all ofthe correct statements is: A} 1,2,3 B) 1

232883. Airplane ATPL CPL The stall speed lines in the manoeuvring load diagram originate from a point where the: A) B) C) D)

speed = Vs' load factor = O. speed = 0, load factor = +1. speed = VA' load factor = +1. speed = 0, load factor = O.

232884. Airplane ATPL CPL The stall speed line in the manoeuvring load diagram runs through a point where the:

C) 3 D) 2

232775. Airplane ATPL CPL Low speed pitch-up can be caused by a significant thrust: A) decrease with engines located on the rear fuselage. B) increase with podded engines located beneath a low-mountedwing. C) decrease with podded engines located beneath a low-mounted wing. D) increase with engines located on the rear fuselage.

A) B) C) D)

speed = VB' load factor = gust load factor. speed = 0, load factor = +1. speed =Vs' load factor =O. speed = VA' load factor =limit load factor.

232885. Airplane ATPL CPL The stall speed line in the manoeuvring load diagram runs through a point where the: A) B) C) D)

speed = VB' load factor =+1. speed = 0, load factor =+1. speed =VA' load factor = +1. speed =Vs' load factor = +1.

01-09 CLMAX Augmentation 4191. Airplane ATPL CPL After takeoff the slats (when installed) are always retracted later than the flaps. Why? A) Because slats extended provide a better view from the cockpit than flaps extended B) Because slats extended give a large decrease in stall speed with relatively less drag. C) Because VMCA with slats extended is more favourable compared to the flaps extended situation. D) Because flaps extended give a large decrease in stall speed with relatively less drag. (Refer to figure 081-E104) Both slats and flaps give more lift coefficient, but the flaps increase drag much more than slats. After takeoff a good climb performance is required, but that needs a larger excess thrust. Retraction of flaps gives the higher reduction in drag and thus an increase in excess thrust.

4203. Airplane ATPL CPL The trailing edge flaps when extended: A) B) C) D)

increase the zero lift angle of attack. worsen the best angle of glide. significantly increase the angle of attack for maximum lift. significantly lower the drag.

(Refer to figure 081-El08) Tangent to the angle of glide is DIL. Extended flaps increase the drag significantly and will therefore give a larger sinus, which is equal to a bigger - or worse -angleofglide.

4208. Airplane ATPL CPL Deploying a Fowler flap, the flap will: A) B) C) D)

(Refer to figure 081-E55) The Fowler flap moves rearwards and then down, initially giving an increase in wing area and then an increase in camber.

4229. Airplane ATPL CPL What is the purpose of an auto-slat system? A) Provide automatically slat in selection after takeoff. B) Extend automatically when a certain value of angle of attack is exceeded. C) Ensures that the slats are always extended when the ground/ flight system is in the ground position. D) Assist the ailerons during rolling. Auto-slat system extends the slats when required, that is at slow speed where the angle of attack is increased to maintain level flight. The slats will therefore extend when the angle of attack approaches the stalling angle to delay stall.

4235. Airplane ATPL CPL An aeroplane has the following flap settings: 0°, 15°, 30° and 45°. Slats can also be selected. Which of the following selections will most adve~sely affect the CL/CD ratio? A) B) C) D)

Flaps from 15° to 30°. The slats. Flaps from 0° to 15°. Flaps from 30° to 45°.

(Refer to figure 081-El08) Slats will increase C, with only a moderate increase in Co and have therefore not a huge impact on the C,ICo ratio. Flaps will increase C, Significantly at low settings with moderate increase in CD' but higher settings only give small increase in C, with large increase in CD' The worst impact on the C,ICo ratio is therefore when choosing the highest flap setting, i.e. from 30° to 45°.

turn down, then move aft. move aft, then turn down. just turn down. just move aft.

1232730 (0) 1232775 (8) 1232883 (0) 1232884 (0) 1232885 (0) 1 4191 (8)

1 4203 (8)

1 4208 (8) 1 4229 (8) 1 4235 (0) 1

Aviationexam Test Prep Edition 2012

4241. Airplane ATPL CPL Which of the following occurs when trailing edge flaps are extended? . A) B) C) D)

The critical angle of attack decreases and CLMAX increases. CLMAX increases and the critical angle of attack increases. The critical angle of attack is constant, but CLMAX increases. The critical angle of attack remains constant and stall speed increases.

(Refer to figure 081-E98) In the illustration are the Cia-curves for a plain profile and the same profile with different flap types. It can be seen that extending flaps (irrespective of type) will increase CL but decrease the critical angle of attack.

4261. Airplane ATPL CPL Which statement is correct? A) Spoiler extension decreases the stall speed and the minimum rate of descent, but increases the minimum descent angle. B) Extension of flaps will increase (C/C Dma) , causing the minimum rate of descent to decrease. C) Extension of flaps has no influence on the minimum rate of descent, as only the TAS has to be taken into account. D) Extension of flaps causes a reduction of the stall speed, the maximum glide distance also reduces. (Refer to figure 081-El08) Extension of flaps will increase CLMAX and thus the stall speed, but extended flaps also increase drag. Glide distance is proportional to the LID ratio, and with a larger D, the LID ratio is decreased.

4269. Airplane ATPL CPL What is the effect of deploying leading edge flaps? A) B) C) D)

Decrease CLMAX ' Decrease the critical angle of attack. Not affect the critical angle of attack. Increase the critical angle of attack.

4277. Airplane ATPL CPL Ignoring downwash effects on the tailplane, extension of Fowler-type flaps, will produce: a nose-down pitching moment. no pitching moment. a nose-up pitching moment. a force which reduces drag.

(Refer to figure 081-EI24) Deflecting a trailing edge flap will move the centre ofpressure rearwards. This shift in the location of the CP further behind the CG will cause a nose down pitching moment.

7663. Airplane ATPL CPL Compared with the flap up configuration the maximum angle of attack for the flaps down configuration is: A) B) C) D)

A) B) C) D)

Flaps only extended, clean wing, slats only extended. Clean wing, flaps only extended, slats only extended. Slats only extended, clean wing, flaps only extended. Slats only extended, flaps only extended, clean wing.

For explanation refer to question #23733 on page 55.

7684. Airplane ATPL CPL What is the purpose of a slat on the leading edge? A) Decelerate the air over the top surface. B) Thicken the laminar boundary layer over the top surface. C) Increase the camber ofthe wing. D) Allow greater angle of attack. (Refer to figure 081-E84)

A slat at the leading edge creates a slot that allows higher pressure air to accelerate the boundary layer on the upper side of the wing. This increases the energy in the boundary layer and delays the separation point moving forward when angle of attack is increased.

7687. Airplane ATPL CPL When flaps are deployed at constant angle of attack the lift coefficient will: A) B) C) D)

remain the same. decrease. increase. vary as the square of lAS.

(Refer to figure 081-E98) As shown in the illustration, deployment of flaps will increase the lift coefficient for a particular angle of attack.

(Refer to 'figure 08l-E96) In the illustration are the Cia-curves for a plain profile and the same profile with leading edge flaps. It can be seen that extending leading edge flaps will increase the critical angle of attack.

A) B) C) D)

7673. Airplane ATPL CPL Which of the following series of configurations has an increasing critical angle of attack?

unchanged. larger. smaller. smaller or larger depending on flap deflection.

(Refer to figure 081-E98) In the illustration are the Cia-curves for a plain profile and the same profile with different flap types. It can be seen that extending flaps (irrespective of type) will decrease the critical angle of attack.

7688. Airplane ATPL CPL An aeroplane with swept back wings is equipped with slats andlor leading edge (LE) flaps. One possible efficient way to arrange the leading edge devices on the wings is? A) B) C) D)

Wing roots: LE flaps; wing tips: no devices. Wing roots: slats; wing tips: LEflaps. Wing roots: slats; wing tips: no devices. Wing roots: LE flaps; wing tips: slats.

The problem with swept wing is the tendency for tip stall. Slats will increase the critical angle of attack and is therefore advisable at the tips. Leading edge flaps at the wing root will increase the lift coefficient, but the critical angle of attack is only increased to a minor degree, promoting stall to start at the root.

7692. Airplane ATPL CPL What must happen to the CL when flaps are deployed while maintaining a constant lAS in straight and level flight? A) B) C) D)

Increase then decrease. Remain constant. Decrease. Increase.

The lift equation: LIFT = J.2pV'SCL' where: • CL = coefficient of lift. This represents angle of attack of the airfoil and the shape of the airfoil. This described in terms of thicknesslchord ratio and a camber and can be altered in flight, for example, by lowering the flaps. • p = The density of the air. For any given altitude during subsonic flight, the density may be considered to be constant. • V' = The velocity of the aircraft, squared. • S = The wing area. To maintain level flight at constant lAS the lift must be unchanged. Constant lAS means unchanged dynamic pressure. From the lift equation it can be seen that to maintain constant lift with J.2pV' constant, CL must also remain constant.

I

4241 (A)

I

4261 (D)

I

4269 (0)

I

4277 (A)

I

7663 (C)

I

7673 (A)

I

7684 (0)

I

7687 (C)

I

7688 (0)

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7692 (8)

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01 Subsonic Aerodynamics

7706. Airplane ATPL CPL The function of the slot between an extended and the leading edge of the wing is to: A) B) C) D)

allow space for vibration of the slat. cause a venturi effect which energizes the boundary layer. reduce the wing loading. slow the air flow in the slot so that more pressure is created under the wing.

(Refer to figures 081-£56 and 081-£84) The slot allows passage of air from the high pressure region below the wing to the low pressure region above it. Additional kinetic energy is added to the airflow through the slot by the slat forming a convergent duct, which in turn re-energise the boundary layer.

7737. Airplane ATPL CPL What is true regarding deployment of slats I Krueger flaps? A) Slats increase the critical angle of attack, Krueger flaps do not. B) Krueger flaps increase the critical angle of attack, slats do not. C) Krueger flaps form a slot, slats do not. D) Slats form a slot, Krueger flaps do not. (Refer to figure 081-£56) A slat at the leading edge creates a slot that allows higher pressure air to accelerate the boundary layer on the upper side of the wing. This allows for higher angles of attack before stall. Krueger flaps are parts of the lower surface of the leading edge, which can be rotated about their forward edges and increase the camber of the leading edge. Their effect is as for slat/slots, delay of stall.

7739. Airplane ATPL CPL Deflection of leading edge flaps will: A) B) C) D)

the suction peak on the slat, so that CLMAX is reached at lower angles of attack. B) increase the boundary layer energy and increase the suction peak on the fixed part of the wing, so that the stall is postponed to higher angles of attack. C) increase the boundary layer energy, move the suction peak from the fixed part of the wing to the slat, so that the .stall is postponed to higher angles of attack. D) increase the camber of the aerofoil and increase the effective angle of attack, so that CLMAX is reached at higher angles of attack.

slat

(Refer to figures 081-£54,081-£56 and 087-£84) The effect of the slat is to prolong the lift curve by delaying boundary layer separation until a higher angle of attack. When operating at high angles ofattack the slat itself is generating a high lift coefficient because of its marked camber. The action of the slat is to flatten the marked peak of low-pressure envelope at high angles of attack and to change it to one with a more gradual pressure gradient which allow the boundary layer to retain much of its kinetic energy. The boundary layer is then able to penetrate almost the full chord of the wing before separating. The illustration shows the suction peak is spread unto the fixed part of the wing.

7785. Airplane Vortex generators:

For explanation refer to question #7779 on this page.

increase critical angle of attack. decrease CLMAX ' decrease drag. not affect critical angle of attack.

7801. Airplane ATPL CPL During the extension of the flaps at a constant angle of attack the aeroplane starts to (all other factors of importance being constant):

7757. Airplane ATPL CPL In order to maintain straight and level flight at a constant airspeed, whilst the flaps are being retracted, the angle of attack will: increase. decrease. remain constant. increase or decrease depending on type of flap.

(Refer to figure 081-£108) When the flaps are retracted, the lift coefficient decreases. This would mean a descent, unless the angle of attack is increased to compensate the decrease

A) B) C) D)

ATPL

7802. Airplane ATPL CPL What is the most effective flap system? A) B) C) D)

CPL

A) take energy from the laminar flow to induce boundary layer separation. B) use free stream flow to induce laminar flow. C) prevent spanwise flow. D) use free stream flow to increase energy in the turbulent boundary layer.

A) decrease

I

7706 (8)

I

the

7737 (D)

ATPL

CPL

boundary

I

7739 (A)

layer energy and

I

7757 (A)

I

decrease

7779 (D)

I

Single slotted flap. Split flap. Plain flap. Fowler flap.

(Refer to figures 081-£55 and 081-£98) The Fowler flap moves rearwards and then down, initially giving an increase in wing area and then an increase in camber. Because of the combined effects of area and camber, the Fowler flap gives the greatest increase in lift.

7803. Airplane ATPL CPL The maximum angle of attack for the flaps down configuration, compared to flaps up is: A) greater. B) smaller. C) unchanged. D) smaller or greater, depending on CG position.

Vortex generators are rows ofsma//, thin aerofoil shaped blades which projects vertically into the airstream. They each generate a small vortex which causes the free stream flow of high energy air to mix with and add kinetic energy to the boundary layer.

7781. Airplane A deployed slat will:

sink suddenly. bank. climb. yaw.

(Refer to figure 081-£108) The extension of flaps will increase the camber of the aerofoil and increase the lift coefficient Cc With all other factors unchanged this will increase lift, and the aircraft will climb.

inCL'

7779. Airplane Vortex generators:

CPL

A) transfer energy from the free airflow into the boundary layer. B) change the turbulent boundary layer into a laminar boundary layer. C) reduce the spanwise flow on swept wing. D) take kinetic energy out of the boundary layer to reduce separation.

For explanation refer to question #4269 on page 62.

A) B) C) D)

ATPL

(Refer to figure 081-£98) Deployment of flaps shifts the CL-curve upwards and slightly to the left which means the maximum, corresponding to the stalling angle, shifts to a smaller angle of attack.

7781 (8)

I

7785 (A)

I

7801 (C)

I

7802 (D)

I

7803 (8)

I

Aviationexam Test Prep Edition 2012 7813. Airplane ATPL CPL What increases the stalling angle of attack? Use of: A) B) C) D)

flaps. slats. spoilers. fuselage mounted speed-bra,kes.

(Refer to figure 081-E104) In the illustration it is shown that slats are the only option that extends the C/a curve so that the maximum CL occurs at a higher angle of attack.

7838. Airplane ATPL CPL A plain flap will increase CLMAX by: A) B) C) D)

increasing the camber of the aerofoil. increasing angle of attack. boundary layer control. centre of lift movement.

(Refer to figure 081-E55) When the flap is deflected it produces an increase of camber. Although, per definition, the angle of attack is also increased, it is customary to focus on the camber change,

7874. Airplane ATPL CPL Lowering the inboard flaps causes the wing CP: A) B) C) D)

to move forward. to move outboard towards the wing tips. to move inboard towards the wing root. to move inward and forward.

(Refer to figure 081-E124) Lowering flaps increases the lift coefficient and thus produce more lift. If only the inboard flaps are lowered, the increase in lift will be near the root. This will move the centre ofpressure for the whole wing inboard.

7880. Airplane ATPL CPL When a trailing edge flap is lowered fully: A) B) C) D)

the CP moves to the rear and lift/drag ratio is unaffected. the CP moves to the rear and lift/drag ratio is decreased. the CP moves forwards and lift/drag ratio is decreased. the CP moves to the rear and lift/drag ratio is increased.

(Refer to figure 081-E124) As shown in the illustration, deployment of flaps will move the centre of pressure rearwards. The polar shows that the clean wing (red) has a higher UD ratio than the wing with flaps deployed (black).

7885. Airplane ATPL CPL When trailing edge flaps are extended whilst maintaining straight and level flight at constant lAS: A) B) C) D)

the lift coefficient and the drag coefficient increase. the centre of pressure moves aft. the stall speed increases. the total boundary layer becomes laminar.

(Refer to figure 081-E124) As shown in the illustration, deployment of flaps will move the centre ofpressure rearwards.

7890. Airplane ATPL CPL When flaps are extended whilst maintaining straight and level flight at constant lAS, the lift coefficient will: A) eventually remain the same. B) eventually increase. C) eventually decrease. D) first increase and then decrease. (Refer to figure 081-E108) Deploying flaps will increase the lift coefficient. Considering the lift formula (LIFT = ~p\f2SCJ the possibilities now to maintain the same amount of lift would be to reduce the speed or reduce the lift coefficient again. Since the question states that lAS is to be maintained constant the only way how to maintain

the original amount oflift that existed before flap extension would be to again reduce the lift coefficient. Without changing the flap position this can only be achieved by changing the angle ofattack => reduced angle of attack means a reduced coefficient of lift. Hence, after extending the flaps the pilot will have to reduce the angle of attack to maintain straight flight and thus maintain the original coefficient of lift.

7908. Airplane ATPL CPL A slotted flap will increase the CLMAX by: A) B) C) D)

increasing the critical angle of attack. decreasing the skin friction. increasing only the camber of the aerofoil. increasing the camber of the aerofoil and improving the boundary layer.

(Refer to figure 081-E55) The slotted flap increases the camber of the aerofoil, but the slot will direct higher pressure from the lower surface over the flap and re-energise the boundarylayer.

7944. Airplane ATPL CPL During the retraction of the flaps at a constant angle of attack the aeroplane starts to (all other factors of importance being constant): A) B) C) D)

bank. sink suddenly. climb. yaw.

(Refer to figure 081-E108) When the flaps are retracted, the lift coefficient decreases. This means a descent when all other factors (speed and angle of attack) are constant.

7958. Airplane ATPL CPL The use of a slot in the leading edge of the wing enables the aeroplane to fly at a slower speed because: A) B) C) D)

it changes the camber of the wing. the laminar part of the boundary layer gets thicker. it decelerates the upper surface boundary layer air. it delays the stall to a higher angle of attack.

(Refer to figures 081-E56 and 081-E84) The slot allows passage of air from the high pressure region below the wing to the low pressure region above it. Additional kinetic energy is added to the airflow through the slot by the slat forming a convergent duct, which in turn re-energise the boundary layer. The separation is then delayed allowing a higher angle of attack.

7967. Airplane ATPL CPL On a wing fitted with a fowler type trailing edge flap, the Full extended position will produce: A) B) C) D)

an an an an

unaffected wing area and increase in camber. increase in wing area and camber. unaffected CD' at a given angle of attack. increase in wing area only.

For explanation refer to question #4208 on page 61.

7969. Airplane ATPL CPL How do vortex generators work? A) Re-direct spanwise flow. B) Take energy from free stream and introduce it into the boundary layer. C) Reduce kinetic energy to delay separation. D) Reduce the adverse pressure gradient. Vortex generators produce a vortex at the tip which induce high energy from the free stream flow to mix with the boundary layer, thus increasing its kinetic energy.

17813 (8) 1 7838 (A) 1 7874 (C) 1 7880 (8) 1 7885 (8) 1 7890 (A) 1 7908 (0) 1 7944 (8) 1 7958 (0) 1 7967 (8) 1 1 7969 (8) 1

01 Subsonic Aerodynamics The high lift device shown in the figure 2 is a:

15724. Airplane ATPL CPL Trailing edge flap extension will: A) increase the critical angle of attack and increase the ofC LMAx • B) decrease the critical angle of attack and decrease the ofCLMAx • C) increase the critical angle of attack and decrease the ofCLMAx • D) decrease the critical angle of attack and increase the ofCLMAx '

value

A) Krueger flap. B) slat. C) Fowler flap. D) slotted flap.

value

(Refer to figure OB1-E56) Slat forming a slot.

value

value

(Refer to figure OB1-E9B) In the illustration are the Cia-curves for a plain profile and the same profile with different flap types. It can be seen that extending flaps (irrespective of type) will increase CLMAXand decrease the critical angle of attack.

15725. Airplane ATPL CPL Which of the following statements about the difference between Krueger flaps and slats is correct? A) Deploying a Krueger flap will increase critical angle of attack, deploying a slat does not. B) Deploying a slat will form a slot. deploying a Krueger flap does not. C) Deploying a Krueger flap will form a slot, deploying a slat does not. D) Deploying a slat will increase critical angle of attack, deploying a Krueger flap does not. (Refer to figure OB1-E56) Krueger flaps do not form a slot whilst a slat does.

15740. Airplane ATPL CPL Flap extension at constant lAS whilst maintaining straight and level flight will increase the: A) B) C) D)

lift coefficient and the drag. stall speed. lift and the drag. maximum lift coefficient (CLMAX) and the drag.

(Refer to figure OB1-El0B) Flap selection will increase the lift coefficient and the drag, but to maintain straight and level flight at constant lAS, it is necessary to decrease the angle of attack to maintain the same lift coefficient. The flaps will still give increased drag. Consequently, the correct answer is that the maximum lift coefficient increases and drag increases.

15768. Airplane ATPL CPL (Refer to figure 081-11) Which type offlap is shown in the picture 4? A) B) C) D)

Plain flap. Split flap. Fowler flap. Double slotted flap.

(Refer to figure OB1-E55) Fowler flap is the only type that moves rearwards and then down.

15769. Airplane ATPL CPL (Refer to figure 081-11) Which type of flap is shown in the picture 3? A) Plain flap. B) Split flap. C) Single slotted flap. D) Fowler flap. (Refer to figure OB1-E55) The split flap forms part of the lower wing surface of the wing trailing edge, the upper surface contour being unaffected when the flap is lowered.

15770. Airplane ATPL CPL (Refer to figure 081-11)

15771. Airplane ATPL CPL (Refer to figure 081-11) The high lift device shown in the figure 1 is a: A) B) C) D)

slot or slat. Krueger flap. Fowler flap. slotted flap.

(Refer to figure OB1-E56) The sketch number 1 shows a Krueger Flap.

16672. Airplane ATPL CPL If the flaps are lowered but the airspeed is kept constant, to maintain level flight: A) B) C) D)

the nose must be pitched down. the nose must be pitched up. the altitude must be held constant. spoilers must be deployed.

(Refer to figures OB1-E1OB and OB1-E50) To maintain level flight at constant lAS, the lift coefficient must remain constant. Deploying flaps will increase the lift coefficient which means the angle of attack must be decreased.

16681. Airplane ATPL CPL When deploying the flaps the effective angle of attack: A) B) C) D)

decreases. remains the same. increases. may increase of decrease depending on the aircraft type.

The chord of the profile will be steeper with flaps deployed and thus increase the effective angle of attack.

16682. Airplane ATPL CPL The lift coefficient CL of a wing at a given angle of attack: A) B) C) D)

is dependent on the surface area of the wing. is increased by the use of high lift devices. is constant and not affected by high lift devices. is reduced when high lift devices are used.

(Refer to figure OB1-E104) .All high lift devices will increase the lift coefficient CL at a given angle of attack, except for slatfslots. .

16687. Airplane ATPL CPL CLMAX may be increased by the used of: A) B) C) D)

flaps. slats. boundary layer control. all answers are correct.

(Refer to figure OB1-El03) The illustration shows the Cia-curves for flaps, slats and boundary layer control. As can be seen, all devices will increase the value of CLMAX'

16717. Slats: A) B) C) D)

Airplane

ATPL

CPL

increase CLMAX ' decrease the minimum angle of attack. both answers are correct. neither answer is correct.

115724 (0) 115725 (8) 115740 (0) 115768 (C) 1 15769 (8) 1 15770 (8) 1 15771 (8) 116672 (A) 116681 (C) 116682 (8) 1 116687 (0) 1 16717 (A) 1

Aviationexam Test Prep Edition 2012 (Refer to figures 087-E56 and 087-E84) As shown in the illustration slats increase both CLMAX and the critical angle of attack. The CL can be increased. indirectly: by allowing a higher AoA to be achieved, hence increasing the CL•

21014. Airplane Slat extension:

ATPL

CPL

A) decreases the camber of the aerofoil and divert the flow around the sharp leading edge. B) delays the stall to a higher angle of attack. C) increases the lift by increasing the wing area and the camber of the aft portion of the wing. D) provides a boundary layer suction on the upper surface of the wing. (Refer to figure 087-E84) As shown in the illustration slats increases the critical angle of attack => delays the stall to a higher angle of attack.

21023. Airplane ATPL CPL An aeroplane has the following flap positions: 0°, 15°,30°,45°; slats can also be selected. Generally speaking, which selection provides the highest positive contribution to the CLMAX ? A) The flaps from 0° to 15°. B) The flaps from 30° to 45°. C) The slats from the retracted to the takeoff position. D) The flaps from 15° to 30°. (Refer to figures 087-E700, 087-E84 and 087-E98) In the illustration the variation of the lift increment with increasing flap angle is shown compared to the effect of slats. The selection of slats will provide a larger increase in CLMAXthan the increments of flap angles.

21038. Airplane ATPL CPL Compared with the clean configuration, the angle of attack at CLMAX with trailing edge flaps extended is: A) B) C) D)

smaller or larger depending on the degree of flap extension. larger. unchanged. smaller.

(Refer to figure 087-E98) In the illustration are the C/a-curves for a plain profile and the same profile with different flap types. It can be seen that extending flaps (irrespective of type) will increase CLMAX but decrease the critical angle of attack compared to the clean wing. .

21057. Airplane ATPL CPL Given the following aeroplane configurations: 1) Clean wing. 2) Slats only extended. 3) Flaps only extended. Place these configurations in order of increasing critical angle of attack:

A) B) C) D)

2,1,3 1,3,2 3,1,2 2,3,1

.D) extends the slats automatically when a certain value of angle

of attack is exceeded. Auto-slat system extends the slats when required, that is at slow speed where the angle of attack is increased to maintain level flight. The slats will therefore extend when the angle of attack approaches the stalling angle to delay stall.

21100. Airplane Slat extension will: A) B) C) D)

ATPL

CPL

increase the critical angle of attack. reduce tip vortices. create gaps between leading edge and engine nacelles. decrease the energy in the boundary layer on the upper side ofthewing.

For explanation refer to question #21074 on this page.

21117. Airplane ATPL CPL The difference between the effects of slat and flap asymmetry is that (illarge" in the context of this question means not or hardly controllable by normal use of controls): A) flap asymmetry causes a large difference in CLMAX whereas slat asymmetry causes a large rolling moment at any speed. B) flap asymmetry causes a large rolling moment whereas slat asymmetry causes a large yawing moment. C) flap asymmetry causes a large yawing moment whereas slat asymmetry causes a large rolling moment at any speed. D) flap asymmetry causes a large rolling moment at any speed whereas slat asymmetry causes a large difference in CLMAX • Flap asymmetry will give different lift on the wings that causes a large roIling moment. This will happen at any speed since flap extension changes the camber of the wing. Slot asymmetry on the other hand will only be noticeable at very high angles of attack because slats extends the lift coefficient curve. The two wings would therefore have a difference in the max. value of Cc There would be a slight difference in drag, but not enough to be termed "Iarge'~

21135. Airplane ATPL CPL Trailing edge flaps once extended: A) degrade the best angle of glide. B) increase the zero lift angle of attack. C) significantly increase the angle of attack for maximum lift. D) significantly lower the drag. (Refer to figure 087-E724) Tangent to the angle of glide is OIL. Extended flaps increase the drag significantly and will therefore give a larger sinus, which is equal to a bigger - or worse - angle ofglide.

21157. Airplane ATPL CPL When Fowler type trailing edge flaps are extended at a constant angle of attack, the following changes will occur: A) B) C) D)

CL increases and Co remains constant. CL increases and the centre of pressure moves forward. CL and CD increase. CD decreases and the centre of pressure moves aft.

(Refer to figure 087-E708) Flap extension means a higher CL and a higher CD at a constant angle of attack.

(Refer to figure 087-E704) The illustration shows that the lowest critical angle of attack is with flaps extended, next the clean wing and the highest critical angle can be obtained with extended slats.

21097. Airplane ATPL CPL On a large transport aeroplane, the auto-slat system: A) assist the ailerons. B) provides for automatic slat retraction after takeoff. C) ensures that the slats are always extended when the ground / flight system is in the "ground" position.

21161. Airplane ATPL CPL When trailing edge flaps are extended in level flight, the change in pitching moment, ignoring any effects on the tail plane, will be: A) B) C) D)

dependent on CG location. nose up. zero. nose down.

(Refer to figure 087 -E724) Deflecting a trailing edge flap will move the centre of pressure rearwards

1 21014 (8) 121023 (C) 121038 (0) 121057 (C) 121097 (0) 1 21100 (A) 1 21117 (0) 1 21135 (A) 1 21157 (C) 1 21161 (0) 1

01 Subsonic Aerodynamics

(refer to the attached figure). This shift in the location of the centre of pressure will cause a nose down pitching moment as a result of the CP moving further behind the CG.

23270.

Airplane

ATPL

CPL

If flaps are slightly asymmetric this would cause: A) a roll to a given bank angle which may be correctable with rudder. B) a steady rate of roll which maybe correctable with ailerons. e) a steady rate of pitch which may be correctable with elevators. D) a roll to a given bank angle which may be correctable with ailerons. Asymmetric flaps will give a difference in lift on the two wings causing a roll. This roll will be aerodynamically dampened just as an aileron roll giving a steady rate of roll. A roll is corrected by using ailerons.

23271.

Airplane

ATPL

CPL

Because of the reduction in CL when flaps are raised, to maintain a constant lift force: A) the angle of attack must be decreased. B) the angle of attack must be increased. C) the angle of attack must remain the same. D) the nose of the aircraft should be lowered. (Refer to figure 087-£108) Increase CL is done by increasing angle of attack.

23305.

Airplane

ATPL

CPL

The purpose of vortex generators is: A) to delay stall by reducing boundary layer separation. B) to increase the lift of the wing. e) to counteract the effect of the wing tip vortices. D) to delay the stall by reducing the kinetic energy of the boundary layer. Vortex generators are rows ofsmall, thin aerofoil shaped blades which projects vertically into the airstream. They each generate a small vortex which causes the free stream flow of high energy air to mix with and add kinetic energy to the boundary layer. The higher energy level delays the boundary layer separation and thus the stall.

23306.

Airplane

ATPL

CPL

If the increased downwash at the tail plane due to lowering trailing edge flaps is considered in isolation: A) a nose up pitching moment will be generated. B) a nose down pitching moment will be generated. e) the direction of the pitch change will depend on the initial direction of the tail load. D) tail plane angle of attack will be decreased, causing a nose up pitching moment. (Refer to figure 087-£50) As shown in the illustration the increased down wash on the tailplane causes a nose up pitching moment.

23307.

Airplane

ATPL

CPL

Split flaps have the characteristic of: A) increasing the lift and decreasing the drag for takeoff. B) increasing the drag without appreciable increase in lift when moved from intermediate to fully down. C) changing the main plane area and thus reducing the wing loading. D) allowing optimum wing flexing. (Refer to figure 087-£85) Since the split flap does not increase the camber as much as other flap types, the additional lift generated to fully down is limited. However, split flaps create a high amount ofdrag due to the deeper wake.

23308.

Airplane

ATPL

CPL

If the trailing edge flaps are lowered and lAS kept constant, to maintain level flight: A) the nose must be lowered and thrust increased. B) the nose must be raised and thrust increased. e) attitude and thrust must be kept constant. D) attitude must be increased and thrust increased. For explanation refer to question #76672 on page 65.

23309.

Airplane

ATPL

CPL

A slat is: A) a leading edge high lift device, hinged at its forward edge, which increases the camber and leading edge radius of the main aerofoil when deployed. B) a trailing edge device which is automatically deployed by movement of the stagnation point at high angles of attack. e) an auxiliary, cambered aerofoil positioned forward of the main aerofoil so as to form a slot. D) a fixed slot in the leading edge of some older types of aircraft. (Refer to figures 087-£56 and 087-£84) A slat is a small auxiliary aerofoil attached to the leading edge of the wing. When deployed, the slat forms a slot which allows passage of air from the high pressure region below the wing to the low pressure region above it.

23333.

Airplane

ATPL

CPL

Vortex generators are fitted in front of control surfaces to: A) tip stall at low speed for better handling. B) re-energise the boundary layer. C) prevent control surface flutter. D) increase the effective angle of attack. For explanation refer to question #23305 on this page.

23345.

Airplane

ATPL

CPL

A Krueger flap is: A) part of the upper surface of the leading edge, which moves forward. B) part of the lower surface of the leading edge, hinged at its forward edge. e) a flap which extends rearward from the trailing edge. D) a flap which extends from the upper surface of the wing, to increase drag. (Refer to figure 087-£56)

23348.

Airplane

ATPL

CPL

Because of the reduction in CL when the flaps are raised in flight, to maintain level flight, the angle of attack: A) would have to be decreased. B) would have to be increased. e) would be required to remain the same. D) would have to be decreased, then increased. (Refer to figure 087-£108) To maintain level flight at constant lAS, the lift coefficient must remain constant. Retracting flaps will decrease the lift coefficient which means.the angle of attack must be increased.

23349.

Airplane

ATPL

CPL

If flaps are raised in flight while speed and attitude are kept constant: A) the aircraft will gain height. B) the aircraft will sink. C) the aircraft will maintain height. D) the aircraft will stall. (Refer to figure 087 -£108) Raising flaps will decrease the lift coefficient and thus the lift. Keeping speed

1 23270 (8) 1 23271 (8) 123305 (A) 1 23306 (A) 1 23307 (8) 1 23308 (A) 1 23309 (C) 1 23333 (8) 123345 (8) 1 23348 (8) 1 123349 (8) 1

Aviationexam Test Prep Edition 2012 and attitude (angle of attack) constant means that the aircraft will descent.

23364. Airplane ATPL CPL An automatic leading edge slat is operated by: A) B) C) D)

an automatic speed controlled switch. a switch controlled by the pilot. aerodynamic forces acting on the leading edge. changes in dynamic pressure acting on the stagnation point.

Automatic leading edge slats are normally spring loaded. During normal flight the drag will keep the slats in the closed position, but when speed is reduced (and more lift coefficient is required) the springs will deploy the slats.

23366. Airplane ATPL CPL One of the main functions of flaps during an approach and landing is to: A) decrease the angle of descent without increasing the airspeed. B) provide the same amount of lift at a slower speed. C) decrease lift, thus enabling a steeper than normal approach to be made. D) increase lift more than drag. (Refer to figure 081-£98) Flaps increase the lift coefficient and thus allows lower speed with the same amount of/ift.

23420. Airplane ATPL CPL If trailing edge flaps are lowered asymmetrically, this will cause: A) B) C) D)

a nose up pitching moment. a nose down pitching moment. a rolling moment. a yawing moment.

Asymmetric flaps will give a difference in lift on the two wings causing a roll.

23538. Airplane ATPL CPL What would be the effect of taking off with full flaps deployed? A) Acceleration would not be affected and the TOD would be shorter than normal. B) Acceleration would be reduced and the attitude required to climb would be more nose down than normal. C) Acceleration would be reduced because of the extra drag and climb ability would be improved because ofthe extra lift. D) Acceleration would be less, TOD would be less and climb gradient would be improved. (Refer to figure 081-£108) Fully deployed flaps cause an increase in drag, which reduces the acceleration and thus extends the takeoff distance. Climb performance will be reduced because of the increased drag. Sinus to the angle of climb is (T-D)/W, and with excessive D, the angle will be smaller.

23539. Airplane ATPL CPL When flaps are lowered, the downwash behind the wing: A) B) C) D)

decreases and gives a decrease of tail plane effective AOA. increases and gives an increase of tailplane effective AOA. decreases and gives an increase of tail plane effective AOA. increases and gives a decrease of tailplane effective AOA.

(Refer to figure 081-£50) As shown in the illustration the increased downwash on the tailplane causes a nose up pitching moment due to the increased effective angle of attack of the tailplane.

23691. Airplane ATPL CPL Which of the following increases the stall angle? A) slats B) flaps C) spoilers

D) ailerons For explanation refer to question #7813 on page 64.

23698. Airplane ATPL CPL In order to maintain straight and level flight when trailing edge flaps are retracted, the angle of attack must: A) B) C) D)

be increased or decreased depending on type of flap. be decreased. be increased. stay the same because the lift requirement will be the same.

(Refer to figure 081-£108) To maintain level flight, the lift coefficient must remain constant. Retracting flaps will decrease the lift coefficient which means the angle of attack must be increased to maintain CL'

23702. Airplane ATPL CPL On a highly swept back wing with leading edge flaps and leading edge slats, which device would be fitted in the following locations? A) B) C) D)

Slats inboard I flaps outboard. Slats outboard I flaps inboard. Alternating slats and flaps. No preferred positions.

For explanation refer to question #7688 on page 62.

24542. Airplane ATPL CPL The increased upwash experienced at the leading edge of a wing when trailing edge flaps are lowered causes: A) an increase in the angle of attack. B) a rearwards movement of the CG. C) a forward movement ofthe CPo D) a reduction in CLMAX ' An increased upwash will increase the angle of attack since the air flow will come from a more horizontal direction.

26766. Airplane ATPL CPL When a trailing edge flap is lowered during flight from takeoff position to fully down position, one will experience: A) B) C) D)

a large increase in lift and a small increase in drag. a large increase in lift and a large increase in drag. a small increase in lift and a small increase in drag. a small increase in lift and a large increase in drag.

(Refer to figure 081-£108)

As shown in the illustration the lift coefficient increases significantly in the takeoffpOSition for a moderate increase in drag coefficient. The fully down position corresponds to the landing position in the illustration, and it can be seen that only a small increment in lift coefficient gives a considerable increase in drag coefficient.

26802. Airplane ATPL CPL When vortex generators are fitted they will normally be found: A) B) C) D)

near the wing leading edge. towards the wing root to act as a stall inducer. on the underside of the wing towards the leading edge. towards the wing trailing edge.

Vortex generators delay flow separation and aerodynamic stalling; they improve the effectiveness of control surfaces. They are typically installed on the leading edge of a wing in order to maintain steady airflow over the control surfaces at the rear of the wing. They are typically rectangular or triangular, tall enough to protrude above the boundary layer, and run in spanwise lines near the thickest part of the wing. They can be seen on the wings and vertical tails of many airliners. Vortex generators are positioned in such a way that they have an angle of attack with respect to the local airflow.

A vortex generator creates a tip vortex which draws energetic, rapidly-moving air from outside the slow-moving boundary layer into contact with

123364 (C) 123366 (8) 123420 (C) 123538 (8) 123539 (D) 123691 (A) 123698 (C) 1 23702 (8) 1 24542 (A) 1 26766 (D) 1 126802 (A) 1

01 Subsonic Aerodynamics the aircraft skin. The boundary layer normally thickens as it moves along the aircraft surface, reducing the effectiveness of trailing-edge control surfaces; vortex generators can be used to remedy this problem, among others, by re-energizing the boundary layer.

26807.

Airplane

ATPL

CPL

When (in flight) you lower the trailing edge flaps fully down: A) the wing CP moves forward and the LID ratio increases. B) the wing CP moves aft and the LID ratio decreases. C) the stalling angle increases and the LID ratio reduces. D) the stalling angle reduces and the LM ratio increases. (Refer to figure 081-EI24) Deflecting a trailing edge flap will move the centre of pressure rearwards (see illustration). This shift in the location of the centre of pressure will cause a nose down pitching moment. The LID ratio decreases with flaps deployed.

26810.

Airplane

ATPL

CPL

The purpose of deploying leading edge slats is to: A) decrease induced and profile drag. B) decrease the critical angle. C) increase the stalling angle. D) increase profile drag. (Refer to figure 081-E84) Slats increases the critical angle of attack and offers higher values of lift coefficient as seen in the illustration. Of the possible answers, Cis the only appropriate.

26979.

Airplane

ATPL

CPL

232410.

Airplane

ATPL

CPL

An large jet transport aeroplane has the following four flap positions: Up, Take-off, Approach and Landing and two slat positions: Retracted and Extended. Generally speaking, the selection that provides the highest positive contribution to (LMAX is: A) flaps from Take-off to Approach. B) flaps from Up to Take-off. C) flaps from Approach to Landing. D) slats from Retracted to Extended. 232413.

Airplane

ATPL

CPL

The main function of a trailing edge flap is to: A) trim the aeroplane longitudinally. B) alter the position of the centre of gravity. C) increase the angle of attack at which a wing will stall. D) increase the maximum lift coefficient of the wing. 232415.

Airplane

ATPL

CPL

What is the effect on an aeroplane's characteristics of extending Fowler flaps to their fully extended position? A) CD remains constant for a given angle of attack. B) wing area and camber increase. C) wing area remains constant but camber increases. D) CL MAX occurs at a higher angle of attack. For explanation refer to question #4208 on page 61.

Flaps are used in order to: A) decrease stalling speed and reduce max angle of attack thereby achieving a more nose down attitude near and at stalling speed. B) increase max lift coefficient by increasing max angle of attack. C) increase max LID. D) reducing drag. (Refer to figure 081-E98) As seen in the illustration flaps increases the maximum lift coefficient and thus decreases the stalling speed. The maximum lift coefficient is obtained at a lower value of angle of attack compared to the plain profile.

232408.

Airplane

ATPL

CPL

Slat or flap asymmetry occurring after either extension or retraction, may have an effect on controllability since: A) slat and flap asymmetry both cause a large yawing moment. B) slat asymmetry causes a yawing moment, whereas flap asymmetry causes a large rolling moment. C) slat and flap asymmetry both cause a large rolling moment. D) slat asymmetry causes a large rolling moment, whereas flap asymmetry causes a large yawing moment. 232409.

Airplane

ATPL

CPL

The purpose of correctly setting the leading and trailing edge devices on the wing of an aeroplane during take-off, approach and landing is to: A) increase stall speed and CLMAX during take-off, but reduce stall speed with a relatively high drag during approach and landing. B) reduce stall speed and drag during take-off and landing. C) reduce the take-off roll and increase the landing roll. D) reduce stall speed, increase CLMAX with minimum increase in drag for take-off, but with a relatively high drag for approach and landing.

232421.

Airplane

ATPL

CPL

A slotted flap will increase the (LMAX by: A) decreasing the skin friction. B) increasing only the camber of the aerofoil. C) increasing the critical angle of attack. D) increasing the camber of the aerofoil and re-energising the airflow. 232429.

Airplane

ATPL

CPL

From an initial condition of level flight the flaps are retracted at a constant pitch attitude. The aeroplane will subsequently: A) start to sink. B) start to climb. C) start to bank. D) maintain level flight. 232430.

Airplane

ATPL

CPL

From an initial condition of level flight the flaps are extended at a constant pitch attitude. The aeroplane will SUbsequently: A) maintain level flight. B) start to climb. C) start to bank. D) start to sink. 232444.

Airplane

ATPL

CPL

For most jet transport aeroplanes, slat extension has: A) a minor effect on stall speed whereas flap extension has a significant effect. B) the same minor effect on stall speed as flap extension. C) a greater effect on stall speed than flap extension. D) the same significant effect on stall speed as flap extension.

126807 (8) 126810 (C) 126979 (A) 1232408 (8) 1232409 (D) 1232410 (D) 1232413 (D) 1232415 (8) 1232421 (D) 1232429 (A) 1 1232430 (8)1232444 (e) 1

Aviationexam Test Prep Edition 2012

01-10 Means to Reduce the CL - Co Ratio 4257. Airplane ATPL CPL Extending air brakes during an approach will: A) B) C) D)

the adverse yaw from the ailerons.

21180. Airplane ATPL CPL Which statement is correct?

increase induced drag. increase minimum drag speed (VOM1N ). reduce the minimum drag speed (VOMIN). decrease profile drag.

Configuration changes which increase the "parasite area'~ such as undercarriage, flaps or speed brakes, increases parasite drag, increases total drag and decreases VMD .

7720. Airplane ATPL CPL Wing spoiler extension causes: A) B) C) D)

Spoilers consist of movable panels on the upper wing surface, hinged at their forward edge, which can be raised hydraulically. A raised spoiler will disturb the airflow over the wing and reduce lift and increase drag. The reduced lift will increase stall speed, while the increased drag increases both rate ofdescent (ROD = (PR-P)+W) and angle of descent (tane =DIL).

an increase in lift and drag. an increase in lift only. an increase in drag and decrease in lift. decrease in lift and drag.

Spoilers consist of movable panels on the upper wing surface, hinged at their forward edge, which can be raised hydraulically. A raised spoiler will disturb the airflow over the wing, thus reducing the coefficient of lift (decreasing overall lift) and increasing the coefficient of drag (increasing overall drag). If thrust and airspeed is maintained constant the extension of spoiler panels will result in an increased rate of descent. If thrust is maintained constant while maintaining a level flight the airspeed will be reduced.

7871. Airplane ATPL CPL Upon extension of a spoiler on a wing: A) B) C) D)

A) Flap extension reduces the maximum lift/drag ratio thus reducing the minimum rate of descent. B) Spoiler extension increases the stall speed, the minimum rate of descent and the minimum angle of descent. C) Flap extension reduces the stall speed, which increases the maximum glide distance. D) Flap extension has no effect on the minimum rate of descent as this is only affected by TAS.

23328. Airplane ATPL CPL When air brakes are deployed: A) B) C) D)

the minimum drag speed will reduce. the minimum drag speed will remain the same. the lift / drag ratio will remain constant. the minimum drag speed will increase.

(Refer to figure 081-E99) The drag resulting from the operation ofspeed brakes is profile drag, so will not only increase the total drag but will also decrease VMD.

only CL is decreased (Co remains unaffected). Co is increased and CL is decreased. both CL and Co are increased. CD is increased, while CL remains unaffected.

23461. Airplane ATPL CPL Spoiler surfaces on the top surface of a wing when operated symmetrically:

Spoilers consist of movable panels on the upper wing surface, hinged at their forward edge, which can be raised hydraulically. A raised spoiler will disturb the airflow over the wing and reduce CL and increase CD'

15727. Airplane ATPL CPL When spoilers are used as speed brakes:

A) are used to trim the aircraft. B) are for use on landing only, to reduce speed. C) may be used as air brakes in flight. D) cannot be used as air brakes in flight because of excessive buffeting.

Spoilers consist of movable panels on the upper wing surface, hinged at their forward edge, which can be raised hydraulically. A raised spoiler will disturb the airflow over the wing and reduce lift and increase drag.

(Refer to figure 081-E76) Speed brakes are devices to increase the drag of an aircraft when it is required to decelerate quickly or to descent rapidly. Speed brake = spoiler. Typically divided into 2 groups - those that operate in the air (flight spoilers) + those that operate on the ground to aid the deceleration after landing (ground spoilers). On the ground both the ground and flight spoilers deploy when used for the deceleration. When used in the air or on the ground as speed brake the spoilers deploy symmetrically upwards on both wings.

21159. Airplane ATPL CPL When roll spoilers are extended, the part of the wing on which they are mounted:

Spoilers can also aid in controlling the roll of the aircraft together with ailerons.ln this case the spoilers deploy asymmetrically (they deploy upwards only on the down-going wing during the roll manoeuvre and remain stowed on the up-going wing).

A) at same angle of attack, CL remains unaffected. B) at same angle of attack, CD is increased and CL is decreased. C) CLMAX ofthe polar curve is not affected. D) they do not affect wheel braking action during landing.

A) stalls. This causes a difference in lift between both wings, which generates the desired rolling moment. B) experiences extra drag, which generates a yawing moment. The speed difference between both wings generates the desired rolling moment. C) experiences a reduction in lift, which generates the desired rolling moment. In addition there is a local increase in drag, which suppresses adverse yaw. D) is forced downwards as a reaction to the increased drag.

23710. Airplane ATPL CPL The result of spoiler surfaces deploying are: A) lift and drag increases. B) lift and drag decreases. C) lift increases and drag decreases. D) drag increases and lift decreases. For explanation refer to question #15727 on this page.

Spoilers consist of movable panels on the upper wing surface, hinged at their forward edge, which can be raised hydraulically. A raised spoiler will disturb the airflow over the wing and reduce lift and increase drag. Roll spoilers are raised on the wing with the up going aileron (down-going wing), proportionalto aileron input. The reduced lift helps generating the roll moment, while the increased drag gives a benign yaw moment that reduces (or eliminates)

1 4257 (C)

1 7720 (C)

1 7871 (8)

115727 (8) 1 21159 (C) 1 21180 (8) 123328 (A) 123461 (C) 123710 (0) 1

01 Subsonic Aerodynamics

26763. Airplane ATPL CPL Speed brakes are a device used on large transport category aircraft: A) for speed reduction after landing. B) and are an old version of anti block system. C) to increase drag in order to maintain a steeper gradient of descent. D) used at high speeds for turning when a yaw. damper is not installed. Speed brakes are devices to increase the drag of an aircraft when it is required to decelerate quickly or to descent rapidly. Speed brake = spoiler. Typically divided into 2 groups - those that operate in the air (flight spoilers) + those that operate on the ground to aid the deceleration after landing (ground spoilers). On the ground both the ground and flight spoilers deploy when used for the deceleration.

232446. Airplane ATPL CPL Upon extension of a wing spoiler, if the angle of attack remains constant: A) both CL and CD increase. B) CL decreases but CD remains unaffected. C) CD increases and CL decreases. D) CD increases but CL remains unaffected. Airplane ATPL CPL 232448. Wing spoilers are deflected symmetrically in flight in order to:

A) CD increases but CL remains unaffected. B) both CL and CD increase. C) CL decreases but CD remains unaffected. D) CD increases but CL decreases. Spoilers consist of movable panels on the upper wing surface, hinged at their forward edge, which can be raised hydraulically. A raised spoiler will disturb the airflow over the wing, thus reducing the coefficient of lift (decreasing overall lift) and increasing the coefficient of drag (increasing overall drag). If thrust and airspeed is maintained constant the extension of spoiler panels will result in an increased rate ofdescent. If thrust is maintained constant while maintaining a level flight the airspeed will be reduced. This question asks about the effect of spoiler extension on lift and drag while maintaining a constant speed and 19 straight and level flight. The only way how a constant speed and level flight could be achieved in practice after spoiler extension is to increase the thrust and increase the angle of attack - it is the only way how the additional drag created by the extended spoilers can be balanced. By increasing the angle of attack and the thrust the potion of the wing ahead of the spoiler will create more lift (higher CL) while the lift produced by the potion of the wing behind the spoiler will still be "degraded" by the spoiler. The sum of the lift values generated by the area in front and behind the spoiler will then be equal to the overall lift produced by the wing before the spoiler extension. Also, constant speed and level flight implies a constant lift, therefore the correct answer to this type of question would be an increase in drag (CJ and a constant lift (CJ.

232452. Airplane ATPL CPL Upon wing spoiler extension in straight and level flight, ifthe speed and load factor remain constant: A) both lift and drag increase. B) drag increases but lift remains unaffected. C) lift decreases but drag remains unaffected. D) drag increases but lift decreases.

A) decelerate the aeroplane and/or increase its rate of descent. B) assist the ailerons in obtaining a higher roll rate. C) improve glide performance (increase lift /drag ratio). D) prevent aeroplane yaw.

For explanation refer to question #232451 on this page.

232451. Airplane ATPL CPL Upon wing spoiler extension in straight and level flight, if the speed and load factor remain constant:

01-11 The Boundary Layer 4206. Airplane ATPL CPL The transition point located on the wing is the point where: A) airflow starts separating from the wing. B) the boundary layer changes from laminar flow to turbulent flow. C) the static pressure reaches its highest value. D) the airflow changes from subsonic to supersonic flow. (Refer to figure 081-E33)

7674. Airplane ATPL CPL A laminar boundary layer is __ and has __ drag than a turbulent layer: A) thick; more B) thick; less C) thin; more D) thin; less (Refer to figure 081-E33) The turbulent boundary layer with its characteristic eddies gives a greater mixing of the slower moving layers with the faster moving air further away from the surface. This mixing increases the kinetic energy in the boundary layer, but it also thickens and produce more drag.

7721. Airplane ATPL CPL The boundary layer is considered to be turbulent: A) just in front of the transition point. B) between the transition and separation points. C) just aft of the separation point. D) just in front of the centre of pressure. (Refer to figure 081-E33) The boundary layer changes from laminar to turbulent at the transition point. The turbulent boundary layer separates at the separation point.

7875. Airplane ATPL CPL One important advantage a turbulent boundary layer has over a laminar layer is that the turbulent boundary layer: A) has lower skin friction drag. B) is thinner. C) has less tendency to separate from the surface. D) has less energy. The turbulent boundary layer with its characteristic eddies gives a greater mixing of the slower moving layers with the faster moving air further away from the surface. This mixing increases the kinetic energy in the boundary layer that gives it less tendency to separate from the surface. Note: an EDDY is the swirling of a fluid and the reverse current created when the fluid flows past an obstacle.

126763 (C) 1232446 (C) 1232448 (A) 1232451 (A) 1232452 (8) 1 4206 (8)

1 7674 (D)

1 7721 (8) 1 7875 (C) 1

IIDI

Aviationexam Test Prep Edition 2012

15611. Airplane ATPL CPL Which of the following statements about boundary layers is correct? A) The turbulent boundary layer is thinner than the laminar boundary layer. B) The turbulent boundary layer gives a lower skin friction than the laminar boundary layer. C) The turbulent boundary layer will separate more easily than the laminar boundary layer. D) The turbulent boundary layer has more kinetic energy than the laminar boundary layer. For explanation refer to question #23660 on page 55.

15736. Airplane ATPL CPL A laminar boundary layer is a layer, in which: A) B) C) D)

the vortices are weak. the velocity is constant. the temperature varies constantly. no velocity components exist normal to the surface.

In the laminar boundary layer the flow moves parallel to the surface in layers with velocity increasing with the distance from the surface as the molecules travel on top of those below, but there is no movement perpendicular to the surface.

15752. Airplane ATPL CPL After the transition point between the laminar and turbulent boundary layer: A) B) C) D)

the mean speed increases and the friction drag decreases. the boundary layer gets thicker and the speed decreases. the mean speed and friction drag increases. the boundary layer gets thinner and the speed increases.

The turbulent boundary layer with its characteristic eddies gives a greater mixing of the slower moving layers with the faster moving air further away from the surfa'ce, and thus increasing the mean speed in the layer. The higher speed will increase the friction drag.

23610. Airplane ATPL CPL When considering the properties of a laminar and turbulent boundary layer, which of the following statements is correct? A) B) C) D)

Friction drag is the same. Friction drag higher in laminar. Friction drag higher in turbulent. Separation point is most forward with a turbulent layer.

(Refer to figure 081-E33) The turbulent boundary layer with its characteristic eddies gives a greater mixing of the slower moving layers with the faster moving air further away from the surface. This mixing increases the kinetic energy in the boundary layer, but it also thickens and produce more drag.

26812. Airplane ATPL CPL The following takes place at the transition point on a wing: A) the airflow separates completely from the wing surface. B) the boundary layer makes the transition from laminar flow to the turbulent boundary layer. C) the total dynamic and static pressures come to a standstill. D) the laminar flow meets the separation point. (Refer to figure 081-E33)

232334. Airplane ATPL CPL Behind the transition point in a boundary layer: A) the mean speed increases and the friction drag decreases. B) the boundary layer gets thinner and the mean speed increases. C) the boundary layer gets thicker and the mean speed decreases. D) the mean speed and friction drag increase. Airplane ATPL CPL 232335. Which of these statements about boundary layers is correct? A) A laminar boundary layer is thicker than a turbulent one. B) A turbulent boundary layer produces less friction drag than a laminar one. C) Compared with a laminar boundary layer, a turbulent boundary layer is better able to resist a positive pressure gradient before it separates. D) A turbulent boundary layer becomes laminar at the transition point. Airplane ATPL CPL 232336. Which boundary layer, when considering its velocity profile perpendicular to the flow, has the greatest change in velocity close to the surface? A) Laminar boundary layer. B) The boundary layer in the transition between turbulent and laminar. C) No difference. D) Turbulent boundary layer. 232338. Airplane ATPL CPL Which of these statements about boundary layers is correct? A) A turbulent boundary layer produces less friction drag than a laminar one. B) A laminar boundary layer is thinner than a turbulent one. C) Compared with a turbulent boundary layer, a laminar boundary layer is better able to resist a positive pressure gradient before it separates. D) A turbulent boundary layer turns into a laminar one at the transition point. Airplane ATPL CPL 232339. Which of these statements about boundary layers is correct? A) A laminar boundary layer is thicker than a turbulent one. B) A turbulent boundary layer produces more friction drag than a laminar one. C) A turbulent boundary layer turns into a laminar one at the transition point. D) Compared with a turbulent boundary layer, a laminar boundary layer is better able to resist a positive pressure gradient before it separates. Airplane ATPL CPL 232340. Which of these statements about boundary layers is correct? A) A laminar boundary layer turns into a turbulent one at the transition point. B) A turbulent boundary layer produces less friction drag than a laminar one. C) A laminar boundary layer is thicker than a turbulent one. D) Compared with a turbulent boundary layer, a laminar boundary layer is better able to resist a positive pressure gradient before it separates.

1 15611 (0) 115736(0) 115752 (C) 1 23610 (C) 1 26812 (8) 1232334 (0) 1232335 (C) 1232336 (0) 1232338 (8) 1232339 (8) 1 1232340 (A) 1

01 Subsonic Aerodynamics

01-12 Aerodynamic Degradation 4264. Airplane ATPL CPL In which phase of the takeoff is the aerodynamic effect of ice located on the wing leading edge most critical? A) B) C) D)

The takeoff run. The rotation. All phases are equally important. During climb with all engines operating.

The build up of ice on the profile will alter it and the first effect is a reduction in the maximum lift coefficient. This decreases the critical angle of attack. In the last part of the rotation the angle of attack is large and could then exceed the critical value.

7666. Airplane ATPL CPL The effects of very heavy rain (tropical rain) on the aerodynamic characteristics of an aeroplane are: A) B) C) D)

decrease of CLMAX and increase of drag. decrease of CLMAX and decrease of drag. increase of CLMAX and increase of drag. increase of CLMAX and decrease of drag.

If the wing is contaminated with water due to heavy rain, The profile is in practice altered causing the lift characteristics to be degraded. Typically, the value of (LMAX will be significantly lower. Also, the boundary layer may be become turbulent further forward on the wing. This will cause increased drag.

7792. Airplane ATPL CPL Which of the following is the most important result I problem caused by ice formation? A) B) C) D)

Increased drag. Increased weight. Blockage of the controls. Reduction in CLMAX •

All options mentioned are serious, but the reduction in (LMAX is the most important, because reduced (LMAX on the wing will give a higher stalling speed and the decreased ('MAX of the tailplane could cause it to stall when the aircraft is flying at low speed, particularly if the wing down wash is increased as a result offlap extension. Tailplane stall will result in loss oflongitudinal control.

23382. Airplane ATPL CPL Which is the effect of ice, snow or frost formation on an aeroplane? A) B) C) D)

Decreased angle of attack for the stall. Decreased stall speed. Increased tendency to be stable in roll. Increased angle of attack for stall.

(Refer to figure 087-E92) As shown in the illustration, the formation of ice, snow or frost will decrease the critical angle of attack. This will in turn increase stall speed.

23540. Airplane ATPL CPL When considering the approach to an airframe icing induced stall, which ofthe following statements is most correct? A) Can easily be detected by the flight crew. B) Will give the same indications as any other stall. C) Can be so insidious that the pilot may be unaware that the aircraft has stalled. D) Will cause a nose down pitching moment due to the rearward movement of the CP at the stall. The increase in stall speed due to ice formation is not easy to quantify, as the shape of the ice formation is impossible to detect.

23643. Airplane ATPL CPL The effect of rain on drag and stall speed would be to: A) increase I increase. B) increase I decrease. C) decrease I increase. D) decrease I decrease. Rain will contaminate the profile and cause less laminar boundary layer. The stall speed increases, and so does the drag.

27032. Airplane ATPL CPL If ice is present on the leading edge of the wings, it may increase the landing distance due to higher V'h with: A) 5-10%

21188. Airplane ATPL CPL While flying under icing conditions, the largest ice build-up will occur, principally, on: A) B) C) D)

the upper and lower surfaces on the rear of the wing. the frontal areas of the aircraft. the upper and lower rudder surfaces. the pitot and static probes only.

Ice will accumulate first on the parts of the aircraft in the most direct contact with the air flow, i.e. the frontal areas.

23381. Airplane ATPL CPL An accumulation offrost on an aircraft's wing will result in: A) B) C) D)

a decrease in lift and drag. an increase in lift and a decrease in drag. a decrease in lift and an increase in drag. an increase in lift and drag.

B) 10-20% C) 30-40% D) 40-50% Ice can reduce lift by as much as 30% causing the threshold speed to be at least 20% higher to maintain sufficient lift to balance weight. The landing distance is increased by the square of the touch down speed, that is (7,2), = 7,44, or around 40% longer.

232385. Airplane ATPL CPL The most important problem of ice accretion on a transport aeroplane during flight is: A) B) C) D)

reduction in CLMAX • blocking of control surfaces. increase in weight. increase in drag.

Frost on a wing will alter the profile and reduce the lift coefficient. The frost also increase surface roughness and increases the drag coefficient. The result is less lift and more drag.

1 4264 (8) 1 7666 (A) 1 7792 (0) 1 21188 (8) 123381 (C) 1 23382 (A) 123540 (C) 123643 (A) 1 27032 (C) 1232385 (A) 1

Aviationexam Test Prep Edition 2012

02 High Speed Aerodynamics

HIGH SPEED AERODYNAMICS 02-01 Speeds 2630. Airplane ATPL Assuming ISA conditions, which statement with respect to the climb is correct?

decrease, causing the local speed of sound to decrease. Mach number will therefore increase, and while CLMAXis fairly constant, above M 0.4 CLMAXdecreases. From V"g = veL+(Y2pSCLMAX }) it can be seen, that the stall speed will increase.

3780. Airplane ATPL The regime of flight from the critical Mach number up to approximately M = 1.3 is called the:

A) At constant lAS the Mach number decreases. B) At constant Mach number the lAS increases. C) At constant lAS the lAS decreases. D) At constant lAS the Mach number increases.

A) hypersonic range. B) supersonic range. e) transonic range. D) subsonic range.

Increasing altitude means decreasing temperature and thus a lower speed of sound. Mach number is TAS divided by local speed of sound, and since a constant lAS also means lower TAS, the Mach number will decrease. Increasing altitude means that the difference between TAS and lAS increases.

(Refer to figure 081-E80)

3662. Airplane ATPL A jet transport aeroplane is in a straight climb at a constant lAS and constant weight. The operational limit that may be exceeded is:

A) VNE

3788. Airplane ATPL If the altitude is increased and the TAS remains constant in the troposphere under standard atmospheric conditions, the Mach number will: A) not change. B) decrease. e) increase. D) increase or decrease, depends on the type of aeroplane.

B) VMO e)

MMO

D) Vo Climbing with a constant lAS means the margin to the Vs will not change, but the TAS will increase. At the same time the temperature decreases and therefore also the local speed of sound. The Mach number could therefore exceedMMo •

3777. Airplane ATPL The formula for the Mach number is: (a = speed of sound)

The definition of Mach number is true air speed divided by the local speed of sound, or M = TAS + a. The speed of sound varies with the temperature, and since the temperature decreases in the standard troposphere, the speed of sound will decrease with increasing altitude. With constant TAS, the Mach number will therefore increase.

3790. Airplane ATPL An aeroplane is descending at a constant Mach number from FL350. What is the effect on true airspeed?

A) M=lASa B) M=a+ lAS e) M=lAS+a D) M=IAS+a

A) It remains constant. B) It decreases as pressure increases. C) It decreases as altitude decreases. D) It increases as temperature increases.

The definition of Mach number is true air speed divided by the local speed of sound, or M = TAS + a.

3778. Airplane ATPL The speed of sound is affected by the:

Descending from FL 350 means a descent in the troposphere. The Mach number is true air speed divided by the local speed of sound, or M = TAS + a. Rewritten, this gives TAS = M x a. The speed of sound varies with the temperature, and since the temperature increases in the standard troposphere, the speed of sound will increase with decreasing altitude. With constant M, the TAS will therefore increase.

A) pressure of the air. B) density ofthe air. e) temperature of the air. D) humidity of the air. Speed of sound is a = VyRT, where y and Rare constants. This means the speed ofsound is proportional only to the square root of the absolute temperature.

3798. Airplane ATPL The two areas of speed instability in transonic aircraft are: A) above V OMIN' above M OA. B) below V OMIN' M 0,89 to 0,98. e) above VOMIN' M 0,75 to 0,81. D) below V OMIN' above M 1,0.

3779. Airplane ATPL At higher altitudes, the stall speed (lAS): A) decreases until the tropopause. B) decreases. C) remains the same. D) increases. (Refer to figure 081-E81) As altitude is increased at a constant lAS, TAS will increase and temperature

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2630 (D)

I

3662 (C)

I

3777 (C)

I

3778 (e)

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3779 (D)

I

The low area of speed instability is due to the drag curve increasing with decreasing speed below VMO• A slower speed means more thrust. At the high speed area, the speed instability is because instead of an increasing push force being required as speed increases, a pull force becomes necessary to prevent the aircraft accelerating further.

3780 (C)

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3788 (C)

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3790 (D)

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3798 (8)

Aviationexam Test Prep Edition 2012

3814. Airplane ATPL In the transonic range the are strongly determined by the: A) B) C) D)

aeroplane

characteristics

CAS. TAS. lAS. Mach number.

A) EAS remains the same. B) EASfalls. C) EAS rises. D) The effect depends on the temperature.

The aeroplane characteristics in the transonic region are influenced by the degree of compressibility. The Mach number is a measure of compressibility.

3818. Airplane ATPL Climbing at a constant Mach number up to FL350 the TAS will: A) B) C) D)

decrease. first increase, then remain constant. increase. remain constant.

Climbing up to FL 350 means a climb in the troposphere. The Mach number is true air speed (TAS) divided by the local speed of sound (a), or M = TAS + a. Rewritten, this gives TAS = M x a. The speed of sound varies proportionally with the square root of the absolute temperature, and since the temperature decreases in the standard troposphere, the speed of sound will decrease with increasing altitude (up to 71,5 km /37.700 ft). Therefore, with constant M and increasing altitude the TAS will decrease.

3826. Airplane ATPL Theflight Mach number is 0,8 and the TAS is 400 kts. The speed of sound is: A) B) C) D)

480 kts 320 kts 500 kts 600 kts

3839. Airplane ATPL Compressibility effects depend on:

The higher the altitude the greater the correction and consequently the more the lAS will overread when holding a constant lAS.

21034. Airplane ATPL Assuming ISA conditions, climbing at a constant Mach number up the tropopause the TAS will: A) first increase, then decrease. B) decrease. C) increase. D) remain constant. The Mach number is true air speed divided by the local speed of sound, or M = TAS + a. Rewritten, this gives TAS = M x a. The speed of sound varies with the temperature, and since the temperature decreases in the troposphere, the speed of sound will decrease with increasing altitude. With constant M, the TAS will therefore decrease.

A) B) C) D)

remain constant. decrease initially and increase subsequently. increase. increase initially and remain constant subsequently.

The Mach number is true air speed divided by the local speed of sound, or M = TAS + a. Constant lAS during a climb means maintaining a constant dynamic pressure, ~plf2, where V is TAS. Density decreases with altitude, so to maintain the same dynamic pressure, TAS increases. The speed of sound varies with the temperature, and since the temperature decreases in the troposphere, the speed of sound will decrease with increasing altitude. In total, since TAS increases and a decreases, the Mach number will increase.

lAS EAS TAS Mach number

One of the most important Hnumbers" in aerodynamics is the Mach number, the relation between the speed regarding the speed of sound. It is the governing Hnumber': aside from the "Re-" number for subsonic airflow, which determines the behaviour of fluids. And this is the reason, why it depends predominantlyon the Mach Number, whether we have compressibility or not. You can also describe the Mach number with dynamic pressure q (so in a way your CAS): Mach number =const. x v(q + ps) ps =static pressure q = dynamic pressure const. = constant

So it is not only the CAS, you must also have a look on the prevailing static pressure at the time, so the answer is Mach number.

3861. Airplane ATPL Which statement with respect to the speed of sound is correct? A) B) C) D)

(Refer to figure 081-E128) Equivalent airspeed (EAS) is the airspeed at sea level which represents the same dynamic pressure as that flying at the true airspeed (TAS) at altitude. At sea level EAS is the same as true airspeed (TAS) and calibrated airspeed (CAS). At high altitude, EAS may be obtained from CAS by correcting for compressibilityerror. EAS = TAS x v(Actual Air Density + Standard Air Density).

21043. Airplane ATPL During a climb at a constant lAS, the Mach number will:

From the formula for Mach number, M = TAS + a, the local speed of sound can be expressed as: a = TAS + M.ln this case, the speed of sound is calculated as a = 400 kts + 0,8 = 500 kts.

A) B) C) D)

4213. Airplane ATPL What is the effect on EAS as height is increased when you are holding a constant lAS?

Varies with the square root of the absolute temperature. Increases always if the density of the air decreases. Is independent of altitude. Doubles if the temperature increases from go to 36°C.

For explanation refer to question #3778 on page 75.

21124. Airplane ATPL The Mach number is the ratio between the: A) TAS of the aeroplane and the speed of sound at sea level. B) TAS of the aeroplane and speed of sound of the undisturbed flow. C) lAS of the aeroplane and the speed of sound of the undisturbed flow. D) lAS of the aeroplane and the speed of sound at sea level. For explanation refer to question #3777 on page 75.

21136. Airplane Transonic speed is:

ATPL

A) a speed at which locally around the aeroplane both supersonic and subsonic speeds exist. B) a speed at which locally an oblique shock wave has developed in the flow along the aeroplane. C) a speed at which compressibility effects are first noticeable. D) the speed range between MCRIT and MMo' (Refer to figure 081-E80) As shown in the illustration, the transonic speed range is from M 0.75 to M 1.2, and in that range the local Mach number (M) is both less than and higher than Mach 1.

1 3814 (D)

EI

1 3818 (A)

1 3826 (C) 1 3839 (D) 1 3861 (A)

1 4213 (8)

121034 (8) 121043 (C) 1 21124 (8) 1 21136 (A) 1

02 High Speed Aerodynamics 23274. Airplane ATPL An aircraft flying at M 0,5 would be flying at: A) half the speed of sound at ground level only. B) half the speed of sound at the tropopause only. C) half the speed of sound under all conditions in the atmosphere. D) half the speed of sound at sea level only. The definition of Mach number is true air speed divided by the local speed of sound, or M = TAS + a. Flying Mach 0,5 is therefore flying at half the speed ofsound in that level of the atmosphere.

23503. Airplane ATPL The Mach number corresponding to a given TAS will: A) B) C) D)

be greater if temperature increases. be less iftemperature increases. be the same at all temperatures. temperature does not affect the Mach number because it is a ratio.

Speed of sound is a = VyRT, where y and R are constants. This means the speed ofsound is proportional to the square root of the absolute temperature. A higher temperature means therefore a higher speed of sound. Mach number is TAS + a, so a higher temperature will at a given TAS mean a lower Mach number.

23504. Airplane ATPL For a constant flight level and lAS, if the OAT increases, the Mach number will: A) B) C) D)

increase decrease remain constant remain constant initially, then increase.

The Mach number is true air speed (TAS) divided by the local speed of sound (a), or M = TAS + a. Constant lAS means maintaining a constant dynamic pressure, *pIP, where V is TAS. Density decreases with increasing temperature, so to maintain the same dynamic pressure, TAS increases with the square root of the temperature. The speed of sound is proportional to the square root of the absolute temperature. If the temperature increases, speed of sound will increase and TAS also increase. In total, the Mach number M =TAS + a remains constant.

23553. Airplane ATPL VMO can be exceeded in a descent at a constant Mach number because: A) VMO is an lAS and descending at a constant Mach will require a decrease in TAS which will reduce dynamic pressure. B) as altitude is reduced the speed of sound will increase which increases lAS. C) as altitude decreases the ASI will start to under-read due to the increasing air density. D) VMO is an lAS and descending at a constant Mach will require an increase in TAS which will increase dynamic pressure. The Mach number is true air speed (TAS) divided by the local speed of sound (a), or M = TAS + a. The speed of sound is proportional to the square root of the absolute temperature. In a descent the temperature increases, so descending with constant Mach number means increasing TAS. VMO value is represented by lAS, but an lAS is also a measurement of the dynamic pressure, &fracI2;ρlP, where V is TAS. In the descent the density increases, and as already determined, so does the TAS. The result is, that VMO could easily be exceeded.

23604. Airplane ATPL An aircraft is descending at a constant Mach number and a constant weight. Which of the following operational speed limitations may likely be exceeded?

A) VMO B) VNE C)

MMO

D) VD

For explanation refer to question #23553 on this page.

23619. Airplane ATPL The speed of sound is determined only by: A) density B) humidity C) pressure D) temperature For explanation refer to question #3778 on page 75.

23640. Airplane ATPL In the transonic speed range, what affects the flight handling characteristics? A) lAS B) CAS C) TAS D) Mach number The transonic speed range is determined by the Mach number, so the flight handling characteristics (e.g. tuck under) depend on the Mach number.

23680. Airplane ATPL What happens to Mach number if lAS is increased when flying at FL390? A) B) C) D)

Remains constant. Increases. Decreases. Depends on the OAT.

The Mach number is true air speed divided by the local speed of sound, or M = TAS + a. The speed of sound is proportional to the square root of the absolute temperature. Maintaining altitude means constant temperature, so the speed of sound will be constant. lAS is a measurement of the dynamic pressure, *pIP, where V is TAS. Constant altitude means the density is also constant, so an increased lAS means an increase in TAS. The result is, that the Mach number increases.

24459. Airplane In a steady climb:

ATPL

A) at a steady lAS, Mach number remains constant because Mach number is only proportional to TAS and inversely proportional to the local speed of sound. B) at steady lAS, Mach number will increase. C) at a steady lAS, Mach number will remain constant because the local speed of sound is proportional to the square root of the absolute temperature. D) at a steady lAS, Mach number will decrease because the absolute temperature will decrease. For explanation refer to question #21043 on page 76.

26818. Airplane ATPL How does temperature influence the speed of sound? A) B) C) D)

Speed of sound increases with temperature increase. Speed of sound decreases with temperature increase. Speed of sound is not influenced by temperature. Speed of sound remains constant.

Speed of sound is a = V(y x R x T), where y is the ratio of specific heat which is approximately 1,4 for air; R is the universal gas constant of 287 J/kg K; and T is the absolute temperature. Speed of sound thus increases with increasing temperature.

232463. Airplane ATPL if the Mach number is 0,8 and the TAS is 480 kts, what is the speed of sound? A) B) C) D)

750 kts. 560 kts. 600 kts. 384 kts.

1 23274 (C) 123503 (8) 123504 (C) 123553 (0) 123604 (A) 1 23619 (0) 123640 (0) 1 23680 (8) 1 24459 (8) 1 26818 (A) 1 1232463 (C) 1

Aviationexam Test Prep Edition 2012

232469. Airplane ATPL How does the Mach number change during a climb at constant lAS from sea level to 40.000 ft? A) Initially remains constant until approximately 25.000 ft and then decreases with increasing altitude. B) Increases with increasing altitude. C) Initially remains constant until approximately 25.000 ft and then increases with increasing altitude. D) Decreases with increasing altitude. Airplane ATPL 232470. Assuming ISA conditions and a descent below the tropopause at constant Mach number and aeroplane mass, the: A) lift coefficient decreases. B) lAS decreases. C) TAS remains constant. D) lift coefficient increases. 232473. Airplane ATPL During a descent at a constant Mach number (assume zero thrust and standard atmospheric conditions): A) the pitch angle will increase. B) the descent angle will decrease. C) the TAS will decrease. D) the angle of attack will decrease. Airplane ATPL 232477. The speed range from approximately M ly M = 5 is called the:

=1.3 to approximate-

A) transonic range. B) subsonic range. C) hypersonic range. D) supersonic range. 232479. Airplane ATPL A transonic Mach number is a Mach number: A) between the buffet onset Mach number and the Mach number corresponding to total supersonic flow. B) at which only supersonic local speeds occur. C) in the range between MCRIT and MMo' D) at which both subsonic and supersonic local speeds occur. 232480. Airplane ATPL Which of these statements about the transonic speed range is correct? A) The airflow everywhere around the aeroplane is subsonic. B) The airflow everywhere around the aeroplane is supersonic. C) The transonic speed range starts at MCRIT and extends to Mach numbers above M = 1. D) The transonic speed range starts at M = 0,5 and ends at McRlr

232481. Airplane ATPL Regarding the transonic speed range: A) it starts at a Mach number equal to 1. B) it starts at a Mach number just above 1. C) both subsonic and supersonic speeds exist in the flow around the aeroplane. D) it starts at McRITand extends to Mach number equal to 1. 232482. Airplane ATPL The subsonic speed range: A) ends at a Mach number just above M = 1. B) implies both subsonic and supersonic speeds exist in the flow around the aeroplane. C) ends at M = 1. D) ends at McRlr 232483. Airplane ATPL Which of these statements about the supersonic speed range is correct? A) The airflow everywhere around the aeroplane is supersonic. B) The supersonic speed range starts at a Mach number below M = 1 and extends to Mach numbers above M = 1. C) The airflow around the aeroplane is transonic. D) The supersonic speed range starts at M = 1 and ends at McRlr 232534. Airplane ATPL If lAS remains constant, the effect of decreasing aeroplane mass is that M CRIT: A) remains unchanged. B) decreases as altitude increases and increases as altitude decreases. C) increases. D) decreases, assuming the temperature remains constant. 232536. Airplane ATPL Whilst flying at a constant lAS and at n mass decreases, the value of M CRIT:

=1, as the aeroplane

A) remains constant. B) decreases. C) is independent of the angle of attack. D) increases. 232868. Airplane ATPL For most jet transport aeroplanes, the maximum operating limit speed, VMO: A) is replaced by MMO at higher altitudes. B) is expressed as a true air speed. C) is lower than VNE' D) is equal to VD'

02-02 Shock Waves 2632. Airplane ATPL When the air is passing through an expansion wave the static temperature will: A) decrease. B) increase.

EI

C) stay constant.

D) decrease and beyond a certain Mach number start increasing again. (Refer to figure 087-E74) As the name implies, the supersonic flow expands through an expansion wave.

1232469(8) 1232470 (A) 1232473(0) 1232477(0) 1232479(0) 1232480 (C) 1232481 (C) 1232482(0) 1232483 (A) 1232534 (C) 1 1232536(0) 1232868 (A) 1 2632(A) 1

02 High Speed Aerodynamics The velocity increases while the pressure, density and temperature decrease (the opposite behavior than through a shock wave). The local speed of sound, being proportional with the temperature, will decrease. With an increased TA5 and a lower speed ofsound, the Mach number increases.

3586. Airplane ATPL In case of supersonic flow retarded by a normal shock wave a high efficiency (low loss in total pressure) can be obtained if the Mach number in front ofthe shock is: A) B) C) D)

3590. Airplane ATPL Shockwaves at M FS above MDET will be: sufficient to slow the local airflow to subsonic values. normal. oblique. detached.

3593. Airplane ATPL At what speed does the front of a shock wave move across the Earth's surface? The speed of sound at ground level. The ground speed of the aeroplane. The speed of sound at flight level. The true air speed of the aeroplane.

Its ground speed is therefore the same as the ground speed of the aircraft.

3594. Airplane ATPL When a supersonic airflow passes through an oblique shockwave static pressure will __ and temperature will ___ • rise; rise fall; rise fall; fall rise;fall

a

1) The temperature in front of an expansion wave is higher than the temperature behind it. 2) The speed in front of an expansion wave is higher than the speed behind it. 1) is incorrect; 2) is incorrect. 1) is correct; 2) is correct. 1) is incorrect; 2) is correct. 1) is correct; 2) is incorrect.

The compression of air immediately in front of the aircraft raises the air temperature. The effect of this increase in temperature is of course to increase the local speed of sound in this area which results in the propagation of waves ahead of the aircraft at a rate faster than the normal rate (speed of sound). This increased local speed of sound extends ahead of the aircraft to a point where temperature is restored to ambient. As the aircraft speed approaches Mach 1 the waves ahead of the object tend to form as discussed above, but they will do this well ahead of the object to form the bow wave. As the aircraft speed exceeds Mach 1 the increased speed of wave propagation ahead of the aircraft is offset by the increased speed of the aircraft, now travelling at a speed faster than Mach 1. 50 although the forward waves are projected out faster than a speed equal to Mach 1, due to the increased speed of sound, the aircraft partly 'catches up: The effect of all this is to bring the bow wave closer to the aircraft until the aircraft is travelling at such a speed that the bow wave 'attaches'to the leading edge.

The blunter the leading edge, the greater the compression and temperature rise, and consequently the greater the increase in local speed of sound. The greater the increase in the local speed of sound, the more difficult it is for the bow wave to attach.

3605. Airplane ATPL Which statement about an expansion wave in a supersonic flow is correct?

I

3593 (8)

I

3594 (A)

A) B) C) D)

1) is correct; 2) is correct. 1) is correct; 2) is incorrect. 1) is incorrect; 2) is correct. 1) is incorrect; 2) is incorrect.

For explanation refer to question #2632 on page 7B.

3611. Airplane ATPL How will the density and static temperature change in a supersonic flow from a position in front of a shock wave to behind it? A) B) C) D)

Density will Density will Density will Density will

increase, temperature will increase. increase, temperature will decrease. decrease, temperature will increase. decrease, temperature will decrease.

(Refer to figure OBI-E74) The normal shock wave is a boundary between a supersonic and a subsonic flow. Behind the shock wave the Mach number is therefore less than Mach 1. Normal shock waves will occur at any part of the aircraft where the local Mach number exceeds Mach 1. When the flow passes through a shock wave, the static pressure, density and the temperature increase and the velocity decreases.

For explanation refer to question #2632 on page 7B.

3586 (8) [3590 (C)

a free stream Mach number just below M = 1. a free stream Mach number exactly equal to 1. a free stream Mach number just above M = 1. the critical Mach number.

(Refer to figure OBI-E46) At Mach 1.0 the air receives no warning of the aircraft approaching,

shock wave,

3596. Airplane ATPL Which statement about an expansion wave in supersonic flow is correct?

I

A) B) C) D)

1) The density in front of an expansion wave is higher than behind. 2) The static pressure in front of an expansion wave is higher than behind it.

(Refer to figure OBI-E74) The pressure and temperature will increase through both oblique and normal.

A) B) C) D)

For explanation refer to question #2632 on page 7B.

The ability of the bow wave to attach is determined by the flow ahead of the aircraft, which in turn is determined by the shape of the aircraft or wing.

A shock wave will obviously travel with the same speed as the aircraft.

A) B) C) D)

decreased or increased, depending on Mach number. decreased. increased. unchanged.

and it would have to turn through a right angle to flow around the leading edge, which is not possible in the distance available. The flow velocity therefore decelerates to subsonic and a normal shock wave forms, the bow wave.

(Refer to figure OBHBO) Detachment Mach number (MDd is the upper limit of the transonic region (see illustration). At free stream Mach numbers (MF1 above MDETmeans that all values of the local Mach number is supersonic, and all shock waves are therefore oblique (no deceleration to subsonic).

A) B) C) D)

A) B) C) D)

3598. Airplane ATPL The bow wave will first appear at:

high (supersonic). small but still supersonic. lower than 1. exactly 1.

The Mach number must be over 1 for a normal shock wave to form. The greater the Mach number above 1 ahead of the shock wave, the greater the reduction in velocity, and hence the greater the energy loss.

A) B) C) D)

3597. Airplane ATPL When air has passed an expansion wave, the static pressure is:

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3596 (0)

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3597 (8)

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3598 (C)

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3605 (A)

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3611 (A)

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Aviationexam Test Prep Edition 2012 The total pressure being the sum of the static pressure and dynamic pressure ('hp1f') will thus decrease. The energy required for these changes means a decrease in the kinetic energy of the flow.

3614. Airplane ATPL When the air is passing through an expansion wave, the Mach number will: A) decrease. B) increase. e) stay constant. D) decrease and beyond a certain Mach number start increasing again. For explanation refer to question #2632 on page 78.

3617. Airplane ATPL If the Mach number of an aeroplane in supersonic flight is increased, the shock wave angles will: A) decreases, then increases above certain Mach number. B) increase. e) stay constant. D) decrease. (Refer to figures 087-£72 and 087-£73) When travelling at supersonic speeds the Mach cone represents the limit of travel of the pressure disturbances created by the aircraft, anything forward of the Mach cone cannot be influenced by the disturbance. Sinus to the Mach cone semi-angle f1 is sin f1 = 7 + M, where M is the Mach number. Increasing speed means a higher Mach number, and thus a smaller semi-angle.

3769. Airplane ATPL When air has passed through a shock wave, the speed of sound is? A) Decreased. B) Not affected. e) Increased. D) Decreased and beyond a certain Mach number start increasing again. (Refer to figure 087-£74) The temperature increases through a shock wave. Speed of sound is proportional to the square root of the absolute temperature, and it will therefore increase.

3773. Airplane ATPL Compared with an oblique shock wave at the same Mach number a normal shock wave has a: A) smaller compression. B) higher expansion. e) higher compression. D) smaller expansion. (Refer to figure 087-£74) The changes through an oblique shock wave are less abrupt than through a normal shock wave. The increase in pressure is therefore less through an oblique than through a normal shock wave.

3789. Airplane ATPL The least energy loss through a normal shock wave occurs when the local Mach number is: A) well above M 1,0. B) just above M 1,0. e) just below M 1,0. D) exactly M 1,0.

3795. Airplane ATPL When the air has passed through a normal shock wave 3614 (8) 3815 (0)

A) Higher than before. B) Lower than before but still greater than 1. e) Equal to 1. D) Less than 1. (Refer to figure 087-£74) Whenever supersonic airflow is slowed to subsonic speed without change in direction, a normal shock wave will form as a boundary between the supersonic and subsonic region.

3796. Airplane ATPL In the transonic range lift will decrease at the shock stall duetothe: A) first appearance of a shock wave at the upper side ofthewing. B) attachment of the shock wave on the trailing edge of the wing. e) separation of the boundary layer at the shock waves. D) appearance of the bow wave. (Refer to figure 087-£26) Shock stall is the separation of the boundary layer behind a normal shock wave caused by the increase in static pressure and reduction of energy of the airstream that happens through the shock wave. This will cause a reduction in lift as shown in the illustration.

3806. Airplane ATPL If an aeroplane is flying at transonic speed with increasing Mach number the shock wave on the upper side of the wing: A) moves into leading edge direction. B) moves into trailing edge direction. e) stays all the time at the same position. D) disappears. (Refer to figure 087-£26)

3807. Airplane ATPL Which statement is correct about a normal shock wave? A) The airflow expands when passing the aerofoil. B) The airflow changes direction. C) The airflow changes from subsonic to supersonic. D) The airflow changes from supersonic to subsonic. For explanation refer to question #3671 on page 79.

3813. Airplane Shock stall is:

ATPL

A) separation ofthe flow behind the bow wave. B) separation of the boundary layer behind the shock wave. e) separation of the flow at high angles of attack and at high Mach numbers. D) separation of the flow at the trailing edge of the wing at high Mach numbers. (Refer to figure 087-£25) Shock stall is the separation of the boundary layer behind a normal shock wave caused by the increase in static pressure and reduction of energy of the airstream that happens through the shock wave. It occurs when the critical Mach number is exceeded, but since this is at very high speed, the angle of attack is small.

3815. Airplane ATPL The loss of total pressure in a shock wave is due to the fact that:

(Refer to figure 087-£74) Minimum energy loss through a normal shock wave will occur when the Mach number of the airflow in front of the shock wave is small, but supersonic.

I I

the Mach number is?

I I

3617 (0)

I

3769 (C)

I

3773 (C)

I

A) the friction in the boundary layer is higher. B) the speed reduction is too high. e) the static pressure decrease is comparatively high. D) kinetic energy in the flow is changed into heat energy. For explanation refer to question #3671 on page 79.

3789 (8)

I

3795 (0)

I

3796 (C)

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3806 (8)

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3807 (0)

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3813 (8)

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02 High Speed Aerodynamics 3817. Airplane ATPL A shock stall occurs when laminar flow breaks down:

A) behind the shock wave. B) behind the trailing edge. e) behind the leading edge. D) at a high angle of attack and high Mach number. Shock stall is the separation of the boundary layer behind a normal shock wave caused by the increase in static pressure and reduction of energy of the airstream that happens through the shock wave.

Airplane ATPL When the Mach number is slowly increased in straight and level flight the first shock waves will occur: 3827.

A) on the lower surface of the wing. B) on the upper surface at the wing root. e) somewhere on the fin. D) somewhere on the horizontal tail.

3865. Airplane ATPL When the air is passing through a shock wave, the density will:

A) decrease and beyond a certain Mach number start increasing again. B) decrease. e) stay constant. D) increase. For explanation refer to question #3611 on page 79.

3866. Airplane ATPL At what speed does a shock wave move forward over the ground?

A) Speed of sound at ground level. B) Flight level airspeed. e) Aircraft ground speed. D) AircraftTAS. For explanation refer to question #3593 on page 79.

Normal shock waves will occur at any part of the aircraft where the local Mach number exceeds Mach 1. This will be at the upper side of the wing where the local thickness to chord ratio is greatest = at the wing root. When the flow passes through a shock wave, the static pressure, density and the temperature increase and the velocity decreases. The energy required for these changes means a decrease in the kinetic energy of the flow.

3843. Airplane ATPL Compared with an oblique shock wave a normal shock wave has a:

A) higher total temperature. B) higher total pressure. e) higher loss in total pressure. D) lower static temperature.

15730. Airplane ATPL In supersonic flight, all an aeroplane are:

disturbances

produced

A) in front of the aeroplane. B) very weak and negligible. C) in between a conical area, depending on the Mach number. D) outside the conical area depending on the Mach number. For explanation refer to question #3677 on page 80.

21013. Airplane ATPL A normal shock wave is a discontinuity plane:

For explanation refer to question #3773 on page 80.

3851. Airplane ATPL Just above the critical Mach number the first evidence of a shock wave will appear at the:

A) upper side of the wing. B) lower side of the wing. e) leading edge of the wing. D) trailing edge of the wing. The first occurrence of shock waves will be where the local speed is highest. This will be at the upper side of the wing.

Airplane ATPL Air passes a normal shock wave. Which of the following statements is correct? 3856.

A) The temperature increases. B) The pressure decreases. C) The temperature decreases. D) The velocity increases.

A) across which the pressure drops suddenly. B) across which the temperature drops suddenly. e) that is always normal to the local flow. D) that is always normal to the surface. (Refer to figure 081-£74) The normal shock wave gets its name from the fact it is perpendicular (normal) to the local flow direction.

21177. Airplane ATPL Which statement is correct regarding a shock wave on a lift generating wing?

A) It is located at the greatest wing thickness when the aeroplane reaches the speed of sound. B) It reaches its highest strength when flying at the critical Mach number. C) It moves forward when the Mach number is increased. D) It moves slightly aft when an aileron is deflected downward. Deflecting the aileron downward will increase the camber of the wing and thus accelerate the flow over the upper surface. The supersonic region on the upper side will therefore increase and the normal shock wave, being a boundary between supersonic and subsonic flow, will move slightly aft.

For explanation refer to question #3611 on page 79.

23505.

Airplane ATPL When the air is passing through a shock wave, the static temperature will: 3864.

A) increase. B) decrease. C) stay constant. D) decrease and beyond a certain Mach number start increasing again.

Airplane

ATPL

At MeR1l' a shockwave will appear first: A) at the leading edge. B) near to the point of maximum wing thickness. e) at the trailing edge. D) on the underside of the wing. For explanation refer to question #3827 on this page.

For explanation refer to question #3611 on page 79.

1 3817 (A) 1 3827 (8) 1 3843 (C) 1 3851 (A) 1 21177 (0) 123505 (8) 1

by

1 3856 (A) 1 3864 (A) 1 3865 (D) 1 3866 (C) 115730 (C) 1 21013 (C) 1

Aviationexam Test Prep Edition 2012 23517. Airplane ATPL The effect of a shock wave on control surface hinge moment will be:

A) none on powered flying controls, reversal on manual controls .. B) none, the shock wave forms forward of the flying control surfaces. C) stalling ofthe control surfaces. D) rapid fluctuation of hinge moments, causing a high frequency "buzz". If a shock wave is situated near to a control hinge a control movement may cause the shock wave to move over the hinge, resulting in rapid changes of hinge moment which can set up an oscillation of the control surface called control buzz. 23518.

Airplane

ATPL

The velocity behind a (i) normal and an (ii) oblique shock wave is: A) B) C) D)

(i) decreased to subsonic; (ii) decreased but still supersonic. (i) increased to supersonic; (ii) decreased to subsonic. (i) decreased but still supersonic; (ii) increased to supersonic. (i) increased to supersonic; (ii) increased but still subsonic.

(Refer to figure 081-£74) The flow becomes subsonic when passing a normal shock wave, whereas it stays supersonic behind an oblique shockwave. 23556.

Airplane

Static pressure increases/temperature decreases. Static pressure decreases/temperature decreases. Static pressure decreases/temperature increases. Static pressure increases/temperature increases.

(Refer to figure 081-£74)

Airplane ATPL A normal shock wave: 23613.

A) is a discontinuity plane which is always normal to the surface. B) develops anytime an aircraft is in the transonic range. C) is a discontinuity plane where pressure changes. D) none of the above. The free stream Mach number at which the local velocity first reaches Mach 1 is called the Critical Mach Number. The transonic speed range begins at this Mach number, and ends when the flow over the entire aircraft is supersonic. In the transonic range there will therefore be locations where the supersonic flow is retarded to subsonic, and this happens through a normal shock wave. 23679.

Airplane

ATPL

What is a normal shock wave perpendicular to? A) B) C) D)

A) not move. B) move towards the leading edge. C) disappear. D) move towards the trailing edge. 232488.

Airplane

ATPL

Which of these statements about Mcrit is correct? A) Shock waves cannot occur at speeds below M cRir B) Flight at any speed above MCRIT causes severe vibration of the aeroplane. C) As speed increases above MCRIT' parasite drag decreases rapidly. D) Mcrit is always greater than 1. 232489. Airplane ATPL A shock wave on a lift generating wing will:

A) move forward as Mach number is increased. B) reach its highest strength when flying at the critical Mach number. C) be situated at the greatest wing thickness when the aeroplane reaches the speed of sound. D) move slightly aft in front of a downward deflecting aileron.

ATPL

What happens to the pressure and temperature of supersonic airflow through an oblique shock wave? A) B) C) D)

232487. Airplane ATPL As the Mach number increases in straight and level flight, a shock wave on the upper surface of the wing will:

Angle of attack. Angle of incidence. Aircraft longitudinal axis. The relative airflow.

For explanation refer to question #27013 on page 81. 25469. Airplane ATPL At what speed do shock waves occur on most aerofoils?

232498.

Airplane

ATPL

What is the effect of aeroplane mass on shock wave intensity at constant Mach number? A) Increasing mass increases shock wave intensity. B) A change in mass does not influence shock wave intensity. C) Decreasing mass increases shock wave intensity at below standard temperatures. D) Decreasing mass increases shock wave intensity. 232499. Airplane ATPL When supersonic airflow passes through an oblique shock wave, how do ___ static pressure, __ density, and ___ local speed of sound change?

A) increases; increases; increases B) decreases; decreases: decreases C) increases: increases: decreases D) remains constant; decreases; increases 232502.

Airplane

ATPL

Which of these statements about an oblique shock wave are correct or incorrect? I. The static temperature in front of an oblique shock wave is lower than behind it. II. The static pressure in front of an oblique shock wave is lower than behind it. A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is incorrect.

A) MO,99 B) MO,5 C) M 1,15 D) M 0,85 Because the velocity increases over the top surface of an aerofoi! it locally reaches Mach 1 at a lower Mach number than the free stream velocity. For most aerofoi!s the critical Mach number is around M 0.85.

1 23517 (0) 1 23518 (A) 123556 (0) 1 23613 (8) 123679 (0) 125469 (0) 1232487 (0) 1232488 (A) 1232489 (0) 1232498 (A) 1 1232499 (A) 1232502 (A) 1

02 High Speed Aerodynamics

232503. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect? I. The static temperature in front of an oblique shock wave is higher than behind it. II. The static pressure in front of an oblique shock wave is higher than behind it. A) I is incorrect, II is incorrect. B) I is correct, II is correct. C) I is incorrect, II is correct. D) I is correct, II is incorrect.

232504. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect? I. The static temperature in front of an oblique shock wave is higher than behind it. II. The static pressure in front of an oblique shock wave is lower than behind it. A) I is incorrect, II is correct. B) I is correct, II is correct. C) I is incorrect, II is incorrect. D) I is correct, II is incorrect.

232505. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect? . I. The static temperature in front of an oblique shock wave is lower than behind it. II. The static pressure in front of an oblique shock wave is higher than behind it. A) B) C) D)

I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is correct. I is correct, II is incorrect.

232506. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect? I. The density in front of an oblique shock wave is lower than behind it. II. The total pressure in front of an oblique shock wave is higher than behind it. A) I is incorrect, II is incorrect. B) I is incorrect, II is correct. C) I is correct, II is correct. D) I is correct, II is incorrect.

232507. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect? I. The density in front of an oblique shock wave is higher than behind it. II. The total pressure in front of an oblique shock wave is lower than behind it. A) I is correct, II is correct. B) I is incorrect, II is incorrect. C) I is correct, II is incorrect. D) I is incorrect, II is correct.

232508. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect? I. The density in front of an oblique shock wave is higher than behind it. II. The total pressure in front of an oblique shock wave is higher than behind it. A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct.

232509. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect? I. The density in front of an oblique shock wave is lower than behind it. II. The total pressure in front of an oblique shock wave is lower than behind it. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is correct. I is incorrect, II is correct. I is correct, II is incorrect.

232510. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect? I. The local speed of sound in front of an oblique shock wave is lower than behind it. II. The Mach number in front of an oblique shock wave is higher than behind it. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is correct. I is incorrect, II is correct. I is correct, II is incorrect.

232511. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect? I. The local speed of sound in front of an oblique shock wave is higher than behind it. II. The Mach number in front of an oblique shock wave is lower than behind it. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is incorrect. I is correct, II is correct. I is incorrect, II is correct.

232512. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect? I. The local speed of sound in front of an oblique shock wave is higher than behind it. II. The Mach number in front of an oblique shock wave is higher than behind it. A) I is incorrect, II is correct. B) I is correct, II is correct. C) I is correct, II is incorrect. D) I is incorrect, II is incorrect.

1232503 (A) 1232504 (A) 1232505 (0) 1232506 (C) 1232507 (8) 1232508 (0) 1232509 (0) 1232510 (8) 1232511 (8) 1232512 (A) 1

\~-.~

Aviationexam Test Prep Edition 2012

232513. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect?

232518. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect?

I. The local speed of sound in front of an oblique shock wave is lower than behind it. II. The Mach number in front of an oblique shock wave is lower than behind it.

I. The Mach number behind an oblique shock wave is lower than in front of it. II. The total pressure behind an oblique shock wave is lower than in front of it.

A) I is incorrect, II is incorrect. B) I is correct, II is incorrect. C) I is correct, II is correct. 0) I is incorrect, II is correct.

A) B) C) 0)

I is incorrect, II is incorrect. I is correct, II is correct. I is incorrect, II is correct. I is correct, II is incorrect.

232514. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect?

232519. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect?

I. The density behind an oblique shock wave is higher than in front of it. II. The local speed of sound behind an oblique shock wave is higher than in front of it.

I. The Mach number behind an oblique shock wave is higher than in front of it. II. The total pressure behind an oblique shock wave is higher than in front of it.

A) I is correct, II is incorrect. B) I is correct, II is correct. C) I is incorrect, II is correct. 0) I is incorrect, II is incorrect.

A) B) C) 0)

I is incorrect, II is incorrect. I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is correct.

232515. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect?

232520. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect?

I. The density behind an oblique shock wave is lower than in front of it. II. The local speed of sound behind an oblique shock wave is lower than in front of it.

I. The Mach number behind an oblique shock wave is higher than in front of it. II. The total pressure behind an oblique shock wave is lower than in front of it.

A) I is correct, II is correct. B) I is incorrect, II is correct. C) I is correct, II is incorrect. 0) I is incorrect, II is incorrect.

A) B) C) 0)

I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct.

232516. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect?

232521. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect?

I. The density behind an oblique shock wave is lower than in front of it. II. The local speed of sound behind an oblique shock wave is higher than in front of it.

I. The Mach number behind an oblique shock wave is lower than in front of it. II. The total pressure behind an oblique shock wave is higher than in front of it.

A) B) C) 0)

I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct. I is incorrect, II is incorrect.

A) B) C) 0)

I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct.

232517. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect?

232522. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect?

I. The density behind an oblique shock wave is higher than in front of it. II. The local speed of sound behind an oblique shock wave is lower than in front of it.

I. The static temperature behind an oblique shock wave is higher than in front of it. II. The static pressure behind an oblique shock wave is higher than in front of it.

A) I is correct, II is incorrect. B) I is incorrect, II is correct. C) I is incorrect, II is incorrect. 0) I is correct, II is correct.

A) I is correct, II is incorrect. B) I is incorrect, II is incorrect. C) I is incorrect, II is correct. 0) I is correct, II is correct.

1232513 (8) 1232514 (8) 1232515 (0) 1232516 (8) 1232517 (A) 1232518 (8) 1232519 (A) 1232520 (0) 1232521 (A) 1232522 (0) 1

02 High Speed Aerodynamics

232523. Airplane ATPL Which of these statements about an oblique shock wave are correct or incorrect? I. The static temperature behind an oblique shock wave is lower than in front of it. II. The static pressure behind an oblique shock wave is lower than in front of it. A) B) C) D)

I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is correct. I is incorrect, II is incorrect.

Airplane ATPL 232524. Which of these statements about an oblique shock wave are correct or incorrect? I. The static temperature behind an oblique shock wave is lower than in front of it. II. The static pressure behind an oblique shock wave is higher than in front of it. A) I is correct, II is correct. B) I is incorrect, II is incorrect. e) I is incorrect, II is correct. D) I is correct, II is incorrect. Airplane ATPL 232525. Which of these statements about an oblique shock wave are correct or incorrect? I. The static temperature behind an oblique shock wave is higher than in front of it. II. The static pressure behind an oblique shock wave is lower than in front of it.

232527. Airplane ATPL In supersonic flight, any disturbance around a body affects the flow only: A) outside the Mach cone. B) within the Mach cone. e) in front of the normal shock wave. D) in front of the body. Airplane ATPL 232530. The relation between the Mach angle (mu) and the corresponding Mach number is: A) sin mu = 1 / M B) tan mu = 1 / M e) sin mu=M D) sin 2mu = 1 / M Airplane ATPL 232531. The sonic boom of an aeroplane flying at supersonic speed is created by: A) aerodynamic heating. B) shock waves around the aeroplane. e) the centre of pressure, which is moving aft on the aerofoil. D) the expansion flow behind the aeroplane. Airplane ATPL 232549. Shock induced separation can occur: A) at high Mach numbers, only at high angles of attack. B) at high Mach numbers, only at low angles of attack. e) in supersonic flow only. D) behind a strong normal shock wave, independent of angle of attack.

A) I is incorrect, II is correct. B) I is correct, II is correct. e) I is incorrect, II is incorrect. D) I is correct, II is incorrect.

02-03 Effects of Exceeding 3584. Airplane ATPL If a symmetrical aerofoil is accelerated from subsonic to supersonic speed the centre of lift will move: A) forward to the leading edge. B) aft to the trailing edge. e) aft to the mid chord. D) forward to the mid chord. (Refer to figure OBI-EB2) As shown in the illustration the centre of pressure moves rearwards with increasing Mach number in the transonic region. Although the profile in the illustration is cambered, the centre of pressure on a symmetrical profile behaves in a similar fashion.

3587. Airplane ATPL When the speed over an aerofoil section increases from subsonic to supersonic, its aerodynamic centre:

MeRIT

(Refer to figure OBI-EB2) Although not mentioned in most text books, the aerodynamic centre, that in the lower subsonic speed region is fixed, will behave much like the centre of pressure in the trans- and supersonic speed region = move to about mid chord (50% chord position).

3588. Airplane ATPL In supersonic flight aerofoil pressure distribution is: A) the same as in subsonic flight. B) irregular. e) rectangular. D) triangular. (Refer to figure OBI-E26) As shown in the illustration the pressure pattern changes shape through the transonic region. The second and third distribution can be described as rectangular.

A) moves from approximately 25% to about 50% of the chord. B) moves aft by approximately 10% of the chord. e) does not move. D) moves slightly forward.

1232523 (D) 1232524 (C) 1232525 (D) 1232527(8) 1232530 (A) 1232531 (8) 1232549 (D) 1 3584(C) 1 3587(A) 1 3588 (C) 1

\

Em

~----~~--~-~-

Aviationexam Test Prep Edition 2012 3591. Airplane ATPL If an aeroplane is accelerated from subsonic to supersonic speeds, the centre of pressure will move: A) B) C) D)

to a position near the trailing edge. forward. to a position near the leading edge. to the mid chord position.

For explanation refer to question #3584 on page 85.

3595. Airplane ATPL The aft movement of the centre of pressure during the acceleration through the transonic flight regime will: A) B) C) D)

increase the static longitudinal stability. decrease the longitudinal stability. increase the static lateral stability. decrease the static lateral stability.

The aft movement of the centre ofpressure is equivalent to the centre ofgravity moving forward, a movement that increases the longitudinal stability.

3603. Airplane ATPL The additional increase of drag at Mach numbers above the critical Mach number is due to: A) B) C) D)

increased angle of attack. wave drag. increased interference drag. increased skin friction.

(Refer to figure 081-£25) The increase in drag due to the separation of the boundary layer behind a normal shock wave is termed wave drag. Therefore, wave drag will only occur at speeds above M cRrr

3785. Airplane ATPL The critical Mach number of an aeroplane is the free stream Mach number at which for the first time, somewhere on the aeroplane, the following occurs: A) B) C) D)

buffet. local sonic flow. shock wave. supersonic flow.

The free stream Mach number at which the local velocity of the airflow over the airfoil first reaches Mach 1 (sonic flow) is called the Critical Mach Number. With a slight change of the statement, the Critical Mach Number can also be regarded as the highest speed where there is no supersonic flow (M>l) over any portion of the airfoil (over the upper side of the wing where the flow speed increases).

3787. Airplane ATPL "Tuck under" is caused by ___ (i) movement of the centre of pressure of the wing and ___ (ii) change of the downwash angle at the location of the stabiliser. A) B) C) D)

(i) forward; (ii) increasing. (i) forward; (ii) decreasing. (i) aft; (ii) increasing. (i) aft; (ii) decreasing.

(Refer to figures 081-£25 and 081-£82) The critical mach number is a speed below M 1 at which first part of the airflow over the upper surface of the wing first exceeds a local speed of M 1 - it is because the airflow around the upper wing surface is accelerated as it flows over the cambered wing. At this point a shock wave is created at the position where the accelerated airflow reaches supersonic speed. Typically this is at around 25% of the wing chord. The airflow ahead of the shock wave is laminar, but a boundary layer separation occurs behind the shock wave and the wing stops producing lift in this area. The separated boundary layer causes buffeting (Mach buffet), just like with a low speed stall. It is an indication of an impending shock stall (/oss of lift due to formation of shock waves). The acceleration of the airflow over the upper wing surface will be most pronounced on sections where the wing has the largest camber =>

I

3591 (D)

I

3595 (A)

I

3603 (8)

I

3785 (8)

I

typically at the wing root close to the fuselage. This is therefore the first place where the shock waves start to form as the aircraft exceeds the Critical Mach number. Since we now have a section of the wing which does not produce lift and this section is located close to the fuselage, consequently the Centre of Pressure (CP) - the imaginary point through which the summation of all of the wing's lifting forces is said to act as a single lift vector - moves away from the fuselage closer towards the wing tips, because that's where more of the lift is produced now. Since transport jet airplanes use the swept wing design it means that as the CP moves away from the fuselage towards the tips it also moves aft as the wing sweeps aft. Along the longitudinal axis of the aircraft, the CP is located behind the Centre of Gravity (CG) of the aircraft, thus creating a constant pitch-down moment which is counterbalanced in flight by the downward lift of the horizontal stabilizer. As the CP moves further aft as a result of the shock wave formation its distance from the fixed CG increases and thus a pitch down moment is created. If this increased pitch down moment is not compensated by an increased downward lifting force of the horizontal stabilizer, the aircraft will pitch down. This is referred to as the HMach Tuck Hor HTuck under'~ Another factor increasing the pitch-down tendency at high mach numbers is the fact that the presence of shock waves along the upper wing surface and the resulting loss of lift decreases the down wash angle on the horizontal stabilizer and thus reducing its effectiveness. As the aircraft speed further increases above the critical mach number the shock waves will progressively move towards the trailing edge of the wing and also form on wing sections progressively further away from the wing root - towards the wing tip. This will result in a gradual shift of the CP further aft along the longitudinal axis of the airplane to about 50% of the chord. The attached illustration shows however, that this aft movement is somewhat irregular as the speed increases - depending on the specific design of the wing and other factors, but in general the CP settles at around 50% chord after a certain supersonic speed is reached. To prevent Mach Tuck when operating at speeds close to the critical mach number modern jet aircraft are equipped with a system called the HMach Trim'~ This aircraft system is automatically activated when a certain speed is exceeded - for example on a 8737 this Hactivation speedHis Mach 0.615. When Mach Trim operates the flight control computers receive information on the actual Mach number flown and automatically adjust the elevators up as the speed increases. The Mach Trim system also repositions the Helevator feel and centering unit Hwhich is responsible for the transmission of the correct forces into the controls in the cockpit => normal stick force characteristics and gradient are maintained, as well as the control column (stick) neutral position. In case of Mach Trim system malfunction, or if inoperative, the pilots must limit the cruise speed of the airplane => to stay well below the critical mach number (e.g. on the 8737-300 the speed limit is Mach.74 when Mach Trim is inoperative).

3797. Airplane ATPL Shock induced separation results in: A) B) C) D)

constant lift. decreasing lift. increasing lift. decreasing drag.

For explanation refer to question #3796 on page 80.

3802. Airplane ATPL For minimum wave drag, an aircraft should be operated at which of the following speeds? A) B) C) D)

Mach 1,0. High supersonic. Low supersonic. Subsonic.

Drag is large at low speed because of the high angle of attack necessary to produce sufficient lift and will decrease as speed increases. However, when reaching the critical Mach number, the wave drag increases because of shock stall. In supersonic flight, the bow wave will cause an energy loss that is drag on the aircraft.

3787 (D)

I

3797 (8)

I

3802 (D)

I

02 High Speed Aerodynamics 3809. Airplane ATPL As an aircraft accelerates through the transonic speed range: A) the coefficient of drag increases then decreases. B) the coefficient of drag increases. C) the coefficient of drag decreases then increases. D) the coefficient of drag decreases. (Refer to figure 087-f78)

3811. Airplane ATPL The consequences of exceeding MCRIT in a swept-wing aeroplane may be: (assume no corrective devices, straight and level flight) A) buffeting of the aeroplane and a tendency to pitch up. B) an increase in speed and a tendency to pitch up. C) engine unbalance and buffeting. D) buffeting of the aeroplane and a tendency to pitch down. For explanation refer to question #3787 on page 86.

3819. Airplane ATPL Tuck under can occur: A) only above the critical Mach number. B) only at the critical Mach number. C) only below the critical Mach number. D) above or below the critical Mach number depending on the angle of attack. For explanation refer to question #3787 on page 86.

3821. Airplane ATPL In the transonic range CLMAX will ___ and the 1 G stalling speed will

A) M 0,75 to M 0,98 B) M 0,81 to M 1,4 C) M 0,75 to M 0,89 D) M 0,89 to M 0,98 (Refer to figures 087-f26 and 087-f82) When exceeding the critical Mach number, the shock stall causes the centre of pressure to move forward. Accelerating further into the transonic speed region will cause the shock wave to move towards the trailing edge as more and more of the upper surface experience supersonic flow. This in turn will reduce the separated area on the upper surface and the centre of pressure will start moving rearwards. As shown in the illustration the rearward movement of the centre ofpressure happens in the M 0,89 - 0,98 range.

3847. Airplane ATPL MCRIT is the free stream Mach number at which: A) shock stall occurs. B) Mach buffet occurs. C) somewhere about the airframe Mach 1 is reached locally. D) the critical angle of attack is reached. For explanation refer to question #3785 on page 86.

7776. Airplane ATPL Total drag at high Mach numbers is a combination of: A) wave drag, interference drag, form drag, and induced drag. B) induced drag, wave drag, form drag, skin friction drag and interference drag. C) profile drag, form drag, induced drag and wave drag. D) induced drag, form drag, interference drag and zero lift drag. At high Mach numbers an additional drag must be considered because of shock stall. This drag is called wave drag as it is cause by the shock wave. The drag for all speeds is of course still present, and consists of: induced drag,

A) decrease; increase B) decrease; decrease C) increase; decrease D) increase; increase

form drag, skin friction drag and interference drag.

(Refer to figure 087-f87) ClMAXdecreases in the transonic speed range. A lower value ofClMAXcorresponds to a higher stall speed.

3824. Airplane ATPL The Mach trim system will: A) pump the fuel from tank to tank, depending on the Mach number. B) keep the Mach number automatically constant. C) adjust the stabilizer, depending on the Mach number. D) adjust the elevator trim tab, depending on the Mach number. For explanation refer to question #3787 on page 86.

3829. Airplane ATPL On a typical symmetrical airfoil, as the free stream Mach number approaches Mach 1, the centre of pressure will: A) move from 25% chord to the leading edge. B) move forward to about 25% chord. C) move aft to about 45% chord. D) move aft to the trailing edge.

moving rearwards.

1 3821 (A)

15716. Airplane ATPL Tuck under may happen: A) at low Mach numbers. B) at all Mach numbers. C) only at low altitudes. D) at high Mach numbers. For explanation refer to question #3787 on page 86.

15729. Airplane ATPL The Mach trim system will prevent: A) dutch roll. B) buffeting. C) shock stall. D) tuck under. For explanation refer to question #3787 on page 86.

15731. Airplane ATPL In transonic flight the ailerons will be less effective than in subsonic flight because:

(Refer to figure 087-f82) As shown in the illustration, the centre of pressure moves aft when approaching Mach 7 and eventually ends up at about 50% chord. When exceeding the critical Mach number, the shock stall causes the centre of pressure to move forward. Accelerating further into the transonic speed region will cause the shock wave to move towards the trailing edge as more and more of the upper surface experience supersonic flow. This in turn will reduce the separated area on the upper surface and the centre of pressure will start

1 3809 (A) 1 3811 (D) 1 3819 (A) 115729 (0) 1 15731 (0) 1

Airplane ATPL 3835. On a typical transonic airfoil the transonic rearward shift ofthe CP occurs at about:

A) behind the shock wave pressure is lower. B) aileron down deflection moves the shock wave forward. C) aileron deflection only affects the air in front of the shock wave. D) aileron deflection only partly affects the pressure distribution around the wing. At low speed, movement of a control surface modifies the pressure distribution over the whole aerofoi/. If there is a shock wave ahead of the control surface, movement of the control cannot affect any part of the aerofoi/ ahead of the shock wave.

1 3824 (C) 1 3829 (C) 1 3835 (0) 1 3847 (C) 1 7776 (8) 115716 (0) 1

Aviationexam Test Prep Edition 2012

15732. Airplane ATPL An aeroplane is flying through the transonic range whilst maintaining straight and level flight. As the Mach number increases the centre of pressure of the wing will move aft. This movement requires: A) B) C) D)

much more thrust from the engines. a higher lAS to compensate the nose down effect. a pitch up input of the stabilizer. a stability augmentation system to improve dynamic stability.

For explanation refer to question #3787 on page 86.

21001. Airplane "Tuck under" is the:

ATPL

A) nose down pitching tendency as speed is increased in the transonic range. B) nose up pitching tendency as speed is increased in the transonic range. C) shaking of the control column at high Mach number. D) nose down pitching tendency when the control column is pulled rearwards. For explanation refer to question #3787 on page 86.

21030. Airplane ATPL An aeroplane should be equipped with a Mach trimmer, if: A) stickforce stability becomes independent of lAS and altitude. B) at transonic Mach numbers the aeroplane displays an unacceptable decrease in longitudinal stick force stability. C) stick force per g strongly decreases at low Mach numbers. D) at high lAS and low altitude the aeroplane displays an unacceptable decrease in longitudinal stick force stability. For explanation refer to question #3787 on page 86.

21041. Airplane ATPL Critical Mach number is the free stream Mach number at which: A) B) C) D)

there is supersonic flow over all parts of the aeroplane. there is subsonic flow over all parts of the aeroplane. local sonic flow first exists on any part of the aeroplane. the aeroplane has zero buffet margin.

For explanation refer to question #3785 on page 86.

21049. Airplane ATPL During which type of stall does the angle of attack have the smallest value? A) B) C) D)

Deep stall. Accelerated stall. Low speed stall. Shock stall.

A shock stall occurs when the speed exceeds the critical Mach number, that is at very high TAS. Flying level at high TAS means flying with a small lift coefficient and angle of attack.

21114. Airplane ATPL The critical Mach number of an aerofoil is the free stream Mach number at which: A) B) C) D)

a shock wave appears on the upper surface. the maximum operating temperature is reached. sonic speed (M=l) is first reached on the upper surface. a "supersonic bell" appears on the upper surface.

For explanation refer to question #3785 on page 86.

23507. Airplane ATPL At speeds just above the critical Mach number, the drag coefficient:

~ ~

A) B) C) D)

will start to increase. will start to decrease. will remain constant. is inversely proportional to the Mach number.

(Refer to figure 087-£26) Above the critical Mach number a normal shock wave forms on the upper side of the wing causing the boundary laye~ to separate. The separation increases drag.

23510. Airplane ATPL At speeds just above the critical Mach number the LID ratio will: A) increase. B) decrease. C) remain the same. D) unable to determine due to lack of additional information. Above the critical Mach number a normal shock wave forms on the upper side of the wing causing the boundary layer to separate. The separation increases drag. The LID ratio will therefore decrease.

23511. Airplane ATPL During acceleration from subsonic to supersonic speed the centre of pressure movement will be: A) forward. B) rearward. C) remain stationary. D) irregular, forward and aft, but overall rearward to the 50% chord. (Refer to figure 087-£82) As shown in the illustration the centre of pressure moves irregularly but ends up at about half chord with increasing Mach number in the transonic region.

23519. Airplane ATPL With increasing Mach number the CP moves: A) B) C) D)

remains stationary. forwards. rearwards. rearwards initially, then moves forward to a position in front of the leading edge.

(Refer to figure 087-£82) The centre ofpressure moves aft with increasing Mach number and eventually ends up at about 50% chord.

23555. Airplane ATPL What movement of the centre of lift occurs when accelerating an aircraft with a symmetrical aerofoil to supersonic speed? A) Forward to the leading edge. B) Irregular, but in an overall rearward direction towards the centre ofthe chord. C) Aft to the trailing edge. D) No movement occurs. (Refer to figure 087-£82) As shown in the illustration the centre of pressure moves irregularly but ends up at about half chord with increasing Mach number in the transonic region. Although the profile in the illustration is cambered, the centre of pressure on a symmetrical profile behaves in a similar fashion.

23560. Airplane ATPL When an aerofoil section has accelerated from subsonic to supersonic speeds, its aerodynamic centre will have: A) B) C) D)

shifted from approximately 25% to about 50% ofthe chord. shifted aft by about 10%. shifted slightly forward. not moved.

For explanation refer to question #3584 on page 85.

115732 (C) 121001 (A) 121030 (8) 121041 (C) 121049 (0) 1 21114 (C) 123507 (A) 123510 (8) 123511 (0) 1 23519 (C) 1 123555 (8) 123560 (A) 1

02 High Speed Aerodynamics 23595. Airplane ATPL What causes a large increase in drag at high transonic speed? A) B) C) D)

An increase in parasite drag due to shock wave formation. An increase in induced drag due to shock wave formation. The reduction in thrust due to shock wave formation. Wave drag.

(Refer to figure 087-£25) The increase in drag due to the separation of the boundary layer behind a normal shock wave is termed wave drag.

23675. Airplane ATPL What is the movement of the Aerodynamic Centre from subsonic to supersonic? A) Oto25% B) Oto50% C) 50%to25% D) 25% to 50% (Refer to figure 087-£82) As shown in the illustration the centre of pressure moves from around 25% to 50% chord with increasing Mach number in the transonic region.

23678. Airplane ATPL Deflecting a control surface down will cause MeRIT to: A) B) C) D)

increase. decrease. remain the same. not possible to answer without knowing the actual Mach number and the MeRIT values.

Deflecting the aileron downward will increase the camber of the wing and thus accelerate the flow over the upper surface. This will in turn cause the flow on the upper surface to reach Mach 7 at a lower speed. The critical Mach number will therefore decrease.

25472. Airplane ATPL When can shock stall occur? A) B) C) D)

At low speed. At negative angles of attack. At any angle of attack. In the ground effect.

Shock stall occurs when exceeding the critical Mach number and is not dependant on the angle of attack.

224764. Airplane ATPL An aeroplane should be equipped with a Mach trimmer, if: A) at transonic Mach numbers the aeroplane demonstrates unconventional elevator stick force characteristics. B) at high airspeed and low altitude the aeroplane demonstrates unconventional elevator stick force characteristics. C) stick force per g strongly decreases at low Mach numbers. D) stick force stability is independent of the airspeed and altitude. For explanation refer to question #3787 on page 86.

232130. Airplane ATPL Assuming no flow separation and no compressibility effects the location of the aerodynamic centre of an aerofoil section: A) moves backward when the angle of attack increases. B) is at approximately 50% !=hord irrespective of angle of attack. C) moves forward when the angle of attack increases. D) is independent of angle of attack. Airplane ATPL 232131. Assuming no flow separation and no compressibility effects the location of the centre of pressure of a symmetrical aerofoil section: A) B) C) D)

is at approximately 25% chord irrespective of angle of attack. moves backward when the angle of attack decreases. moves forward when the angle of attack decreases. is at approximately 50% chord irrespective of angle of attack.

232132. Airplane ATPL Assuming no flow separation and no compressibility effects the location of the centre of pressure of a symmetrical aerofoil section: A) is at approximately 50% of the chord irrespective of angle of attack. B) moves forward when the angle of attack decreases. C) moves backward when the angle of attack decreases. D) is independent of angle of attack. Airplane ATPL 232215. Assuming no compressibility effects, induced drag at constant lAS is affected by: A) B) C) D)

outside air temperature. altitude. engine thrust. aeroplane mass.

232540. Airplane ATPL The critical Mach number of an aeroplane is the Mach number: A) above which, locally, supersonic flow exists somewhere over the aeroplane. B) at which the aeroplane has zero buffet margin. C) at which there is supersonic flow over a part of the aeroplane. D) at which there is subsonic flow over all parts of the aeroplane. 232541. Airplane ATPL What is the highest speed possible without supersonic flow over the wing? A) B) C) D)

Initial Mach buffet speed. M= 1. Tuck under speed. Critical Mach number.

For explanation refer to question #3785 on page 86.

232129. Airplane ATPL Assuming no flow separation and no compressibility effects the location of the aerodynamic centre of an aerofoil section: A) B) C) D)

is at approximately 50% chord irrespective of angle of attack. moves backward when the angle of attack increases. moves backward when the angle of attack decreases. is at approximately 25% chord irrespective of angle of attack.

232545. Airplane ATPL Which type of buffet will occur if a jet aeroplane slowly accelerates in level flight from its cruise speed in still air at high altitude? A) B) C) D)

Mach buffet. Low speed buffet. Flutter speed buffet. Accelerated stall buffet.

123595 (0) 123675 (0) 123678 (8) 125472 (C) 1224764 (A) 1232129 (0) 1232130 (0) 1232131 (A) 1232132 (0) 1232215 (0) 1 1232540 (A) 1232541 (0) 1232545 (A) 1

Aviationexam Test Prep Edition 2012 232546. Airplane Shock stall:

ATPL

A) occurs when the lift coefficient, as a function of Mach number, reaches its maximum value. B) results from flow separation at the underside of the aerofoil. e) results from flow separation behind the bow wave. D) occurs as soon as MCRIT is exceeded. Airplane ATPL 232548. Which of these statements on shock stall is correct? A) Shock stall is caused by sudden loss of lift due to a rise in load factor. B) Shock stall is a stall due to flow separation at high angles of attack. e) elmox does not change as the Mach number increases. D) Shock stall is a stall due to flow separation caused by a shock wave. 232552. Airplane ATPL When shock stall occurs, lift will decrease because: A) the bow wave appears. B) of the existence of a shock wave being located at the trailing edge ofthe wing. e) flow separation occurs behind the shock wave. D) Mcrit is reached. Airplane ATPL 232553. The increase in stall speed (lAS) with increasing altitude isdueto: A) exceedance of MCRIT" B) compressibility effects. e) the larger angle of attack necessary in lower-density air to obtain the same lift as at sea level. D) an increase in lAS. 232560. Airplane ATPL Which of these statements about "tuck under" are correct or incorrect? 1) "Tuck under" is caused by an aft movement of the centre of pressure of the wing. 2) "Tuck under" is caused by a reduction in the downwash angle at the location of the horizontal stabiliser. A) 1) is incorrect, 2) is correct. B) 1) is correct, 2) is correct. e) 1) is correct, 2) is incorrect. D) 1) is incorrect, 2) is incorrect. For explanation refer to question #3787 on page 86.

232562. Airplane ATPL As the Mach number increases from subsonic to supersonic, the centre of pressure moves: A) forward. B) to the mid chord position. C) to a position near the trailing edge. D) to a position near the leading edge. Airplane ATPL 232572. What is the effect of exceeding MeRIT on the stick force stability of an aeroplane with swept-back wings without any form of stability augmentation? A) A decrease, due to loss of lift in the wing root area. B) No effect, because stick force stability is independent of Mach number.

e) An increase, due to shock wave formation in the wing root

area. D) No effect, because MeRIT is not relevant when considering stick force stability. 232574. Airplane ATPL The position of the centre of pressure on an aerofoil of an aeroplane cruising at supersonic speed when compared with that at subsonic speed is: A) undetermined since there is no defined centre of pressure location at supersonic speeds. B) further forward. e) further aft. D) identical. 232575. Airplane ATPL Which of these statements about "tuck under" are correct or incorrect? 1) A contributing factor to "tuck under" is a forward movement of the centre of pressure of the wing. 2) A contributing factor to "tuck under" is an increase in the downwash angle at the .location of the horizontal stabiliser. A) 1) is incorrect, 2) is correct. B) 1) is correct, 2) is incorrect. e) 1) is correct, 2) is correct. D) 1) is incorrect, 2) is incorrect. For explanation refer to question #3787 on page 86.

232576. Airplane ATPL Which of these statements about "tuck under" are correct or incorrect? 1) A contributing factor to "tuck under" is an aft movement of the centre of pressure of the wing. 2) A contributing factor to "tuck under" is an increase in the downwash angle at the location of the horizontal stabiliser. A) 1) is correct, 2) is incorrect. B) 1) is correct, 2) is correct. e) 1) is incorrect, 2) is incorrect. D) 1) is incorrect, 2) is correct. For explanation refer to question #3787 on page 86.

232577. Airplane ATPL Which of these statements about "tuck under" are correct or incorrect? 1) A contributing factor to "tuck under" is an forward movement of the centre of pressure of the wing. 2) A contributing factor to "tuck under" is a reduction in the downwash angle at the location of the horizontal stabiliser. A) 1) is correct, 2) is correct. B) 1) is correct, 2) is incorrect. C) 1) is incorrect, 2) is correct. D) 1) is incorrect, 2) is incorrect. For explanation refer to question #3787 on page 86.

232588.

Airplane

ATPL

MeRIT is increased by: A) sweepback, thin aerofoils and area ruling. B) dihedral, thin aerofoils and supercritical aerofoil sections. e) sweepback, area ruling and high aspect ratio. D) sweepback, dihedral and thin aerofoils.

1232546 (A) 1232548 (D) 1232552 (C) 1232553(8) 1232560(8) 1232562(8) 1232572 (A) 1232574 (C) 1232575(0) 1232576 (A) 1 1232577 (C) 1232588 (A) 1

02 High Speed Aerodynamics

02-04 Buffet Onset 3836. Airplane ATPL The maximum acceptable crulsmg altitude is limited by a minimum acceptable load factor because exceeding that altitude:

2631. Airplane ATPL The speed range between high and low speed buffet: A) decreases during a descent at a constant Mach number. B) is always positive at Mach numbers below MMo' C) increases during a descent at a constant lAS. D) increases during climb.

A) turbulence may induce Mach buffet. B) turbulence may exceed the limit load factor. C) a sudden necessary bank angle may exceed the limit load factor. D) Mach buffet will occur immediately.

(Refer to figure OB7-E95) The low speed buffet limit is more or less constant when flying lAS while the high speed buffet limit is at an increasing lAS when altitude is reduced.

3782. Airplane The buffet margin:

ATPL

A) increases during a descent with a constant lAS. B) is always greatest after a step climb has been executed. C) decreases during a descent with a constant Mach number. D) is always positive at Mach numbers below MMo' (Refer to figure OB7-EI15) Looking at the illustration where the buffet margin at FL 290 is drawn, it is clear that the buffet margin is increased at lower altitudes. lAS = a dynamic pressure indicated on an instrument. Ifyou want to descent and maintain the same lAS reading (dyn. pressure), you have to slow down, because at lower altitudes there is a higher density. That means that by descending at constant lAS, you automatically slow down an in this way increase your buffet margin.

3801. Airplane ATPL The high speed buffet is induced by: A) a shift of the centre of gravity. B) boundary layer control. C) expansion waves on the wing upper side. D) boundary layer separation due to shock wave formation. (Refer to figure OB7-E25) Buffeting is induced by the turbulence in separated boundary layer hitting other parts of the aircraft, typically the empennage. At high speed the boundary layer separation is caused by shock stall.

3804. Airplane ATPL What data may be obtained from the Buffet Onset Boundary chart? A) The values of MMO at different weights and altitudes. B) The values of the Mach number at which low speed and Mach buffet occur at different weights and altitudes. C) The values of MeRIT at different weights and altitudes. D) The values of the Mach number at which low speed and shock stall occur at different weights and altitudes.

The altitude indicated in the question is normally the altitudes found in the 7,3 G buffet boundary charts. Exceeding that altitude will bring the aircraft into an area where moderate turbulence places the aircraft outside buffet boundaries.

3846. Airplane ATPL A jet aeroplane is cruising at high altitude with a Mach number, that provides a buffet margin of 0,3 G incremental. In order to increase the buffet margin to 0,4 G incremental the pilot must: A) fly at a lower altitude and the same Mach number. B) extend the flaps to the first selection. C) fly at a higher Mach number. D) fly at a larger angle of attack. (Refer to figure OB7-EI19) The best way to explain this concept is to refer to the Buffet Onset Boundary Chart (in the attached illustration): 7) Let's select for example a FL390 in the left section of the chart (outlined in blue). 2) Find its highest point (the top) note the corresponding Mach number on the bottom scale = approx. M O.BO. 3) From the highest point of limit curve for FL390 draw a horizontal line to the right until you intersect a vertical line representing a Load Factor value of"1.3". 4) The intersection point will be located on the diagonal line representing a mass of 720 t. 5) In the lower-right section of the chart, locate the Load Factor value of"1.4" and draw a vertical line until you intersect the line representing a mass of 720 t. 6) From this intersection point draw a line to the left until you intersect a vertical line representing a speed ofM O.BO. 1) Determine for which limit curve this point would be the highest one on the curve =a limit curve for approximately FL377.

(Refer to figure OBHI16) The Buffet Onset Chart gives the buffet margin at different weights and altitudes. None of the other suggested possibilities can be found in the chart.

In conclusion we can say that that if we fly at FL390, our available speed range during straight and level flight (00 bank angle 7g) will be roughly from M 0.65 to M 0.84. Let's assume that we are cruising at M O.BO = well inside the safe range. At this Flight Level and speed we have a buffet margin of 0.3 g => we can increase the Load Factor up to 7.3 g and still not stall the aircraft due to Low- or High- speed stall. If we wanted to have a OAg margin, we would have to descend to lower FL - in this case to approximately 31 100 ft (FL311), because that's where the aerodynamic ceiling would be reached for the given mass (720 t), speed (M O.BO) and a Load Factor of 7.4.

3816. Airplane ATPL Should a transport aeroplane fly at a higher Mach number than the 'buffet-onset' Mach number in 1g flight?

3859. Airplane ATPL (Refer to figure 081-03) Given the following information: • Level flight (1G) .Cruising at FL340 • Aircraft mass 110000 kg .CG of 350/0

A) Yes, but only during approach. B) Yes, this causes no problems. C) No, this is not acceptable. D) Yes, if you want to fly fast at very high altitudes. Because of the high dynamic pressure when an aircraft is operating in the transonic speed region, any shock induced buffet will have a greater potential of severe airframe damage. High speed buffet must be completely avoided.

I

2631 (C)

I

3782 (A)

I

3801 (0)

I

3804 (8)

I

3816 (C)

=

I

The Low-speed buffet boundary is __ (i) and the High-speed buffet boundary is __ (ii):

3836 (A)

A) B) C) D)

I

i) M 0,54 i) M 0,60 i) M 0,49. i) M 0,52

3846 (A)

ii) M 0,82 ii) M 0,78 ii) MMO ii) M 0,84

I

3859 (0)

Aviationexam Test Prep Edition 2012 (Refer to figure 087-E717) Using the Buffet Onset chart follow the steps below: 1) On the right side locate the mass of 770 000 kg (710 t) and the corresponding line. Follow this line diagonally down and to the left until you intersect the 7G "Load Factor" vertical line. 2) From this intersection point continue horizontally to the left until you intersect the 35% CG vertical reference line. 3) From this intersection point continue diagonally down and to the left along the reference lines (above and below) until you intersect the main vertical reference line of the "CG" section = line that represents 25% CG. 4) From this intersection point continue horizontally to the left until the left edge of the chait. 5) Since the left section of the chart (Mach number) does not include a limit curve for FL340, we will have to draw it ourselves (blue line in the explanation illustration) - by interpolation between FL330 and FL350. Make sure that your FL340 line remains in the middle between the two adjacent ref lines at all times throughout its range. 6) Find the intersection points of the FL340 limit curve and the line you have drawn in step number 4. The left intersection point will be the Low-speed Mach buffet boundary and the right intersection point will be the Highspeed Mach buffet boundary (just track vertically down from the intersection points to read the corresponding Mach numbers on the scale at the bottom). 7) If there is no intersection point for the High-speed Mach buffer boundary, use theMMolimit-in this case Mach 0.84. In conclusion, for this question the correct results are: • Mach 0.52 for the Low-speed boundary, and • Mach 0.84 for the High-speed boundary.

3860. Airplane ATPL (Refer to figure 081-01) At an aircraft weight of 70.000 Ibs your aerodynamic ceiling in 1 g level flight will be: A) B) C) D)

FL320 FL390 FL420 FL440

(Refer to figure 087-E727) Note that the solution of this question is illustrated by YELLOW / ORANGE color in the explanation picture. The aerodynamic ceiling is the altitude / FL where only one speed exists

at which the aircraft can fly. Lower speed would result in a low-speed stall, whereas a higher speed would result in a high-speed stall due to exceeding the critical Mach number. To find the aerodynamic ceiling, follow the steps below: 1} Identify the "limit curve" representing the mass of 70000 Ibs (identified by number "70" in the chart). 2} Find the upper-most point of this curve (top of this curve) 3) Draw a horizontal line to the left and read the corresponding Flight Level on the left vertical scale of the chart => approx. FL420 = aerodynamic ceiling for 70000 Ibs.

15695. Airplane ATPL (Refer to figure 081-02) A jet transport aeroplane weighing 100 tons carries out a steady level 50° bank turn at FL350. The buffet free speed range extends from: A) M = 0,72 to M > 0,84. B) M =0,65 to M > 0,84. C) M = 0,74 to M = 0,84. D) M = 0,69 to M > 0,84. (Refer to figure 087-E720) Using the Buffet Onset chart follow the steps below: 1) On the right side locate the mass of 700 000 kg (700 t) and the corresponding line. Follow this line diagonally down and to the left until you intersect the 50° bank angle vertical line (approx. 7,5 g). 2) From this intersection point continue horizontally to the left edge of the chart. 3) Since the left section of the chart (Mach number) does not include a limit curve for FL350, we will have to draw it ourselves (blue line in the explanation illustration) - by interpolation between FL340 and FL360. Make sure that your FL350 line remains in the middle

between the two adjacent ref lines at all times throughout its range. 4) Find the intersection pOints of the FL350 limit curve and the line you have drawn in step number 2. The left intersection point will be the Low-speed Mach buffet boundary and the right intersection point will be the Highspeed Mach buffet boundary (just track vertically down from the intersection points to read the corresponding Mach numbers on the scale at the bottom). 5) If there is no intersection point for the High-speed Mach buffer boundary, use the MMO limit - in this case approximately Mach 0.84. In conclusion, for this question the correct results are: • Mach 0.69 for the Low-speed boundary, and • Mach 0.84 for the High-speed boundary.

15728. Airplane ATPL Which of the following flight phenomena can only happen at Mach numbers above the critical Mach number? A) Elevator stall. B) Mach buffet. C) Dutch roll. D) Speed instability. (Refer to figure 087-E25) Mach buffet is caused by shock stall when the boundary layer separates behind the normal shock wave. This shock wave does first appear when exceeding the critical Mach number.

21055. Airplane ATPL From the buffet onset graph of a given jet transport aeroplane it is determined that at FL310 at a given mass buffet free flight is possible between M 0,74 and M 0,88. In what way would these numbers change ifthe aeroplane is suddenly pulled up?

=

=

A) Both Mach numbers decrease.

B) The lower Mach number decreases and the higher Mach number increases. C) The lower Mach number increases and the higher Mach number decreases. D) Both Mach numbers increase. (Refer to figure 087-E716) Using the illustration as an example, it is easy to see, that if the aircraft suddenly pulls up, and the load factor therefore increases, the buffet margin will be smaller, i.e. the low Mach number increases and the high Mach number decreases.

21094. Airplane Mach buffet occurs:

ATPL

A) directly after exceeding McRlr B) when the Mach number has increased to McRlr C) following boundary layer separation due to shock wave formation. D) when the stall angle of attack is exceeded. For explanation refer to question #75728 on this page.

21150. Airplane ATPL What is the significance of the maximum allowed cruising altitude, based on the 1,3 G margin? At this altitude: A) a manoeuvre with a load factor of 1,3 will cause a Mach num-

ber at which accelerated low speed stall occurs. B) a manoeuvre with a load factor of 1,3 will cause MCRIT to be exceeded. C) a manoeuvre with a load factor of 1,3 will cause buffet onset. D) exceeding a load factor of 1,3 will cause permanent deformation of this aeroplane. The 7,3 G margin corresponds to 40° bank angle or moderate turbulence buffet boundaries.

1 3860 (C) 115695 (D) 115728 (8) 121055 (C) 121094 (C) 1 21150 (C)

02 High Speed Aerodynamics

23655. Airplane ATPL What is determined by the buffet onset chart? A) Values of low speed and Mach buffet at different weights and altitudes. B) Values of MeRIT at different weights and altitudes. C) Values of stall and shock stall. D) Values of stall. For explanation refer to question #3804 on page 91.

23715. Airplane ATPL The Mach buffet margin: A) increases as altitude decreases at constant lAS. B) decreases as altitude decreases at constant Mach number. C)

remains constant at MMO'

D) is better using a step climb technique. (Refer to figure 081-£l1S) Looking at the illustration, where the buffet margin at FL 290 is drawn, it is clear that the buffet margin is increased at lower altitudes.

24461. Airplane ATPL (Refer to figure 081-03) What are the low and high buffet onset speeds given the following conditions: FL350 Mass: Bankangle: A) B) C) D)

(Refer to figure 081-£118) Using the Buffet Onset chart follow the steps below: 1) On the right side locate the massof110000kg (110 t} and the corresponding line. Follow this line diagonally down and to the left unti! you intersect the 50° Bank Angle vertical line. 2) From this intersection point continue horizontally to the left - since the question does not mention CG, we will assume standard CG => continue all the way to the left edge of the chart. 3) In the left section of the chart identify the limit curve that represents FL3S0 (outlined in blue color in the explanation illustration). 4) Find the intersection points of the FL3S0 limit curve and the line you have drawn in step number 2. The left intersection point will be the Low-speed Mach buffet boundary and the right intersection point will be the Highspeed Mach buffet boundary ljust track vertically down from the intersection points to read the corresponding Mach numbers on the scale at the bottom}. In conclusion, for this question the correct results are: • Mach 0.73 for the Low-speed boundary, and • Mach 0.83 for the High-speed boundary.

232887. Airplane ATPL The significance of VA for jet transport aeroplanes is reduced at high cruising altitudes because: A) the engine has insufficient thrust to reach the limit load

factor. B) buffet onset limitations normally become limiting. C) at high altitudes the bank angle is normally limited to 15°

110.000 kg 50°

to prevent exceeding the limit load factor. D) the elevator deflection is limited to prevent exceeding the limit load factor.

M 0,69 and> M 0,84. M 0,72 and> M 0,84. M 0,73 and M 0,83. M 0,62 and M 0,83.

02-05 Means to Influence MeRIT 3767. Airplane ATPL Reducing the thickness/chord ratio on a wing will: A) B) C) D)

and lateral stability, but has no beneficial effect on longitudinal stability.)

3783. Airplane ATPL Vortex generators on the upper side of the wing surface will:

reduce the transonic variations in drag coefficient. reduce the transonic variations in lift coefficient. delay the onset of shock wave formation. all ofthe above.

On a low thicknesslchord ratio wing, the flow acceleration is reduced, thus raising the value of the critical Mach number which delays the onset of shock wave formation. The thinner wing will also mean weaker shock waves and thus reduce the variation in lift and drag coefficients through the transonic speed range.

3771. Airplane ATPL When comparing a rectangular wing and a swept back wing of the same wing area and wing loading, the swept back wing has the advantage of: A) B) C) D)

lower stalling speed. greater strength. increased longitudinal stability. higher critical Mach number.

(Refer to figure 081-£109) In the illustration the free stream velocity is broken down to a component perpendicular to the leading edge and a component parallel to the leading edge. The component perpendicular to the leading edge is less then the free stream velocity and it is this velocity component which determines the magnitude of the pressure distribution and hence MeRIT' Sweep back will therefore increase MeRIT' (A swept back wing will have higher stalling speed because its lower value of CLMAX ' It will not have greater strength. It will improve directional

123655 (A)

I 23715 (A) I 24461

(C) 1232887 (8)

I

3767 (0)

I

A) decrease the intensity of shock wave induced flow separation. B) increase the critical Mach number. C) decrease the span wise flow at high Mach numbers. D) increase the magnitude of the shock wave. Vortex generators are rows of sma//, thin aerofoi! shaped blades which project vertically into the airstream. They each generate a small vortex which causes the free stream flow of high energy air to mix with and add kinetic energy to the boundary layer. The higher energy level helps the flow through the shock wave with much less separation and hence a decreased wave drag.

3786. Airplane ATPL The critical Mach number can be increased by: A) B) C) D)

an increase in wing aspect ratio. positive dihedral of the wings. a Hail. sweep back of the wings.

(Refer to figure 081-£109) In the illustration the free stream velocity is broken down to a component perpendicular to the leading edge and a component parallel to the leading edge. The component perpendicular to the leading edge is less then the free stream velocity and it is this velocity component which determiries the magnitude of the pressure distribution and hence MeRIT Sweep back will therefore increase MeRIT' On. low thickness to chord ratio wings, the flow acceleration is reduced,

3771 (0)

I

3783 (A)

I

3786 (0)

I

Aviationexam Test Prep Edition 2012 thus raising the value of MeRIT' The right picture in the illustration shows how drag, and thus the drag coefficient, increases less for a straight wing at supersonic speeds.

3808. Airplane ATPL Two methods to increase the critical Mach number are: A) thin aerofoils and sweep back of the wing. B) thin aerofoils and dihedral of the wing. e) positive cambering of the aerofoil and sweep back of the wing. D) thick aerofoils and dihedral of the wing. For explanation refer to question #3786 on page 93.

3812. Airplane ATPL Compared to a normal transonic airfoil section a supercritical section has: A) a more cambered top surface. B) a flatter top surface. e) a flatter bottom surface. D) a very sharp leading edge. (Refer to figure 081-£31)

3823. Airplane ATPL What is the effect of a decreasing aeroplane weight on MeRIT at n=1, when flying at constant lAS? The value of MeRIT: A) increases. B) remains constant. e) is independent of the angle of attack. D) decreases. With decreased weight the angle of attack can be lowered for the same lAS. A smaller angle of attack means a reduced acceleration of the flow on the upper side of the wing. This means that a higher speed is possible before the flow on the wing reaches Mach 1, which is the critical Mach number.

3825. Airplane ATPL The critical Mach number of an aeroplane can be increased by: A) dihedral of the wings. B) vortex generators. C) control deflection. D) sweep back of the wings. For explanation refer to question #3786 on page 93.

3828. Airplane ATPL What is the influence of decreasing aeroplane weight on MeRIT at constant lAS? A) MeRIT increases as a result of flying at a smaller angle of attack. B) MeRIT increases as a result of compressibility effects. e) MeRIT decreases. D) MeRIT decreases as a result of flying at a greater angle of attack. For explanation refer to question #3823 on this page.

3830. Airplane ATPL Vortex generators mounted on the upper wing surface will: A) decrease the shock wave induced separation. B) decrease the interference drag of the trailing edge flaps. C) decrease the stalling speed by increase of the tangential velocity of the swept wing. D) increase the effectiveness of the spoiler due to increase in parasite drag. For explanation refer to question #3783 on page 93.

3837. Airplane ATPL Compared to a straight wing of the same airfoil section a wing swept at 30° should theoretically have an MeRIT __ _ times MeRIT for the straight wing, but will, in practice gain __ that increase. A) cosine 30; twice B) 1,154; half e) sine 30; half D) 1,414; twice (Refer to figure 081-£109) In the illustration the free stream velocity is broken down to a component perpendicular to the leading edge and a component parallel to the leading edge. The component perpendicular to the leading edge is equal to the free stream velocity (V) multiplied by cosine to the sweep angle (cos a). It is this velocity component which determines the magnitude of the pressure distribution and hence MeRIT' The theoretical free stream velocity at MeRIT will therefore be 1 + cos 30° = 1 + 0,86603 = 1,154. However, in practice only about half of the theoretical value is achieved.

3838. Airplane ATPL Vortex generators on the upper side of the wing: A) increase critical Mach number. B) increase wave drag. e) decrease wave drag. D) decrease critical Mach number. For explanation refer to question #3783 on page 93.

3840. Airplane ATPL Which ofthe following (i) aerofoils and (ii) angles of attack will produce the lowest MeRIT values? A) (i) thick; (ii) small B) (i) thick; (ii) large e) (i) thin; (ii) large D) (i) thin; (ii) small Thick aero foils and high angles of attack increase the acceleration of the flow on the upper side of the wing. This means that the flow on the wing reaches M 1,0, which is the critical Mach number, at a lower speed.

3848. Airplane ATPL Maintaining thickness/chord ratio but changing to a supercritical wing section will: A) lead to more prominent shock wave formation. B) make lateral stability more critical. C) give the aircraft an increased range. D) reduce the aft shift of ep in the transonic range. A supercritical profile delays formation of shock waves and thus reduces drag when thickness to chord ratio is unchanged. Less drag means lower fuel consumption and therefore greater range. A supercritical profile has no influence on lateral stability, nor does it significantly change the shift in CP movement.

3855. Airplane ATPL The application of the area rule on aeroplane design will decrease the: A) wave drag. B) skin friction drag. e) induced drag. D) form drag. Area rule is a design feature that gives the aircraft a reasonable smooth crosssectional area distribution along the aircraft's longitudinal axis, which in turn reduces the transonic drag rise. To offset the relatively larger cross-sectional area of the fuselage in the area where wings are attached, the fuselage is given a smaller area further behind, a bit like the appearance of a coke bottle.

I 3808 (A) 13812(8) I 3823 (A) I 3825 (D) I 3828(A) I 3830(A) 13837(8) I 3838 (C) 13840(8) I 3848 (C) I I 3855 (A) I

02 High Speed Aerodynamics

7939. Airplane ATPL A function of vortex generators in the transonic regime is to: A) reduce boundary layer separation drag when shock waves form. B) prevent the rearward shift of ep on swept wing stalls. e) reduce wing root compression effects. D) increase directional static stability. Vortex generators produce a vortex at the tip which induce high energy from the free stream flow to mix with the boundary layer, thus increasing its kinetic energy and helping it flow through the shock wave with much less separation.

20877. Airplane ATPL Some aeroplanes have a "waist" or "coke bottle" contoured fuselage. This is done to: A) improve the low speed characteristics. B) apply area rule. e) increase the strength of the wing root junction. D) fit the engine intakes better to the fuselage. For explanation refer to question #3855 on page 94.

20878. Airplane ATPL To increase the critical Mach number of a conventional aerofoil section:

232603. Airplane ATPL In comparison to a conventional aerofoil section, typical shape characteristics of a supercritical aerofoil section are: A) a larger nose radius,flatter upper surface and negative as well as positive camber. B) a sharper pointed nose, flatter lower surface and positive camber at the rear of the aerofoil section. e) a larger nose radius, flatter lower surface and negative as well as positive camber. D) a sharper pointed nose, negative camber and a flatter upper surface. 232604. Airplane ATPL One advantage of a supercritical wing aerofoil over a conventional one is: A) that there is no need for spoilers. B) a lower value of Mcrit at the same relative thickness. e) it allows a wing of increased relative thickness to be used for approximately the same cruise Mach number. D) improved Dutch roll damping at cruise altitude.

A) it should be flown at higher angles of attack. B) its leading edge radius should be increased. e) its thickness to chord ratio should be reduced. D) its camber should be increased. On low thickness to chord ratio wings, the flow acceleration is reduced, thus raising the value of MCRfr

23646. Airplane ATPL Which of the following combinations would result in the lowest value of MeRIT? A) Small camber I thin aerofoil. B) Large camber I thick aerofoil. e) Small camber Ithickaerofoil. D) Large camber I thin aerofoil. The critical Mach number is defined as the Mach number where the local speed reach Mach 1. This will be at the upper side of the wing where the flow increases speed. The increase in speed is greatest when the camber is large and when the thickness to chord ratio is large, i.e. thick aerofoi/s.

232590. Airplane ATPL The effect of increasing angle of sweep is: A) a decrease in the critical Mach number. B) a decrease in stall speed. e) an increase in longitudinal stability. D) an increase in the critical Mach number. 232602. Airplane A supercritical wing:

ATPL

A) will develop no noticeable shock waves when flying just .above McRir B) will develop no transonic flow just above McR,r e) will be free of Mach buffet in the transonic range. D) always cruises at MCR,r

1 7939 (A) 120877 (8) 120878 (C) 123646 (8) 1232590 (D) 1232602 (A) 1232603 (A) 1232604 (C) 1

Aviationexam Test Prep Edition 2012

04 Stability

STABILITY 04-01 Static and Dynamic Stability 3877. Airplane ATPL CPL An aeroplane that has positive statiC stability: A) is never dynamically stable. B) is always dynamically stable. C) can be dynamically stable, neutral or unstable. D) is always dynamically unstable. (Refer to figure 081-£126) Static stability means a tendency to return to equilibrium. The dynamic stability is defined by the reSUlting motion with time, and can be positive, neutral or negative.

3884. Airplane ATPL CPL A statiCally unstable aeroplane is: A) B) C) D)

always dynamically stable. never dynamically stable. sometimes dynamically stable. sometimes dynamically unstable.

(Refer to figure 081-£126) Dynamic stability presupposes static stability. A statically unstable aircraft can therefore never be dynamically stable.

3905. Airplane ATPL CPL One of the requirements for dynamiC stability is: A) B) C) D)

positive static stability. a large deflection range of the stabilizer trim. a small CG range. an effective elevator.

(Refer to figure 081-E126) Dynamic stability presupposes static stability.

3914. Airplane ATPL CPL If the total moments about an axis are not zero, what will be the result around that axis? A) B) C) D)

Equilibrium. Constant angular velocity. Angular acceleration. Constant angular displacement.

(Refer to figure 081-£126) Dynamic stability presupposes static stability.

3935. Airplane ATPL CPL If the total sum of moments about one of its axis is not zero, an aeroplane would: A) B) C) D)

fly a path with a constant curvature. be difficult to control. experience an angular acceleration about that axis. not be affected because the situation is normal.

An unbalanced moment about an axis will create an angular acceleration about the axis as long as it is not neutralised by another equal and opposite moment.

15715. Airplane ATPL CPL Positive statiC stability of an aeroplane means that following a disturbance from the equilibrium condition: A) the tendency is to move with an oscillatory motion of decreasing amplitude. B) the tendency is to move with an oscillatory motion of increasing amplitude. C) the initial tendency is to return towards its equilibrium condition D) the initial tendency is to diverge further from its equilibrium condition. (Refer to figure 081-£126) Stability in general means that the aircraft disturbed from equilibrium will return to equilibrium without pilot interference.

21007. Airplane ATPL CPL (Refer to figure 081-07) The aeroplane motion, schematiCally illustrated in the annex, is an example of a dynamiCally: A) B) C) D)

unstable periodic motion. indifferent periodic motion. stable periodic motion. indifferent aperiodic motion.

An unbalanced moment about an axis will create an angular acceleration as long as it is not neutralised by another equal and opposite moment.

(Refer to figure 081~£126) As the amplitude of the motion increases over time, the motion is dynamically unstable.

3926. Airplane ATPL CPL WhiCh of the following statements is correct?

23339. Airplane ATPL CPL Damping is the property that:

A) Dynamic stability means that after being displaced from original equilibrium condition, the aeroplane will return to that condition without oscillation. B) Static stability means that the aeroplane is also dynamically stable about the relevant axis. C) Dynamic stability is possible only when the aeroplane is statically stable about the relevant axis. D) A dynamically stable aeroplane would be almost impossible to fly manually.

A) slows down the rate or diminishes the amplitude of vibrations or cycles. B) makes a body decelerate when thrust is reduced. C) requires an increased amount of energy to be used to accelerate a body when it approaches the speed of sound. D) makes an aircraft more stable at high altitude. Damping is dissipation of energy which will diminish the amplitude of vibrations.

1 3877 (C) 1 3884 (8) 1 3905 (A) 1 3914 (C) 1 3926 (C) 1 3935 (C) 115715 (C) 121007 (A) 123339 (A) 1

Aviationexam Test Prep Edition 2012

23544. Airplane ATPL CPL If an aircraft has negative dynamic and positive static stability, this will result in: A) B) C) D)

(Refer to figure 081-EI26) Stability of a body is its tendency to return to its original attitude after having been disturbed by an external force.

undamped oscillations. convergent oscillations. divergent oscillations. damped oscillations.

(Refer to figure 081-EI26) The positive static stability will cause the oscillations attempting to bring the aircraft in equilibrium, but negative dynamic stability means the returns to equilibrium is with increasing velocity such that the amplitude continues to increase with time, also know as divergent oscillation.

23627. Airplane ATPL CPL If an aircraft has positive static stability: A) it is always dynamically stable. B) it is always dynamically unstable. C) it can be dynamically neutral, stable or unstable. D) it is always dynamically neutral. For explanation refer to question #3877 on page 9Z

23709. Airplane ATPL CPL The sum of the moments in flight are not zero, therefore movement would take place about: A) B) C) D)

theCG. the neutral point. the manoeuvre point. theCP.

The aircraft always rotates about its eG.

25489. Airplane ATPL CPL If a body is dynamically unstable, any oscillations would be: A) damped B) divergent C) neutral D) contained (Refer to figure 081-EI26) Dynamic instability means the damping is less than the impulse which will increase the amplitude of the oscillation.

25495. Airplane ATPL CPL If an object is statically unstable, it will: A) B) C) D)

move in the direction of the displacement. stop moving. return to the original position. oscillate.

(Refer to figure 081-EI26) A statically unstable object will move away from its equilibrium position in the direction of the initial displacement.

25516. Airplane ATPL CPL From displacement a divergent oscillation is: A) B) C) D)

dynamically stable. neutrally stable. dynamically neutral. dynamically unstable.

ATPL

232620. Airplane ATPL CPL Static stability means that: A) following a disturbance from the equilibrium condition, a force and/or moment is generated that tends to increase the effects of that disturbance. B) following a disturbance from the equilibrium condition, a force and/or moment is generated that tends to counter the effects of that disturbance. C) the amplitude of the oscillatory motion of an aeroplane tends to decrease over time. D) the amplitude of the oscillatory motion of an aeroplane tends to increase over time. 232621. Airplane ATPL CPL For an aeroplane to possess dynamic stability, it needs: A) B) C) D)

sufficient damping only. a large CG range. static stability only. static stability and sufficient damping.

Airplane ATPL CPL 232623. A statically stable aeroplane: A) is never dynamically stable. B) is always dynamically stable. C) can show positive, neutral or negative dynamic longitudinal stability. D) will never show positive dynamic longitudinal stability, but always neutral dynamic longitudinal stability. 232626. Airplane ATPL CPL An aeroplane that tends to return to its pre-disturbed equilibrium position after the disturbance has been removed is said to have: A) B) C) D)

positive static stability. neutral static stability. positive dynamic stability. neutral dynamic stability.

Airplane ATPL CPL 232627. As the stability of an aeroplane decreases: A) B) C) D)

its manoeuvrability increases. its manoeuvrability decreases also. there is no effect on its stability. its tendency to tuck under decreases.

232628. Airplane ATPL CPL As the stability of an aeroplane increases:

(Refer to figure 081-EI26) If the displacement increases, the body is dynamically unstable.

26692. Airplane Stability is:

of flight after a disturbance. D) most difficult to achieve, in the yawing plane, in forward flight.

A) B) C) D)

its manoeuvrability increases also. its tendency to tuck under increases. its manoeuvrability decreases. there is no effect on its stability.

CPL

A) the ability of an aircraft to climb after being disturbed. B) the ability of an aircraft to turn about its axis. C) the tendency of an aircraft to return to its original condition 123544 (C) 1 23627 (C) 1 23709 (A) 1 25489 (8) 125495 (A) 1 25516 (0) 1 26692 (C) 1232620 (8) 1232621 (0) 1232623 (C) 1 1232626 (A) 1232627 (A) 1232628 (C) 1

04 Stability

232645. Airplane ATPL CPL For a statically stable aeroplane, the relationship between the neutral point and centre of gravity (CG) is such that the neutral point is located: A) ahead of the eG. B) at the eG. e) anywhere, provided it is between the eG's forward and aft limits. D) aft of the eG. 232648. Airplane ATPL CPL The most forward CG location may be limited by: 1) Insufficient flare capability. 2) Excessive in-flight manoeuvrability. 3) Insufficient in-flight manoeuvrability. The combination that regroups all of the correct statements is: A) 3 B) 1,3 e) 1,2 D) 2

232649. Airplane ATPL CPL The most aft CG location may be limited by: 1) Insufficient stick force stability. 2) Insufficient flare capability. 3) Excessive in-flight manoeuvrability. 4) Insufficient in-flight manoeuvrability. The combination that regroups all ofthe correct statements is: A) 1,2,4 B) 1,3 e) 1,4

D) 2,3 233114. Airplane ATPL CPL Which of these statements about the equilibrium of forces and moments at VMeA are correct or incorrect?

233115. Airplane ATPL CPL Which of these statements about the equilibrium of forces and moments at VMeA are correct or incorrect? I. Because VMeA must be determined for the case where the critical engine suddenly fails, there is no need to obtain equilibrium of moments about the normal axis. II. Equilibrium of forces along the lateral axis does not require any side slip during a wings level condition. A) B) e) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct.

233116. Airplane ATPL CPL Which of these statements about the equilibrium of forces and moments at VMeA are correct or incorrect? I. Because V MCA must be determined for the case where the critical engine suddenly fails, there is no need to obtain equilibrium of moments about the normal axis. II. Equilibrium of forces along the lateral axis requires either bank angle or side slip or a combination of both. A) I is incorrect, II is correct. B) I is correct, II is correct. C) I is incorrect, II is incorrect. D) I is correct, II is incorrect. Airplane ATPL CPL 233117. Which of these statements about the equilibrium of forces and moments at VMeA are correct or incorrect? I. Equilibrium of moments about the normal axis. is provided by rudder deflection. II. Equilibrium of forces along the lateral axis does not require any side slip during a wings level condition. A) B) e) D)

I is incorrect, II is incorrect. I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is correct.

I. Equilibrium of moments about the normal axis. is provided by rudder deflection. II. Equilibrium of forces along the lateral axis requires either bank angle or side slip or a combination of both. A) B) e) D)

I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect. I is incorrect, II is correct.

04-03 Static and Dynamic Longitudinal Stability 2637. Airplane ATPL CPL What is the effect of an aft shift of the centre of gravity on (i) static longitudinal stability and (ii) the required control deflection for a given pitch change? A) B) e) D)

(i) reduces; (ii) increases.

(i) increases; (iO increases. (0 increases; (ii) reduces. (i) reduces; (ii) reduces.

3849. Airplane ATPL The Mach trim function is installed on most commercial jets in order to minimize the adverse effects of: A) B) e) D)

compressibility effects on the stabilizer. increased drag due to shock wave formation. uncontrolled changes in stabilizer setting. changes in the position of centre of pressure.

For explanation refer to question #3787 on page 86.

Static longitudinal stability decreases as the CG moves aft. Less stability means more controllability, so a decreased static longitudinal stability requires smaller control deflections to achieve the same control. 1232645 (D) 1232648 (8) 1232649 (8) 1233114 (A) 1233115 (8) 1233116 (A) 1233117 (8) 1 2637 (D)

1 3849 (D)

1

Aviationexam Test Prep Edition 2012

3867. Airplane ATPL CPL The max aft position of the centre of gravity is amongst others limited by the: A) B) C) D)

too small effect of the controls on the aeroplane. maximum longitudinal stability of the aeroplane. maximum elevator deflection. minimum value of the stick force per G.

(Refer to figure 081-E101) As shown in the illustration, the stick force per G (slope of the lines) is reduced as the centre of gravity moves aft. The aft limit corresponds to a minimum value for the stick force perG not to lose the "feel" of the aircraft.

3871. Airplane ATPL CPL The effects of CG position on longitudinal static stability and control response will be: A) forward movement of the CG will reduce and increase control response. B) forward movement of the CG wili reduce control and increase stability. C) rearward movement of the CG will increase and reduce control response. D) rearward movement of the CG will reduce and control response.

stability response stability stability

Static longitudinal stability increases as the CG moves forward. More stability means less controllability, so an increased static longitudinal stability requires increased control deflections to achieve the same control.

3875. Airplane ATPL CPL The short period mode is an:

Concerning the subject of principles of flight, the short period oscillation is always in pitch, i.e. about the lateral axis.

3876. Airplane ATPL CPL At constant EAS, what is the effect on aerodynamic damping as height increases? Damping in all axes is reduced. Damping in pitch manoeuvres only is reduced. Damping in roll is increased. Damping in all axes is increased.

(Refer to figure 081-E12) Constant EAS at altitude means higher TAS. The illustration shows the aerodynamic damping in pitch and using that as example, it can be seen that an increase in TAS with the same pitching velocity will cause a smaller increase in tail angle of attack, and hence a reduced aerodynamic damping.

3878. Airplane ATPL CPL For a normal stable aeroplane, the centre of gravity is located: A) aft ofthe neutral point ofthe aeroplane. B) with a sufficient minimum margin ahead ofthe neutral point of the aeroplane. C) at the neutral point of the aeroplane. D) between the aft limit and the neutral point of the aeroplane. (Refer to figure 081-E52) The neutral point is the centre of gravity position where the moment from the wing lift and the tail lift are equal, and the aircraft would be statically neutral. The centre ofgravity must therefore always be in front of the neutral point.

3887. Airplane ATPL CPL Given an aeroplane in steady, straight and level flight at low speed and considering the effects of centre of gravity (CG) location and thrust, the highest value of wing lift occurs at:

I

3867 (D)

..

I

3871 (8)

-~---

I

. . ._

3875 (8)

--

I

3876 (A)

I

Forward CG and take-off thrust. Aft CG and idle thrust. Forward CG and idle thrust. Aft CG and take-off thrust.

With a forward centre of gravity, the wing lift creates a pitch down moment. To counter this, the tailplane must provide a pitch up moment, i.e. give negative lift. The tailplane lift acting downwards now adds to the weight, so the wing has to produce more lift to maintain altitude. The engine thrust from underslung engines will act below the centre ofgravity and therefore give a nose up moment. Engine thrust will thus reduce the amount of negative lift needed from the tailplane and therefore the amount of wing lift. The combination of forward centre of pressure and minimum thrust will therefore require the most wing lift.

3889. Airplane ATPL CPL An aeroplane, with a CG location behind the centre of pressure of the wing can only maintain a straight and level flight when the horizontal tail loading is: A) zero. B) upwards. C) downwards. D) upwards or downwards depending on elevator deflection. With the centre of pressure behind the centre of gravity, the wing lift creates a pitch up moment. To counter this, the tailplane must provide a pitch down moment, i.e. give positive lift.

3892. Airplane ATPL CPL The distance between the CG Datum and the CG Neutral Point in straight and level flight is called the: A) B) C) D)

A) oscillation about the vertical axis. B) oscillation about the lateral axis. C) oscillation about the longitudinal axis. D) unstable movement of the aeroplane, induced by the pilot.

A) B) C) D)

A) B) C) D)

CG forward limit. CG aft limit. CG static margin. CG manoeuvre margin.

(Refer to figure 081-E52) The neutral point is the centre of gravity position where the moment from the wing lift and the tail lift are equal, and the aircraft would be statically neutral. The centre of gravity must therefore always be in front of the neutral point. The distance to the neutral point is termed the static margin.

3893. Airplane ATPL CPL Which statement about stick force per G is correct? A) The stick force per G can only be corrected by means of electronic devices (stability augmentation) in case of an unacceptable value. B) The stick force per G increases, when centre of gravity is moved aft. C) The stick force per G must have both an upper and lower limit in order to assure acceptable control characteristics. D) If the slope of the force line becomes negative, generally speaking this is not a problem for control of an aeroplane. (Refer to figure 081-El0l) As shown in the illustration, the stick force per G (slope of the lines) varies as the centre of gravity moves. There is a maximum and minimum value for the stick force per G. The maximum to maintain the forces required to control the aircraft at a reasonable level, and a minimum not to lose the "feel" of the aircraft.

3894. Airplane ATPL CPL The manoeuvrability of an aeroplane is best when the: A) B) C) D)

CG is on the aft CG limit. speed is low. CG position is on the forward CG limit. flaps are down.

Static longitudinal stability decreases as the CG moves aft. Less stability means more manoeuvrability.

3878 (8)

I

3887 (e)

I

3889 (8)

I

3892 (C)

I

3893 (C)

I

3894 (A)

I

04 Stability

3898. Airplane ATPL In the event of failure of the Mach trimmer: A) the speed must be kept constant. B) the centre of gravity must be moved aft. . C) the Mach number must be limited. 0) the aeroplane mass must be limited. For explanation refer to question #3787 on page 86.

3900. Airplane ATPL CPL When an aeroplane with the centre of gravity forward of the centre of pressure of the combined wing/fuselage is in straight and level flight, the vertical load on the tailplane will be: A) downwards because it is always negative regardless of the position of the centre of gravity. B) upwards. C) zero because in steady flight all loads are in equilibrium. 0) downwards. With the centre ofpressure behind the CG the wing lift will create a nose-down moment. To maintain level flight the tailplane must provide a downword force (i.e. positive lift) to create a nose-up moment to balance the moment from the wing lift => this means the elevator must be deflected upwards.

3902. Airplane ATPL CPL The value of the manoeuvre stability of an aeroplane is 150 N/g. The stick force required to achieve a load factor of 2.5 from steady level trimmed flight is: A) B) C) 0)

150 N 375 N 450 N 225 N

The load factor in straight and level flight is 1, so to a achieve a load factor of 2,5, an increase of 1,5 is required. With the manoeuvre stability of 150 Nlg, the required stick force to achieve 1,5 g is: 150 Nlg xl,S = 225 N.

B) height and speed. C) pitch and load factor.

0) speed and load factor. (Refer to figure 081-E125) The long period phugoid oscillation is a gradual interchange of potential and kinetic energy about some equilibrium airspeed and altitude. Consequently, there is a significant but slow variation in airspeed. The height also changes, but also slowly.

3915. Airplane ATPL CPL After a disturbance about the lateral axis, an aeroplane oscillates about the lateral axis at a constant amplitude. The aeroplane is: A) statically unstable - dynamically neutral. B) statically unstable - dynamically stable. C) statically stable - dynamically unstable. 0) statically stable - dynamically neutral. (Refer to figure 081-E126) Since the aircraft oscillates about the lateral axis, it has static lateral stability. If the amplitude is constant, the dynamic stability is neural; the impulse and damping are equal.

3919. Airplane ATPL CPL If an aircraft has its CG ahead of its CP, in straight and level flight: A) there will normally be an upload on the tail plane. B) the tailplane will have a negative angle of attack. C) there will normally be a download on the tailplane. 0) there will normally be no load on the tailplane. With the centre of pressure located ahead of the centre of gravity, the wing lift creates a pitch down moment. To counter this, the tailplane must provide a pitch up moment, i.e. give negative lift.

3921. Airplane ATPL CPL In what way is the longitudinal stability affected by the degree of positive camber of the aerofoil?

3903. Airplane ATPL CPL If an aircraft has static longitudinal instability, it:

A) Negative, because the lift vector rotates forward at increasing angle of attack. B) Positive, because the centre of pressure shifts rearward at increaSing angle of attack. C) No effect, because camber of the aerofoil produces a constant pitch down moment coeffiCient, independent of angle of attack. 0) Positive, because the lift vector rotates backward at increaSing angle of attack.

A) will be dynamically stable. B) mayor may not be dynamically stable, depending on momentum and damping factors. C) will be dynamically unstable. 0) will be dynamically stable only at low speed. For explanation refer to question #3884 on page 9Z

3904. Airplane ATPL CPL The CG of an aeroplane is in a fixed position forward of the neutral point. Speed changes cause a departure from the trimmed position. Which of these statements about the stick force stability is correct? A) Maintaining a steady speed above the trim speed requires a pull force. B) An increase of 10 kts from the trimmed position at low speed has more effect on the stick force than an increase of 10 kts from the trimmed position at high speed. C) Aeroplane nose up trim decreases the stick force stability. 0) Stick force stability is not affected by trim. (Refer to figure 081-E63) The illustration shows the variation in stick force for three speeds. It is quite clear that the stick force increment is bigger at a departure from the trimmed speed for the low speed.

The degree of positive camber of the wing has no effect on longitudinal stability. The pitching moment about the aerodynamic centre is always negative (pitch down) regardless of the angle of attack.

3924. Airplane ATPL CPL The short period mode of longitudinal dynamic stability is: A) a rapid oscillation about the normal axis. B) a rapid oscillation about the longitudinal axis. C) a rapid oscillation about the lateral axis. 0) always induced by the pilot. (Refer to figure 081-E17) The longitudinal movement of the aircraft is always about the lateral axis.

3932. Airplane ATPL CPL If the aircraft is properly loaded the CG, the neutral point and the manoeuvre point will be in the order given, forward to aft:

3913. Airplane ATPL CPL Longitudinal dynamic oscillation takes two forms. One of these, long period oscillation, involves slow changes in: A) height and load factor. 1 3898 (C) 13900 (0) 1 3902 (0) 1 3903 (C) 1 3904 (8) 1 3913 (8) 1 3932 (C) 1

A) manoeuvre point, neutral point, CG. B) manoeuvre point, CG, neutral point. C) CG, neutral point, manoeuvre point. 0) CG, manoeuvre point, neutral point. 1 3915 (0) 1 3919 (C)

1 3921 (C) 1 3924 (C)

Aviationexam Test Prep Edition 2012 (Refer to figure 081-E57) Refer to the lower section of the attached figure. The NEUTRAL point is the CG position where the moment from the wing lift and the tail lift are equal, and the aircraft would be statically neutral. The CG must therefore always be in front of the neutral point. The MANOEUVRE point is the CG position where the moment from the wing lift and the tail lift are equal during manoeuvring, and this position is always behind the neutral point.

3934. Airplane ATPL CPL Which of the following components is most important in determining longitudinal static stability?

A) Fuselage. B) Wings. C) Engines. D) Horizontal tail plane. The fuselage, wing and most often the engines will all have negative influence on the static longitudinal stability.

3936. Airplane A Mach trimmer:

ATPL

A) has no effect on the shape of the elevator position versus speed (lAS) curve for a fully hydraulic controlled aeroplane. B) increases the stick force per G at high Mach numbers. C) is necessary for compensation of the autopilot at high Mach numbers. D) corrects insufficient stick force stability at high Mach numbers. For explanation refer to question #3787 on page 86.

Airplane ATPL Which of the following statements about a Mach trimmer is correct? 3938.

A) A Mach trimmer reduces the stick force stability of a straight wing aeroplane to zero at high Mach numbers. B) A straight wing aeroplane always needs a Mach trimmer for flying at Mach numbers close to MMo' C) A Mach trimmer corrects the change in stick force stability of a swept wing aeroplane above a certain Mach number. D) The Mach trimmer corrects the natural tendency of a swept wing aeroplane to pitch-up. For explanation refer to question #3787 on page 86.

3941. Airplane ATPL CPL The (i) stick force stability and the (ii) manoeuvre stability are positively affected by:

A) (i) forward CG movement, (ii) forward CG movement. B) (i) forward CG movement, (ii) trimming the aeroplane nose up. C) (i) aft CG movement, (ii) aft CG movement. D) (i) trimming the aeroplane nose up, (ii) trimming the aeroplane nose up. (Refer to figure 081-E51) The stick force stability is proportional to the slope of the curve of stick force vs. speed as shown on the upper part in the illustration. The more forward the centre of gravity, the steeper the curve and hence the higher the stick force stability. Manoeuvre stability is increasing with the static margin, that is the distance between the manoeuvre point ant the centre of gravity. The more forward the centre of gravity, the larger the margin and hence the higher the manoeuvre stability; see the lower part of the illustration.

3946. Airplane ATPL CPL The effect of a highly cambered airfoil on longitudinal stabilitywill be?

as angle of attack increases. D) Positive effect as CP moves backwards as angle of attack increases. For explanation refer to question #3921 on page 701.

3955. Airplane ATPL CPL A CG location beyond the aft limit leads to:

A) a too high pulling stick force during rotation in the takeoff. B) an unacceptable low value of the manoeuvre stability (stick

force per g, Fe/g). C) an increasing static longitudinal stability.

D) a better recovery performance in the spin. For explanation refer to question #3867 on page 700.

3960. Airplane ATPL CPL During landing of a low-winged jet aeroplane, the maximum elevator up deflection is normally required when the flaps are:

A) fully down and the CG is fully forward. B) up and the CG is fully forward. C) fully down and the CG is fully aft. D) up and the CG is fully aft. Flaps fully down will increase downwash at the tail and reduce the dynamic pressure at the tail, both of which are destabilising, i.e. produce a nose up tendency. A forward centre of gravity means an increased static longitudinal stability that in turn decreases the controllability and therefore requires bigger elevator deflections.

3964. Airplane ATPL CPL Longitudinal static stability is created by the fact that the:

A) wing surface is greater than the horizontal tail surface. B) centre of gravity is located in front of the leading edge of the wing. C) centre of gravity is located in front of the neutral point of the aeroplane. D) aeroplane possesses a large trim speed range. (Refer to figure 081-E52) NEUTRAL POINT (also referred to as Manoeuvre point) = the point along the longitudinal axis where the position of the CG causes neutral stability. It is the CG pOSition where the moment from the wing lift and the tail lift are equal, and the aircraft would be statically neutral. When the CG is positioned aft of the neutral point, the increase in stabilizer lift is not great enough, thus a destabilizing moment is created. In this situation the whole aircraft becomes unstable. It will pitch up, causing a higher A.of.A which creates a further increase in lift and a greater nose up moment. Consequently, an unstable aircraft shows a natural tendency to diverge from the trimmed flight attitude. Therefore, the CG must be always located IN FRONT of the neutral point during all phases of flight.

3965. Airplane ATPL CPL Which statement on dynamic longitudinal of a conventional aeroplane is correct?

stability

A) Damping of the short period oscillation is normally very weak. B) Speed remains constant during one period ofthe phugoid. C) Period time of the phugoid is normally 5 sec. D) Damping ofthe phugoid is normally very weak. Phugoid oscillations = long-period oscillations of an aircraft around its lateral axis. It is a slow change in pitch accompanied by equally slow changes in airspeed. Angle of attack changes are negligible and the pilot often corrects for phugoid oscillations without even being aware of them. Since the pitch rate in a phugoid is quite low and only negligible changes in angle of attack take place, damping of the phugoid is weak.

A) Positive effect because the lift vector is inclined rearwards as angle of attack increases. B) No effect. C) Negative effect because the lift vector is inclined forwards

13934(0) 13936(0) I 3938 (C) I 3941 (A) 13946(8) I 3955(8) I 3960 (A) I 3964(C) 13965(0) I

04 Stability

3999. Airplane ATPL CPL The centre of gravity moving aft will: A) B) C) D)

increase the elevator up effectiveness. decrease the elevator up effectiveness. not affect the elevator up or down effectiveness. increase or decrease the elevator up effectiveness, depending on wing location.

Static longitudinal stability decreases as the centre of gravity moves aft. Less stability means more manoeuvrability, and thus increases the elevator effectiveness.

4009. Airplane ATPL CPL In a mechanically controlled aeroplane, the most forward allowable position of the centre of gravity could be limited by the: A) B) C) D)

elevator capability, elevator control forces. engine thrust, engine location. trim system, trim tab surface. wing surface, stabilizer surface.

Static longitudinal stability increases as the centre of gravity moves forward. More stability means less manoeuvrability, i.e. more elevator force required to change pitch. The limit of the elevator capability will therefore limit the forward position of the centre of gravity.

4034. Airplane ATPL CPL On takeoff with the CG at the forward limit: A) elevator stick force is less because of the increased tail plane arm. B) elevator stick force to rotate the aircraft at VR will be unchanged, because the aircraft on the ground rotates about the main wheels. C) VMeG is lower due to the increased fin arm. D) elevator stick forces will be higher at YR' (Refer to figure 081-EI0) The horizontal tail must give a nose up moment big enough to attain the take off attitude at VR• The lift will provide some nose up moment (about the mail wheels), but the weight and the rolling friction will give a nose down moment. The further forward the CG is placed, the more extra tail load down force is required from the horizontal tail.

4057. Airplane ATPL CPL Manoeuvrability is best at: A) B) C) D)

aft CG position. forward CG position. high flap settings. low speed.

Static longitudinal stability decreases as the centre of gravity moves aft. Less stability means more manoeuvrability.

4079. Airplane ATPL CPL What is the effect on the aeroplanes static longitudinal stability of a shift of the centre of gravity to a more aft location and on the required control deflection for a certain pitch up or down? A) The static longitudinal stability is smaller and control deflection is larger. B) The static longitudinal stability is larger and control deflection is smaller. C) The static longitudinal stability is larger and control deflection is larger. D) The static longitudinal stability is smaller and control deflection is smaller.

the required the required the required the required

Static longitudinal stability decreases as the centre of gravity moves aft. Less stability means increased manoeuvrability, i.e. less elevator force required to change pitch.

21008. Airplane ATPL CPL . A downward adjustment of a trim tab in the longitudinal control system, has the following effect: A) B) C) D)

the stick force stability remains constant. the stick position stability increases. the stick position stability remains constant. the stick force stability decreases.

If the aircraft requires the control column to be moved rearward to increase the angle of attack and to trim at low airspeed and forward with decreasing angle of attack and at trim at high airspeeds, then the aircraft is said to have 'stick position stability'. This is not altered by deflection of the trim tab. Stick position stability, or stick force stability, is influenced by the position of the CG, not by trimming.

21012. Airplane ATPL CPL A negative contribution to the static longitudinal stability of conventional jet transport aeroplanes is provided by: A) B) C) D)

a fixed trim position. the tail. the fuselage. a fixed elevator deflection.

(Refer to figure 081-E27) A symmetrical body such as the fuselage develops an unstable pitching moment when given an angle of attack as shown in the illustration.

21020. Airplane ATPL CPL An aeroplane exhibits static longitudinal stability, if when the angle of attack increases: A) B) C) D)

the change in total aeroplane lift acts through the CG. the change in total aeroplane lift acts aft of the CG. the resulting moment is positive. the change in wing lift is equal to the change in tail lift.

A statically stable aircraft should create a nose down moment if the angle

of attack is increased. This moment comes from the total lift acting behind theCG.

21045. Airplane ATPL CPL During a phugoid the speed: A) varies significantly, as it does during a short period oscillation. B) remains approximately constant, as it does during a short period oscillation. C) varies significantly, whereas during a short period oscillation it remains approximately constant. D) remains approximately constant, whereas during a short period oscillation it varies significantly. (Refer to figure 081-E125) The long period phugoid oscillation is a gradual interchange of potential and kinetic energy about some equilibrium airspeed and altitude. Consequently, there is a significant variation in airspeed. In a short period oscillation the airspeed is nearly constant.

21099. Airplane ATPL CPL Positive static longitudinal stability means that a: A) nose up moment occurs with a speed change at constant angle of attack. B) nose down moment occurs after encountering an up-gust. C) nose down moment occurs with a speed change at constant angle of attack. D) nose up moment occurs after encountering an up-gust. (Refer to figure 081-E126) Static stability means that the aircraft has the tendency to return to equilibrium after a disturbance. An up-gust would increase the angle of attack, but the positive longitudinal static stability will create a nose down moment to bring the aircraft back to straight and level.

1 3999 (A) 1 4009 (A) 1 4034 (D) 1 4057 (A) 1 4079 (D) 121008 (C) 121012 (C) 121020 (8) 121045 (C) 121099 (8) 1

Aviationexam Test Prep Edition 2012 21105. Airplane Stick force per G:

ATPL

CPL

A) does not change with increasing altitude. B) is selected by the pilot by electronic means before each flight. C) is dependent on CG location. D) has a maximum value related to acceptable controllability, the minimum value is of no concern. (Refer to figure 081-E51) The stick force stability is proportional to the slope of the curve of stick force vs. speed as shown in the illustration. The more forward the CG, the steeper the curve and hence the higher the stick force stability.

Airplane ATPL CPL The aerodynamic contribution to the static longitudinal stability of the nacelles of aft fuselage mounted engines is: 21106.

A) zero. B) negative. C) positive. D) maximum during cruise.

21139. Airplane ATPL CPL Upward deflection of a trim tab in the longitudinal control results in:

A) the stick position stability remaining constant. B) increasing the stick position stability. C) increasing the stick force stability. D) the stick force stability remaining constant. For explanation refer to question #21008 on page 103.

21147. Airplane ATPL CPL What is the effect of elevator trim tab adjustment on the static longitudinal stability of an aeroplane?

A) Depends on the value of stick force/G. B) No effect. C) Aeroplane nose up trim increases the static longitudinal stability. D) Aeroplane nose down trim increases the static longitudinal stability. The static longitudinal stability is primarily determined by the position

(Refer to figure 081-E27) The nacelle will have a destabilising effect in itself as shown in the illustration. However, this means a down force at the tail end of the aircraft acting in the same direction of the tailplane lift. For the entire aircraft the nacelles will therefore be a positive contribution to the longitudinal stability.

21107. Airplane ATPL CPL The air loads on the horizontal tailplane (tail load} of an aeroplane in straight and level cruise flight:

A) will in principle be zero on transport aeroplanes without an electronic flight control system (Fly by Wire) due to the trim system. B) are generally directed upwards and will increase when CG is moved forward. C) are generally directed downwards and will become less negative when the CG moves aft. D) are generally directed downwards and will always become less negative in a linear fashion with increasing airspeed. (Refer to figure 081-EI8) As shown in the illustration, the wing lift will create a nose-down pitching moment that is countered by the negative tail load giving a nose-up moment. If the centre of gravity moves aft, the arm to the wing lift becomes smaller and the nose-down moment is decreased. In this case a smaller downwards tail load is required.

Airplane ATPL CPL The effect of the wing downwash on the static longitudinal stability of an aeroplane is: 21119.

A) negligible. B) negative. C) positive. D) smallest at high values of the lift coefficient. For explanation refer to question #23356 on page 26.

Airplane ATPL CPL The manoeuvre stability of a large jet transport aeroplane is 280 N/G. What stick force is required, if the aeroplane is pulled to the limit manoeuvring load factor from a trimmed horizontal straight and steady flight (cruise configuration)? 21125.

of the wings' aerodynamic centre in relation to the CG. Although the tail contributes to the stability, the trim tab position has no effect on the static longitudinal stability.

21154. Airplane ATPL CPL When an aeroplane has zero static longitudinal stability, the pitching moment coefficient "em" versus angle of attack line:

A) B) C) D)

is horizontal. is vertical. has a negative slope. has a positive slope.

(Refer to figure 081-E90)

21158. Airplane ATPL CPL When moving the centre of gravity forward the stick force perG will:

A) B) C) D)

decrease. not change. increase. change but only at very high speeds.

For explanation refer to question #21105 on this page.

21167. Airplane ATPL CPL Which of the following statements is correct?

1} A high limit load factor enables the manufacturer to design for a lower stick force per G. 2} The stick force per G is a limitation on the use of an aeroplane, which the pilot should determine from the Aeroplane Flight Manual. A) 1 is correct; 2 is correct. B) 1 is correct; 2 is incorrect. C) 1 is incorrect; 2 is incorrect. D) 1 is incorrect; 2 is correct. If the stick force per G becomes too low, there is a danger of over-stressing the aircraft inadvertently. If the aircraft has higher limit load factor, this danger obviously reduces. Among all the limitations on aircraft, the stick force per G is not one.

A} 1050 N B} 770 N C) 630 N D) 420N The limit load factor is 2,5, but since the load factor in level flight is 1, an increase of 1,5 is required. With the manoeuvre stability of 280 N/G, the required stick force to achieve 1,5 Gis: 280 N/G xl,S 420 N.

=

I 21105 (C)

121106 (C)

I 21107 (C) I 21119 (8) I 21125 (D) I 21139 (A) I 21147 (8) I 21154 (A) I 21158 (C) I 21167 (8) I

04 Stability 21181. Airplane ATPL CPL Which statement is correct?

A) During a phugoid altitude varies significantly, but during a short period oscillation it remains approximately constant. B) During both a phugoid and a short period oscillation altitude remains approximately constant. C) During both a phugoid and a short period oscillation altitude varies significantly. D) During a phugoid altitude remains approximately constant, but during a short period oscillation it varies significantly. (Refer to figure OBI-EI2S) The difference in altitude change can be appreciated in the illustration. Although the short period oscillation has an altitude change in the beginning, it is very quickly dampened to almost zero.

21182. Airplane ATPL CPL Which statement is correct?

A) The phugoid should always be heavily damped. B) The short period oscillation should always be heavily damped. C) When the phugoid is slightly unstable, an aeroplane becomes uncontrollable. D) A slightly unstable short period oscillation is no problem for an aeroplane. Since the short period oscillation can generate damaging flight loads due to the rapid changes in g loading, it is most important it is heavily dampened.

21184. Airplane ATPL CPL Which statement is correct?

1} Stick force per G is independent of altitude. 2) Stick force per G increases when the centre of gravity moves forward. A) B) C) D)

1 is correct; 2 is correct. 1 is incorrect; 2 is correct. 1 is correct; 2 is incorrect. 1 is incorrect; 2 is incorrect.

(Refer to figure OBI-EI07) The pitch damping of the aircraft is related to air density. At high altitudes, the high TAS reduces the change in tail angle ofattackfor a given pitch velocity and reduces the pitch damping. Thus, a decrease in manoeuvring stick force stability can be expected with increased altitude. See illustration (right). When the aircraft has high static stability, i.e. centre of gravity well forward, a high stick force gradient will result. See illustration (left).

23230. Airplane ATPL CPL The CG of an aircraft with a nose wheel is:

A) B) C) D)

forward of the main wheels. behind the main wheels. coincident with the nose undercarriage. in front of the nose wheel.

Forward of the main wheels; otherwise the aircraft would tip on the tail. Coincident or forward of the nose wheel is just pure nonsense.

Airplane ATPL CPL Changes in the centre of pressure of a wing affect the aircraft's: 23341.

A) B) C) D)

lift/drag ratio. lifting capacity. aerodynamic balance and controllability. drag.

Lift acting through the centre ofpressure causes a moment around the aircraft centre ofgravity. This moment is countered by the tailplane giving aerodynamic balance and thus positive stability. Stability and controllability are two sides of the same problem.

23357. Airplane ATPL CPL With the CG on the aft limit the control forces required to pitch

the aircraft would be: A) less than with a forward CG. B) more than with a forward CG. C) the same as with a forward CG. D) the same as with a neutral CG, but more than with a forward CG. For explanation refer to question #4079 on page 703.

23367. Airplane ATPL CPL If the maximum pull force acceptable is 50 Ibs and the design limit G of the aircraft is 6 G, what stick force/G must be achieved to permit the aircraft to be manoeuvred to its design G limit?

A) B) C) D)

10Ibs/G. 8,33 Ibs/G.

6Ibs/G. Sibs/G.

The limit load factor is 6, but since the load factor in level flight is I, an increase of5 is required. With the maximum allowable pull force of 50 Ibs, the stick force per Gis: 50 Ibs/5 G = 70 Ibs/G.

23386. Airplane ATPL CPL Moving the CG rearwards will:

A) B) C) D)

have no effect on stability. increase lateral stability. increase longitudinal stability. reduce longitudinal stability.

(Refer to figure OBI-E52) The destabilizing moment from the wing (Lxx) gets bigger if the CG moves rearwards. The static longitudinal stability will therefore decrease.

23387. Airplane ATPL CPL If the aircraft has a nose up pitch displacement, the effective angle of attack of the tail plane:

A) remains the same. B) changes and causes the tail plane to apply a nose down moment. C) changes and causes the tail plane to apply a nose up moment. D) will not change if the pitch up was due to elevator selection. (Refer to figure OBI-EI2) When the nose pitches up, the tailplane will move downwards and therefore increase the angle of attack. This will increase the taiJplane lift and cause a nose down moment.

23463. Airplane ATPL CPL The magnitUde of the stick force required to pitch, for an aircraft with manual controls, is determined by:

A) B) C) D)

the distance the CG is forward of the neutral point. the distance the CG is forward of the static margin. the distance the CG is forward of the forward CG limit. the neutral stability.

The magnitude of stick force depends on the amount of static longitudinal stability, which in turn depends on the distance between the neutral point and the CG.

23464. Airplane ATPL CPL The stick force gradient is:

A) the force required to change the load factor of the aircraft a given amount. B) the force required to hold the aircraft in a particular pitch attitude. C) due to the dynamic pressure. D) only supplied by an artificial feel unit. (Refer to figure OBI-EB3)

1 21181 (A) 1 21182 (8) 1 21184 (8) 123230 (A) 123341 (C) 123357 (A) 123367 (A) 123386 (D) 123387 (8) 123463 (A) 1 123464 (A) 1

Aviationexam Test Prep Edition 2012 The illustration shows stick force vs. load factor. The stick force gradient is the slope of the curve, and is therefore the force required to change the load factor.

23465. Airplane ATPL CPL For an aircraft with a manually operated elevator: A) B) C) D)

A) is constantly changing AOA making it difficult to reduce the magnitude of the oscillations. B) can be easily controlled by the pilot. C) will display poor trimming qualities. D) is displaying lateral dynamic instability.

the neutral point will be forward of the CG. the neutral point will be aft ofthe CG. the neutral point will be coincident with the CG. there will be a neutral point but no static margin.

(Refer to figure 081-E52) The neutral point is the centre of gravity position where the moment from the wing lift and the tail lift are equal, and the aircraft would be statically neutral. The centre ofgravity must therefore always be in front of the neutral point if the aircraft has manually operated controls, otherwise it would be impossible to fly.

23467. Airplane ATPL CPL For an aircraft in steady level flight, if the tail plane is producing a download, the CP ofthe wing must be: A) B) C) D)

forward of the CG. aft of the CG. coincident with the CG. coincident with the AC.

23484. Airplane ATPL CPL If a stick force of 20 Ibs is required to pull4 G from the position of trim, the stick force gradient is: 6,6Ibs/G Sibs/G 201bs/G 601bs/G

The stick force gradient is the force required to change the load factor. The required load factor is 4, but since the load factor in level flight is 1, an increase of 3 is required. If the stick force is 20 Ibs, the stick force gradient is: 20 Ibs.;. 3 G = 6,66IbsIG.

23541. Airplane ATPL CPL If the CG of an aircraft is moved from the aft limit to the forward limit, how will it affect the stalling speed and stick force? A) Increase stalling speed and stick force. B) Decrease the stalling speed and stick force. C) Decrease the stalling speed and increase the stick force. D) Increase the stalling speed and decrease the stick force. A forward CG means the tailplane must provide a larger down force to maintain equilibrium and thus the need for more lift that is provided by a higher angle of attack. Stall happens when the maximum C, is reached, and that will be at a higher speed when the CG is forward. The stability is increased by a forward CG which means a decrease in controllability. Therefore the stick force will increase.

23542. Airplane ATPL CPL When an aircraft's forward CG limit is exceeded, it will affect the flight characteristics of the aircraft by producing: A) B) C) D)

(Refer to figure 081-EI25) The long period phugoid oscillation is a gradual interchange of potential and kinetic energy about some equilibrium airspeed and altitude. Consequently, there is a significant variation in airspeed, but as the period of oscillation is great, it can easily be controlled by the pilot.

23574. Airplane ATPL CPL What is the position of the CG in relation to the neutral point when the CG is on the aft limit? A) B) C) D)

On the neutral point. Just behind the neutral point. Above the neutral point. In front of the neutral point.

For explanation refer to question #3964 on page 102.

If the tailplane produces a downward force, it gives a nose up moment. The wing lift must consequently produce a nose down moment. For this to happen the wing CP must be behind the CG.

A) B) C) D)

23543. Airplane ATPL CPL If the airspeed increases and decreases during longitudinal phugoid oscillations, the aircraft:

very light elevator control forces. higher stalling speeds and more longitudinal stability. improved performance since it reduces the induced drag. an extremely high tail down force.

(Refer to figure 081-E90) The illustration shows that the maximum lift coefficient decreases with the forward movement ofthe CG. A smallerCLMAXmeans higher stalling speed. Moving the CG forwards also increases the static longitudinal stability.

23575. Airplane ATPL CPL Forward and aft movement of the CG effect on stability and controllability will be: A) rearward movement of the CG will reduce controllability and stability. B) rearward movement of the CG will reduce controllability and increase stability. C) forward movement of the CG will increase stability and reduce controllability. D) forward movement of the CG will reduce stability and increase controllability. Static longitudinal stability increases as the CG moves forward. More stability means less controllability, so an increased static longitudinal stability requires bigger control deflections to achieve the same control.

23576. Airplane ATPL CPL Force on the tail and its effect on V 5 due to CG movement: A) if rearward gives a reduced down force on the will be higher. B) if forward gives a reduced down force on the will be higher. C) if rearward gives a reduced down force on the will be reduced. D) if rearward gives an increased down force on the will be reduced.

tail, Vs tail, Vs tail, Vs tail, Vs

(Refer to figure 081-E90) Moving the centre of gravity rearwards will decrease the Moment Arm of the nose-down moment from the wing lift. Consequently, the down force on the tail can be reduced. The illustration shows that the maximum lift coefficient increases with the rearward movement of the centre of gravity. A larger CLMAX means lower stalling speed.

23580. Airplane ATPL CPL Which of the following wing characteristics would be least affected by turbulence? A) B) C) D)

Straight wing. Swept back wing. winglets. Dihedral wing.

(Refer to figure 081-E93) A change in angle of attack has less influence on the lift coefficient of a swept wing.

I 23465 (8) I 23467 (8) I 23484 (A) I 23541

(A)

I 23542 (8) I 23543 (8) I 23574 (D) I 23575 (C) I 23576 (C) I 23580 (8) I

04 Stability

23690. Airplane ATPL CPL Long period (phugoid) oscillations are characterised by: A) B) C) D)

oscillations taking 5 seconds to damp out. constant speed. long period of damping. rapid and repeated changes in effective angle of attack.

(Refer to figure 081-f125) The long period phugoid oscillation is a gradual interchange of potential and kinetic energy about some equilibrium airspeed and altitude. Consequently, there is a significant variation in airspeed, but the period of oscillation is long.

23694. Airplane ATPL CPL What happens if CG moves behind the aft limit? A) B) C) D)

Stick forces become excessive. Lateral stability will be decreased. Insufficient manoeuvre stability. Longitudinal stability increases.

(Refer to figure 081-f101) As shown in the illustration, the stick force per G (slope of the lines) is reduced as the CG moves aft. There is a minimum value for the stick force per G not to lose the "feel" of the aircraft.

23705. Airplane ATPL CPL Short period oscillation is: A) B) C) D)

pilot induced and unstable. oscillation in pitch. oscillation in roll. oscillation in yaw.

(Refer to figure 081-f125) Concerning the subject of principles of flight, the short period oscillation is always in pitch.

24514. Airplane ATPL CPL The forward and aft CG limits are determined respectively by: A) B) C) D)

roll response, control forces. minimum control response, decreasing stability. Dutch roll, increasing stability. control forces, increasing stability.

Static longitudinal stability increases as the CG moves forward. More stability means less controllability, so an increased static longitudinal stability requires increased control deflections to achieve the same control. Moving the CG aft decreases the static longitudinal stability.

26973. Airplane ATPL CPL The phugoid motion is a long term oscillation around the: A) B) C) D)

normal axis. longitudinal axis. lateral axis. vertical axis.

(Refer to figure 081-£17) Since the oscillation is in pitch, it happens about the lateral axis.

26985. Airplane ATPL CPL If an airplane has poor longitudinal stability in flight, what can be done to increase the stability? A) B) C) D)

27010. Airplane ATPL CPL In order to remain in level balanced flight: A) the wing lift must be greater than weight, if the tailplane is giving a download for balance. B) the wing lift has to be less than weight, if the tailplane is giving a download for balance. C) the wing lift must be equal to weight. D) the wing lift must be less than weight at all times. (Refer to figure 081-£18) To maintain level flight the weight must be balanced by lift, but the force created by the tailplane must also enter the equation. Since the tailplane normally creates a downforce as shown in the illustration, the lift generated by the wings must be higher than the weight.

232368. Airplane ATPL CPL Given an aeroplane in steady, straight and level flight at low speed and considering the effects of centre of gravity (CG) location and thrust, the lowest value of wing lift occurs at: A) B) C) D)

aft CG and idle thrust. forward CG and idle thrust. forward CG and take-off thrust. aft CG and take-off thrust.

232618. Airplane ATPL CPL (Refer to figure 081-17) Assuming no pilot input the motion of the aeroplane in the diagram shows: A) B) C) D)

dynamic longitudinal instability. static longitudinal instability. dynamic longitudinal stability. neutral dynamic longitudinal stability.

Airplane ATPL CPL 232619. (Refer to figure 081-18) Assuming no pilot input the motion of the aeroplane in the diagram shows: A) static longitudinal instability. B) static longitudinal stability and dynamic longitudinal instability. C) static and dynamic longitudinal stability. D) neutral dynamic longitudinal stability. Airplane ATPL CPL 232633. The air loads on the horizontal tailplane (tail load) of an aeroplane in straight and level cruise flight are generally directed: A) downwards and will increase in magnitude as the CG moves aft. B) upwards and will increase in magnitude as the CG moves aft. C) upwards and will reduce in magnitude as the CG moves aft. D) downwards and will reduce in magnitude as the CG moves aft. For explanation refer to question #21107 on page 104.

Reduce in keel surface area. Install a yaw damper. Increase stabilizer surface area. Increase elevator range of movement.

Poor longitudinal stability is due to the stabilizer not providing sufficient balancing force. Increasing the surface area would correct this (ref. L=!6plflSCJ Increasing elevator range of movement would also help, but with an undesirable penalty in increased trim drag.

123690 (C) 123694 (C) 123705 (8) 1 24514 (8) 126973 (C) 126985 (C) 127010 (A) 1232368 (0) 1232618 (0) 1232619 (8) 1 1232633 (0) 1

Aviationexam Test Prep Edition 2012

232637. Airplane ATPL CPL Which of the following statements about static longitudinal stability is correct? I. A requirement for positive static longitudinal stability of an aeroplane is, that the neutral point is behind the centre of gravity. II. A wing with positive camber provides a positive contribution to static longitudinal stability, when the centre of gravity of the aeroplane is in front of the aerodynamic centre ofthe wing. A) B) C) D)

I is incorrect, II is correct. I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect.

Airplane ATPL CPL 232638. The neutral point of an aeroplane is the point where: A) the aeroplane becomes longitudinally unstable when the CG is moved beyond it in an aft direction. B) the velocity of the relative airflow is reduced to zero. C) assuming no flow separation, the pitching moment coefficient does not change with varying angle of attack. D) the boundary layer changes from laminar to turbulent. 232640. Airplane ATPL CPL The contribution of the wing to. the static longitudinal stability of an aeroplane: A) is always negative. B) depends on CG location relative to the wing aerodynamic centre. C) depends on the wing location relative to the fuselage. D) is positive if the wing has a positively cambered aerofoil section and the aerodynamic centre is ahead of the CG. 232643. Airplane ATPL CPL Longitudinal stability is directly influenced by: A) B) C) D)

wing dihedral. the vertical stabiliser. centre of gravity position. elevator deflection only.

232644. Airplane ATPL CPL Which CG position with respect to the neutral point ensures static longitudinal stability? A) B) C) D)

CG and neutral point at the same position. CG ahead ofthe neutral point. CG behind the neutral point. CG can be ahead of or behind the neutral point as long as the forward or aft CG limits are not exceeded.

232646. Airplane An aft CG shift: A) B) C) D)

ATPL

CPL

decreases longitudinal manoeuvrability. increases static longitudinal stability. has no influence on longitudinal manoeuvrability. decreases static longitudinal stability.

232650. Airplane An aft CG shift: A) B) C) D)

ATPL

CPL

has no influence on static longitudinal stability. increases static longitudinal stability. increases longitudinal manoeuvrability. decreases longitudinal manoeuvrability.

232651. Airplane A forward CG shift:

ATPL

CPL

A) increases static longitudinal stability. B) increases longitudinal manoeuvrability. C) decreases static longitudinal stability. D) has no influence on longitudinal manoeuvrability. Airplane 232652. A forward CG shift: A) B) C) D)

ATPL

CPL

decreases static longitudinal stability. has no influence on static longitudinal stability. increases longitudinal manoeuvrability. decreases longitudinal manoeuvrability.

232653. Airplane ATPL CPL (Refer to figure 081-23) Which line in the annexed Cm versus angle of attack graph shows a statically stable aeroplane? A) B) C) D)

Line 3. Line 4. Line 1. Line 2.

232654. Airplane ATPL CPL (Refer to figure 081-24) Which line in the diagram illustrates an aeroplane which is statically longitudinally stable at all angles of attack? A) B) C) D)

Line 1. Line 4. Line 2. Line 3.

232655. Airplane ATPL CPL (Refer to figure 081-29) Where on the curve in the diagram does the aeroplane exhibit static longitudinal stability? A) B) C) D)

Part 1. The whole curve. Part 3. Point 2.

232656. Airplane ATPL CPL (Refer to figure 081-29) Where on the curve in the diagram does the aeroplane exhibit neutral static longitudinal stability? A) B) C) D)

The whole curve. Part 3. Part 1. Point 2.

232647. Airplane ATPL CPL The aft CG limit can be determined by the: A) B) C) D)

maximum static longitudinal stability required. minimum acceptable static longitudinal stability. minimum acceptable elevator deflection. maximum elevator deflection available.

1232637(8) 1232638 (A) 1232640(8) 1232643 (C) 1232644(8) 1232646(0) 1232647(8) 1232650 (C) 1232651 (A) 1232652(0) 1 1232653 (A) 1232654 (8) 1232655 (A) 1232656 (0) 1

04 Stability

232658. Airplane ATPL CPL (Refer to figure 081-24) Which line in the diagram illustrates an aeroplane with neutral static longitudinal stability at all angles of attack?

A) Line 3. B) Line 2. C) Line 4. D) Line 1. Airplane ATPL CPL (Refer to figure 081-24) Which line in the diagram represents decreasing positive static longitudinal stability at higher angles of attack? 232659.

A) Line 4. B) Line 2. C) Line 3. D) Line 1. 232660. Airplane ATPL CPL (Refer to figure 081-24) Which line in the diagram represents an aeroplane with static longitudinal instability at all angles of attack?

A) Line 2. B) Line 4. C) Line 3. D) Line 1. 232661. Airplane ATPL CPL (Refer to figure 081-24) Which statement is correct regarding the pitching moment coefficient Cm versus angle of attack diagram?

A) Line 3 shows an aeroplane with increasing static longitudinal stability at high angles of attack. B) Line 4 shows an aeroplane with a greater static longitudinal stability at low angles of attack than that shown in line 3. C) Line 1 shows an aeroplane with reducing static longitudinal instability at very high angles of attack. D) Line 4 shows an aeroplane with reducing static longitudinal stability at very high angles of attack. 232662. Airplane ATPL CPL (Refer to figure 081-24) Which statement is correct regarding the pitching moment coefficient Cm versus angle of attack diagram?

A) Line 3 shows an aeroplane with increasing static longitudinal stability at high angles of attack. B) Line 4 shows an aeroplane with increasing static longitudinal stability at very high angles of attack. C) Line 1 shows an aeroplane with increasing static longitudinal instability at very high angles of attack. D) Line 4 shows an aeroplane with a greater static longitudinal stability at low angles of attack than that shown in line 3. 232663. Airplane ATPL CPL (Refer to figure 081-24) Which statement is correct regarding the pitching moment coefficient Cm versus angle of attack diagram?

stability at high angles of attack. 232664. Airplane ATPL CPL (Refer to figure 081-24) Which statement is correct regarding the pitching moment coefficient Cm versus angle of attack diagram?

A) Line 1 shows an aeroplane with increasing static longitudinal instability at very high angles of attack. B) Line 3 shows an aeroplane with increasing static longitudinal stability at high angles of attack. C) Line 3 shows an aeroplane with greater static longitudinal stability at low angles of attack than that shown in line 4. D) Line 4 shows an aeroplane with reducing static longitudinal stability at very high angles of attack. 232665. Airplane ATPL CPL (Refer to figure 081-29) Where on the curve in the diagram does the aeroplane exhibit static longitudinal instability?

A) The whole curve. B) Point 2. C) Part 1. D) Part 3. 232666. Airplane ATPL CPL (Refer to figure 081-27) The pitching moment versus angle of attack line in the diagram, which corresponds to a CG located at the neutral point of of a given aeroplane at low and moderate angles of attack is:

A) B) C) D)

line 2. line 3. line 4. line 1.

232668. Airplane ATPL CPL Which part of an aeroplane provides the greatest positive contribution to static longitudinal stability?

A) B) C) D)

The engine. The fuselage. The horizontal tail plane. Thewing.

Airplane ATPL CPL (Refer to figure 081-27) Which of these statements about the pitching moment coefficient versus angle of attack lines in the annex is correct? 232669.

A) The CG position is further aft at line 4 when compared with line 1. B) The CG position is further forward at line 4 when compared with line 1. C) Static longitudinal stability is greater at line 3 when compared with line 4 at low and moderate angles of attack. D) In its curved part line 2 illustrates a decreasing static longitudinal stability at high angles of attack.

A) Line 1 shows an aeroplane with increasing static longitudinally instability at very high angles of attack. B) Line 4 shows an aeroplane with greater static longitudinal stability at low angles of attack than that in shown line 3. C) Line 4 shows an aeroplane with reducing static longitudinal stability at very high angles of attack. D) Line 3 shows an aeroplane with reducing static longitudinal 1232658 (8) 1232659 (C) 1232660 (D) 1232661 (C) 1232662 (8) 1232663 (D) 1232664 (C) 1232665 (D) 1232666 (A) 1232668 (C) 1 1232669 (8) 1

Aviationexam Test Prep Edition 2012

232670. Airplane ATPL CPL (Refer to figure 081-27) Which of these statements about the pitching moment coefficient versus angle of attack lines in the annex is correct? A) Static longitudinal stability is greater at line 3 when compared with line 4 at low and moderate angles of attack. B) In its curved part at high angles of attack line 2 illustrates a decreasing static longitudinal stability. C) The CG position is further aft at line 1 when compared with line 4. D) The CG position is further forward at line 1 when compared with line 4.

Airplane ATPL CPL 232681. The CG of an aeroplane is in a fixed position forward of the neutral point. Speed changes cause a departure from the trimmed position. Which of these statements about the stick force stability is correct? A) An increase of 10 kts from the trimmed position at high speed has less effect on the stick force than an increase of 10 kts from the trimmed position at low speed. B) Maintaining a steady speed below the trim speed requires a push force. C) Stick force stability is not affected by trim. D) Aeroplane nose down trim increases the stick force stability. For explanation refer to question #3904 on page 101.

232671. Airplane ATPL CPL (Refer to figure 081-27) Which of these statements about the pitching moment coefficient versus angle of attack lines in the annex is correct? A) The horizontal part of line 2 illustrates static longitudinal instability. B) Static longitudinal stability is greater at line 3 when compared with line 4 at low and moderate angles of attack. C) In its curved part at high angles of attack line 2 illustrates increasing static longitudinal stability. D) The CG position is further aft at line 4 when compared with line 1. 232672. Airplane ATPL CPL (Refer to figure 081-27) Which of these statements about the pitching moment coefficient versus angle of attack lines in the annex is correct? A) Static longitudinal stability is greater at line 3 compared with line 4 at low and moderate angles of attack. B) In its curved part line 2 illustrates a decreasing static longitudinal stability at high angles of attack. C) Static longitudinal stability is greater at line 4 when compared with line 3 at low and moderate angles of attack. D) The CG position is further forward at line 1 when compared with line 4. 232680. Airplane ATPL CPL How can a pilot recognise static stick force stability in an aeroplane during flight?

232682. Airplane ATPL CPL How can a pilot recognise static stick force stability in an aeroplane during flight? A) To maintain a speed above the trim speed requires a pull force. B) To maintain a speed above the trim speed requires a push force. C) When speed decreases the push-force increases. D) The elevator stick force remains constant with speed changes. Airplane ATPL CPL 232684. Which statement concerning and control is correct?

longitudinal

stability

A) A down spring has the same function as a stick pusher. B) A bob weight reduces the stick force per g. C) A bob weight and a down spring have the same effect on the stick force stability. D) A down spring only improves the manoeuvre stability. Airplane ATPL CPL 232699. During a short period oscillation, the altitude: A) varies significantly, whereas during a phugoid it remains approximately constant. B) varies significantly, as it does during a phugoid. C) remains approximately constant, whereas during a phugoid it varies significantly. D) remains approximately constant, as it does during a phugoid.

A) When speed increases the pull force increases. B) To maintain a speed below the trim speed requires a push force. C) To maintain a speed below the trim speed requires a pull force. D) The elevator stick force remains constant with speed changes.

04-04 Static Directional Stability 3881. Airplane ATPL CPL The effect of a positive wing sweep on static directional stability is as follows: A) B) C) D)

negative dihedral effect. no effect. destabilizing dihedral effect. stabilizing effect.

(Refer to figure 081-£79) A swept wing in a sideslip is shown in the illustration. The inclination of the forward (right) wing to the relative airflow is greater than that of the rearward wing, so there is more lift, and hence more induced drag on the right side. The result of this discrepancy in drag on the two sides of the wing is a yawing moment to the right, which tends to eliminate the sideslip, i.e. a stabilising effect.

1232670(0) 1232671 (0) 1232672(0) 1232680(0) 1232681 (A) 1232682(8) 1232684(0) 1232699(0) 1 3881 (D)

04 Stability

3891. Airplane ATPL CPL The effect of a ventral fin on the static stability of an aeroplane is as follows: (l=longitudinal, 2=lateral, 3=directional) A) 1: no effect; 2: positive; 3: negative. B) 1: positive; 2: negative; 3: negative. C) 1: negative; 2: positive; 3: positive. D) 1: no effect; 2: negative; 3: positive. Ventral fins are placed on the underside of the fuselage (in the rear part). They will have most effect when the angle of attack is large. The force created by a ventral fin acts in the direction of the lateral axis below an behind the centre of gravity. This force will have no effect on the stability about the lateral axis, the longitudinal· stability; it will have a negative effect on the stability about the longitudinal axis, the lateral stability; and have . a positive effect on the stability about the normal axis, the directional stability.

3928. Airplane ATPL CPL Directional static stability is determined by: A) B) C) D)

aircraft weight. tail volume. fin area. elevator angle for trim.

The fin is the major contributor to static directional stability.

3944. Airplane ATPL CPL Which of the following gives an unstable contribution in sideslip? A) B) C) D)

Wing sweep. Flap extension. Dihedral. High wing.

(Refer to figure 087-E73) The deflection of flaps causes the inboard section of the wing to become relatively more effective and these sections have a smaller span wise Moment Arm. Therefore, the changes in wing lift due to sideslip occur closer inboard reducing the wing's stabilising effects.

3950. Airplane ATPL CPL An aeroplane has static directional stability in a side-slip to the right, initially the: A) B) C) D)

nose of the aeroplane tends to move to the left. right wing tends to go down. nose of the aeroplane will remain in the same direction. nose of the aeroplane tends to move to the right.

(Refer to figure 08H77) Sideslip angle "8" is positive to the right (sideslip to the right = nose pointing to the left, airflow coming from the right). In the illustration it is shown, that an aircraft with positive static directional stability (stable) subjected to a positive sideslip angle will result in a positive yawing moment coefficient (C.J, Apositive yawing moment coefficient gives a yaw to the right.

3966. Airplane ATPL CPL The primary function of the fin is to give: A) B) C) D)

lateral stability - arouhd the longitudinal axis. directional stability - around the normal axis. directional stability - around the longitudinal axis. directional stability - around the lateral axis.

(Refer to figure 08H77) The fin is the major contributor to static directional stability. Directional stability is about the normal axis.

21112. Airplane ATPL CPL The contribution of swept back wings to static directional stability: A) is nil. B) is negative. C) is positive.

D) decreases as the sweep back increases. For explanation refer to question #3887 on page 770.

21113. Airplane ATPL CPL The contribution to the static directional stability of a straight wing with high aspect ratio and without dihedral: A) B) C) D)

is always positive. is always negative. is always negligible. becomes more positive as the aspect ratio increases.

The contribution to the static directional stability of a straight wing alone is usually negligible.

26967. Airplane ATPL CPL Directional stability is the stability around the: A) B) C) D)

longitudinal axis. lateral axis. normal axis. pitch axis.

(Refer to figure 087-E77) Directional stability is in the lateral plane about the normal axis (Z axis).

27029. Airplane ATPL CPL Ventral fin has its greatest effect at: A) B) C) D)

speeds above McRlr transonic speed. low speed, high angle of attack. high wing loading.

For explanation refer to question #3897 on this page.

31231. Airplane ATPL CPL Increasing the size of the fin: A) increases lateral stability and directional control. B) increases the directional stability. C) reduces directional stability. D) reduces lateral stability. The fin is the major contributor to static directional stability. Increased area

of the vertical fin results in an increased directional stability. If the nose of an aircraft is yawed to the left, the airflow will strike the right-hand side of the vertical stabiliser. This unbalanced force on the right-hand side of the vertical stabilizer, behind the CG, will cause the nose of the aircraft to yaw to the right and thus restore the aircraft to flight parallel with the airflow.

232702. Airplane ATPL CPL Static directional stability is the: A) tendency of an aeroplane to recover from a skid with the rudder free. B) tendency of an aeroplane to recover from a disturbance about the lateral axis. C) natural ability of an aeroplane to recover from a disturbance about the longitudinal axis. D) tendency of an aeroplane to raise the low wing in a sideslip.

1 3891 (D) 1 3928 (C) 1 3944 (8) 1 3950 (D) 1 3966 (8) 1 21112 (C) 1 21113 (C) 126967 (C) 127029 (C) 1 31231 (8) 1 1232702 (A) 1

III

Aviationexam Test Prep Edition 2012 232703. Airplane ATPL CPL Which of these statements are correct or incorrect regarding a sideslip, with the relative airflow coming from the right, on an aeroplane that exhibits both directional and lateral stability? I. The initial tendency of the nose of the aeroplane is to move to the right. II. The initial tendency of the left wing is to move down. A) I is correct, II is correct. B) I is incorrect, I is correct. C) I is incorrect, II is incorrect. D) I is correct, II is incorrect.

232704. Airplane ATPL CPL Which of these statements are correct or incorrect regarding a sideslip, with the relative airflow coming from the right, on an aeroplane that exhibits both directional and lateral stability? I. The initial tendency of the nose of the aeroplane is to move to the left. II. The initial tendency of the right wing is to move down. A) I is correct, II is correct. B) I is correct, II is incorrect. e) I is incorrect, II is incorrect. D) I is incorrect, I is correct.

232705. Airplane ATPL CPL Which of these statements are correct or incorrect regarding a sideslip, with the relative airflow coming from the right, on an aeroplane that exhibits both directional and lateral stability? I. The initial tendency of the nose of the aeroplane is to move to the right. II. The initial tendency of the right wing is to move down. A) I is incorrect, II is incorrect. B) I is correct, II is incorrect. e) I is incorrect, I is correct. D) I is correct, II is correct.

232706. Airplane ATPL CPL Which of these statements are correct or incorrect regarding a sideslip, with the relative airflow coming from the right, on an aeroplane that exhibits both directional and lateral stability? I. The initial tendency of the nose of the aeroplane is to move to the left. II. The initial tendency of the left wing is to move down. A) B) e) D)

I is correct, II is incorrect. I is incorrect, II is incorrect. I is incorrect, I is correct. I is correct, II is correct.

232707. Airplane ATPL CPL Which of these statements are correct or incorrect regarding a sideslip, with the relative airflow coming from the left, on an aeroplane that exhibits both directional and lateral stability? I. The initial tendency of the nose of the aeroplane is to move to the left. II. The initial tendency of the right wing is to move down. A) B) e) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, I is correct. I is correct, II is incorrect.

232708. Airplane ATPL CPL Which of these statements are correct or incorrect regarding a sideslip, with the relative airflow coming from the left, on an aeroplane that exhibits both directional and lateral stability? I. The initial tendency of the nose of the aeroplane is to move to the right. II. The initial tendency of the left wing is to move down. A) B) e) D)

I is incorrect, I is correct. I is incorrect, II is incorrect. I is correct, II is correct. I is correct, II is incorrect.

232709. Airplane ATPL CPL Which of these statements are correct or incorrect regarding a sideslip, with the relative airflow coming from the left, on an aeroplane that exhibits both directional and lateral stability? I. The initial tendency of the nose of the aeroplane is to move to the left. II. The initial tendency of the left wing is to move down. A) B) e) D)

I is incorrect, I is correct. I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is incorrect.

232710. Airplane ATPL CPL Which of these statements are correct or incorrect regarding a sideslip, with the relative airflow coming from the left, on an aeroplane that exhibits both directional and lateral stability? I. The initial tendency of the nose of the aeroplane is to move to the right. II. The initial tendency of the right wing is to move down. A) B) e) D)

I is incorrect, II is incorrect. I is incorrect, I is correct. I is correct, II is correct. I is correct, II is incorrect.

232712. Airplane ATPL CPL An aeroplane has static directional stability if, when in a sideslip with the relative airflow coming from the left, initially the: A) B) e) D)

right wing tends to go down. nose of the aeroplane tends to yaw right. nose of the aeroplane tends to yaw left. nose of the aeroplane does not move.

232714. Airplane ATPL CPL Static directional stability is mainly provided by: A) B) e) D)

wing dihedral. wing anhedral. the elevator. the fin.

232717. Airplane ATPL CPL Which of the following provides a positive contribution to static directional stability? A) B) e) D)

Moving the centre of gravity aft. A forward swept wing. A dorsal fin. A low wing as compared with a high wing.

1232703 (A) 1232704 (C) 1232705 (B) 1232706 (C) 1232707 (A) 1232708 (B) 1232709 (B) 1232710 (B) 1232712 (C) 1232714 (D) 1 1232717 (C) 1

04 Stability

232718. Airplane ATPL CPL Which of the following statements is correct?

232719. Airplane ATPL CPL The purpose of a dorsal fin is to:

I. A dorsal fin increases the contribution of the vertical tail plane to the static directional stability, in particular at large angles of sideslip. II. A dorsal and a ventral fin both have a positive effect on static lateral stability. A) B) C) D)

A) B) C) D)

provide pitch and yaw control. maintain static directional stability at large sideslip angles. reduce tendency for spiral instability. stabilise forebody vortices.

I is correct, II is incorrect. I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is correct.

04-05 Static Lateral Stability 3868. Airplane ATPL CPL With a swept wing aircraft, with an increase in altitude, which of the following statements about lateral stability is correct? A) Static lateral stability increases. B) Static lateral stability stability decreases. C) Static lateral stability increases. D) Static lateral stability decreases.

increases, dynamic lateral stability

3901. Airplane Dihedral of the wing: A) B) C) D)

remains the same, dynamic lateral decreases, dynamic lateral stability

CPL

is the only way to increase the static lateral stability. increases the static lateral stability. is only positive for aeroplanes with high mounted wings. decreases the static lateral stability.

For explanation refer to question #224799 on page 8.

3870. Airplane ATPL CPL Which of the following lists aeroplane features that each increase static lateral stability? Fuselage mounted engines, dihedral, T-tail. Low wing, dihedral, elliptical wing planform. High wing, sweep back, large and high vertical fin. Sweep back, under-wing mounted engines, winglets.

Of the features mentioned in the answers, the only ones contributing positively to the static lateral stability are: dihedral, high wing, sweep back and large fin (vertical stabilizer).

3908. Airplane ATPL CPL The effect of a swept wing is to give: A) B) C) D)

greater;greater the same; lower lower; greater the same; greater

positive dihedral effect. negative dihedral effect. decreased roll-with-yaw effect. adverse yaw effect.

(Refer to figure 081-E09) The illustration shows an aircraft in a sideslip due to roll to starboard. The wing into the wind has less sweep and an increased lift and the wing out of the wind has more sweep and a decrease in lift. This difference in lift generates a rolling moment that will roll the wings towards level. This is an effect similar to the dihedral effect.

3937. Airplane ATPL CPL What happens to lateral stability when flaps are extended? A) B) C) D)

3886. Airplane ATPL CPL Considering the lateral stability of a swept wing aircraft, at high flight levels the static lateral stability will be __ _ and the dynamic lateral stability will be ___ • A) B) C) D)

ATPL

increases, dynamic lateral stability

The static lateral stability, whatever constructive features contribute, will be independentofthe altitude. However, increasing altitude will decrease aerodynamic damping, which is the major factor in the dynamic stability.

A) B) C) D)

the aircraft to level flight. High wing has therefore a positive dihedral effect.

Lateral stability is decreased. Lateral stability is increased as lift is increased. Lateral stability is unaffected, as the wings are symmetrical. Lateral stability is increased as the centre of pressure moves inboard.

(Refer to figure 087-£13) The deflection of flaps causes the inboard section of the wing to become relatively more effective and these sections have a smaller span wise Moment Arm. Therefore, the changes in wing lift due to sideslip occur closer inboard reducing the lateral stability.

For explanation refer to question #3868 on this page.

3942. Airplane ATPL CPL Which of the following statements about dihedral is correct?

3897. Airplane ATPL CPL The effect of a high wing with zero dihedral is as follows: A) B) C) D)

A) Dihedral is necessary for the execution of slip-free turns. B) Effective dihedral is the angle between the 114-chord line and the lateral axis of the aeroplane. C) Dihedral contributes to dynamic but not to static lateral stability. D) The effective dihedral of an aeroplane component means the contribution of that component to the static lateral stability.

its only purpose is to ease aeroplane loading. negative dihedral effect. positive dihedral effect. zero dihedral effect.

(Refer to figure 081-E75) The illustration shows a high wing aircraft in a sideslip. Because the air has to pass the fuselage, the down going wing will have a greater angle of attack than the up going, and therefore the down going wing produces more lift than the up going. This creates a stabilising roll moment that tends to return

1232718 (A) 1232719 (8)

I

3868 (8)

I

3870 (C)

I

3886 (8)

I

For explanation refer to question #224799 on page 8.

3897 (C)

I

3901 (8)

I

3908 (A)

I

3937 (A)

I

3942 (0)

Aviationexam Test Prep Edition 2012 3954. Airplane ATPL CPL Which wing design feature decreases the static lateral stability of an aeroplane?

A) B) C) D)

Increased wing span. Dihedral. High wing. Anhedral.

21103. Airplane ATPL CPL Static lateral stability should not be too large, because:

(Refer to figure 081-£23) Anhedral has the opposite effect of dihedral. Anhedral decreases the static lateral stability.

3958. Airplane ATPL CPL Which statement is correct for a side slip condition at constant speed and side slip angle, where the geometric dihedral of an aeroplane is increased?

A) The required lateral control force does not change. B) The required lateral control force decreases. C) The required lateral control force increases. D) The stick force per G decreases.

A) too much rudder deflection would be required in a crosswind landing. B) too much aileron deflection would be required in a crosswind landing. C) constant aileron deflection would be required during cruise in case of crosswind. D) the roll trim sensitivity would increase sharply. A high static lateral stability reduces the controllability in roll. In case of a crosswind landing, the static lateral stability would tend to roll the aircraft away from the crosswind. This would mean more aileron deflection required to maintain level flight.

21120. Airplane ATPL CPL The effect on static lateral stability of an aeroplane with a high wing as compared with a low wing is:

For explanation refer to question #224799 on page 8.

A) zero dihedral effect. B) a negative dihedral effect. C) no effect as it is only used to improve aeroplane loading. D) a positive dihedral effect.

Airplane ATPL CPL Lateral static stability is determined by: 3959.

A) aircraft response to sideslip. B) aspect ratio. C) wingspan. D) CG position. Stability is always determined by the reaction to a disturbance. In this case, a sideslip is the only disturbance mentioned, and that is disturbance about the longitudinal axis and thus related to lateral stability.

4043. Airplane ATPL CPL To hold a given sideslip angle and airspeed, increased geometric dihedral would:

A) reduce the stick force to zero. B) have no effect on stick force. C) decrease the stick force. D) increase the stick force. Increased dihedral will increase the static lateral stability. To hold angle, the control force must be increased.

a sideslip

21070. Airplane ATPL CPL How can the designer of an aeroplane with straight wings increase the static lateral stability?

A) By increasing the aspect ratio of the vertical stabiliser, whilst maintaining a constant area. B) By fitting a ventral fin (a fin at the under side of the aeroplane). C) By applying wing twist. D) By increasing anhedral. Ventral fin and increasing anhedral would both decrease the lateral stability, whereas wing twist has no effect. Increasing the aspect ratio of the fin would provide a better static lateral stability, since that would produce a larger correcting force in case of a sideslip.

Airplane ATPL CPL Positive static lateral stability is the tendency of an aeroplane to: 21098.

A) roll to the left in the case of a sideslip angle (with the aeroplane nose pointing to the right of the incoming flow). B) roll to the left in the case of a sideslip (with the aeroplane nose pointing to the left of the incoming flow). C) roll to the right in a right turn. D) roll to the left in a right turn. The static lateral stability should not roll the aircraft in

in a sideslip. If the nose of the aircraft is to the left of the incoming flow, the sideslip is to the right. Positive static lateral stability would in this case roll the aircraft to the left to bring the wings back to level.

(Refer to figure 081-£75) The illustration shows the difference between a high wing and low wing aircraft in a sideslip. Because the air has to pass the fuselage, in case of the high wing, the down going wing will have a greater angle of attack than the up going, and therefore the down going wing produces more lift than the up going. This creates a stabilizing roll moment that tends to return the aircraft to level flight. High wing has therefore a positive dihedral effect. The opposite explanation for the low wing shows, the low wing has a negative dihedral effect.

21172. Airplane ATPL CPL Which statement concerning sweep back is correct?

A) Sweep back provides a positive contribution to static lateral stability. B) Sweep back increases speed stability at Mach numbers above McRir C) Sweep back is mainly intended to increase static directional stability. D) A disadvantage of sweep back is that it decreases McR,r (Refer to figure 081-£09) As shown in the illustration, if the wing is at positive lift coefficient, the wing into the wind (right) has less sweep and an increase in lift and the wing out of the wind (left) has more sweep and a decrease in lift; a negative rolling moment (to the left) will be generated tending to roll the wings towards level. The swept back wing therefore increases the static lateral stability.

23384. Airplane ATPL CPL For an aircraft with neutral static roll stability, following awing drop:

A) the wing would tend to return to the level position. B) the wing would continue to drop. C) the wing would remain in its displaced position. D) the forces of lift and weight would remain in balance. (Refer to figure 081-£126)

A body with neutral static stability, when replaced from equilibrium, has no tendency to return to equilibrium. In this case, the aircraft would continue with the wing in the displaced position.

a turn, but it will

1 3954 (0) 1 3958 (C) 1 3959 (A) 1 4043 (0) 121070 (A) 121098 (8) 1 21103 (8) 1 21120 (0) 1 21172 (A) 123384 (C) 1

04 Stability

23692. Airplane ATPL CPL Which of the following will increase lateral stability? A) Dihedral, wing mounted engines, high wing. B) High wing, high vertical stabiliser, sweep back. C) Low wing, dihedral, elliptical plan form. D) Anhedral, low wing, sweep back. For explanation refer to question #3870 on page 773.

27019. Airplane ATPL CPL Compared to a rectangular wing, a swept wing will for a given angle of attack and wing area: A) B) C) D)

be more laterally stable and produce less lift. produce more lift and be more laterally stable. increase lateral stability with reduced tip stall tendency. advance McRlr

(Refer to figure 087-E79) A swept wing in a sideslip is shown to the left in the illustration. The inclination of the forward (right) wing to the relative airflow is greater than that of the rearward wing, so there is more lift, and hence more induced drag on the right side. The result of this discrepancy in drag on the two sides of the wing is a yawing moment to the right, which tends to eliminate the sideslip, i.e. a stabilising effect. On the right hand side in the illustration are the lift coefficient curves for a straight and a swept wing. The swept wing has a smaller CL for a given angle of attack, so with the same wing area and angle of attack, the swept wing produces less lift.

232722. Airplane ATPL CPL Excessive static lateral stability is an undesirable characteristic for a transport aeroplane because: A) it would result in a proportional decline in static directional stability. B) it would impose excessive demands on roll control during a sideslip. C) it would result in excessive wing loading during a co-ordinated turn. D) performing co-ordinated turns would be very difficult. 232723. Airplane ATPL CPL Which design features improve static lateral stability? 1) High wing. 2) Low wing. 3) Large and high vertical fin. 4) Ventral fin. The combination that regroups all of the correct statements is: A) 1,3

232728. Airplane ATPL CPL An increase in geometric dihedral in a steady sideslip condition at constant speed would: A) decrease the required lateral control force. B) increase the required lateral control force. C) decrease the stick force per g. D) not affect the required lateral control force. 232731. Airplane ATPL CPL The primary purpose of dihedral is to: A) B) C) D)

increase static directional stability. increase dynamic stability. increase static lateral stability. decrease sensitivity to Dutch roll.

For explanation refer to question #224799 on page 8.

232732. Airplane ATPL CPL Static lateral stability will be decreased by: A) B) C) D)

increasing the size of the vertical tail. the use of a low, rather than high, wing mounting. increasing wing sweepback. reducing wing anhedral.

232733. Airplane ATPL CPL Static lateral stability will be decreased by: A) B) C) D)

reducing wing anhedral. increasing the size of the vertical tail. reducing wing sweepback. the use of a high, rather than low, wing mounting.

Airplane ATPL CPL 232734. Static lateral stability will be increased by: A) B) C) D)

reducing wing anhedral. reducing wing sweep back. reducing the size of the vertical tail. the use of a low, rather than high, wing mounting.

232735. Airplane ATPL CPL Static lateral stability will be increased by: A) reducing the size of the vertical tail. B) reducing wing sweep back. C) increasing wing anhedral. D) the use of a high, rather than low, wing mounting.

B) 2,4 C) 1,4

Airplane ATPL CPL 232736. Static lateral stability will be increased by:

D) 2,3 232725. Airplane Wing dihedral:

ATPL

CPL

A) is the only way of ensuring static lateral stability. B) is particularly applied on aeroplanes with high mounted wings. C) does not affect static lateral stability. D) contributes to static lateral stability. For explanation refer to question #224799 on page 8.

232726. Airplane ATPL CPL Static lateral stability will be decreased by: A) B) C) D)

increasing wing anhedral. the use of a high, rather than low, wing mounting. increasing wing sweepback. increasing the size of the vertical tail.

A) B) C) D)

the use of a low, rather than high, wing mounting. increasing wing sweep back. increasing wing anhedral. reducing the size of the vertical tail.

Airplane ATPL CPL 232737. Which design features improve static lateral stability? 1) Anhedral. 2) Dihedral. 3) Forward sweep. 4) Sweep back. The combination that regroups all of the correct statements is: A) 2,3 B) 1,3

C) 2,4 D) 1,4

123692(8) 1 27019 (A) 1232722(8) 1232723 (A) 1232725(0) 1232726 (A) 1232728(8) 1232731 (C) 1232732(8) 1232733 (C) 1 1232734 (A) 1232735(0) 1232736(8) 1232737 (C) 1

Aviationexam Test Prep Edition 2012

232738. Airplane ATPL CPL Which design features reduce static lateral stability?

A) 2,3 B) 1,4 C) 1,3

1) High wing. 2) Low wing. 3) Large and high vertical fin. 4) ventral fin.

D) 2,4

The combination that regroups all of the correct statements is:

A) 2,4 B) 2,3

232761. Airplane ATPL CPL One advantage of mounting the horizontal tail plane on top of the vertical fin is: A) B) C) D)

C) 1,3

D) 1,4

232739. Airplane ATPL CPL Which design features reduce static lateral stability?

to decrease the susceptibility to deep stall. to improve the aerodynamic efficiency of the vertical fin. that it does not require a de-icing system. to decrease fuel consumption by creating a tail-heavy situation.

1) Anhedral. 2) Dihedral. 3) Forward sweep. 4) Sweepback. The combination that regroups all ofthe correct statements is:

04-06 Dynamic Lateral/Directional Stability 3774. Airplane ATPL Which of the following flight phenomena can happen at Mach numbers below the critical Mach number? A) B) C) D)

Dutch roll. Tuck under. Mach buffet. Shock stall.

an increased downward lifting force of the horizontal stabilizer, the aircraft will pitch down. This is referred to as the "Mach Tuck" or "Tuck under':

3880. Airplane ATPL CPL An aircraft is placed in a level balanced turn and the controls released. It is spirally unstable if: A) . B) C) D)

the bank steadily increases. the bank remains the same. the bank reduces. the pitch attitude increases.

(Refer to figures 081-E25 and 081-E82) Only the Dutch Roll phenomenon can appear when the aircraft is flying at a speed below its Critical Mach number. The other phenomena => Tuck under (also referred to as the "Mach Tuck"), Mach buffet and Shock stall are all associated with speeds at or above the critical mach number. Consequently, none of these 3 phenomena can appear below the Critical Mach number.

(Refer to figure 081-E126) Spirally unstable means that the aircraft enters a spiral dive. This happens when the bank angle increases in a level balanced turn without pilot input.

The critical mach number is a speed below M 1 at which first part of the airflow over the upper surface of the wing first exceeds a local speed of M 1 - it is because the airflow around the upper wing surface is accelerated as it flows over the cambered wing. At this point a shock wave is created

3917. Airplane ATPL CPL Which of the following statements about static lateral and directional stability is correct?

at the position where the accelerated airflow reaches supersonic speed. Typically this is at around 25% of the wing chord. The airflow ahead ofthe shock wave is laminar, but a boundary layer separation occurs behind the shock wave and the wing stops producing lift in this area. The separated boundary layer causes buffeting (Mach buffet), just like with a low speed stall. It is an indication of an impending shock stall (loss of lift due to formation of shock waves). The acceleration of the airflow over the upper wing surface will be most pronounced on sections where the wing has the largest camber => typically at the wing root close to the fuselage. This is therefore the first place where the shock waves start to form as the aircraft exceeds the critical mach number. Since we now have a section of the wing which does not produce lift and this section is located close to the fuselage, consequently the Centre of Pressure (CP) - the imaginary point through which the summation ofall of the wing's lifting forces is said to act as a single lift vector - moves away from the fuselage closer towards the wing tips, because that's where more of the lift is produced now. Since transport jet airplanes use the swept wing design it means that as the CP moves away from the fuselage towards the tips it also moves aft as the wing sweeps aft.

A) The effects of static lateral and static directional stability are completely independent of each other because they take place about different axis. B) An aeroplane with an excessive static directional stability in relation to its static lateral stability, will be prone to spiral dive (spiral instability). C) An aeroplane with an excessive static directional stability in relation to its static lateral stability, will be prone to Dutch roll. D) Static directional stability can be increased by installing more powerful engines. When the directional stability is great compared to the lateral stability, the aircraft- when disturbed - would quickly yaw into the wind whilst the weaker lateral stability would not roll the wings level. The sideslip would continue and the nose turn into the wind again etc., ending up in a spiral dive.

Along the longitudinal axis of the aircraft, the CP is located behind the Centre of Gravity (CG) of the aircraft, thus creating a constant pitch-down moment which is counterbalanced in flight by the downward lift of the horizontal stabilizer. As the CP moves further aft as a result of the shock wave formation its distance from the fixed CG increases and thus a pitch down moment is created. If this increased pitch down moment is not compensated by

1232738(A) 1232739 (C) 1232761 (8) 1 3774 (A)

1 3880 (A) 1 3917 (8)

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04 Stability

3933. Airplane ATPL CPL Which aeroplane behaviour will be corrected by a yaw damper? A) Spiral dive. B) Tuck under. C) Dutch roll. D) Buffeting. Aircraft with a tendency to Dutch roll are fitted with yaw damper. This automatically displaces the rudder proportional to the rate ofyaw to damp out the oscillation.

3943. Airplane ATPL CPL Sensitivity for spiral dive will occur when: A) the static directional stability is negative and the static lateral stability is positive. B) the static directional stability is positive and the static lateral stability is relatively weak. C) the static lateral and directional stability are both negative. D) the Dutch roll tendency is too strongly suppressed by the yaw damper. For explanation refer to question #3917 on page 116.

3952. Airplane ATPL CPL With increasing altitude and constant lAS the static lateral stability (i) and the dynamic lateral/directional stability (ii) of an aeroplane with swept back wing will: A) B) C) D)

(i) increase; (ii) increase. (i) increase; (ii) decrease.

(i) decrease; (ii) decrease. (i) decrease; (ii) increase.

reversing the coupled oscillations. This is called Dutch roll. Dutch roll might occur when the lateral stability is large compared to the directional stability. Therefore, the moments involved are roll and yaw. The CG position has little influence on the lateral stability, but an aft CG will reduce the directional stability because the Moment Arm of the stabilizing moment from the fin will decrease and thus increasing the possibility of Dutch roll.

15717. Airplane ATPL CPL Which one of the following systems suppresses the tendency to Dutch roll? A) B) C) D)

Rudder limiter. Yaw damper. Roll spoilers. Spoiler mixer.

For explanation refer to question #3933 on this page.

21080. Airplane ATPL CPL Ifthe static lateral stability of an aeroplane is increased, whilst its static directional stability remains constant: A) its sensitivity to Dutch roll increases. B) its spiral stability decreases. C) turning flight becomes more difficult. D) the nose-down pitching moment in a turn increases. Forexplanation refer to question #4017 on this page.

21104. Airplane ATPL CPL Static lateral stability should not be too small because: A) the aeroplane would show too strong a tendency to spiral dive. B) after a disturbance around the longitudinal axis the aeroplane would show too strong a tendency to return to the original attitude. C) the stick force per G would become unacceptably small. D) the aeroplane would show too strong a tendency to Dutch roll.

The contribution ofsweep back to dihedral effect is proportional to the wing lift coefficient. At higher altitude the density decreases which mean a larger angle of attack is needed to produce a higher lift coefficient. Therefore, the contribution of sweep back to dihedral effect increases and thus the static lateral stability increases. The roll and yaw damping of the aircraft is related to air density. At high altitudes, the high TAS reduces the change in wing angle of attack for a given roll/yaw velocity and reduces the roll damping. Therefore, the dynamic lateral and directional stability decreases.

Spiral divergence (spiral dive) might occur when the directional stability is large compared to the lateral stability. This imbalance would occur if the static lateral stability becomes too small.

4000. Airplane ATPL CPL An aircraft's tendency to Dutch roll may be reduced by:

21152. Airplane ATPL CPL What will increase the tendency to Dutch roll?

A) B) C) D)

reducing the size of the fin. giving the wings an angle of anhedral. sweeping the wings. giving the aircraft longitudinal dihedral.

With a dominant lateral stability this will, when a yaw is introduced, roll the aircraft due to the lift increase on the wing into the wind. The increased induced drag on the rising wing will yaw the aircraft in the opposite direction, reversing the coupled oscillations. This is called Dutch roll. Dutch roll might occur when the lateral stability is large compared to the directional stability. Therefore, the moments involved are roll and yaw. The CG position has little influence on the lateral stability, but an aft CG will reduce the directional stability because the Moment Arm of the stabilizing moment from the fin will decrease and thus increasing the possibility of Dutch roll. To reduce the aircraft tendency to Dutch roll, either the lateral stability should be decreased or the directional stability increased. Of the given possibilities, anhedral would decrease the lateral stability.

4017. Airplane ATPL CPL Which moments or motions interact in a Dutch roll? A) B) C) D)

Rolling and yawing. Pitching and yawing. Pitching and rolling. Pitching and adverse yaw.

With a dominant lateral stability this will, when a yaw is introduced, roll the aircraft due to the lift increase on the wing into the wind. The increased induced drag on the rising wing will yaw the aircraft in the opposite direction,

A) B) C) D)

An increased static lateral stability. An increased static directional stability. A forward movement of the centre of gravity. An increased anhedral.

For explanation refer to question #4017 on this page.

27022. Airplane ATPL CPL An aeroplane is sensitive to Dutch roll when: A) static lateral stability is much more pronounced than static directional stability. B) static lateral stability is much less pronounced than static directional stability. C) static stability is less pronounced than dynamic stability. D) an aeroplane has anhedral. For explanation refer to question #4017 on this page.

27026. Airplane ATPL CPL A yaw damper is a system which: A) B) C) D)

increase lateral stability. decrease lateral stability. increases directional stability. reduce the stall speed.

The yaw damper is a device that automatically displaces the rudder proportional to the rate of yaw to avoid Dutch roll. This phenomenon might occur

1 3933 (C) 1 3943 (8) 1 3952 (8) 1 4000 (8) 1 4017 (A) 1 15717 (8) 121080 (A) 1 21104 (A) 1 21152 (A) 127022 (A) 1 127026 (e) 1

Aviationexam Test Prep Edition 2012

when static lateral stability is large compared to static directional stability. 232743. Airplane ATPL CPL An .example of a combined lateral and directional aperiodic motion isa:

A) short period oscillation. B) phugoid. e) Dutch roll. D) spiral dive. 232745. Airplane ATPL CPL What is the recommended action following failure of the yaw damper(s) of a jet aeroplane, flying at normal cruise altitude and speed prior to encountering Dutch roll problems?

A) Reduce altitude and Mach number. B) No action is required. e) Manually recover any subsequent Dutch roll motion using rudder. D) Increase Mach number to improve aerodynamic damping of any subsequent Dutch roll motion. 232751. Airplane ATPL CPL An example of a combined lateral and directional periodic motion isa:

A) spiral dive. B) Dutch roll. e) short period oscillation. D) phugoid.

1232743(0) 1232745 (A) 1232751 (8) 1

III

OS Control

CONTROL 05-01 General 3956. Airplane ATPL CPL If the sum of moments in flight is not zero, the aeroplane will rotate about:

C) longitudinal axis and the horizontal plane. D) speed vector axis and the longitudinal axis.

The aircraft always rotates about its centre ofgravity.

(Refer to figure 081-E19) Most often, the angles are referenced to the surface of the Earth. The pitch angle is defined as the angle between the longitudinal axis of the aircraft and the horizon. Pitch is usually represented by the Greek letter (pronounced "theta"). The illustration shows the definitions of angle of attack a, measured with respect to the velocity vector, and pitch angle measured with respect to the horizon.

4001. Airplane ATPL CPL Rolling is the rotation of the aeroplane about the:

23360. Airplane ATPL CPL The normal axis of an aircraft is:

A) B) C) D)

A) B) C) D)

the aerodynamic centre of the wing. the neutral point of the aeroplane. the centre of gravity. the centre of pressure of the wing.

4051. Airplane ATPL CPL Rotation around the longitudinal axis is called: sideslip rolling pitching yawing

A) B) C) D)

15713. Airplane ATPL CPL Rotation about the lateral axis is called: yawing slipping pitching rolling

16680. Airplane ATPL CPL The axes of an aircraft by definition must all pass through the: flight desk. aircraft datum. centre of pressure. centre of gravity.

21127. Airplane ATPL CPL The pitch angle is defined as the angle between the: A) chord line and the horizontal plane. B) longitudinal axis and the chord line. 3956 (C) 1 4001 (A) 1 4051 (8)

(Refer to figure 081-E17) Lateral control is about the longitudinal axis using ailerons.

A) B) C) D)

by ailerons around the longitudinal axis. by rudder around the normal axis. by elevator around the lateral axis. by rudder around the longitudinal axis.

(Refer to figure 081-E17) Directional control is by the rudder that turns the aircraft about the normal axis.

23493. Airplane ATPL CPL The elevators control the aircraft around:

(Refer to figure 081-E17) The axes of an aircraft always pass through the centre of gravity.

t

the ailerons around the lateral axis. the elevators around the lateral axis. the rudder around the normal axis. the ailerons around the longitudinal axis.

23416. Airplane ATPL CPL Directional control is:

(Refer to figure 081-E17) The lateral axis is perpendicular to the longitudinal axis in the same plane. Movements about this axis is pitch.

A) B) C) D)

(Refer to figure 081-E17) The normal axis is normal (perpendicular) to the longitudinal axis. The axes of an aircraft always pass through the centre of gravity.

23390. Airplane ATPL CPL Lateral control is given by:

(Refer to figure 081-E17) Roll is about the longitudinal axis.

A) B) C) D)

e,

A) t~e axis passing from nose to tail of the aircraft. B) an axis through the CP, perpendicular to the longitudinal axis. C) an axis through the CG, perpendicular to the longitudinal axis. D) the axis which is a straight line passing through the CG which is parallel to a line passing through the wing tips.

longitudinal axis. vertical axis. lateral axis. wing axis.

(Refer to figure 081-E17) Roll is about the longitudinal axis.

A) B) C) D)

e

A) B) C) D)

the lateral axis. the longitudinal axis. the normal axis. the horizontal stabiliser.

(Refer to figure 081-E17) The elevator controls the aircraft in pitch, which is movement about the lateral axis.

1 15713 (C) 116680 (0) 1 21127 (C) 123360 (C) 123390 (0) 1 23416 (8) 1 23493 (A) 1

Aviationexam Test Prep Edition 2012

24064. Airplane ATPL CPL Rolling is a __ movement about the ___ axis. A) B) C) D)

lateral; lateral lateral; longitudinal longitudinal; lateral longitudinal; longitudinal

26981. Airplane ATPL CPL Pitch is movement around the:

(Refer to figure 081-E17) Roll is a movement about the longitudinal axis and therefore in the lateral plane.

26388. Airplane A pitching motion is: A) B) C) D)

ATPL

CPL

about the lateral axis, related to longitudinal stability. about the lateral axis, related to lateral stability. about the longitudinal axis, related to lateral stability. about the longitudinal axis, related to longitudinal stability.

(Refer to figure 081-E17) Pitch is about the lateral axis, and the stability about that axis is longitudinal stability.

26767. Airplane ATPL CPL The lateral axis is also called the: A) B) C) D)

pitch axis. normal axis. roll axis. horizontal axis.

26829. Airplane Rudder controls:

ATPL

CPL

yaw pitch roll turn

(Refer to figure 081-E17) Rudder is for control in yaw about the normal axis.

26975. Airplane ATPL CPL The pilot uses the rudder to provide control around the: A) B) C) D)

A) B) C) D)

longitudinal axis. vertical axis. yaw axis. lateral axis.

(Refer to figure 081-E17) Pitch is about the lateral axis as shown in the illustration.

26999. Airplane ATPL CPL The movement of an aircraft is defined along three axes which all pass through: A) B) C) D)

the centre of pressure. the centre of gravity. the intersection of the centrelines of the fuselage and wings. the intersection of the normal vertical datum.

(Refer to figure 081-E17) The aircraft is said to move about its centre ofgravity. The three axes therefore pass through that point.

232771. Airplane ATPL CPL Aeroplane manoeuvrability increases for a given control surface deflection when:

(Refer to figure 081-E17) The lateral axis is perpendicular to the longitudinal axis in the same plane. The movement about the lateral axis is therefore pitch, and hence the lateral axis is sometimes termed the pitch axis.

A) B) C) D)

(Refer to figure 081-E17) The rudder is used for control in yaw, which is about the normal axis.

lateral axis. normal axis. longitudinal axis. turn axis.

A) B) C) D)

flaps are retracted at constant lAS. the CG moves forward. lAS decreases. lAS increases.

Airplane ATPL CPL 232772. Aeroplane manoeuvrability decreases for a given control surface deflection when: A) B) C) D)

flaps are retracted at constant lAS. the CG moves aft. lAS increases. lAS decreases.

233068. Airplane ATPL CPL An aeroplane's flight path angle is defined as the angle between its: A) speed vector and the horizontal plane. B) longitudinal axis and the horizontal plane. C) speed vector and its longitudinal axis. D) lateral axis and the horizontal plane.

05-02 Pitch (Longitudinal) Control 3927. Airplane ATPL CPL In a twin-engined jet powered aeroplane (engines mounted below the low wings) the thrust is suddenly increased. Which elevator deflection will be required to maintain the pitching moment zero?

The engine thrust from underslung engines will act below the centre of gravity and therefore give a nose up moment. To create a balancing nose down moment, the tailplane must generate positive lift. For this to happen, the elevator must be deflected downwards.

A) Down. B) Up. C) No elevator movement will be required because the thrust line of the engines remains unchanged. D) It depends on the position of the centre of gravity. 124064 (8) 126388 (A) 1 26767 (A) 126829 (A) 1 26975 (8) 126981 (D) 126999 (8) 1232771 (D) 1232772 (D) 1233068 (A) 1 1 3927 (A) 1

05 Control

3971. Airplane ATPL CPL Which ofthe following is the reason for putting the horizontal stabiliser on top of the fin, known as aT-tail? A) To improve ground clearance during takeoff and landing on a contaminated runway. B) To decrease the tendency for super stall. C) To improve the aerodynamic efficiency of the vertical tail. D) To improve the wing efficiency. The tailplane mounted on top of the fin will act as an endplate that will check any span wise flow along the fin, which otherwise could lead to a breakaway of the flow near the top of the fin in a sideslip.

3977. Airplane ATPL CPL An advantage of locating the engines at the rear of the fuselage, in comparison to a location beneath the wing, is: A) B) C) D)

a wing which is less sensitive to flutter. easier maintenance of the engines. less influence on longitudinal control of thrust changes. lighter wing construction.

Engines located at the rear of the fuselage will have the thrust line in close proximity to the longitudinal axis of the aircraft. The thrust will therefore exercise a smaller pitching moment compared to engines located beneath the wing.

4031. Airplane ATPL CPL When the control column is moved forward and to the right: A) the elevator goes down, the right aileron moves down and the left aileron moves up. B) the elevator goes up, the right aileron moves up and the left aileron moves down. C) the elevator goes down, the right aileron moves up and the left aileron moves down. D) the elevator goes up, the right aileron moves down and the left aileron moves up. Control column forward = nose will pitch-down. In order for the nose to pitch down the tail must go up => positive lift on the elevator => elevator will move down. Control column to the right = roll to the right. For the aeroplane to roll to the right the right wing must go down (lift is decreased => right aileron moves up to decrease the lift) and the left wing must go up (lift is increased => left aileron must move down to increase the lift).

4040. Airplane AWL CPL An aircraft is approaching to land with its CG at the forward limit. It will be ___ to flare and VREF will be _ than normal. A) B) C) D)

difficult; higher easy; lower easy; higher difficult; lower

Static longitudinal stability increases as the centre of gravity moves forward. More stability means less manoeuvrability, i.e. more elevator force required to change pitch. It will therefore be more difficult to flare, and with less pitch control, the angle of attack is limited which will increase V. EF •

4060. Airplane AWL CPL When the CG position is moved forward, the elevator deflection for a manoeuvre with a load factor >1 will be: A) B) C) D)

larger. smaller. unchanged. dependent on trim position.

Static longitudinal stability increases as the centre of gravity moves forward. More stability means less manoeuvrability, i.e. more elevator force required to change pitch. It will therefore be necessary to deflect the elevator more to achieve the increased angle of attack to produce additional lift for a manoeuvre with n > 7.

Airplane ATPL CPL 4069. What is the advantage of a variable incidence tail plane over a fixed incidence tail plane with elevator and trim tab? A) B) C) D)

Linkages and mechanism less complicated. Increased flight stability and less weight. Less trim drag and maximum elevator authority retained. Elevator movement is restricted at high speed.

A movable tailplane has less drag than the combination of tailplane, elevator and trim tabs, especially at high speeds. It is also very powerful and gives an increased ability to trim for larger centre ofgravity and speed range.

16664. Airplane AWL CPL A pitch up could be caused by: A) B) C) D)

forward movement of the centre of gravity. a reduction in varying loads due to G. forward movement ofthe centre of pressure. lateral movementofthe centre of gravity.

Normally the centre of pressure is aft of the centre of gravity causing a nose down moment which is neutralized by negative lift on the tailplane. If the centre ofpressure moves forward, this nose down moment decreases, and a pitch up follows.

16677. Airplane AWL CPL When an aircraft pitches up, the angle of attack of the tailplane will: A) remain the same. B) depend solely upon the rigger's angle of incidence. C) decrease. D) increase. (Refer to figure 087-E72) When the aircraft pitches up the tailplane will be subject to a downwards movement. This in turn makes the tailplane experience an upwards component of airflow. This component added to the TAS provides an increase in the angle of attack of the tailplane.

21011. Airplane ATPL CPL A jet transport aeroplane exhibits pitch up when thrust is suddenly increased from an equilibrium condition, because the thrust line is below the: A) CG.

B) drag line of action. C) neutral point.

D) centre of pressure. The aircraft pitches about the CG. A pitch up therefore means that the force must act from below the CG and that's where you have the engines mounted on the pylons "hanging" below the wings => their thrust-line is located below the CG, causing a pitch-Up moment if thrust is increased.

23292. Airplane AWL CPL On a high wing aircraft, when the undercarriage is lowered: A) B) C) D)

a nose up pitch moment will occur. a nose down pitch moment will occur. the CP will move aft. the CG will move aft.

The undercarriage will give an extra drag force that acts below the centre ofgravity. This force will create a moment about the centre ofgravity that gives pitch down.

23361. Airplane ATPL CPL If an increase in power tends to make the nose of an aeroplane rise, this is the result of the: A) B) C) D)

line of thrust being below the CG. centre of lift being ahead of the CG. centre of lift and CG being collocated. line of thrust being above the CG.

For explanation refer to question #27071 on this page.

1 3971 (C) 1 3977 (C) 1 4031 (C) 1 4040 (A) 1 4060 (A) 1 4069 (C) 116664 (C) 116677 (0) 1 21011 (A) 123292 (8) 1 123361 (A) 1

Aviationexam Test Prep Edition 2012 23371. Airplane ATPL CPL On an aircraft with an all-moving tail plane, backward movement ofthe control wheel in flight causes:

A) an increase in tail plane incidence and nose up pitch. B) an upward movement of the trimming tab and nose up pitch. C) an increase in tail plane incidence and nose down pitch. 0) a decrease in tail plane incidence and nose up pitch. (Refer to figure 081-fI8) As shown in the illustration, the wing lift will create a nose-down pitching moment that is countered by the negative tail load giving a nose-up moment. The tailplane therefore operates with a negative angle of attack. A pull force on the controls means a pitch-up, and the tailplane must produce more negative lift. To accomplish this, the incidence of the tailplane is decreased to get an increased negative angle of attack.

23419. Airplane ATPL CPL If an aircraft has a down load on the tail plane, as the elevator is lowered:

A) the down load is increased. B) the down load is decreased. C) the down load remains the same unless the tail plane incidence is changed. 0) the negative camber is increased. (Refer to figure 081-fI8) As shown in the illustration, the wing lift will create a nose-down pitching moment that is countered by the negative tail load giving a nose-up moment. If the elevator is lowered on the tailplane at negative angle of attack, it means a smaller (negative) angle of attack, and hence a decrease in the negative tail load.

23487. Airplane ATPL CPL When the landing gear is lowered, given that the CG does not move longitudinally, to maintain level flight, the download on the tail plane must:

A) increase. B) decrease. C) remain the same. 0) increase or decrease, depending on whether the position of the lowered landing gear is fore or aft of the CG. The lift acting through the centre of pressure aft of the centre of gravity will cause a nose down moment about the centre of gravity. To counter this, the tailplane must generate a downward acting force. Lowered landing gear produces drag that acts below the centre of gravity and causes a nose down moment. Even more downward force is then required from the tailplane.

23681. Airplane ATPL CPL When is the greatest up elevator angle required for landing?

A) Flaps extended with a forward CG. B) Flaps extended and an aft CG. C) Flaps up with a forward CG. 0) Flaps up with an aft CG. The speed is low at landing and the angle of attack is required to be high. Therefore a large down force is required from the tailplane and the elevator must be moved up. Flaps fully down will increase down wash at the tail and reduce the dynamic pressure at the tail, both of which are destabilising, i.e. produce a nose up tendency. This calls for moving the elevator upwards. A forward centre of gravity will increase the Moment Arm of the wing lift noseup moment, also calling for moving the elevator upwards.

Airplane ATPL CPL When ice is present on the stabilizer, deflection of flaps may cause: 26765.

A) B) C) 0)

the stabilizer to stall and a pitch up situation. the stabilizer to stall and a vertical dive. both wings and stabilizer to stall. a roll movement due to directional instability.

distorted, and its stalling angle reduced. This could cause the tailplane to stall, particularly if the downwash is increased as a result of lowering flaps (it causes the angle ofattack on the horizontal stabilizer increase). With the tailplane stalled its downward acting lift would be reduced and the aircraft would suddenly pitch down and could be recovered only with difficulties, if at all.

26974. Airplane ATPL CPL The purpose of the horizontal stabilizer is to:

A) give the aeroplane sufficient longitudinal stability. B) give the aeroplane sufficient directional stability. C) give the aeroplane enough weight in the tail. 0) give the aeroplane sufficient lateral stability. (Refer to figure 081-fI8) The lift acting through the centre of pressure causes a nose down moment. The tailplane giving negative lift gives a nose up moment balancing the lift moment. Any disturbance that change the angle ofattack of the wing will also change the angle of attack on the tailplane that reverse the disturbance.

Airplane ATPL CPL The elevator deflection required for a given manoeuvre will be: 232764.

A) larger for an aft CG position when compared to a forward position. B) the same at all speeds. C) larger for a forward CG position when compared to an aft position. 0) larger at high lAS when compared to low lAS. 232765. Airplane ATPL CPL For a given elevator deflection, aeroplane longitudinal manoeuvrability increases when:

A) lAS decreases. B) the CG moves aft. C) flaps are retracted at constant lAS. 0) the CG moves forward. 232766. Airplane ATPL CPL Which statement is about CG limits is correct?

A) The aft CG limit is determined by the maximum elevator deflection available. B) If the aft CG limit is correctly chosen, the forward CG limit is automatically determined as well. C) The forward CG limit is mainly determined by the amount of pitch control available from the elevator. 0) The forward CG limit is determined by stability considerations only. Airplane ATPL CPL The elevator deflection required for a given manoeuvre will be: 232767.

A) larger for an aft CG position when compared to a forward position. B) smaller at high lAS when compared to low lAS. C) the same at all speeds. 0) the same for all CG positions. 232768. Airplane ATPL CPL The elevator deflection required for a given manoeuvre will be:

A) larger at low lAS when compared to high lAS. B) the same at all speeds. C) larger for an aft CG position when compared to a forward position. 0) the same for all CG positions.

If ice forms on the tailplane leading edge, its aerofoil shape will be

1 23371 (0) 1 23419 (8) 1 23487 (A) 1 23681 (A) 126765 (8) 1 26974 (A) 1232764 (C) 1232765 (8) 1232766 (C) 1232767 (8) 1 1232768 (A) 1

05 Control 232769. Airplane ATPL CPL The elevator deflection required for a given manoeuvre will be:

A) the same at all speeds. B) smaller for a aft CG position when compared to an forward position. C) larger at high lAS when compared to low lAS. D) larger for an aft CG position when compared to a forward position.

A) The elevator must be deflected upwards. B) No elevator deflection be will required because the thrust line of the engines remains unchanged. C) The elevator must be deflected downward. D) The amount of elevator deflection is independent of CG location. 232781. Airplane ATPL CPL The function of ailerons is to rotate the aeroplane about the:

A) B) C) D)

Airplane ATPL CPL For a given elevator deflection, aeroplane longitudinal manoeuvrability decreases when: 232770.

A) B) C) D)

the CG moves aft. flaps are retracted at constant lAS. the CG moves forward. lAS increases.

longitudinal axis. lateral axis. yaw axis. normal axis.

232794. Airplane ATPL CPL Rotation about the longitudinal axis of an aeroplane can be achieved by:

A) B) C) D)

Airplane ATPL CPL On a jet aeroplane (engines mounted below the low wing) the thrust is suddenly increased. Which of these statements is correct about the elevator deflection required to maintain zero pitching moment? 232773.

elevator deflection and/or slat extension. aileron deflection and/or rudder deflection. symmetrical spoiler deflection and/or elevator deflection. speed brake extension or wing flap deflection.

05-03 Yaw (Directional) Control 4073. Airplane ATPL CPL Left rudder input will cause:

A) left yaw about the vertical axis and left the longitudinal axis. B) right yaw about the vertical axis and right the longitudinal axis. C) left yaw about the vertical axis and right the longitudinal axis. D) right yaw about the vertical axis and left the longitudinal axis.

23392. Airplane ATPL CPL A symmetrical fin will give a side force:

roll about

A) B) C) D)

roll about roll about roll about

Left rudder input causes a left yaw. The right wing will travel a bit faster than the left and create more lift giving a roll to the left.

The rudder acts like a flap and causes a force to the opposite side. The fin, being the major contributor to directional stability, will experience an angle of attack in case ofa rudder application and during the yaw, when a force counteracting the yaw is created. 23494. Airplane ATPL CPL When the rudder pedals are moved to cause a yaw to the left:

23359. Airplane ATPL CPL The fin of an aircraft is a symmetrical aerofoil:

A) the left pedal is moved forward to the right. B) the right pedal is moved forward to the left. C) the left pedal is moved forward to the left: D) the right pedal is moved forward to the right.

A) It will only provide an aerodynamic force when the rudder is moved. B) It will give drag, but no lift because it is a symmetrical aerofoil. C) It can give no lift, only drag. D) It could stall if the fin angle of attack is too great. Like any other aerofoi! the fin will stall if the angle of attack exceeds the critical angle of attack. 23370. Airplane ATPL CPL If the right rudder is pushed forward:

A) the rudder moves to the left and the aircraft yaws to the right. B) the rudder moves to the right and the aircraft yaws to the left. C) the rudder moves to the right and the aircraft yaws to the right. D) the rudder moves to the left and the aircraft yaws to the left. Right rudder input makes the rudder deflect to the right, and the aircraft yaws to the right.

with rudder neutral and no yaw. only when rudder is applied. only when the aircraft yaws. when rudder is applied and when the aircraft yaws.

and the rudder moves and the rudder moves and the rudder moves and the rudder moves

A yaw to the left requires a force to the right from the fin/rudder. The rudder acts like a flap and causes a force to the opposite side. Therefore the rudder must turn left which is done by left pedal moving down. 26381. Airplane ATPL CPL During flight the yaw pedals are used to control:

A) B) C) D)

aircraft heading, balance, slip and skid. aircraft direction, slip and skid. turning, balance, direction and slip. direction of movement and heading.

The rudder is used for control in yaw, not as a directional control as this could cause spiral divergence.

1232769 (8) 1232770 (C) 1232773 (C) 1232781 (A) 1232794 (8) 1 4073 (A) 126381 (A) 1

123359 (D) 1 23370 (C) 123392 (D) 123494 (C) 1

Aviationexam Test Prep Edition 2012 232711. Airplane ATPL CPL An aeroplane's sideslip angle is defined as the angle between the: A) B) C) D)

lateral axis and the horizontal plane. speed vector and the horizontal plane. speed vector and normal axis. speed vector and the plane of symmetry.

Airplane ATPL CPL 232759. Rotation around the normal axis is called: A) B) C) D)

yawing. slipping. rolling. pitching.

05-04 Roll (Lateral) Control 3969. Airplane ATPL CPL Which of the following devices is used to counter adverse yaw on rolling into or out of a turn? A) B) C) D)

Differential ailerons. A yaw damper. A dorsal fin. Vortex generators.

Adverse yaw is caused by the difference in drag between the up- and downgoing aileron. The down-going increases lift and thus induced drag, whereas the up-going decreases lift and induced drag. Differential ailerons are geared to let the up-going aileron move through a larger angle than the down-going causing larger drag on the up-going and less drag on the down-going, and so reducing the difference in drag.

3976. Airplane ATPL CPL During initiation of a turn with speed brakes extended, the roll spoiler function induces a spoiler deflection: A) on the down-going wing only. B) upward on the up-going wing and downward on the downgoing wing. C) on the up-going wing only. D) downward on the up-going wing and upward on the downgoing wing. (Refer to figure 081-E76) As shown in the illustration where the lower picture shows a turn to the left, the roll spoiler input would be to decrease the deflection on the up-going wing and increase it on the down-going.

3987. Airplane ATPL CPL Which of the following statements concerning control is correct? A) In general the maximum downward elevator deflection is larger than upward. B) On some aeroplanes, the servo tab also serves as a trim tab. C) Hydraulically powered control surfaces do not need mass balancing. D) In a differential aileron control system the control surfaces have a larger upward than downward maximum deflection. (Refer to figure 081-E61) With differential ailerons the up-going aileron moves more (greater deflection) than the down-going one. The decreased deflection of the down-going aileron (up-going wing, where more lift is created by the aileron) results in a lower induced drag. At the same time the greater deflection of the up-going aileron creates more. form drag. This situation helps to reduce the difference in drag on both wings and thus lower the adverse aileron yaw effect.

3995. Airplane ATPL CPL The f1aperon is a control that operates simultaneously as: A) flaps and ailerons. B) elevators and ailerons. C) flaps and speed brakes.

D) flaps and elevators. (Refer to figure 081-E24) As the name implies, flaperons are a combination of flaps and ailerons. Working in symmetry, they work as flaps; working differentiated, they will work as ailerons.

4007. Airplane ATPL CPL Differential aileron deflection: A) increases the CLMAX • B) is required to keep the total lift constant when ailerons are deflected. C) equals the drag ofthe right and left aileron. D) is required to achieve the required roll-rate. For explanation refer to question #3987 on this page.

4020. Airplane ATPL CPL When are outboard ailerons (if present) de-activated? A) B) C) D)

Flaps (and slats) retracted or speed above a certain value. Flaps (and/or slats) extended or speed below a certain value. Landing gear retracted. Landing gear extended.

Outboard (low speed) ailerons are locked-out as the flaps retract and the aeroplane accelerates to a certain speed. At low speeds both sets of ailerons work, but at high speed only the inboard ailerons respond to control input.

4048. Airplane ATPL CPL How is adverse yaw compensated for during entry into and roll out from a turn? A) B) C) D)

Anti-balanced rudder control. Horn-balanced controls. Differential aileron deflection. Servo tabs.

For explanation refer to question #3987 on this page.

4058. Airplane ATPL CPL In an aircraft fitted with spoilers for lateral control, and not deployed as speed brakes, a roll to the right is initiated by: A) B) C) D)

right spoiler extended, left spoiler retracted. both spoilers extended. left spoiler extended, right spoiler retracted. right spoiler extended, but left spoiler extended more.

(Refer to figure 081-E76) Spoilers decrease the lift. Spoilers are often used not only as speed brakes, but they also aid in roll control. In the second case they extend asymmetrically - they extend on the upper surface of the down-going wing to assist aileron in decreasing the lift. In a roll only the spoiler on the down going wing will be extended - the spoiler on the up-going wing remains stowed.

If the spoilers are extended for the purpose of speed brakes and then the aeroplane enters a turn, the deflection of the spoiler on the up-going wing is reduced, while the spoiler deflection on the down-going wing is increased.

1232711 (D) 1232759 (A) 1 3969 (A) 1 3976 (0) 1 3987 (0) 1 3995 (A) 1 4007 (C)

------------------

1 4020 (A)

1 4048 (C) 1 4058 (A) 1

OS Control In this case: a roll to the right requires less lift on the right wing, so the spoiler on the right wing is extended, whilst the spoiler on the left wing is not moved to maintain the lift on the left wing.

4072. Airplane ATPL CPL One method to compensate adverse yaw is a:

A) differential aileron. B) balance tab. C) antibalance tab. 0) balance panel. For explanation refer to question #3987 on page 124.

16685. Airplane ATPL CPL If a turbulent gust causes an aeroplane to roll:

A) the down-going wing experiences a decrease in angle of attack. B) the down-going wing experiences an increase in angle of attack. C) the down-going wing has no angle of attack. 0) the angle of attack depends on whether the aeroplane changes speed. (Refer to figure 081-E41)

As shown in the illustration, the aircraft TAS in a vectorial addition with the vertical gust velocity to give an effective airflow from below. The angle of attack will therefore increase.

20879. Airplane ATPL CPL A jet aeroplane equipped with inboard and outboard ailerons is cruising at its normal cruise Mach number. In this case:

A) only the inboard ailerons are active. B) only the outboard aileron are active. C) the inboard and outboard ailerons are active. 0) only the spoilers will be active, not the ailerons. At low speeds the outboard aiierons produce sufficient force for lateral control, whereas at high speeds they would create excessive moments -large enough to cause possible structural damage. At low speeds both outboard and inboard ailerons are used for roll control. Once the flaps are retrocted after takeoff and the aeroplane accelerates above a certain speed, the outboard ailerons become locked in their neutral position and only the inboard ailerons are used. If roll spoilers are fitted, they are also used during high-speed flight to assist the inboard ailerons.

Airplane ATPL CPL An aeroplane is provided with spoilers and both inboard and outboard ailerons. Roll control during cruise is provided by: 21027.

A) B) C) 0)

outboard ailerons and roll spoilers. inboard ailerons and roll spoilers. inboard and outboard ailerons. outboard ailerons only.

For explanation refer to question #20879 on this page.

21089. Airplane ATPL CPL In what phase of flight are the outboard ailerons (if fitted) not active?

A) B) C) 0)

Takeoff, until lift-off. Cruise. Approach. Landing with a strong and gusty crosswind, to avoid overcontrolling the aeroplane.

For explanation refer to question #20879 on this page.

Airplane ATPL CPL Which component of drag increases most when an aileron is deflected upwards? 21164.

A) Induced drag. 1 4072 (A)

B) Interference drag. C) Wave drag. 0) Form drag. An upwards deflected aileron decreases lift and thus decreases induced drag. It does, however, change the profile of the wing and causes eddies. It therefore increases form drag.

23358. Airplane ATPL CPL While an aircraft is rolling, the down-going and up-going wing:

A) provides a force to increase the rate of roll. B) provides a damping force which reduces the rate of roll. C) has a reduced effective angle of attack. 0) will stall due to the increased effective angle of attack. (Refer to figure 081-E41)

As shown in the illustration, for the down-going wing the aircraft TAS in a vectorial addition with the vertical velocity to give an effective airflow from below. The angle of attack and the lift will therefore increase. On the up-going wing the effective airflow will come from above and decrease angle of attack and lift. This change in lift will cause a roll moment in the opposite direction than the roll of the aircraft providing a damping effect.

Airplane ATPL CPL On an aircraft on which the ailerons are assisted by spoilers to give lateral control, if the control wheel is turned to the right: 23373.

A) the right aileron moves up, right spoiler remains retracted, left spoiler moves up, left aileron down. B) the right aileron moves up, right spoiler up, left spoiler remains retracted, left aileron down. C) the right aileron moves down, right spoiler up, left spoiler remains retracted, left aileron up. 0) the right aileron moves up, right spoiler up, left spoiler moves up only slightly, left aileron down. (Refer to figure 081-E76) Spoilers are often used not only as speed brakes, but they also aid in roll control. In the second case they extend asymmetrically - they extend on the upper surface of the down-going wing to assist aileron in decreasing the lift. In a roll only the spoiler on the down going wing will be extended - the spoiler on the up-going wing remains stowed. If the spoilers are extended for the purpose of speed brakes and then the aeroplane enters a turn, the deflection of the spoiler on the up-going wing is reduced, while the spoiler deflection on the down-going wing is increased. In this case: control input to the right gives a roll to the right. The left wing must create more lift than the right wing. The left aileron will move down, whilst the right aileron moves up. Spoilers can only reduce lift, so the left spoiler is not moved, whilst the right moves up.

23389. Airplane ATPL CPL For a given lAS and angle of aileron deflection, increasing altitude will:

A) B) C) 0)

reduce the rate of roll. increase the rate of roll. increase the rate of turn. reduce the rate of turn.

With a constant lAS the aerodynamic damping decreases with altitude. The rate of roll will therefore increase.

23394. Airplane ATPL CPL The aileron on which the leading edge protrudes below the wing when the aileron is raised, but not above it when the aileron is lowered is:

A) B) C) 0)

a differential aileron. a drooped aileron. a frise aileron. a mass balanced aileron.

(Refer to figure 081-E57)

116685 (8) 120879 (A) 121027 (8) 121089 (8) 121164 (0) 123358 (8) 123373 (8) 123389 (8) 123394 (C) 1

Aviationexam Test Prep Edition 2012 Adverse yaw is caused by the difference in drag between the up- and downgoing ailerons. The down-going aileron increases lift and thus induced drag, whereas the up-going decreases lift and induced drag. Frise ailerons have an asymmetrical leading edge; the leading edge of the up-going aileron protrudes below the lower surface of the wing, causing high drag. The leading edge of the down-going aileron remains shrouded and causes less drag. This difference in drag reduces the adverse yaw.

23398. Airplane ATPL CPL Spoilers are operated asymmetrically: A) B) C) D)

to provide pitch control. to provide roll control. to provide yaw control. as air brakes in flight.

(Refer to figure 081-E76) Spoilers are often used not only as speed brakes, but they also aid in roll control. In the second case they extend asymmetrically - they extend on the upper surface of the down-going wing· to assist aileron in decreasing the lift. In a roll only the spoiler on the down-going wing will be extended - the spoiler on the up-going wing remains stowed. If the spoilers are extended for the purpose of speed brakes and then the aeroplane enters a turn, the deflection of the spoiler on the up-going wing is reduced, while the spoiler deflection on the down-going wing is increased.

23417. Airplane ATPL CPL When the control column is moved back and to the left: A) B) C) D)

the elevators move down and the left aileron moves down. the left aileron moves up and the elevators move up. the elevators move up and the left aileron moves down. the left aileron moves down and the elevators move down.

Control column moved back means a nose-up pitch, i.e. the elevator moves up to create a larger down force. Control column moved to the left means a roll to the left => the right aileron moves down (to increase the lift on the right - up going wing) while the left aileron moves up (to decrease the lift on the left - down going wing).

23422. Airplane ATPL CPL Adverse yaw during a turn entry is caused by: A) decreased induced drag on the lowered wing and increased induced drag on the raised wing. B) increased induced drag on the lowered wing and decreased induced drag on the raised wing. C) increased parasite drag on the raised wing and decreased parasite drag on the lowered wing. D) decreased induced drag on the raised wing and decreased induced drag on the lowered wing. Adverse yaw is caused by the difference in drag between the up- and downgoing ailerons. The down-going aileron (on the up-going wing) increases lift and thus increases induced drag, whereas the up-going aileron (on the downgoing wing) decreases lift and induced drag. The difference in the amounts of drag on each wing yaws the aeroplane to the opposite of the roll (roll to the left =yaw to the right).

23423. Airplane ATPL CPL When rolling out of a steep banked turn, what causes the lowered aileron to create more drag than when rolling into the turn? A) The wing being raised is travelling faster through the air than the wing being lowered. B) The wing being lowered is travelling faster through the air and producing more lift than the wing being raised. C) The angle of attack of the wing being raised is greater as the rollout is started. D) None of the above. During a banked turn the angle of attack is higher than at level flight to provide sufficient lift for maintaining altitude. Therefore, as the rollout is started, the lowered aileron will increase the angle of attack even more. When rolling into the bank, the lowered aileron would increase the angle of attack, but then

from a smaller initial angle.

23427. Airplane ATPL CPL When an aircraft is rolled to the left, adverse aileron yaw will be reduced: A) by a frise aileron being effective on the left wing. B) by frise ailerons producing increased drag on both surfaces. C) by the leading edge of the down-goirig aileron protruding into the airflow. D) by the down-going aileron moving through a greater angle of deflection than the up-going aileron. For explanation refer to question #23394 on page 125.

23485. Airplane ATPL CPL On an aircraft with a differential aileron control system, when the control wheel is turned to the right: A) the right aileron moves up, and the left aileron moves down through a greater angle. B) the right aileron moves down and the left aileron moves up through a greater angle. C) the left aileron moves down and the right aileron moves up through a greater angle. D) the left aileron moves up and the right aileron moves down through a greater angle. (Refer to figure 081-E61) With differential ailerons the up-going aileron moves more (greater deflection) than the down-going one. The decreased deflection of the down-going aileron (up-going wing, where more lift is created by the aileron) results in a lower induced drag. At the same time the greater deflection of the up-going aileron creates more form drag. This situation helps to reduce the difference in drag on both wings and thus lower the adverse aileron yaw effect. In this case (in a right turn) the left aileron moves down, the right aileron moves up. The right aileron moves up more than the left aileron moves down.

23496. Airplane ATPL CPL In a turn, differential ailerons: A) B) C) D)

reduce the drag on the inner wing. reduce the drag on the outer wing. reduce the drag on both wings. increase the drag on the upper wing.

For explanation refer to question #3987 on page 124.

23651. Airplane ATPL CPL Which of the following is the correct example of differential aileron deflection to initiate a left turn? A) B) C) D)

Left aileron up 5° / right aileron down 2°. Right aileron up 5° / left aileron down 2°. Left aileron up 2° / right aileron down 5°. Right aileron up 2° / left aileron down 5°.

(Refer to figure 081-E61) With differential ailerons the up-going aileron moves more (greater deflection) than the down-going one. The decreased deflection of the down-going aileron (up-going wing, where more lift is created by the aileron) results in a lower induced drag. At the same time the greater deflection of the up-going aileron creates more form drag. This situation helps to reduce the difference in drag on both wings and thus lower the adverse aileron yaw effect. Ofthe given possibilities the only one to fit this is: left 5° up; right 2° down.

23657. Airplane ATPL CPL Which of the following phenomena is counteracted by the use of differential ailerons? A) B) C) D)

Adverse yaw. Turn co-ordination. Sensitivity to spiral dive. Aileron reversal.

For explanation refer to question #3987 on page 124.

123398 (8) 1 23417 (8) 123422 (A) 123423 (C) 1 23427 (A) 123485 (C) 123496 (8) 1 23651 (A) 123657 (A) 1

05 Control 24078. Airplane ATPL CPL An aeroplane fitted with differential ailerons is in a level turn to the right. Which of the following statements is correct?

A) The left aileron moves up more than the right aileron moves down. B) The left aileron moves down more than the right aileron moves up. C) The right aileron moves up more than the left aileron moves down. 0) The right aileron moves down more than left aileron moves up. For explanation refer to question #23485 on page 726.

Airplane ATPL CPL When inner and outer ailerons are mounted, outer ailerons are used: 27034.

A) B) C) 0)

during takeoff only. at high speeds. at low speeds. when flaps are in landing configuration only.

For explanation refer to question #20879 on page 725. 232449. Airplane ATPL CPL Spoilers mounted on the wing upper surface can be used to:

A) increase lift and drag. B) assistthe ailerons. C) assist the elevators. 0) prevent aeroplane yaw following engine failure. 232755. Airplane ATPL CPL Which statement about elevators is correct?

A) The elevator is used only to trim an aeroplane and is normally operated by a dedicated control wheel, which is usually situated close to the throttle. B) The elevator is the primary control surface for control about the longitudinal axis and is operated by a left or right rotation of the control wheel. C) The elevator is the primary control surface for control about the lateral axis and is operated by a forward or backward movement of the control wheel or stick. 0) The elevator is the primary control surface for control about the longitudinal axis and is operated by a forward or backward movement of the control wheel or stick. 232757. Airplane ATPL CPL An aeroplane's bank angle is defined as the angle between its:

A) B) C) 0)

longitudinal axis and the horizontal plane. speed vector and the horizontal plane. speed vector and longitudinal axis. lateral axis and the horizontal plane.

232776. Airplane ATPL CPL Flaperonsare controls, which combine the function of:

A) B) C) 0)

flaps and speed brakes. flaps and elevator. ailerons and flaps. ailerons and elevator.

232777. Airplane ATPL CPL Ajet aeroplane equipped with inboard and outboard ailerons as well as spoilers is cruising at its normal cruise Mach number. In this case:

B) the inboard and outboard ailerons are active. C) only the spoilers will be active, not the ailerons. 0) spoilers are locked out. 232782. Airplane ATPL CPL Outboard ailerons (if present) are normally used: A) in high speed flight only.

B) at transonic and supersonic speeds only. C) when the landing gear is up.

0) in low speed flight only. 232783. Airplane ATPL CPL What are the primary roll controls on a conventional aeroplane?

A) The rudder. B) Symmetrically deflected spoilers. C) The ailerons. 0) Asymmetrically extended leading edge flaps. 232784. Airplane ATPL CPL Aileron deflection causes a rotation around the longitudinal axis by:

A) aileron secondary effect. B) causing sideslip, which generates a rolling moment. C) changing the wing camber and the two wings therefore produce different lift values resulting in a moment about the longitudinal axis. 0) changing the wing drag and the two wings therefore produce different lift values resulting in a moment about the longitudinal axis. 232786. Airplane ATPL CPL When a turn is initiated, adverse yaw is:

A) the tendency of an aeroplane to yaw in the same direction of turn due to the different wing speeds. B) a momentary yawing motion opposite to the turn due to an incorrect differential aileron movement. C) the tendency of an aeroplane to yaw in the opposite direction of turn mainly due to the difference in induced drag on each wing. 0) the tendency of an aeroplane to yaw in the opposite direction of turn mainly due to the difference in aileron form drag. 232795. Airplane ATPL CPL Yaw is followed by roll because the:

A) rudder is located above the longitudinal axis and when it is deflected, it causes a rolling moment in the same direction as the yaw. B) yawing motion generated by rudder deflection causes a speed increase of the inner wing, which increase the lift on that wing so that the aeroplane starts to roll in the same direction as the yaw. C) yawing motion generated by rudder deflection causes a speed increase of the outer wing, which increases the lift on that wing so that the aeroplane starts to roll in the same direction as the yaw. 0) rolling motion generated by rudder deflection causes a speed increase of the outer wing which increases the lift on that wing so the aeroplane starts to roll in the direction of the turn.

A) outboard ailerons are locked out. 1 24078 (C) 1 27034 (C) 1232449 (8) 1232755 (C) 1232757 (0) 1232776 (C) 1232777 (A) 1232782 (0) 1232783 (C) 1232784 (C) 1 1232786 (C) 1232795 (C) 1

Aviationexam Test Prep Edition 2012

05-05 Roll/Yaw Interaction 4081. Airplane ATPL CPL When a jet aircraft enters a turn or straightens up from a turn, what device ensures correct response? A) Dorsal fin. B) Yaw damper. e) Aileron - rudder coupling. D) Vortex generators. Since a roll always produces a yaw (and vice versa), the device will be aileronrudder coupling.

21078. Airplane ATPL CPL If the nose of an aeroplane yaws to the left, this causes: A) a roll to the right. B) a decrease in relative airspeed on the right wing. e) an increase in lift on the left wing. D) a roll to the left.

Since a roll always produces a yaw (and vice versa), the secondary effect of the rudder is a roll and the secondary effect of the ailerons is a yaw.

23393. Airplane ATPL CPL If left rudder is applied: A) the aircraft will roll to the left and yaw to the right. B) the aircraft will yaw to the left and roll to the right. e) the aircraft will yaw to the left and roll to the left. D) the aircraft will yaw to the left, but there will be no rolling moment. Left rudder input causes a left yaw (to port side). During the yaw, the right wing will travel slightly faster than the left wing and thus create more lift => creating a roll to the left.

23495. Airplane ATPL CPL When the rudder is moved to the right, the force acting onthefin:

Ayaw to the left will cause the right wing to travel a bit faster than the left wing. There will be more lift on the right than the left wing, causing a roll to the left.

23369. Airplane ATPL CPL What are the secondary effects of rudder and aileron respectively? A) Yaw and roll. B) Roll and yaw. e) Pitch and roll. D) Yaw and pitch.

A) gives a yawing moment but no rolling moment. B) gives a rolling moment to the left. e) gives a rolling moment to the right. D) gives a nose-up pitching moment because the force is applied above the eG. The rudder moved to the right will produce a force to the left. This force will give a yaw to the right. This yaw will cause the left wing to travel a bit faster than the right wing. There will be more lift on the left than the right wing, causing a roll to the right.

05-06 Means to Reduce Control Forces 4003. Airplane ATPL CPL Examples of aerodynamic balancing of control surfaces are: A) spring tab, servo tab and power assisted control. B) balance tab, horn balance and mass balance. e) mass in the nose of the control surface, horn balance and mass balance. D) servo tab, spring tab, seal between the wing trailing edge and the leading edge of control surface. Powered controls and mass balance are not aerodynamic balancing.

4006. Airplane ATPL CPL A horn balance in a control system has the following purpose: A) to decrease the effective of the aeropla ne. B) to prevent flutter. e) to obtain mass balancing. D) to decrease stick forces.

longitudinal

dihedral

(Refer to figure 087-£62) The horn balance (see illustration) is forward of the hinge line, and forces on this part of the surface give hinge moments which are in opposite direction to the moments on the main part of the surface. The overall hinge moment . is reduced, and hence the stick force decreased.

4012. Airplane ATPL CPL If an aircraft is fitted with powered flying controls, which of the following would be used in the case of manual reversion?

A) Horn balance. B) Mass balance displacement. C) Spring tab. D) Servo tab. Manual reversion = controlling the fully powered controls manually (in case of the fully powered control system failure, such as a complete loss of hydraulic system). The forces required to manually move powered controls would be extremely large. Of the proposed tabs, the servo tab is the only one that can be operated without moving the control itself. Where servo tabs are used, the controls in the cockpit are directly linked

to the servo tab instead of the control surface. When a control movement is made, the tab is moved and the aerodynamic force from the tab causes the control surface to be moved in the opposite direction to the movement of the tab (e.g if the tab moves up it causes a down movement of the main control surface). The principle of the servo tab is that it is far easier for the pilot to move the small tab surface than the large control surface. Since the pilot does not move the control surface itself, but rather the servo tab, the position of the control surface on the ground during taxiing may not be known.

4027. Airplane ATPL CPL Which kind of tab is commonly used in case of manual reversion of fully powered flight controls? A) Balance tab . B) Spring tab. e) Servo tab. D) Anti-balance tab. For explanation refer to question #4072 on this page.

1 4081 (C) 121078 (0) 123369 (8) 123393 (C) 123495 (C) 1 4003 (0) 1 4006 (0) 1 4012 (0)

1 4027 (C) 1

05 Control

4036. Airplane ATPL CPL Aerodynamic balance can be obtained by: A) a weight mounted forward ofthe control surface hinge line. B) an external balance, provided by a seal from the wing to the trailing edge of the aileron. C) an internal balance (the leading edge of the aileron is housed within a box inside the wing trailing edge, vented to atmosphere, with a seal from the wing to the leading edge of the aileron). D) the down-going aileron moving through a smaller angle than the up-going aileron. (Refer to figure 081-£58)

4050. Airplane ATPL CPL Stick forces, provided by an elevator feel system, depend on: A) stabilizer position, static pressure. B) elevator deflection, dynamic pressure. C) elevator deflection, static pressure. D) stabilizer position, total pressure. On fully powered flying controls the pilots would not be aware of the aerodynamic forces/resistance on the control without a system referred to as "Q-feel" (or artificial fee/). Without this system it would be easy to aerodynamically over-stress the aeroplane. The stick force will consist of the hinge moment from the elevator deflection, and the resistance from the artificial feel unit. Q feel unit gets its input from the pitot tube and the static port; i.e. the dynamic pressure (PDYN = Pr-P). Q= v,p V2

4055. Airplane ATPL CPL When power assisted controls are used for pitch control: A) trimming is superfluous. B) a part of the aerodynamic forces is still felt on the column. C) aerodynamic balancing of the control surfaces is meaningless. D) they only function in combination with an elevator trim tab. Power assisted controls are designed to ease the manual control forces, but in such a way that part of the aerodynamic forces are still felt on the column to ensure that the pilot does not lose "feel" of speed.

4063. Airplane ATPL CPL Which statement about a primary control surface controlled by a servo tab, is correct? A) The position is undetermined during taxiing, in particular with tailwind. B) The servo tab can also be used as a trim tab. C) The control effectiveness of the primary surface is increased by servo tab deflection. D) Due to the effectiveness of the servo tab the control surface area can be smaller. (Refer to figure 081-£67) The controls in the cockpit are directly linked to the servo tab instead of the control surface. When a control movement is made, the tab is moved and the aerodynamic force from the tab causes the control surface to be moved in the opposite direction to the movement of the tab until an equilibrium position is reached (e.g if the tab moves up it causes a down movement of the main control surface). The principle of the servo tab is that it is far easier for the pilot to move the small tab surface than the large control surface. However, at slow speeds, the aerodynamic forces are lower than at high speeds and thus the control effectiveness is lower during a slow flight. Since the pilot does not move the control surface itself, but rather the servo tab, the position of the control surface on the ground during taxiing may not be known.

20880. Airplane ATPL CPL Which statement is correct about a spring tab? A) B) C) D)

(Refer to figure 081-£64) The spring tab is a modification of the servo tab such that the movement is proportional to the applied stick force; see illustration. Maximum tab assistance is required at high speed when the stick force is greatest. High dynamic pressure will prevent the surface from moving, so the spring is compressed by the pilot input and the tab moves the surface (like a servo tab). The spring is not compressed at low lAS, so the pilot input deflects the control surface and the tab, increasing the surface area and control effectiveness at low speed. At low speeds, the tab does not become operational until the control surface has been deflected bya certain number of degrees and at high speeds, the degree of tab deflection is small to prevent overbalancing. The effectiveness of a control is dependent upon its angle of deflection and the speed of the airflow.

21050. Airplane ATPL CPL Examples of aerodynamic balancing of control surfaces are: A) weight in the nose of the control surface, horn balance. B) upper and lower rudder, seal between wing's trailing edge and leading edge of a control surface. C) seal between wing's trailing edge and leading edge of a control surface, horn balance. D) fowler flaps, upper and lower rudder. (Refer to figures 081-£58 and 081-£62) Fowler flaps, upper and lower rudder, and mass balance are not aerodynamic balancing. Internal balance (sea/) and horn balance are the aerodynamic balancing means.

21149. Airplane ATPL CPL What is the fundamental difference between a trim tab and a servo tab? A) A servo tab affects the stick force stability, whereas a trim tab does not. B) The purpose of a trim tab is to reduce continuous stick force to zero, a servo tab only reduces stick force. C) A trim tab is automatically adjusted when its particular control surface moves, whereas a servo tab is moved independently of its particular control surface. D) The functioning of a trim tab is based on aerodynamic balancing, whereas a servo tab is usually adjusted via a screwjack. A trim tab is operated by a trimmer switch, and not by the stick/pedals, and will give the control surface a constant deflection that zeroes-out the stick force. Pilot control input deflects the servo tab only, the aerodynamic force on the tab then moves the control surface until an equilibrium position is reached.

21187. Airplane ATPL CPL Which three aerodynamic means decrease manoeuvring stick forces? A) B) C) D)

Servo tab - horn balance - spring tab. Servo tab - trim tab - balance tab. Spring tab - trim tab - mass balancing weight. Spring tab - horn balance - bobweight.

Trim tab, mass balance, and bobweight do not decrease manoeuvring stick forces.

23374. Airplane ATPL CPL A servo tab on the rudder moves: A) when the rudder pedals are moved. B) when the rudder is moved. C) when the rudder trim wheel is moved. D) in the same direction as the rudder to make the rudder more effective at low speed. For explanation refer to question #4063 on this page.

At high lAS it behaves like a fixed extension of the elevator. Its main purpose is to increase stick force per G. At high lAS it behaves like a servo tab. At low lAS it behaves like a servo tab.

1 4036 (C) 1 4050 (8) 1 4055 (8) 1 4063 (A) 120880 (C) 121050 (C) 1 21149 (8) 1 21187 (A) 1 23374 (A) 1

Aviationexam Test Prep Edition 2012 23395. Airplane ATPL CPL On an aileron with an inset hinge, the leading edge of the control surface may protrude above or below the wing surface when the control is moved. This is to: A) B) C) D)

give assistance to the pilot to move the control. increase the effectiveness of the control. increase the drag in a turn. give a mass balance.

(Refer to figure 081-E62) Setting the hinge back into the control surface makes the part of the control surface ahead of the hinge line deflect in the opposite direction to the actual surface. Air striking this part will help turning the surface by reducing the hinge moment which is aerodynamic balancing. The illustration shows this principle in the horn balance, where only part of the span of the control surface is used for balancing.

23397. Airplane Balance tabs:

ATPL

CPL

A) move in the same direction as the control surface. B) move in the same direction as control surfaces and trim tabs. C) move in the opposite direction to control surfaces and the same direction as trim tabs. D) move in the opposite direction to both control surfaces and trim tabs. (Refer to figure 081-E65) The balance tab moves in the opposite direction to the control surface and provides a force that reduces the stick force; i.e. aerodynamic balance. The tab operates automatically when the control surface moves. Note: the trim tab operates in the same fashion, but directly controlled by the pilot.

23428. Airplane ATPL CPL The aerodynamic force on a control surface: A) increases as speed increases. B) depends only on the control angle and is independent of speed. C) depends only on the air density. D) decreases as speed increases.

23431. Airplane ATPL CPL An inset hinge is an example of ___ balance and a horn balance is an example of __ balance. A) B) C) D)

mass; mass mass; aerodynamic aerodynamic; mass aerodynamic; aerodynamic

Both cases are aerodynamic balancing. Aerodynamic balance involves using the aerodynamic forces on the control surface to reduce the hinge moment and thus the stick force.

23432. Airplane ATPL CPL An aileron control surface is provided with an inset hinge: A) B) C) D)

to to to to

prevent flutter. prevent adverse aileron yaw. provide aerodynamic balance. increase the stick force.

For explanation refer to question #23395 on this page.

23434. Airplane ATPL CPL A graduated horn balance: A) gives a high degree of assistance at high speed. B) ensures that only a limited degree of assistance is available at low speed. C) prevents over balance resulting from excess balance at high speed. D) provides the required amount of aerodynamic assistance to the pilot at low speed. Horn balances are prone to snatch, as they are deflected, they change the area into the airflow at once. To overcome this problems a graduated horn balance is able to progressively increase the amount of control surface area into the airflow. With a fixed horn balance, the aerodynamic force of the control surface might move forward of the hinge line at high speed, and a condition known as overbalance would exist. As the force moved forward, a reduction then a reversal of the stick force would occur, which would be very dangerous. By reducing the horn balance at higher speed, this problem is avoided.

All aerodynamic forces depend on the dynamic pressure, i.e. ~pV2.

23429. Airplane ATPL CPL Aerodynamic balance on a flying control is used to: A) B) C) D)

prevent flutter of the flying control. reduce the load required to move the control. reduce the control load to zero. balance the aircraft about its axes.

Aerodynamic balance involves using the aerodynamic forces on the control surface to reduce the hinge moment and thus the stick force.

23430. Airplane ATPL CPL If the control surface hinge is placed too far back from the control surface leading edge: A) B) C) D)

control effectiveness will be reduced. the controls will be too heavy. range of control surface movement will be reduced. control surface CP may move ahead of the hinge and cause overbalance.

If the hinge is moved too far back, the aerodynamic force of the control surface might move forward of the hinge line, a condition known as overbalance would exist. As the force moved forward, a reduction then a reversal of the stick force would occur, which would be very dangerous.

23435. Airplane ATPL CPL To reduce the stick force required, the control surface may be: A) B) C) D)

mass balanced. aerodynamic balanced. static balanced. anti-balanced.

For explanation refer to question #23429 on this page.

23440. Airplane ATPL CPL An anti-balance tab moves in the: A) opposite direction to the control surface and increases control effectiveness. B) same direction as the control surface and increases control effectiveness. C) opposite direction to the control surface and decreases control effectiveness. D) same direction as the control surface and decreases control effectiveness. (Refer to figure 081-E66) An anti-balance tab moves in the same direction as the control surface and increases control effectiveness, but will increase the hinge moment and give heavier stick forces. The point is that anti-balance tab is actually an aerodynamic balance but not in the purpose of reducing the efforts of the pilots like the other aerodynamic balance devices. Its purpose is to increase the efforts on some control surfaces that would otherwise be too easy to move and would lead to over-stressing the airframe due to excessive deflection.

123395 (A) 123397 (C) 123428 (A) 1 23429 (8) 123430 (D) 123431 (D) 123432 (C) 123434 (C) 123435 (8) 123440 (8) 1

05 Control 23441. Airplane ATPL CPL Which of the following devices is used to provide aerodynamic balance?

A) lrimtab. B) Frise ailerons. C) Anti balance tab. D) Mass balance fitted forward of the hinge line. Only the anti-balance tab provides aerodynamic balancing. Other answer possibilities are incorrect: Trim tab gives a constant control surface deflection without pilot input; Frise ailerons reduce adverse yaw; mass balance eliminates flutter.

Airplane ATPL CPL For an aircraft fitted with servo operated controls, if external locks are fitted to the main control surfaces: 23458.

A) they will prevent movement of the control wheel, the control surfaces and the servo tabs. B) they will prevent movement of the control surfaces but not the control wheel or the servo tabs. C) they will prevent movement of the control wheel and the control surfaces but not the servo tabs. D) they will prevent movement of the control wheel and the servo tabs but not the control surfaces. Since pilot control input deflects the servo tab only, a lock fitted to the control surface would not interfere with the servo tab or the control wheel. 23459. Airplane ATPL CPL In a servo tab operated control system, movement of the tab:

A) is always in the same direction as the control surface. B) is always in the opposite direction to the control surface. C) may be either opposite or in the same direction as the control surface. D) is controlled directly by the main control surface. For explanation refer to question #4063 on page 729. 23460. Airplane ATPL CPL For an aircraft fitted with servo tabs:

A) locks fitted on the control surface will not prevent movement of the control wheel. B) locks on the control surface will prevent movement of the control wheel. C) locks on the control surface will prevent movement ofthetabs. D) none ofthe above. For explanation refer to question #23458 on this page.

Airplane ATPL CPL Aerodynamic balance may be achieved by: 23486.

A) B) C) D)

a fixed trimming tab. a horn balance. a weight attached forward of the control hinge. a spring attached to the rudder control circuit.

24073. Airplane ATPL CPL Power assisted flying controls:

A) give no feel. B) are irreversible. C) give no manual reversion. D) give some feel. With a power assisted flying control, only a certain portion of the force required to oppose the hinge moment is provided by the pilot, the hydraulic system provides most of the force. Although the pilot does not have to provide all the force required, the natural 'feel' of the controls is retained. 232802. Airplane ATPL CPL Which aerodynamic design features can be used to reduce control forces?

A) Mass balance, horn balance, artificial feel system.

B) Balance tab, control surfaces with increased area behind the hinge, artificial feel system. C) Horn balance, balance tab, servo tab. D) Servo tab, bobweight, control surfaces with increased area. 232805. Airplane ATPL CPL In general, control forces are reduced by:

A) mass balancing, a trim tab and spring tab.

B) a balance tab, forward shift of the CG and a servo tab. a horn balance, servo tab and spring tab. D) a servo tab, spring tab and mass balancing.

C)

232807. Airplane ATPL CPL Artificial feel is required: A) with power assisted flight controls.

B) when the flight control surfaces are fitted with control tabs or trim tabs. C) when there is a trimmable stabiliser. D) with fully powered flight controls. Airplane ATPL CPL What is the primary input for an artificial feel system? 232809.

A) Mach number.

B) Static pressure. C) lAS.

D) lAS. 232848. Airplane ATPL CPL Flutter of control surfaces is:

A) divergent oscillatory motion of a control surface caused by the interaction of aerodynamic, inertia and friction forces. B) a divergent oscillatory motion of a control surface caused by the interaction of aerodynamic forces, inertia forces and the stiffness of the structure. C) aileron reversal. D) the accelerated stall of a wing.

(Refer to figure 087-E62) Trim tab gives a constant control surface deflection without pilot input; mass balance eliminates flutter; spring in the control circuit is used to tailor the stick forces, but it is not aerodynamic balancing. 23573. Airplane ATPL CPL If servo tabs are fitted to a main control surface:

A) they make the control surface effective allowing for a reduced size to be used. B) they also act as trim tabs. C) they are activated by movement of the control surface. D) the controls are less effective at low speed. For explanation refer to question #4063 on page 729. 1 23441 (C) 1 23458 (8) 1 23459 (8) 123460 (A) 1 23486 (8) 1 23573 (0) 1 24073 (0) 1232802 (C) 1232805 (C) 1232807 (0) 1 1232809 (0) 1232848 (8) 1

Aviationexam Test Prep Edition 2012

05-07 Mass Balance 3986. Airplane ATPL CPL Mass balance to reduce control flutter is not required on: A) aircraft with a fully powered irreversible control system with no manual emergency system. S) aircraft with a fully powered irreversible control system. C) aircraft limited to speeds below 200 kts. D) aircraft with short rigid wings. Flutter can be prevented either by mass balancing or by making the controls irreversible (fully powered controls with no manual reversion).

4078. Airplane ATPL CPL When flutter damping of control surfaces is obtained by mass balancing, these weights will be located with respect to the hinge of the control surface: A) S) C) D)

above the hinge. below the hinge. in front of the hinge. behind the hinge.

Flutter of control surfaces is caused by the CG of the surface positioned behind the hinge line. To move the CG forward, the weights must be placed in front of the hinge line. This is called mass balancing.

21075. Airplane ATPL CPL If an aeroplane exhibits insufficient stick force per G, this problem can be resolved by installing: A) a spring which pulls the stick backwards. S) a bobweight in the control system which pulls the stick forwards. C) a spring which pushes the stick forwards. D) a bobweight in the control system which pulls the stick backwards. (Refer to figure 081-E68)

21095. Airplane ATPL CPL Mass-balancing of control surfaces is used to: A) increase the stick force stability. S) limit the stick forces. C) ensure that the control surfaces are in the mid-position during taxiing. D) prevent flutter of control surfaces. For explanation refer to question #4078 on this page.

21185. Airplane ATPL Which statement is correct?

CPL

1} On fully hydraulic powered flight controls there is no need for mass balancing. 2) On fully hydraulic powered flight controls there is no need for trim tabs. A) S) C) D)

1) is incorrect; 2) is correct. 1) is incorrect; 2) is incorrect. 1) is correct; 2) is correct. 1) is correct; 2) is incorrect.

Flutter can be prevented either by mass balancing or by making the controls irreversible (fully powered controls with no manual reversion). The artificial feel unit provides a force to resist the movement of the cockpit controls. To remove this force (i.e. to trim) the datum of the feel unit can be adjusted so that it no longer gives any load on the cockpit controls.

26989. Airplane ATPL CPL In flight the flutter of a control surface is normally reduced by: A) S) C) D)

use of balance tabs. weights acting aft of the hinge line. weights acting forward of the hinge line. weights acting on the hinge line.

For explanation refer to question #4078 on this page.

A bobweight improves stick force stability. Since the bobweight mass is subjected to the same acceleration as the aircraft, the bobweight will provide an increment in stick force by pulling the stick forward in direct proportion to the load factor.

05-08 Trimming 3973. Airplane ATPL CPL An aeroplane has a servo tab controlled elevator. What will happen when only the elevator jams during flight? A) S) C) D)

The pitch control forces double. Pitch control has been lost. The servo tab now works as a negative trim tab. Pitch control reverses direction.

The servo tab deflects in the opposite direction to the elevator and thus creates a force that turns the elevator in the desired direction. If the elevator is jammed, the servo tab will act as a small elevator, but since it moves in the opposite direction, the pitch control is reversed.

3978. Airplane ATPL CPL Power assisted flying control systems have trim controls primarily in order to:

D) bring the control forces to zero in steady flight. The main purpose of trimming is to zero the control forces in steady flight, regardless of control system.

3980. Airplane ATPL CPL Which of the following is an advantage of engines mounted on the rear fuselage over those mounted in wing pods? A) S) C) D)

Wings can have a lighter form of construction. The wing is less likely to suffer from flutter. Easier maintenance access. Longitudinal trim is less affected by changes in thrust.

For explanation refer to question #3977 on page 121.

A) allow the pilot to maintain control in case of hydraulic failure. S) relieve stresses on the trim tab. C) relieve stresses on the hydraulic actuators. 1 3986 (A) 1 4078 (C) 1 21075 (8) 121095 (0) 1 21185 (A) 126989 (C) 1 3973 (0) 1 3978 (0) 1 3980 (0) 1

05 Control

3984. Airplane ATPL CPL One advantage of a movable-stabilizer system compared with a fixed stabilizer system is that: A) B) C) D)

the systems complexity is reduced. the structure weighs less. it leads to greater stability in flight. it is a more powerful means of trimming.

Changing the angle ofattack for the stabilizer provides more control force than elevator deflection on a fixed stabilizer.

4022. Airplane ATPL CPL What should be usually done to perform a landing with the stabilizer jammed in the cruise flight position? A) If possible, relocate as many passengers as possible to the front of the cabin. B) Choose a lower landing speed than normal. C) Choose a higher landing speed than normal and/or use a lower flap setting for landing. D) Use the Mach trimmer until after landing.

tailplane, trim changes are made by: A) B) C) D)

adjusting the trim tab on the trailing edge of the elevator. changing the angle of the entire tailplane. varying the spring bias trimming system. adjusting the Q feel unit.

As implied by the name, the entire tailplane is moved for trimming.

4061. Airplane ATPL CPL Which statement about the trim position is true related to centre of gravity and adjustable stabiliser position? A) A nose heavy aeroplane requires that the stabiliser leading edge is lower than compared with a tail heavy aeroplane. B) Because characteristic speeds at takeoff do not vary with centre of gravity location, the need for stabiliser adjustment is dependent on flap position only. C) A nose heavy aeroplane requires that the stabiliser leading edge is higher than compared with a tail heavy aeroplane. D) At the forward limit for centre of gravity, stabiliser trim is adjusted maximum nose down to obtain maximum elevator authority at takeoff rotation.

With a jammed stabilizer there is very little additional control force to increase the angle of attack. To avoid too much loss of altitude, the speed should therefore be higher than normal. Flap extension moves the centre ofpressure aft creating a nose down moment. A jammed stabilizer cannot correct this, so again a higher speed would be required.

To rotate the aircraft a nose up moment is required. If the aircraft is nose heavy. more downward force from the stabiliser is needed than compared with a tail heavy aircraft. The stabiliser will therefore need a bigger negative angle of attack, that is the leading edge lower than normal.

4029. Airplane ATPL CPL In general jet transport aeroplanes with power assisted flight controls are fitted with an adjustable stabiliser instead of trim tabs on the elevator. This is because:

4062. Airplane ATPL CPL What is the position of the elevator in relation to the trimmable horizontal stabilizer of a power assisted aeroplane, which is in trim?

A) the pilot does not feel the stick forces at all. B) effectiveness of trim tabs is insufficient for those aeroplanes. C) mechanical adjustment of trim tabs creates too many problems. D) trim tab deflection increases MeRIT

A) The position depends on speed, the position of slats and flaps and the position of the centre of gravity. B) The elevator deflection (compared to the stabilizer position) is always zero. C) At a forward CG the elevator is deflected upward and at an aft CG the elevator is deflected downward. D) The elevator is always deflected slightly downwards in order to have sufficient remaining flare capability.

Adjustable stabilisers are very powerful and give an increased ability to trim for larger centre of gravity and speed range.

4035. Airplane ATPL CPL Which statement about a jet transport aeroplane is correct, during takeoff at the maximum allowable forward centre of gravity limit, while the THS (Trimmable Horizontal Stabilizer) has been positioned at the maximum allowable nose-down position? A) The rotation will require extra stick force. B) If the THS position is just within the limits of the green band, the takeoff warning system will be activated. C) Early nose wheel raising will take place. D) Nothing special will happen. With a CG at the forward limit the aircraft would have a strong static longitudinal stability which would require larger control forces. To rotate the aircraft a nose up moment is required, but with the stabilizer trimmed max. nose down. extra stick force is needed to rotate.

4037. Airplane ATPL CPL The reason for having a trim system on power assisted flying controls is to: A) enable the pilot to maintain control in case of hydraulic failure. B) relieve stresses on the trim tab. C) relieve stresses on the hydraulic actuators. D) enable the stick force to be reduced to zero. The main purpose of trimming is to zero the control forces in steady flight, regardless of the control system used.

4053. Airplane ATPL CPL When a large modern aircraft employs a variable incidence

4066. Airplane ATPL CPL If the elevator trim tab is deflected up, the cockpit trim indicator shows: A) B) C) D)

nose left. neutral. nose up. nose down.

When the elevator trim is moved up, it will force the elevator to move down and thus decreasing the down force from the stabiliser. This will cause a nose down moment from the wing lift, so the cockpit trim indicator should show nose down.

4068. Airplane ATPL CPL In straight flight, as speed is increased, whilst trimming to keep the stick force zero: A) the elevator and trim tab do not move. B) both elevator and trim tab are deflected further downwards. C) the elevator is deflected further upwards and the trim tab further downwards. D) the elevator is deflected further downwards and the trim tab further upwards. (Refer to figure 081-E63) Less rearward stick force is required for a higher speed while maintaining a level flight. A speed increase means lower angle ofattack and therefore less down force from the horizontal stabiliser. Since the stabiliser operates with negative angle of attack, the elevator must move down to decrease the negative angle of attack. This is accomplished by an upward deflection of the trim tab.

13984(0) I 4022 (C) 14029(8) I 4035 (A) 14037(0) 14053(8) 14061 (A) I 4062 (A) 14066(0) 14068(0) I

Aviationexam Test Prep Edition 2012

15776. Airplane ATPL CPL In straight flight, as speed is reduced, whilst trimming to keep the stick force zero:

creates an aerodynamic force that moves the elevator in the desired direction. If the elevator is jammed, the trim tab will act as a small elevator, but since it moves in the opposite direction, the pitch control is reversed.

A) the elevator is deflected further downwards and the trim tab further upwards. B) the elevator is deflected further upwards and the trim tab further downwards. C) both elevator and trim tab are deflected further upwards. D) the elevator and trim tab do not move.

23444. Airplane ATPL CPL A tab fitted to zero the loads on the pilot's control during flight is known as:

(Refer to figure 081-£63) Rearward stick force is required for lower speed while maintaining a level flight. A speed decrease means more angle of attack and therefore mores down force from the horizontal stabiliser. Since the stabiliser operates with negative angle of attack, the elevator must move up to increase the negative angle of attack. This is accomplished by a downward deflection of the trim tab.

16708. Airplane ATPL CPL An aircraft is equipped with an all flying tail plane which has a combined anti balance and trimming tab. The top of the trim wheel is moved forward. Which of the following statements is most correct? A) The tab moves up, so that less effort is required when the pilot attempts to move the control column to the rear. B) The tab moves up, so that more effort is required when the pilot attempts to move the control column to the rear. C) The tab moves down, so that less effort is required when the pilot attempts to move the control column to the rear. D) The tab moves down, so that more effort is required when the pilot attempts to move the control column to the rear. Trim wheel forward means nose down trim, i.e. less down force from the horizontal stabiliser. Since the stabiliser operates with negative angle of attack, the elevator must move down to decrease the negative angle of attack. This is accomplished by an upward deflection of the trim tab. If the pilot attempts to move the control column to the rear and lift the nose, he will feel more resistance because the trim is nose down.

21174. Airplane ATPL CPL Which statement in respect of a trimmable horizontal stabiliser is correct? A) Because takeoff speeds do not vary with centre of gravity location, the need for stabiliser adjustment is dependent on flap position only. B) An aeroplane with a forward CG requires the stabiliser leading edge to be lower than for one with an aft CG in the same trimmed condition. C) An aeroplane with a forward CG requires the stabiliser leading edge to be higher than for one with an aft CG in the same trimmed condition. D) At the forward CG limit, stabiliser trim is adjusted fully nose down to obtain maximum elevator authority at rotation during takeoff. With the CG moved forward the aircraft would have a stronger nose down moment from the wing lift compared with the CG further back. A larger down force from the horizontal stabiliser is required to maintain equilibrium, so the leading edge of the stabiliserwould be lower to achieve a larger negative angle of attack.

23376. Airplane ATPL CPL In the unlikely event of an aircraft becoming airborne with the elevator control lock engaged, operation of an elevator trim tab control in the normal direction to counteract a nose up tendency would: A) B) C) D)

A) B) C) D)

a balance tab. a spring tab. an anti-balance tab. a trim tab.

A trim tab is operated by a trimmer switch and will give the control surface

a constant deflection that zeroes-out the stick force. 23445. Airplane ATPL CPL When checking the range of movement of an elevator trim tab as part of the pre-flight check, movement of the trim wheel or trim switches will move the: A) B) C) D)

tab and control column. elevator. tab. tab, elevator and control column.

Operating the elevator trim control only moves the trim tab. The elevator only moves when sufficient airspeed is present (the tab produces elevator movement only as a result of aerodynamic force).

23446. Airplane ATPL CPL If the control column is pushed forward, a trim tab on the elevator: A) B) C) D)

will move up relative to the elevator. will move down relative to the elevator. will only move relative to the elevator at high speed. will not move relative to the elevator unless the trim wheel is moved.

The trim tab only moves when the trim control is operated. Moving the control surface does not affect the trim tab position relative to the elevator.

23447. Airplane ATPL CPL Which direction from the primary control surface does an elevator adjustable trim tab move when the control surface is moved? A) Same direction. B) Opposite direction. C) In the same direction at high speeds to increase the stick force, but in the opposite direction at low speed. D) Remains fixed for all positions. For explanation refer to question #23446 on this page.

23448. Airplane ATPL CPL In order to zero the load if a rearward force on the control column is required to maintain level flight: A) B) C) D)

the elevator trim tab must be moved up. the elevator trim tab must be moved down. the incidence of a trimming tail plane must be increased. the elevator will be required to remain neutral.

If a rearward stick force (nose-up force) is required that means more angle of attack and therefore more down force from the horizontal stabiliser is required. Since the stabiliser operates with negative angle of attack, the elevator must move up to increase the negative angle of attack. This is accomplished by an downward deflection of the trim tab.

have no effect. result in a reduction of the nose up tendency. result in an increase in the nose down pitching moment. result in an increase of the nose up tendency.

The trim tab deflects in the opposite direction to the elevator and thus

1 15776 (8) 116708 (8) 1 21174 (8) 1 23376 (0) 123444 (0) 123445 (C) 123446 (0) 123447 (0) 1 23448 (8) 1

OS Control

23449. Airplane ATPL CPL On an aircraft with a variable incidence trimming tail plane, the tail plane incidence changes: A) B) C) D)

if the control column is moved. ifthe trim wheel is turned. automatically if the elevator moves. by re-setting it on the ground.

In this case the trim controls move the adjustable tail plane (stabilizer) only - there are no trim tabs. The adjustable stabilizer is moved only by the trim controls (autopilot or pilot controlled).

23450. Airplane ATPL CPL On a variable incidence tail plane with elevators fitted at the trailing edge, longitudinal trimming will be done by adjusting the: A) B) C) D)

elevators with the control wheel. elevators with the trim wheel. tail plane incidence with the control wheel. tail plane incidence with the trim wheel.

23451. Airplane ATPL CPL If the elevator trim wheel is moved fully back, what will happen to the control range? No effect on range. Increase elevator range. Decrease elevator range. Exceed the stall limits.

(Refer to figure 081-£69) If the elevator trim wheel is moved fully back the elevator is trimmed nose up which reduces the elevator authority as shown in the illustration.

23452. Airplane ATPL CPL If the elevator trim tab has been moved fully to the aircraft nose up position, the available aircraft nose up pitch authority will be: A) B) C) D)

increased. reduced. not affected. reversed.

To correct the right wing low tendency, the right aileron should move down to produce more lift on the right wing. The trim tab on the right aileron must therefore move slightly up which causes the right aileron moving down. Or, alternatively adjust the aileron on the left wing to produce less lift by deflecting the aileron up by moving its trim tab slightly down.

23455. Airplane ATPL CPL Down movement of the elevator trimming tab will: A) B) C) D)

make the aircraft nose heavy. overcome a tendency to fly nose heavy. overcome a tendency to fly tail heavy. make the aircraft pitch nose down.

23456. Airplane ATPL CPL Some aircraft are fitted with fixed trimming tabs: A) B) C) D)

these are set by the manufacturer and must not be altered. these may be adjusted only on the ground. these may be adjusted by the pilot in flight. these may be adjusted manufacturer.

Movable trim tabs are operated by a trimmer switch or by a trim wheel = by the pilot. The fixed trim tabs can only be adjusted manually by the aircraft mechanics on the ground.

23457. Airplane ATPL CPL A small piston engined aircraft keeps yawing to the left, you would trim it by: A) moving the fixed trimming tab on the rudder over to the left. B) moving the adjustable trim tab to the right. C) adjusting the rudder bar to keep the left rudder pedal forward. D) adjusting the aileron trim tab wheel to the right. You want a right yaw, i.e. the rudder to the right. This is done by moving the trim tab to the left.

(Refer to figure 081-£69) The aircraft nose up pitch authority reduces with the elevator trimmed more aircraft nose up. The illustration shows up elevator authority reduced from 10°

toSo.

23453. Airplane ATPL CPL When an aileron trim control in the cockpit is moved to correct a tendency to fly left wing low, an aileron trim tab on the left aileron will move: A) up and this causes the left aileron to and the right one to move up. B) up and this causes the left aileron to but the right aileron will remain neutral. C) down and this causes the left aileron and the right aileron to move down. D) down and this causes the left aileron and the right aileron to move up.

move down, move down,

to move up

To correct the left wing low tendency, the left aileron should move down therefore move up, and as the ailerons are coupled, the right aileron moves up when the left moves down.

23454. Airplane ATPL CPL To counteract a right wing low tendency, a fixed tab on the left aileron would: (C)

23545. Airplane ATPL CPL To trim an aircraft which tends to fly tail heavy with hands off, the top of the elevator trimming wheel mounted on a shaft running laterally would be rotated: A) B) C) D)

forward / trim tab down / elevator up. rearward / trim tab up / elevator up. rearward / trim tab down / elevator down. forward / trim tab up / elevator down.

To counter the tail heavy tendency of the aircraft in flight, the elevator should be moved down to make the tailplane produce less negative lift and thus create a nose down moment. The trim wheel should be moved forward to create up-movement of the elevator trim tab that will in turn move the elevator down.

to move up

to produce more lift on the left wing. The trim tab on the left aileron must

I 23449 (8) I 23450 (0) I 23451 123648 (A) I

be moved up causing the left aileron to come up. be moved up causing the right aileron to come down. be moved down causing the left aileron to go down. be moved down causing the left aileron to come up.

When the elevator trim tab is moved down, it will force the elevator to move up and thus increasing the down force from the stabiliser. This wilJcause a nose up moment from the wing lift, so the cockpit trim indicator should show nose-up. Moving the trim tab down will overcome a tendency to fly nose heavy.

For explanation refer to question #23449 on this page.

A) B) C) D)

A) B) C) D)

23648. Airplane ATPL CPL What position must the stabiliser be in during takeoff with a nose heavy aircraft, compared to a "balanced" aircraft? A) B) C) D)

More nose up trim/decreased stabiliser incidence. More nose down trim/decreased stabiliser incidence. Less nose up trim/increased stabiliser incidence. Less nose down trim/increased stabiliser incidence.

To rotate the aircraft a nose up moment is required. If the aircraft is nose heavy, more downward force from the stabiliser is needed. This means more nose up trim or a decreased (more negative) stabiliser incidence.

I 23452 (8) I 23453 (A) I 23454 (0) I 23455 (8) I 23456 (8) I 23457 (A) I 23545 (0) I

Aviationexam Test Prep Edition 2012

23666. Airplane ATPL CPL Why does a transport aircraft with powered controls use a horizontal stabiliser trim? A) B) C) D)

Pilot input is not subject to aerodynamic control forces. Trim tabs are not effective enough. Overly complex mechanism. Trim tabs would increase McRlr

Adjustable stabiliser is very powerful and gives an increased ability ~o trim for larger centre of gravity and speed range. Powered control indicate that the control forces required are large which makes trim tabs alone pretty useless.

23729. Airplane ATPL CPL When the trim tab on the elevator is deflected down, the cockpit indication of trim is: A) nose up. B) nose down. C) nose left. D) nose right. For explanation refer to question #23455 on page 135.

27007. Airplane ATPL CPL Deflecting the elevator up, when the trim tab is in neutral, will cause the tab to: A) B) C) D)

move down relative to the elevator chord line. move up relative to the elevator chord line. remain in line with the tailplane. remain in line with the elevator.

The trim tab only moves when the trim control is operated. Merely deflecting the elevator will not change the trim tab's position relative to the elevator.

232674. Airplane ATPL CPL Consider an aeroplane with: 1. a trim tab. 2. fully powered hydraulic controls and an adjustable horizontal stabiliser. For both cases and starting from a trimmed condition, how will the neutral position of the control column change, after trimming for a speed increase? A) B) C) D)

1. moves forward, 2. moves forward. 1. does not change, 2. does not change. 1. does not change, 2. moves forward. 1. moves forward, 2. does not change.

Airplane ATPL CPL 232676. After an aeroplane has been trimmed: A) the stick position stability will be unchanged. B) the stick position stability will be increased. C) the trim-tab will always be deflected in the same direction as the control surface itself. D) the stick force per g is reduced. Airplane ATPL CPL 232678. Consider two elevator control systems: 1. is fitted with a trim tab. 2. is fitted with fully powered hydraulic and an adjustable horizontal stabiliser.

controls

For both cases and starting from a trimmed condition, how will the neutral position of the control column change, after trimming for a speed decrease? A) B) C) D)

1. moves aft, 2 does not change. 1. moves forward, 2 moves forward. 1. does not change, 2 does not change. 1. does not change, 2 moves aft.

232693. Airplane ATPL CPL The stick force per g of a heavy transport aeroplane is 300 N/g. What stick force is required, if the aeroplane in the clean configuration is pulled to the limit manoeuvring load factor from a trimmed horizontal straight and steady flight?

A) 450 N. B) 750 N. C) 1125 N. D) 825 N. 232760. Airplane ATPL CPL (Refer to figure 081-14) What kind of horizontal control surface is shown in the figure? A) B) C) D)

Canard. All-flying tail. Elevator. Frise type control.

232797. Airplane ATPL CPL (Refer to figure 081-12) The tab in the figure represents: A) B) C) D)

an antibalance tab. a balance tab that also functions as a trim tab. a control tab. a trim tab.

Airplane ATPL CPL 232798. (Refer to figure 081-13) The tab in the figure represents: A) a servo tab. B) a trim tab. C) a balance tab. D) an anti-balance tab. 232815. Airplane ATPL CPL When comparing a stabiliser trim system with an elevator trim system, which of these statements is correct? A) a stabiliser trim is more sensitive to flutter. B) an elevator trim is more suitable for aeroplanes with a large CG range. C) a stabiliser trim is able to compensate larger changes in pitching moments. D) an elevator trim is able to compensate larger changes in pitching moments. Airplane ATPL CPL 232816. The most important factor determining the required position of the Trimmable Horizontal Stabiliser (THS) for take off is the: A) B) C) D)

total mass of the aeroplane. position of the aeroplane's centre of gravity. stall speed. centre of gravity position of the fuel.

232818. Airplane ATPL CPL In general jet transport aeroplanes with power assisted flight controls are fitted with an adjustable stabiliser instead of trim tabs on the elevator. This is because: A) mechanical adjustment of trim tabs creates too many problems. B) an adjustable stabiliser is a more powerful means to generate the tail loads required for these kind of aeroplanes. C) trim tab deflection increases VMO. D) the pilot does not feel the stick forces at all.

123666 (8) 1 23729 (A) 127007 (D) 1232674 (0) 1232676 (A) 1232678 (A) 1232693 (A) 1232760 (8) 1232797 (8) 1232798 (A) 1 1232815 (C) 1232816 (8) 1232818 (8) 1

05 Control For explanation refer to question #4029 on page 733.

232819. Airplane ATPL CPL What is the position of the elevator in relation to the trimmable horizontal stabiliser of an aeroplane with fully hydraulically operated flight controls that is in trim? A) The position depends on speed, the position of flaps and slats and the position of the centre of gravity. B) At a forward CG, the elevator is deflected upward and at an aft CG, it is deflected downward. C) Elevator deflection is zero. D) The elevator is always deflected slightly downward in order to have sufficient remaining flare capability. 232820. Airplane ATPL CPL What is the effect on landing speed when a trimmable horizontal stabiliser jams at high lAS? A) No effect with a forward CG. B) In most cases, a higher than normal landing speed is required. C) In most cases, no effect. D) No effect when landing on a high elevation runway. 232824. Airplane ATPL CPL When a jet transport aeroplane takes off with the CG at the forward limit and the trimmable horizontal stabiliser (THS) is positioned at the maximum allowable nose up position for take-off: A) there will be a tendency to over-rotate. B) early nose wheel raising will take place. C) rotation will require a higher than normal stick force. D) rotation will be normal using the normal rotation technique. Airplane ATPL CPL 232825. When a jet transport aeroplane takes off with the CG at the aft limit and the trimmable horizontal stabiliser (THS) is positioned at the maximum allowable nose down position for take-off: A) B) C) D)

there will be a tendency to under-rotate. early nose wheel raising will take place. rotation will be normal using the normal rotation technique. rotation will require higher than normal stick force.

Airplane ATPL CPL 232826. When a jet transport aeroplane takes off with the CG at the aft limit and the trimmable horizontal stabiliser (THS) is positioned at the maximum allowable nose up position for take-off: A) B) C) D)

early nose wheel raising will take place. rotation will require higher than normal stick force. rotation will be normal using the normal rotation technique. there will be a tendency to under-rotate.

Airplane ATPL CPL 232827. Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab, which of these statements are correct or incorrect? I. When trimmed for zero elevator stick force an elevator trim tab causes more drag. II. A horizontal trimmable stabiliser enables a larger CG range.

D) I is correct, II is incorrect. 232828. Airplane ATPL CPL Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab which of these statements are correct or incorrect? I. When trimmed for zero elevator stick force a horizontal trimmable stabiliser causes more drag. II. An elevator trim tab enables a larger CG range. A) B) C) D)

I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is incorrect. I is correct, II is correct.

Airplane ATPL CPL 232829. Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab, which of these statements are correct or incorrect? I. When trimmed for zero elevator stick force a horizontal trimmable stabiliser causes more drag. II. A horizontal trimmable stabiliser enables a larger CG range. A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is incorrect.

232830. Airplane ATPL CPL Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab, which of these statements are correct or incorrect? I. When trimmed for zero elevator stick force an elevator trim tab causes more drag. II. An elevator trim tab enables a larger CG range. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is incorrect. I is correct, II is correct. I is incorrect, II is correct.

Airplane ATPL CPL 232831. Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab, which statement is correct? I. A trim tab is less suitable for jet transport aeroplanes because of their large speed range. II. A stabiliser trim is a more powerful means of trimming. A) B) C) D)

I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is incorrect. I is correct, II is correct.

232832. Airplane ATPL CPL Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab, which statement is correct? I. A stabiliser trim is less suitable for jet transport aeroplanes because of their large speed range. II. A trim tab is a more powerful means of trimming. A) I is correct, II is correct. B) I is incorrect, II is incorrect. C) I is correct, II is incorrect. D) I is incorrect, II is correct.

A) I is incorrect, II is correct. B) I is correct, II is correct. C) I is incorrect, II is incorrect.

1232819 (C) 1232820(8) 1232824 (D) 1232825 (C) 1232826 (A) 1232827(8) 1232828 (A) 1232829 (C) 1232830 (A) 1232831 (D) 1 1232832 (8) 1

Aviationexam Test Prep Edition 2012

232833. Airplane ATPL CPL Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab, which statement is correct? I. A stabiliser trim is less suitable for jet transport aeroplanes because of their large speed range. II. A stabiliser trim is a more powerful means of trimming. A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct.

Airplane ATPL CPL 232834. Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab, which statement is correct? I. A trim tab is less suitable for jet transport aeroplanes because of their large speed range. II. A trim tab is a more powerful means of trimming. A) I is incorrect, II is incorrect. B) I is correct, II is correct. C) I is incorrect, II is correct. D) I is correct, II is incorrect. Airplane ATPL CPL 232835. Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab, which of these statements are correct or incorrect? I. A stabiliser trim is more suitable to cope with the large trim changes generated by the high lift devices on most jet transport aeroplanes. II. A t~im tab runaway causes less control difficulty. A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is incorrect.

Airplane ATPL CPL 232836. Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab, which of these statements are correct or incorrect? I. A elevator trim tab is more suitable to cope with the large trim changes generated by the high lift devices on most jet transport aeroplanes. II. A stabiliser trim runaway causes less control difficulty. A) B) C) D)

I is incorrect, II is correct. I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect.

232837. Airplane ATPL CPL Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab, which of these statements are correct or incorrect? I. A elevator trim tab is more suitable to cope with the large trim changes generated by the high lift devices on most jet transport aeroplanes. II. A trim tab runaway causes less control difficulty. A) B) C) D)

232838. Airplane ATPL CPL Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab, which of these statements are correct or incorrect? I. A stabiliser trim is more suitable to cope with the large trim changes generated by the high lift devices on most jet transport aeroplanes. II. A stabiliser trim runaway causes less control difficulty. A) B) C) D)

I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct.

Airplane ATPL CPL 232839. Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab, which of these statements are correct or incorrect? I. The effects of a stabiliser trim runaway are more serious. II. Ajammed trim tab causes less control difficulty. A) B) C) D)

I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is correct. I is correct, II is incorrect.

232840. Airplane ATPL CPL Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab, which of these statements are correct or incorrect? I. The effects of a trim tab runaway are more serious. II. Ajammed stabilisertrim causes less control difficulty. A) B) C) D)

I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is correct. I is correct, II is incorrect.

Airplane ATPL CPL 232841. Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab, which of these statements are correct or incorrect? I. The effects of a trim tab runaway are more serious. II. Ajammed trim tab causes less control difficulty. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct.

Airplane ATPL CPL 232842. Comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab, which of these statements are correct or incorrect? I. The effects of a stabiliser trim runaway are more serious. II. Ajammed stabilisertrim causes less control difficulty. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct. I is incorrect, II is incorrect.

I is incorrect, II is correct. I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect.

1232833(0) 1232834(0) 1232835 (A) 1232836(0) 1232837 (A) 1232838 (A) 1232839 (C) 1232840 (A) 1232841 (C) 1232842 (A) 1

05 Control

232843. Airplane ATPL CPL Which of these statements about a trimmable horizontal stabiliser is correct? A) A trimmed aeroplane with an aft CG requires the stabiliser leading edge to be higher than in the case of a forward CG in the same condition. B) A trimmed aeroplane with an aft CG requires the stabiliser leading edge to be lower than in the case of a forward CG in the same condition. C) Because take-off speeds do not vary with CG position, the need for stabiliser adjustment is dependent on flap position only. D) At the aft CG limit, stabiliser trim is adjusted fully nose up to obtain maximum elevator authority at rotation during take-off. Airplane ATPL CPL 232844. When comparing an elevator trim system with a stabiliser trim system, which ofthese statements is correct? A) an elevator trim is able to compensate larger changes in pitching moments. B) an elevator trim is more sensitive to flutter. C) an elevator trim is able to compensate larger changes in pitching moments. D) an elevator trim is more suitable for aeroplanes with a large CG range. Airplane ATPL CPL 232845. When comparing a stabilisertrim system with an elevator trim system, which of these statements is correct? A) an elevator trim is more suitable for aeroplanes with a large CG range. B) an elevator trim is able to compensate larger changes in pitching moments. C) a stabiliser trim is less sensitive to flutter. D) a stabiliser trim is not as capable to compensate large changes in pitching moments. Airplane ATPL CPL 232846. When comparing a stabiliser trim system with an elevator trim system, which of these statements is correct? A) an elevator trim is less suitable for aeroplanes with a large CG range. B) a stabiliser trim is more sensitive to flutter. C) an elevator trim is able to compensate larger changes in pitching moments. D) a elevator trim is able to compensate larger changes in pitching moments.

1232843 (A) 1232844 (8) 1232845 (C) 1232846 (A) 1

Aviationexam Test Prep Edition 2012

06 Limitations

LIMITATIONS 06-01 Operating Limitations 3635.

Airplane

3655.

ATPL

What is the relationship of V MO and MMo' in a climb and descent? A) If climbing at VMO' Mach number is decreasing. B) If climbing at MMo' Indicated Airspeed is increasing. C) If climbing at VMO' it is possible to exceed MMO. D) If descending at MMO' VMO cannot be exceeded. VMO is an lAS and will therefore mean higher TAS with increasing altitude. MMO is a Mach number (TAS -;- (local speed of sound)) that means a lower TAS with increasing altitude, because the speed of sound is proportional to the square root of the absolute temperature, which decrease with increasing altitude. Increasing altitude flying VMO might therefore exceed MMO.

3638. Airplane ATPL (Refer to figure 081-01) In a high speed descent at MMO you will reach V MO at:

A) B) C) D)

MO,8 FL270 350 kts FL250

+ RED colors

Identify the line that represents MMO (outlined in blue color). Identify the line that represents VMO (outlined in blue color). Find the point where the MMO line intersects the VMO line. From this intersection point draw a horizontal line to the left (outlined in red color) and read the corresponding Flight Level on the left vertical scale of the chart => approx. FL270.

Conclusion: if the aircraft is descending at the MMO' it will reach the VMO speed at FL270. This VMO speed will be approximately 377 kts (read from the bottom scale of the chart directly below the intersection point found in step 3).

3644.

ATPL

CPL

A) The use of flaps during severe turbulence reduces the stall speed and the risk of exceeding structural limitations decreases. B) Extending flaps in turbulence reduces the stall speed but will reduce the margin to structural limitations. C) By extending flaps during extreme turbulence, the CP moves aft which will increase the margin to structural limitations. D) By extending flaps during severe turbulence it is possible to reduce speed and increase the margins to structural limitations. For explanation refer to question #3644 on this page.

15747.

Airplane

ATPL

V MO:

(Refer to figure 081-EI21) Note that the solution of this question is illustrated by BLUE in the explanation picture. 1) 2) 3) 4)

Airplane

Which of the following statements is correct?

Airplane

ATPL

CPL

Which of the following statements is true? A) Limiting factors in severe turbulence are the possibility of a stall and the margin to the structural limitations. B) Through extension of the flaps in severe turbulence it is possible to reduce the speed and increase the margins to the structural limits. C) By increasing the flap setting in severe turbulence the stall speed will be reduced and the risk for exceeding the structurallimits will be decreased. D) Through extension of the flaps in severe turbulence the centre of pressure will move aft which will increase the margins to the structural limits. Extending flaps for turbulence penetration in the cruise would reduce the stall speed and increase the margin to stall, but the margin to structural limitations will be reduced by a greater amount.

A) B) C) D)

is equal to the design speed for maximum gust intensity. should be chosen in between Vc and YD. should not be less than VD. should be not greater than Vc

VMO is a speed that may not be deliberately exceeded in any regime of the flight. VMO must not be greater than Vc and must be sufficiently below VD to make it highly improbable that VD will be inadvertently exceeded in operations.

16686.

Airplane

ATPL

CPL

Aileron reversal can be caused by: A) B) C) D)

twisting of the wing above reversal speed. fries type ailerons at low angles of attack. both answers are correct. neither answer is correct.

(Refer to figure 081-E59) In the illustration the aileron have been deflected downwards to increase the lift. On the rigid wing on the left this will happen, but on the elastic wing on the right the aerodynamic forces acting upwards on the aileron will twist the wing. If the speed is high enough the angle of attack will decrease instead of increasing, causing aileron reversal. The effect is shown again the speed below. The reversal speed is the point where the curve intersects the horizontal axis.

21000.

Airplane

ATPL

CPL

Wing flutter may be caused by a: A) B) C) D)

combination of bending and torsion of the wing structure. combination of fuselage bending and wing torsion. combination roll control reversal and low speed stall. aerodynamic wing stall at high speed.

A combination of bending and torsion and the elastic properties of the structure can cause the structure to oscillate. If a structure is subject to a 'forcing' frequency near the frequency determined by mass and stiffness, a resonant condition can result giving an unstable oscillation which can rapidly lead to destruction.

1 3635 (C)

1 3638 (8)

1 3644 (A)

1 3655 (8)

1 15747 (0) 116686 (A) 1 21000 (A) 1

Aviationexam Test Prep Edition 2012 21071. Airplane ATPL CPL How can wing flutter be prevented? A) By installing the fuel tanks in the fuselage. B) By increasing the aspect ratio of the wing. e) By mounting the engines on the fuselage. D) By locating mass in front of the torsion axis of the wing. Mass in front of the torsion axis will move the axis nearer to the aerodynamic centre of the wing. Changes in lift will therefore have a much smaller torsion moment, and flutter is less likely.

21140. Airplane VLE is defined as the:

ATPL

CPL

A) maximum landing gear extended speed. B) maximum speed at which the landing gear may be extended or retracted. e) maximum flap extended speed. D) maximum authorised speed. Definition: VLE is the max. speed with landing gear extended. VLO is the max. speed at which the landing gear may be extended or retracted.

23391. Airplane ATPL CPL Aileron reversal may be caused by: A) the wing twisting and increasing incidence when the aileron is lowered. B) the wing twisting and reducing incidence when the aileron is lowered. e) the aileron being pushed in the reverse direction by aileron drag. D) the wing twisting and reducing incidence when the aileron is raised. (Refer to figure 087-£59) In the illustration the aileron have been deflected downwards to increase the lift. On the rigid wing on the left this will happen, but on the elastic wing on the right the aerodynamic forces acting upwards on the aileron will twist the wing. If the speed is high enough the angle of attack will decrease instead of increasing, causing aileron reversal.

23512. Airplane V NE is defined as:

ATPL

CPL

A) never exceed speed. B) maximum nose wheel extended speed. e) maximum landing gear extended speed. D) maximum flap extended speed. Definition.

23513. Airplane ATPL can be exceeded in a climb at a constant lAS because:

MMO

A) maintaining a constant lAS requires an increase in TAS. B) as altitude increases the local speed of sound increases. e) at reduced density the Machmeter will under read. D) position error increases. Climbing with a constant lAS means higher TAS. MMO is a Mach number (TAS+(/ocal speed of sound)}. The speed of sound is proportional to the square root of the absolute temperature, which decrease with increasing altitude. Increasing altitude flying a constant lAS might therefore exceed MMO'

23514. Airplane ATPL CPL Aileron reversal1'lt high CL results from:

of attack beyond the critical. D) the increased drag of the down going aileron causing the aircraft to yaw in the opposite direction. (Refer to figure 087-£60) The down-going aileron increases the angle of attack. If the wing is already operating at a high angle of attack (high CL ), the aileron could increase the angle of attack over the stalling angle.

23515. Airplane ATPL CPL When considering a high speed jet, if flaps are selected down at a speed greater than V FE: A) the flaps will move to the selected position, causing structural damage. B) flap movement will be prevented by the flap load relief system. e) the flap selector lever cannot be moved because it is locked in position by a solenoid at these speeds. D) the flaps will stall and a violent nose up pitch will result. On some large high speed jet transport aircraft, a device is fitted in the flap operating system to prevent the flaps deploying if the aircraft speed is too high. The pilot can select the flaps, but they will not extend until the airspeed is below the flap extend speed (V'E)'

23516. Airplane ATPL CPL Control surface flutter is: A) a rapid oscillation of the control surface in flight. B) buffeting of the controls, caused by separation of the airflow over the control surface. e) the tendency of the control surface to move onto its stops due to overbalance. D) movement of the control, due to gusts, when the aircraft is on the ground. Flutter is an oscillation of the control surface which can occur due to the bending and twisting of the structure under load.

232849. Airplane ATPL CPL Wing flutter can be prevented by: A) ensuring that the wing eG is ahead of its torsional axis. B) mounting the engines on the fuselage. e) increasing wing elasticity. D) increasing the aspect ratio of the wing. 232850. Airplane ATPL CPL Aileron flutter can be caused by: A) aileron reversal. B) cyclic deformations generated by aerodynamic, inertial and elastic loads on the wing. e) continuous deformations in one direction generated by bending and twisting of the wing. D) the elastic centre of the wing section coinciding with the centre of gravity of that wing section. Airplane ATPL CPL 232851. Flutter sensitivity of an aeroplane wing is reduced by: A) a high speed (lAS). B) locating the engine ahead of the torsional axis of the wing. e) empty tanks near the wing tip. D) a low torsion stiffness in relation to the bending stiffness.

A) dynamic pressure acting on the aileron twisting the wing in the opposite direction, possibly causing the aircraft to bank in a direction opposite to that intended. B) dynamic pressure reducing the stick force, making the ailerons act in the reverse sense. e) the down-going aileron increasing the semi-span angle 121071 (0) 1 21140 (A) 123391 (8) 123512 (A) 123513 (A) 123514 (C) 123515 (8) 1 23516 (A) 1232849 (A) 1232850 (8) 1 1232851 (8) 1

06 Limitations

232854. Airplane ATPL CPL Control surface flutter can be eliminated by: A) reducing structural stiffness of the control surface attachment structure. B) mass balancing ofthe control surface. C) aerodynamic balancing ofthe control surface. D) increasing airspeed. 232855. Airplane ATPL CPL Which of these statements about flutter are correct or incorrect? I. Wing mounted engines extending ahead of the wing contribute to wing flutter suppression. II. Excessive free play or backlash reduces the speed at which control surface flutter occurs. A) B) C) D)

I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect. I is incorrect, II is correct.

232856. Airplane ATPL CPL Which of these statements about flutter are correct or incorrect? I. Moving the engines from the wing to the aft fuselage improves wing flutter suppression. II. Excessive free play or backlash increases the speed at which control surface flutter occurs. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct.

Airplane ATPL CPL 232857. Which of these statements about flutter are correct or incorrect? I. Moving the engines from the wing to the fuselage improves wing flutter suppression. II. Excessive free play or backlash reduces the speed at which control surface flutter occurs. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is correct.

232858. Airplane ATPL CPL Which of these statements about flutter are correct or incorrect? I. Wing mounted engines extending ahead of the wing contribute to wing flutter suppression. II. Excessive free play or backlash increases the speed at which control surface flutter occurs. A) B) C) D)

I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is correct, II is correct.

232859. Airplane ATPL CPL Which of these statements about flutter are correct or incorrect?

A) B) C) D)

I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is correct. I is correct, II is incorrect.

Airplane ATPL CPL 232860. Which of these statements about flutter are correct or incorrect? I. Aero-elastic coupling does not affect flutter characteristics. II. Occurrence of flutter is independent of lAS. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is correct.

Airplane ATPL CPL 232861. Which of these statements about flutter are correct or incorrect? I. Aero-elastic coupling does not affect flutter characteristics. II. The risk of flutter increases as lAS increases. A) B) C) D)

I is correct, II is correct. I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect.

Airplane ATPL CPL 232862. Which of these statements about flutter are correct or incorrect? I. Aero-elastic coupling affects flutter characteristics. II. Occurrence of flutter is independent of lAS. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is correct.

232863. Airplane ATPL CPL Which of these statements about flutter are correct or incorrect? I. If flutter occurs, lAS should be reduced. II. Resistance to flutter increases with increasing wing stiffness. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is incorrect. I is correct, II is correct. I is incorrect, II is correct.

232864. Airplane ATPL CPL Which of these statements about flutter are correct or incorrect? I. If flutter occurs, lAS should be kept constant. II. Resistance to flutter increases with reducing wing stiffness. A) B) C) D)

I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is incorrect. I is correct, II is correct.

I. Aero-elastic coupling affects flutter characteristics. II. The risk of flutter increases as lAS increases.

1232854(8) 1232855 (A) 1232856 (A) 1232857 (D) 1232858 (C) 1232859 (C) 1232860(8) 1232861 (8) 1232862(8) 1232863 (C) 1 1232864 (A) 1

Aviationexam Test Prep Edition 2012

232865. Airplane ATPL CPL Which of these statements about flutter are correct or incorrect?

232866. Airplane ATPL CPL Which of these statements about flutter are correct or incorrect?

I. If flutter occurs, lAS should be kept constant. II. Resistance to flutter increases with increasing wing stiffness.

I. If flutter occurs, lAS should be reduced. II. Resistance to flutter increases with reducing wing stiffness.

A) I is correct, II is incorrect. B) I is incorrect, II is correct. e) I is incorrect, II is incorrect. D) I is correct, II is correct.

A) I is correct, II is correct. B) I is incorrect, II is correct. C) I is incorrect, II is incorrect. D) I is correct, II is incorrect.

06-02 Manoeuvring Envelope 3618.

Airplane

ATPL

CPL

VA is: A) the speed that should not be exceeded in the climb. B) the maximum speed at which rolls are allowed. e) the speed at which a heavy transport aeroplane should fly in turbulence. D) the maximum speed at which maximum elevator deflection up is allowed.

3642. Airplane ATPL CPL By what percentage does VA (EAS) change when the aeroplane's weight decreases by 10%? A) 19% higher. B) 10% lower. e) No change. D) 5%lower. The stall speed depends on the aircraft weight. Expressed in a formula.: VSI9NEW

used to be Manoeuvre Speed, i.e. the lowest speed where the max. allowed load factor could be applied without stalling. It is now modified to the max. speed at which sudden, full elevator deflection (nose up) can be made without exceeding the design limit load factor.

=V"g OLDv(New Weight + Old Weight). VA = V"gvn, and since the load factor n is the same for all weights, the new VA must be: VA NEW = VA OLD v(New Weight + Old Weight). In this case: VA NEW = VA OLD v(0,9 + 7) = VA OLD v(0,9) = VA OLD 0,95 =>

3619. Airplane ATPL CPL Which load factor determines VA?

3653. Airplane ATPL CPL Which has the effect of increasing load factor? (all other relevant factors being constant)

VA

A) Manoeuvring flap limit load factor. B) Manoeuvring ultimate load factor. e) Gust load factor at 66 ftlsec gust. D) Manoeuvring limit load factor.

5% lower.

A) Rearward eG location. B) Increased aeroplane mass. e) Increased air density. D) Vertical gusts.

For explanation refer to question #3678 on this page.

3628. Airplane ATPL CPL How does VA (EAS) change when the aeroplane's mass decreases by 19%? A) does not change. B) 4,36% reduced. e) 19% reduced. D) 10% reduced. The stall speed depends on the aircraft weight. Expressed in a formula.: V"9NEW = V S1g OLDv(New Weight + Old Weight). VA = V"g vn, and since the load factor "n" is the same for all weights, the new VA must be: VA NEW = VA OLD v(New Weight + Old Weight). In this case: VA NEW = VA OLD V (0,87 + 7) = VA OLD v(0,87) = VA OLD 0,9 (70% lower).

3641. Airplane ATPL CPL The relationship between the stall speed Vs and VA (EAS) for a large transport aeroplane can be expressed in the following formula: A) VA < Vs x .J(2,5) B) VA > Vs x .J(2,5) e) VA = Vs x .J(2,5)

The load factor is the actual lift divided by the weight. In answers A, 8, and C, the lift is equal to the weight, so the load factor is 7. A vertical gust can increase the angle of attack which increases the lift, giving a load factor larger than 7.

3654. Airplane ATPL CPL What can happen to the aeroplane structure flying at a speed just exceeding VA? A) It may break if the elevator is fully deflected upwards. B) It may suffer permanent deformation if the elevator is fully deflected upwards. e) It may suffer permanent deformation because the flight is performed at too large dynamic pressure. D) It will collapse if a turn is made. VA is the max. speed at which sudden, full elevator deflection (nose up) can be made without exceeding the design limit load factor, because the aircraft would stall before that. Therefore, if a full elevator deflection is made above VA' the design limit load factor could be exceeded. The consequences might be structural damage.

3656. Airplane ATPL CPL The positive manoeuvring limit load factor for a large jet transport aeroplane with flaps extended is:

= V"g Vn. The design load factor for large transport aircraft is 2,5 g - therefore VA = V"g v(2,5).

VA

A) 3,75 B) 1,5

e) 2,5 D) 2,0 Limit load factors are specified by the EASA certification requirements

1232865 (8) 1232866 (D) 1 3618 (0)

1 3619 (0)

1 3628 (0)

1 3641 (0)

1 3642 (0)

1 3653 (0) 1 3654 (8)

1 3656 (0) 1

06 Limitations for different aeroplane categories. The maximum load factors for different classes of airplanes are typically: -In transport category, from -7 g to +2.5 g (+2 g with flaps extended) -In normal category, from -7.52 g to +3.8 g -In utility category, from -7.76 g to +4.4 g -In aerobatic category, from -3 g to +6 g

3659. Airplane Load factor is:

ATPL

Airplane ATPL CPL 21126. The manoeuvring speed VA' expressed as indicated airspeed, of a transport aeroplane: A) depends on aeroplane mass and pressure altitude. B) is a constant value. C) is independent of aeroplane mass, but dependent on pressure altitude. D) depends on aeroplane mass and is independent of pressure altitude.

CPL

A) Lift + Weight B) Weight + Lift C) 1 + Bank angle D) wing loading The load factor is defined as the actual lift divided by the weight.

3665. Airplane ATPL CPL An aircraft has a mass of 60.000 kg and a limiting positive load factor of 2,5 G. VA is calculated as the EAS at which full positive elevator deflection will give the limiting load factor at the stall, and is 237 kts. If the aircraft mass is reduced to 40.000 kg by fuel burn, what will be the new VA? A) 375 kts B) 194 kts C) 237 kts D) 150 kts The stall speed depends on the aircraft weight. Expressed in a formula: VS,g NEW = VS,g OLDv(New Weight + Old Weight}. VA = VS19vn, and since the load factor UnU is the same for all weights, the new VA must be: VA NEW =VAOLDv(New Weight + Old Weight}. In this case: VANEW =237 kts v(40.000 kg + 60.000 kg} =237 kts v(0,6667} =237 kts x 0,8765 = 793,5 kts - 794kts.

3666. Airplane ATPL CPL The positive manoeuvring limit load factor for a light aeroplane in the utility category in the clean configuration may not be less than:

VA is the max. speed at which sudden, full elevator deflection (nose up) can be made without exceeding the design limit load factor. The pressure altitude determines air density which in turn influences the lift and the forces created by the elevator. The load factor is lift/weight. So both weight and pressure altitude influence VA.

23588. Airplane ATPL CPL When flying slightly faster than VA: A) the airframe may collapse in a turn. B) possible permanent deformation of the structure may occur with full elevator deflection. e) a high speed warning will be activated. D) the aircraft cannot stall. VA used to be Manoeuvre Speed, i.e. the lowest speed where the max. allowed load factor could be applied without stalling. It is now modified to the max. speed at which sudden, full elevator deflection (nose up) can be made without exceeding the design limit load factor. Consequently, at speed above VA' it is possible to exceed the limit load factor without stalling.

24079. Airplane ATPL CPL An aeroplane is flying at a speed of 1,3 VA and full nose up elevator deflection is applied. This is likely to: A) make the wing collapse. B) cause excess dynamic pressure because the aeroplane is flyi ng so fast. e) break the aeroplane. D) possibly cause permanent deformation of the aeroplane.

A) 2,5

B) 4,4 e) 3,8

For explanation refer to question #23588 on this page.

D) 6,0

24559. Airplane ATPL CPL Which of the following formula is correct for JAR-25?

For explanation refer to question #3656 on page 744.

A) VA =VS19 x vCN max B) VS19 = VA x VCN max e) VA =VS19 x vn 2 D) VA =VS19 x n

3667. Airplane ATPL CPL What is the limit load factor of a large transport aeroplane? A) 6 B) 4,4 C) .3,75 D) 2,5

The design manoeuvre speed VA is defined as the stalling speed (Vs,) multiplied by the square root of the limit load factor (CN), hence VA = VS,gxVCNmax.

For explanation refer to question #3656 on page 744.

21019.

Airplane

ATPL

CPL

An aeroplane enters a horizontal turn with a load factor n=2 from straight and level flight whilst maintaining constant indicated airspeed. The: A) B) e) D)

lift doubles. induced drag doubles. lift becomes four times its original value. total drag becomes four times its original value.

Load factor is defined as the actual lift divided by the normal lift, i.e. the weight. If the load factor is 2 then the actual lift is the double of the lift at straight and level flight.

26770. Airplane ATPL CPL What is the danger when recovering from an emergency descent? A) Engine stall. B) Structural damage. C) Directional stability. D) The landing gear may collapse. In recovery from a descent the lift is increased to provide centripetal force to level off. The load factor would increase, and thus a danger of exceeding the limit load factor.

232352. Airplane ATPL CPL The load factor is greater than 1 (one): A) B) C) D)

I

3659 (A) 1232352 (8)

I I

3665 (8)

I

3666 (8)

I

3667 (D)

I 21019 (A) I 21126 (A)

during a steady co-ordinated horizontal turn. when lift is greater than weight. during a wings level stall before recovery. in steady wings level horizontal flight.

123588 (8) 124079 (0) 124559 (A) 126770 (8)

I

Aviationexam Test Prep Edition 2012

232875. Airplane ATPL CPL For an aeroplane with one fixed value of VA the following applies. VA is: A) the maximum speed in smooth air.

B) the speed at which the aeroplane stalls at the manoeuvring

limit load factor at MTOW. C) just another symbol for the rough air speed. D) the speed at which unrestricted application of elevator

control can be used, without exceeding the maximum manoeuvring limit load factor. 232878. Airplane ATPL CPL A fundamental difference between the manoeuvring limit load factor and the gust limit load factor is, that: A) the gust limit load factor has a fixed value for every transport aeroplane, whereas the manoeuvring limit load factor has not. B) the gust limit load factor is independent of the wing's aspect ratio, whereas the manoeuvring limit load factor is not. C) the gust limit load factor can be higher than the manoeuvring limit load factor. D) the manoeuvring limit load factor is independent of the size of the aeroplane, whereas the numerical value of the gust limit load factor is laid down in the regulations. 232879. Airplane ATPL CPL Which factor should be taken into account when determining VA? A) The limit load factor. B) The safety factor. C) The ultimate load factor. D) The calculation factor.

232891. Airplane ATPL Load factor is increased by:

CPL

A) forward CG movement. B) a decrease in air density. C) upward gusts. D) an increase in aeroplane mass. 233142. Airplane ATPL CPL In general, directional controllability with one engine inoperative on a multiengine aeroplane is favourably affected by: 1) High temperature. 2) Low temperature. 3) Aft CG location. 4) Forward CG location. S) High altitude. 6) Low altitude.

The combination that regroups all ofthe correct statements is:

A) 2,3,5 B) 1,4,6 C) 1,4, 5

D) 2,4,6 233143. Airplane ATPL CPL In general, directional controllability with one engine inoperative on a multiengine aeroplane is adversely affected by: 1) High temperature. 2) Low temperature. 3) Aft CG location. 4) Forward CG location. S) High altitude. 6) Low altitude.

The combination that regroups all of the correct statements is:

232882. Airplane ATPL CPL What may happen if the "ultimate load factor" is exceeded? A) Flutter. B) Structural failure. C) No structural failure, only plastic or permanent deformation. D) Elastic or temporary deformation only.

A) 1,4, 5

B) 2,3,5

C) 2,3,6 D) 1,4,6

06-03 Gust Envelope 3620. Airplane ATPL CPL Which of the following is a correct statement of gust factors applied in certification under JAR-2S? A) 55 ft/sec at VeB) 66 ftlsec at VD. C) 50 ft/sec at VeD) 25 ft/sec at VB.

Design diving speed VD•

3632. Airplane ATPL CPL Which statement regarding the gust load factor on an aeroplane is correct (all other factors of importance being constant)? 1) Increasing the aspect-ratio of the wing will increase

(Refer to figure 081-£88)

the gust load factor. 2) Increasing the speed will increase the gust load factor.

3631. Airplane ATPL CPL The extreme right limitation for both V-n (gust and manoeuvre) diagrams is created by the speed:

A) B) C) D)

A) VD

B) Vc C)

Vflutter

D) VMO (Refer to figure 081-£86)

1 and 2 are incorrect. 1 is incorrect and 2 is correct. 1 and 2 are correct. 1 is correct and 2 is incorrect.

(Refer to figure 081-£91) 1. For a given gust speed and aircraft TAS, the increment in the load factor depends on the increase in CL per change in angle of attack due to the gust, i.e. the slope of the lift curve. A high aspect wing has a steeper CL curve (illustration), and therefore the gust load factor will be higher.

1232875 (B) 1232878 (C) 1232879 (A) 1232882 (B) 1232891 (C) 1233142 (C) 1233143 (C) 1 3620 (C) 13631 (A) 1 3632(C) 1

06 Limitations 2. The increment in lift by the increase off angle of attack is proportional to the speed squared (L = ~pV2SCJ, so the gust load factor increases with speed. .

Airplane ATPL CPL What wing shape or wing characteristic is the least sensitive to turbulence: 3633.

Airplane ATPL CPL Which combination of speeds is applicable for structural strength in gust (clean configuration)? 3637.

A) 66 ftlsec and VD'

B) 50 ft/sec and Vee) 65 ft/sec at all speeds. D) 55 ftlsec and VB' (Refer to figure 081-E88)

3640. Airplane ATPL CPL Which statement is correct about the gust load on an aeroplane (lAS and all other factors of importance remaining constant)? 1) The gust load increases, when the weight decreases. 2) The gust load increases, when the altitude increases.

A) 1 is

incorrect and 2 is correct. B) 1 and 2 are correct. e) 1 and 2 are incorrect. D) 1 is correct and 2 is incorrect. 1. The lift increment produced by the gust is a smaller proportion of the original lift force for a heavy aircraft, which means the gust load factor is smaller for a heavy aircraft. 2. The lift increment produced by the gust is a smaller proportion of the original lift force when flying at altitude where the angle of attack is already high, which means the gust load factor is smaller at altitude.

3643. Airplane ATPL CPL An aircraft flying at a given EAS is subject to a positive gust of 50 kts EAS. Which of the following correctly describes the increase in positive G felt by the aircraft?

More at high aircraft weight. B) More with a high aspect ratio straight wing. e) Less at altitude. D) More with a swept wing. A)

(Refer to figure 081-E91) For a given gust speed and aircraft TAS, the increment in the load factor depends on the increase in CL per change in angle of attack due to the gust, i.e. the slope of the lift curve. A high aspect straight wing has a steeper CL curve (illustration), and therefore the gust load factor will be higher.

Airplane ATPL CPL The shape of the gust load diagram is also determined by the following three vertical speeds in ft/s (clean configuration):

(Refer to figure 081-E88)

1 3633 (8) 1 3637 (8) 123686 (0) 1

speed = 0, load factor = O. speed =0, load factor =+1. speed =Vs' load factor =O. speed =VB' load factor =+1.

21122. Airplane ATPL CPL The gust load factor due to a vertical up-gust increases when:

(Refer to figure 081-E91) For a given gust speed and aircraft TAS, the increment in the load factor depends oil the increase in CL per change in angle of attack due to the gust, i.e. the slope of the lift curve. A swept wing has a flatter CL curve (illustration), and therefore the gust load factor will be lower.

A) 25, 55, 75. B) 15, 56, 65. C) 25, 50, 66. D) 35, 55,66.

A) B) e) D)

(Refer to figure 081-E88)

A) straight wings. B) swept wings. e) wing dihedral. D) winglets.

3645.

21015. Airplane ATPL CPL All gust lines in the V-n graph originate from a point where the:

weight increases. B) the gradient of the eL-alpha graph increases. e) altitude increases. D) wing loading increases.

A)

(Refer to figure 081-E91) For a given gust speed and aircraft TAS, the increment in the load factor depends on the increase in CL per change in angle of attack due to the gust, i.e. the slope of the lift curve. The steeper the curve, the higher the gust load factor.

Airplane ATPL CPL Which of the following statements is true? 21169.

A) Flight

in severe turbulence may lead to a stall and/or structural limitations being exceeded. B) Flap extension in severe turbulence at constant speed increases both the stall speed and the structural limitation margins. e) By increasing the flap setting in severe turbulence at constant speed the stall speed will be reduced and the risk for exceeding the structural limits will be decreased. D) Flap extension in severe turbulence at constant speed moves the centre of pressure aft, which increases the structural limitation margins. Turbulence can increase the stall speed by increasing angle of attack. This might increase the lift and thus the load factor, even to a value exceeding the structural limitations.

21176. Airplane ATPL CPL Which statement is correct about the gust load factor on an aeroplane? 1) When the mass increases, the gust load factor increases. 2) When the altitude decreases, the gust load factor increases.

A) 1 is correct; 2 is correct. B) 1 is incorrect; 2 is incorrect.

e) 1 is incorrect; 2 is correct. D) 1 is correct; 2 is incorrect. For explanation refer to question #3640 on this page.

23578. Airplane ATPL CPL Which of the following is a correct design gust value?

A) 25 ft/sec at VB' B) 66 ft/sec at VB' e) 50 ft/sec at VD' D) 55 ftlsec at VD' (Refer to figure 081-E88)

23686. Airplane ATPL Which of the following in the V-n diagram?

A) B) e) D)

CPL

are the

gust

values

66 ftlsec / 55 ft/sec / 35 ftlsee. 75 ftlsec / 25 ftlsec / 50 ft/see. 20 ft/sec /-55 ft/sec /70 ft/see. 50 ftlsec / 66 ft/sec / 25 ft/see.

(Refer to figure 081-E88)

1 3640 (0) 1 3643 (8) 1 3645 (C) 1 21015 (8) 1 21122 (8) 1 21169 (A) 1 21176 (C) 123578 (8) 1

used

Aviationexam Test Prep Edition 2012 24464. Airplane ATPL CPL Which of the following wing planforms will be least affected by turbulence? A) Straight, high aspect ratio. B) Swept, low aspect ratio. C) Straight, moderate aspect ratio. D) Swept, high aspect ratio. (Refer to figure 087-E93) Turbulence means changes in angle of attack. The illustration shows that a change in angle of attack from A to B gives a much bigger change in CL for a straight wing (a) than for a swept wing (b). As for the aspect ratio, the two Cia curves in the illustration could be "HIGH aspect ratio" instead of "STRAIGHT" and "LOW aspect ratio" instead of "SWEPT': The swept wing with a low aspect ratio has therefore the least sensitivity to turbulence.

27023. V RA is: A) B) C) D)

Airplane

ATPL

CPL

a speed just below Mach buffet. the recommended turbulence penetration airspeed. a speed just above low speed buffet. the stall speed in turbulent conditions.

The Operational rough air speed, V.A is the speed recommended for flying in turbulence. Consequently, it is the speed for penetration of severe turbulence, not merely light turbulence.

232136. Airplane ATPL CPL An aeroplane in straight and level flight at 300 kts is subjected to a sudden disturbance in speed. Assuming the angle of attack remains constant initially and the load factor reaches a value of approximately 1,2: A) B) C) D)

the speed will the speed will the speed will the speed will

have decreased by 30 kts. have increased by 30 kts. have decreased by 60 kts. have increased by 60 kts.

232144. Airplane ATPL CPL An aeroplane flying at 100 kts in straight and level flight is subjected to a disturbance that suddenly increases the speed by 20 kts. Assuming the angle of attack remains constant, the load factor will initially: A) increase to 1,21. B) remain unchanged, since the angle of attack does not change. C) increase to 1,44. D) increase to 1,10.

232880. Airplane ATPL CPL Which statement regarding the manoeuvre and gust load diagram in the clean configuration is correct? I. The gust load diagram has a symmetrical shape with respect to the n = 1 line for speeds above VB' II. The manoeuvre load diagram does not extend beyond the speed Vc' A) B) C) D)

I is correct, II is correct. I is incorrect, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect.

232892. Airplane ATPL CPL An aeroplane maintains straight and level flight at a speed of 2 * Vs' If a vertical gust causes a load factor of 2, the load factor n caused by the same gust at a speed of 1,3 Vs would be: A) n = 1,65 B) n = 1,3 C) n = 1,69 D) n=4

232893. Airplane ATPL CPL All gust lines in the gust load diagram originate from a point where the: A) B) C) D)

speed = 0, load factor = O. speed = Vs' load factor = O. speed = 0, load factor = +1. speed =VB' load factor = +1.

232894. Airplane ATPL CPL Which of these statements concerning flight in turbulence is correct? A) VB is the recommended turbulence penetration air speed. B) VRA is the recommended turbulence penetration air speed. C) In severe turbulence, speed should be reduced to approximately 1,2 Vs' D) The load factor in turbulence may fluctuate above and below 1, but will not become negative.

232895. Airplane ATPL CPL Which of these statements concerning flight in turbulence is correct? A) In severe turbulence, speed should be reduced to approximately 1,2 Vs' B) VB is the design speed for maximum gust intensity. C) The load factor in turbulence cannot exceed the ultimate load factor. D) The load factor in turbulence may fluctuate above and below 1, but will not become negative.

232896. Airplane ATPL CPL Which of these statements concerning flight in turbulence is correct? A) When encountering turbulence during flight, the speed should be adjusted to the design speed for maximum gust intensity VB' B) Above VB the aeroplane can never be overstressed by a gust. C) The load factor in turbulence may fluctuate above and below 1 and can even become negative. D) In severe turbulence, speed should be reduced to approximately 1,2 Vs'

232902. Airplane ATPL CPL Which of these statements about· the gust load factor on an aeroplane are correct or incorrect? I. When the mass decreases, the gust load factor increases. II. When the altitude increases, the gust load factor increases. A) B) C) D)

I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct.

124464 (8) 1 27023 (8) 1232136 (8) 1232144 (C) 1232880 (C) 1232892 (A) 1232893 (C) 1232894 (8) 1232895 (8) 1232896 (C) 1 1232902 (A) 1

06 Limitations

232905. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the mass decreases, the gust load factor increases. II. When the altitude decreases, the gust load factor increases. A) I is incorrect, II is incorrect. B) I is incorrect, II is correct. C) I is correct, II is incorrect. D) I is correct, II is correct.

232906. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the mass increases, the gust load factor increases. II. When the altitude increases, the gust load factor increases. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is correct.

232907. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the mass increases, the gust load factor decreases. II. When the altitude increases, the gust load factor decreases. A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct.

232908. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the mass decreases, the gust load factor decreases. II. When the altitude decreases, the gust load factor decreases. A) I is correct, II is incorrect. B) I is correct, II is correct. C) I is incorrect, II is incorrect. D) I is incorrect, II is correct.

232909. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the mass decreases, the gust load factor decreases. II. When the altitude increases, the gust load factor decreases. A) I is correct, II is incorrect. B) I is incorrect, II is incorrect. C) I is incorrect, II is correct. D) I is correct, II is correct.

232910. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the mass increases, the gust load factor decreases. II. When the altitude decreases, the gust load factor decreases. A) I is incorrect, II is incorrect.

B) I is incorrect, II is correct. C) I is correct, II is correct. D) I is correct, II is incorrect.

232911. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the slope of the lift versus angle of attack curve increases, the gust load factor increases. II. When the wing loading increases, the gust load factor decreases. A) I is incorrect, II is incorrect. B) I is correct, II is incorrect. C) I is incorrect, II is correct. D) I is correct, II is correct.

232912. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the slope of the lift versus angle of attack curve increases, the gust load factor decreases. II. When the wing loading increases, the gust load factor increases. A) I is incorrect, II is incorrect. B) I is correct, II is incorrect. C) I is incorrect, II is correct. D) I is correct, II is correct.

232913. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the slope of the lift versus angle of attack curve increases, the gust load factor decreases. II. When the wing loading increases, the gust load factor decreases. A) I is incorrect, II is correct. B) I is incorrect, II is incorrect. C) I is correct, II is incorrect. D) I is correct, II is correct.

232914. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the slope of the lift versus angle of attack curve increases, the gust load factor increases. II. When the wing loading increases, the gust load factor increases. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is correct.

232915. Airplane ATPL CPL Which of these statements about the gust load factor· on an aeroplane are correct or incorrect? I. When the slope of the lift versus angle of attack curve decreases, the gust load factor decreases. II. When the wing loading decreases, the gust load factor increases. A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is incorrect.

1232905 (0) 1232906 (C) 1232907 (A) 1232908 (C) 1232909 (C) 1232910 (0) 1232911 (0) 1232912 (A) 1232913 (A) 1232914 (8) 1 1232915 (A) 1

Aviationexam Test Prep Edition 2012 232916. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the slope of the lift versus angle of attack curve decreases, the gust load factor increases. II. When the wing loading decreases, the gust load factor decreases. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is correct.

232917. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the slope of the lift versus angle of attack curve decreases, the gust load factor increases. II. When the wing loading decreases, the gust load factor increases. A) I is correct, II is incorrect. B) I is incorrect, II is correct. C) I is correct, II is correct. D) I is incorrect, II is incorrect.

232918. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the slope of the lift curve versus angle of attack curve decreases, the gust load factor decreases. II. When the wing loading decreases, the gust load factor decreases. A) I is correct, II is incorrect. B) I is incorrect, II is correct. C) I is incorrect, II is incorrect. D) I is correct, II is correct.

232919. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the wing area increases, the gust load factor increases. II. When the EAS increases, the gust load factor increases. A) B) C) D)

I is incorrect, II is correct. I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect.

232920. Airplane ATPL CPL which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the wing area increases, the gust load factor decreases. II. When the EAS increases, the gust load factor decreases. A) I is correct, II is correct. B) I is incorrect, II is correct. C) I is incorrect, II is incorrect. D) I is correct, II is incorrect.

232921. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the wing area increases, the gust load factor

decreases. II. When the EAS increases, the gust load factor increases. A) B) C) D)

I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is correct. I is correct, II is incorrect.

232922. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the wing area increases, the gust load factor increases. II. When the EAS increases, the gust load factor decreases. A) B) C) D)

I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is correct. I is correct, II is incorrect.

232923. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the wing area decreases, the gust load factor decreases. II. When the EAS decreases, the gust load factor decreases. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct. I is incorrect, II is incorrect.

232924. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the wing area decreases, the gust load factor increases. II. When the EAS decreases, the gust load factor increases. A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct.

232925. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the wing area decreases, the gust load factor increases. II. When the EAS decreases, the gust load factor decreases. A) B) C) D)

I is incorrect, II is correct. I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is incorrect.

232926. Airplane ATPL CPL Which of these statements about the gust load factor on an aeroplane are correct or incorrect? I. When the wing area decreases, the gust load factor decreases. II. When the EAS decreases, the gust load factor increases. A) B) C) D)

I is incorrect, II is correct. I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is incorrect.

1232916(8) 1232917(8) 1232918 (A) 1232919(8) 1232920 (C) 1232921 (8) 1232922 (D) 1232923 (C) 1232924(8) 1232925 (A) 1 1232926 (8) 1

07 Propellers

PROPELLERS 07-01 Conversion of Engine Torque to Thrust 3672.

Airplane

ATPL

3689.

CPL

Propeller efficiency may be defined as the ratio between: A) the usable (power available) power and the maximum power. B) the thrust and the maximum thrust. C) usable (power available) power of the propeller and shaft power. D) the thermal power of fuel-flow and shaft power. Efficiency is POWER OUT + POWER IN. For the propeller it means THRUST POWER + SHAFT POWER. The "Power Out" is the product of Thrust x TAS, or power available. The "Power In" is the engine torque x rotational velocity, or shaft power.

3674.

Airplane

ATPL

CPL

During a glide with idle power and constant lAS, if the RPM lever of a constant speed propeller is pulled back from its normal cruise position, the propeller pitch will: A) B) C) D)

decrease and the rate of descent will increase. increase and the rate of descent will increase. decrease and the rate of descent will decrease. increase and the rate of descent will decrease.

Pulling the RPM lever back causes the propeller pitch to increase (coarse pitch). Increasing the propeller pitch will move the chord of the blade towards the direction of movement. The propeller will thus create less drag. The LID ratio of the blade will therefore increase. The rate of descent in a glide is (PR - P) + W, and with less drag, power required will decrease and the rate of descent will decrease. With the throttle at idle, the RPMs will decrease because of reduction in negative propeller torque.

3681.

Airplane

ATPL

A) B) C) D)

The constant speed unit will change pitch when the aircraft TAS changes to maintain constant engine RPM. In horizontal turbulence the TAS will vary, but only with reasonably small amounts compared to the aircraft TAS. The pitch will therefore change but only slightly.

3686.

Airplane

ATPL

A) B) C) D)

Airplane

ATPL

forward velocity increases and RPM decreasing. velocity and RPM increase. RPM increases and forward velocity decreases. velocity and RPM decrease.

3696.

Airplane

ATPL

3672 (C)

I

3674 (D)

I

3681 (0)

I

3686 (A)

I

3689 (C)

I

CPL

For a fixed-pitch propeller designed for cruise, the angle of attack of each blade, measured at the reference section: A) is lower in ground run than in flight (with identical engine RPM). B) decreases when the aircraft speed decreases (with identical engine RPM). C) is optimum when the aircraft is in a stabilized cruising flight. D) is always positive during idling descent. (Refer to figure 081-E42) Answer Cis the logical answer, and the illustration shows the other possibilities to be false.

3698.

Airplane

ATPL

CPL

Propeller efficiency is: A) the ratio of power available (Thrust x TAS) to shaft power (Torque x RPM). B) greater with a larger number of blades. C) a number greater than one. D) maximum when TAS is zero. For explanation refer to question #3672 on this page.

(Refer to figure 087-E42) The constant speed unit will change pitch when the aircraft TAS changes to maintain a constant angle of attack. If the aircraft TAS increases, the blade angle has to be increased to maintain the angle of attack.

I

CPL

(Refer to figure 081-E42) As seen in the illustration, angle of attack is determined by the added vectors of propeller RPM (which depends on power) and TAS. Increasing power and increasing TAS, or reducing power and reducing TAS, might increase angle of attack depending on the new ratio of RPM and TAS, but increasing power and reducing TAS will definitely increase the angle of attack.

CPL

The blade angle increases with increasing aeroplane speed. The propeller system keeps the aeroplane speed constant. The RPM decreases with increasing aeroplane speed. The selected RPM is kept constant by the manifold pressure.

decrease and the rate of descent will decrease. increase and the rate of descent will increase. increase and the rate of descent will decrease. decrease and the rate of descent will increase.

3691.

Which of the following statements about a constant speed propeller is correct? A) B) C) D)

CPL

The angle of attack of a fixed pitch propeller blade increases when:

CPL

Yes, but only if the pitch is full-fine. Yes strongly. No. Yes slightly.

ATPL

For explanation refer to question #3674 on this page.

Does the pitch-angle of a constant-speed propeller alter in medium horizontal turbulence? A) B) C) D)

Airplane

If the propeller pitch, within its constant speed range and at constant power, during descent at constant lAS is increased, the aeroplane lift to drag ratio will:

3691 (C)

I

3696 (C)

I

3698 (A)

I

Aviationexam Test Prep Edition 2012

3703. Airplane ATPL The propeller CTM will: A) B) C) D)

will __ propeller alpha.

CPL

A) decrease; decrease B) increase; decrease C) decrease; increase D) increase; increase

cause the propeller CSU to pitch lock. tend to move the blades to a coarse pitch. move the blades about their longitudinal axis. act in reverse when propeller braking is applied.

(Refer to figure 081-E34) CTM = Centrifugal Turning Moment. The centrifugal force on the blade at position 1 in the illustration acts along the pitch change axis of the blade, whilst the centrifugal forces at positions 2 and 3 can be resolved both parallel to the pitch change axis (the axial vector - green) and parallel to the direction of movement (the in-plane vector - yellow). As shown on the right side of the attached illustration, the in-plane vectors will create a turning moment, thus turning the blade about the pitch change axis = along the longitudinal axis of the blade.

3707. Airplane ATPL CPL Which of the following definitions of propeller parameters is correct? A) Blade angle is the angle between chord line and propeller axis. B) Geometric propeller pitch is the theoretical distance travelled forward by the propeller in one rotation. C) Critical tip speed is the propeller speed at which there is a risk of the flow separating at some part of the propeller. D) Blade angle of attack is the angle between chord line and propeller vertical axis. (Refer to figure 087-£02) Blade angle = the angle between chord and plane of rotation; Blade angle of attack = the angle between chord and relative airflow; Critical tip speed - the separation would be at the tip, not "some part of the propeller'~

3722. Airplane ATPL CPL With a constant speed propeller, which of the following statements is true? A) B) C) D)

Pitch angle increases with increasing TAS. Pitch angle decreases with increasing TAS. RPM decreases with increasing TAS. RPM increases with increasing TAS.

(Refer to figure 081-E42) Under the given circumstances the constant speed propeller will maintain the angle of attack. As seen in the illustration, angle of attack is determined by the added vectors of propeller RPM (which depends on power) and TAS. The Constant Speed Unit (CSU) will change pitch when the aircraft TAS changes to maintain a constant angle of attack. Increasing speed at constant RPM would decrease angle of attack, so the CSU will increase the pitch. With the same angle of attack, the propeller drag is unchanged, and the propeller torque remains constant.

3725. Airplane ATPL CPL Constant-speed propellers deliver better performance than fixed-pitch propellers because they: A) have a higher maximum propeller efficiency than a fixedpitch propeller. B) operate at a relatively high propeller efficiency over a wider speed range than a fixed pitch propeller. C) produce a relatively higher thrust than a fixed-pitch propeller. D) have more blade surface area than a fixed-pitch propeller. (Refer to figure 087-£97) The propeller efficiency at a given pitch angle varies with forward speed. By varying the pitch continuously through the speed range, a high efficiency can be maintained over a much wider range of operating conditions.

3730. Airplane ATPL CPL With a fixed pitch propeller increasing speed will ___ propeller alpha and increasing power and therefore propeller RPM 1 3703 (C)

1 3707 (8)

1 3722 (A)

1 3725(8)

(Refer to figure 081-E42) As seen in the illustration, angle of attack is determined by the added vectors of propeller RPM (which depends on power) and TAS. Increasing speed at constant RPM will decrease angle of attack, and increasing RPM at constant TAS will increase the angle of attack.

3736. Airplane ATPL CPL The angle of attack for a propeller blade is the angle between blade chord line and: A) aeroplane heading. B) direction of propeller axis. C) local air speed vector. D) principal direction of propeller blade. (Refer to figure 081-E42)

3743. Airplane ATPL CPL If the RPM lever of a constant speed propeller is moved forward during a glide with idle power and whilst maintaining constant airspeed, the propeller pitch will: A) B) C) D)

decrease and the rate of descent will increase. increase and the rate of descent will decrease. increase and the rate of descent will increase. decrease and the rate of descent will decrease.

Pushing the RPM lever forward causes the propeller pitch to decrease (fine pitch). Decreasing the propeller pitch will move the chord of the blade away from the direction of movement. The propeller will thus create more drag. The UD ratio of the blade will therefore decrease. The rate of descent in a glide is (PR - P)"," \Iv, and with more drag, power required will increase and the rate of descent will increase.

3754. Airplane ATPL CPL If the propeller pitch, within its constant speed range and at constant power, during descent at constant lAS is decreased, the aeroplane lift to drag ratio will: A) B) C) D)

decrease and the rate of descent will decrease. increase and the rate of descent will increase. decrease and the rate of descent will increase. increase and the rate of descent will decrease.

For explanation refer to question #3743 on this page.

16691. Airplane ATPL CPL A fixed pitch propeller is usually: A) B) C) D)

at too coarse an angle for takeoff. at too fine and angle for takeoff. at too coarse an angle in the cruise. at its optimum angle on takeoff.

(Refer to figure 081-E42) The fixed propeller has a pitch optimized for the cruise. As seen in the illustration, angle of attack is determined by the added vectors of propeller RPM (which depends on power) and TAS. With TAS being zero at the take-off, a fixed propeller will have a large angle of attack. The pitch is therefore too coarse to be efficient for take-off.

16692. Airplane ATPL CPL Running an engine fitted with a fixed pitch propeller at full throttle with the aircraft stationary and nose into strong wind will result in: A) B) C) D)

a variable RPM depending on the CSU. higher RPM than in still air. lower RPM than in still air. the same RPM as in still air.

1 3730 (C) 1 3736 (C) 1 3743 (A)

1 3754 (C) 116691 (A) 116692 (8) 1

07 Propellers (Refer to figure 081-£42) As seen in the illustration, angle of attack is determined by the added vectors of propeller RPM (which depends on power) and TAS. With TAS actually being the wind speed, a fixed propeller will have a smaller angle of attack than in still air. A smaller angle ofattack means less propeller drag, and hence higher RPMs.

16700. Airplane ATPL CPL A reversible propeller is one that: A) B) C) D)

will deliver negative thrust. is mounted behind the main wing. is a pusher rather than a tractor. can be operated in either direction of rotation.

(Refer to figure 081-£39) A reversible propeller can be regulated to give a large negative angle of attack on the blades. As shown in the illustration this will produce negative thrust whilst the propeller is still driven by the engine.

23526. Airplane ATPL CPL Propeller slip is the difference between the: A) B) C) D)

geometric pitch and the blade angle. geometric pitch and the effective pitch. plane of rotation and the aircraft's forward velocity. RPM of the engine and the RPM of the propeller.

(Refer to figure 081-£02)

23527. Airplane ATPL CPL The blade angle of a propeller is the angle between: A) the root chord and the tip chord of the propeller. B) the chord and the airflow relative to the propeller. C) the chord of the propeller and the longitudinal axis of the aircraft. D) the propeller chord and the plane of rotation of the propeller. (Refer to figure 081-£42)

21025. Airplane ATPL CPL An aeroplane is fitted with a constant speed propeller. If the aeroplane speed increases while manifold pressure remains constant (i) propeller pitch and the (ii) propeller torque will: A) B) C) D)

(i) (i) (i) (i)

decrease; (ii) decrease. increase; (ii) increase. increase; (ii) remain constant. decrease; (ii) remain constant.

For explanation refer to question #3722 on page 152.

21110. Airplane ATPL CPL The angle of attack of a propeller blade element is the angle between the blade element chord line and the: A) B) C) D)

propeller axis. resultant air speed vector. propeller plane. TAS vector.

(Refer to figure 081-£42)

21165. Airplane ATPL CPL Which definition of propeller parameters is correct? A) Blade angle is the angle between the blade chord line and the propeller axis. B) Geometric pitch is the theoretical distance a propeller would advance in one revolution at zero blade angle of attack. C) Angle of attack is the angle between the blade chord line and the propeller vertical plane. D) Critical tip velocity is the propeller speed at which flow separation first occurs at some part of the blade. (Refer to figure 081-£02)

21190. Airplane ATPL CPL Why is a propeller blade twisted from root to tip? A) B) C) D)

To ensure that the tip produces most thrust. To ensure the angle of attack is greatest at the tip. To ensure that the root produces most thrust. To maintain a constant angle of attack along the whole length of the propeller blade.

(Refer to figure 081-£01) To maintain a uniform angle of attack on the blade, and thus have a more reasonable distribution of thrust along the blade, propellers will have washout, that is decreasing pitch from root to tip. See illustration. The angle of attack is the angle between the chord and the relative airflow made up of the added vectors ofTAS and rotational speed of the blade. Nearer the tip the rotational speed is high requiring a finer pitch.

23528. Airplane ATPL CPL What is the primary advantage of a constant speed propeller? A) To obtain and maintain a selected pitch angle of the blades regardless of the flight situation or power setting. B) To maintain a specific engine speed. C) To obtain a pitch setting that is suitable for each flight situation and power setting. D) To ensure that the propeller RPM is always greater than the manifold pressure. (Refer to figure 081-£97) Constant speed propellers are controlled automatically to vary their pitch so that the propeller revolves at a given rate decided by the pilot, and remains at that rate irrespective of throttle opening or the manoeuvres of the aircraft. Thus engine and propeller can work at their best efficiency irrespective of flight conditions.

23529. Airplane ATPL CPL A constant speed propeller is one which: A) rotates at a constant speed by altering the blade angle. B) is most efficient at a constant aircraft speed. C) rotates at a constant speed by maintaining a constant blade angle. D) maintains a constant aircraft speed by altering blade angle. Constant speed propellers are controlled automatically to vary their pitch so as to maintain a selected RPM.

23530. Airplane ATPL CPL The aerodynamic loads on a propeller which produce forward thrust will tend to: A) B) C) D)

increase RPM. bend the tips forward. increase tip velocity to supersonic speeds. bend the tips backwards.

The thrust on the blade increases to a maximum at around 75% radius. This force acting forward will tend to bend the tips forward.

23531. Airplane ATPL CPL The forces acting on a propeller are: A) B) C) D)

thrust only. thrust and drag only. torque only. thrust and torque.

The total reaction on the blade is resolved into thrust in the direction

of movement and perpendicular to that, torque.

116700 (A) 121025 (C) 1 21110 (8) 1 21165 (8) 121190 (D) 123526 (8) 123527 (0) 123528 (C) 123529 (A) 123530 (8) 1 123531 (0) 1

Aviationexam Test Prep Edition 2012

23558. Airplane ATPL CPL An aircraft with constant speed propeller decreases its speed with constant manifold pressure. The propeller pitch will __ _ and the propeller torque will ___• A) decrease; remain constant B) increase; increase e) decrease; increase 0) remain constant; decrease (Refer to figure 081-E42) 1. The constant speed unit will change pitch when the aircraft TAS changes to maintain a constant blade angle. Referring to the illustration, if the aircraft TAS decreases, the blade angle has to be decreased to maintain the angle of attack. 2. Constant speed propellers are controlled automatically to vary their pitch so as to maintain a selected RPM, that means the torque remains constant.

23654. Airplane ATPL CPL When an aircraft with a fixed pitch propeller climbs, the angle of attack of the propeller: A) gets smaller. B) remains the same. e) gets bigger. 0) reduces to zero.

A) feather the propeller. B) reduce the RPM lever setting. e) push the RPM lever fully forward. 0) close the throttle. Before doing anything else it is obvious to eliminate the power input to the propeller by closing the throttle.

26803. Airplane ATPL CPL A typical fixed pitch propeller (e.g. C-172) is designed to achieve its optimum angle of attack at: A) low forward speeds, such as during takeoff. B) cruise speed. e) rest to case engine starting. 0) maximum speed for high performance. Normally a fixed pitch propeller is optimized for the cruise condition in which the aircraft is expected to operate for the major part of operations.

232927. Airplane For any propeller:

ATPL

CPL

(Refer to figure 081-E42) With increasing altitude engine power will decrease and thus thrust decreases slowing the aircraft. The effective pitch will decrease and reduce the helix angie. As seen in the iIIustrotion, a smaller helix angle means an increased angle of attack on a fixed pitch propeller.

A) thrust is the component of the total aerodynamic force on the propeller in the plane of rotation. B) thrust is the component of the total aerodynamic force on the propeller parallel to the rotational axis. C) the force contributing to propeller torque is perpendicular to the propeller plane of rotation. 0) the total aerodynamic force on a blade element may be resolved into two components, torque and lift.

23669. Airplane ATPL CPL The angle of attack of a fixed pitch propeller designed for cruising flight, measured at its reference station is:

Airplane ATPL CPL 232928. The reference section of a propeller blade with radius R is usually taken at a distance from the propeller axis equal to:

A) optimum in steady cruising flight only. B) increases with an increase in lAS. e) decreases with an increase in RPM. 0) will always be positive in a power off glide. (Refer to figure 081-E42) Typical fixed pitch propeller is optimized for maximum efficiency during the cruise phase of the flight. Answer A is the logical answer, and the illustration shows the other possibilities to be false.

23726. Airplane ATPL CPL The angle of attack of a fixed pitch propeller: A) is lower in the takeoff run than in flight. B) is optimum in flight. e) is optimum in stabilized cruise flight. 0) decreases with decrease in speed at constant engine RPM. (Refer to figure 081-E42) Typical fixed pitch propeller is optimized for maximum efficiency during the cruise phase of the flight. Answer C is the most correct answer. Answer B is too unspecific to be correct, and the illustration shows the other possibilities to be false.

23728. Airplane ATPL CPL Propeller blade angle of attack is the angle between the chord and the: A) direction of axis of the propeller. B) aeroplane heading. e) relative airflow. 0) vector ofTAS. (Refer to figure 081-E42)

26799. Airplane ATPL CPL The first action in event of propeller runaway (overs peed condition), should be to:

A) 0,50 R. B) 0,90 R. C) 0,75 R. 0) 0,25 R.

232932. Airplane ATPL CPL (Refer to figure 081-15) The angle of attack of a rotating propeller blade element shown in the annex is: A) angle 1. B) angle 3. e) not correctly indicated in the diagram. 0) angle2. 232933. Airplane ATPL CPL (Refer to figure 081-15) The helix or advance angle of a rotating propeller blade element shown in the annex is: A) angle 2. B) angle 3. e) not correctly indicated in the diagram. 0) angle 1. 232934. Airplane ATPL CPL (Refer to figure 081-15) The blade angle of a rotating propeller blade element shown in the annex is: A) angle 2. B) angle 3. e) angle 1. 0) not correctly indicated in the diagram.

123558 (A) 123654 (C) 123669 (A) 1 23726 (C) 1 23728 (C) 126799 (D) 126803 (8) 1232927 (8) 1232928 (C) 1232932 (A) 1 1232933(8) 1232934 (A) 1

~~~~~-

-----

07 Propellers

232937. Airplane ATPL CPL Which statement is correct? I. A propeller with a small blade angle is referred to as being in fine pitch. II. A propeller with a large blade angle is referred to as being in coarse pitch. A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is incorrect.

232938. Airplane ATPL CPL Which statement is correct? I. A propeller with little blade twist is referred to as being in fine pitch. II. A propeller with significant blade twist is referred to as being in coarse pitch. A) I is correct, II is correct. B) I is incorrect, II is incorrect. C) I is incorrect, II is correct. D) I is correct, II is incorrect. 232939. Airplane ATPL CPL Which statement is correct? I. A propeller with little blade twist is referred to as being in fine pitch. II. A propeller with a large blade angle is referred to as being in coarse pitch. A) B) C) D)

I is correct, II is correct. I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect.

232940. Airplane ATPL CPL Which statement is correct? I. A propeller with a small blade angle is referred to as being in fine pitch. II. A propeller with significant blade twist is referred to as being in coarse pitch. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is incorrect. I is correct, II is correct. I is incorrect, II is correct.

232941. Airplane ATPL CPL Which statement is correct? I. A propeller with a small blade angle is referred to as being in coarse pitch. II. A propeller with a large blade angle is referred to as being in fine pitch. A) B) C) D)

I is correct, II is correct. I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect.

232944. Airplane ATPL CPL Propeller blade twist is the: A) varying of the helix angle from the root to the tip of a propellerblade. B) angle between the relative airflow and the propeller blade's angle of attack. C) angle between the blade angle and the direction of the flight

of the aeroplane. D) varying of the blade angle from the root to the tip of a propeller blade. Airplane ATPL CPL 232945. (Refer to figure 081-19) The correct sequence of cross-sections representing propeller blade twist is: A) B) C). D)

sequence 3. sequence 1. sequence 4. sequence 2.

232946. Airplane ATPL CPL (Refer to figure 081-20) The correct sequence of cross-sections representing propeller blade twist is: A) sequence 3. B) sequence 1. C) sequence 4. D) sequence 2. 232947. Airplane ATPL CPL (Refer to figure 081-21) The correct sequence of cross-sections representing propeller blade twist is: A) B) C) D)

sequence 1. sequence 2. sequence 4. sequence 3.

232948. Airplane ATPL CPL (Refer to figure 081-22) The correct sequence of cross-sections representing propeller blade twist is: A) B) C) D)

sequence 3. sequence 2. sequence 1. sequence 4.

232949. Airplane ATPL CPL For a fixed-pitch propeller, the blade angle of attack: A) decreases when the aeroplane speed decreases (with constant engine RPM). B) is lower in ground run than in flight (with constant engine RPM). C) can become negative during high-speed idle descent. D) is always positive during idling descent. 232959. Airplane ATPL CPL Which of these statements about propellers is correct or incorrect? I. A cruise propeller has a greater geometric pitch when compared with a climb propeller. II. A coarse pitch propeller is less efficient during take-off and in the climb, but more efficient in the cruise, when compared with a fine pitch propeller. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is correct.

1232937 (A) 1232938(8) 1232939(8) 1232940 (A) 1232941 (C) 1232944 (D) 1232945 (C) 1232946(8) 1232947(8) 1232948 (A) 1 1232949 (C) 1232959 (D) 1

Aviationexam Test Prep Edition 2012

232960. Airplane ATPL CPL Assuming that the RPM remains constant throughout, the angle of attack of a fixed pitch propeller will: A) decrease with increasing airspeed. B) remain constant at a fixed value only if the airspeed decreases. C) remain constant at a fixed value irrespective of any airspeed changes. D) increase with increasing airspeed. Airplane ATPL CPL 232961. For an aeroplane equipped with a two-position variable pitch propeller it is advisable to select a: A) B) C) D)

fine pitch for cruise and coarse pitch for landing. fine pitch for cruise. fine pitch for take-off and climb. coarse pitch for take-off and climb.

232962. Airplane ATPL CPL For a given RPM of a fixed pitch propeller, the blade angle of attack will: A) B) C) D)

increase when the TAS increases. remain constant when the TAS decreases. remain constant when the TAS increases. decrease when the TAS increases.

Airplane ATPL CPL 232963. For a given RPM of a fixed pitch propeller, the blade angle of attack will: A) B) C) D)

decrease when the TAS decreases. remain constant when the TAS increases. remain constant when the TAS decreases. increase when the TAS decreases.

232964. Airplane ATPL CPL For a fixed-pitch propeller in flight at a given TAS, the blade angle of attack will: A) B) C) D)

remain constant if RPM increases. remain constant if RPM decreases. decrease if RPM increases. increase if RPM increases.

232965. Airplane ATPL CPL For a fixed-pitch propeller in flight at a given TAS, the blade angle of attack will: A) B) C) D)

remain constant if RPM increases. increase if RPM decreases. decrease if RPM decreases. remain constant if RPM qecreases.

232966. Airplane ATPL CPL (Refer to figure 081-16) A rotating propeller blade element produces an aerodynamic force F that may be resolved into two components: - a force T perpendicular to the plane of rotation (thrust) - a force R generating a torque absorbed by engine power The diagram representing a windmilling propeller is: A) diagram 4. B) diagram 3. C) diagram 2. D) diagram 1.

232967. Airplane ATPL CPL (Refer to figure 081-16) A rotating propeller blade element produces an aerodynamic force F that may be resolved into two components: - a force T perpendicular to the plane of rotation (thrust) - a force R generating a torque absorbed by engine power The diagram representing a rotating propeller blade element during the cruise is: A) diagram 2. B) diagram 1. C) diagram 4. D) diagram 3. 232968. Airplane ATPL CPL (Refer to figure 081-16) A rotating propeller blade element produces an aerodynamic force F that may be resolved into two components: - a force T perpendicular to the plane of rotation (thrust) - a force R generating a torque absorbed by engine power Which diagram is correct during the cruise? A) B) C) D)

diagram 2. diagram 3. diagram 1. diagram 4.

232969. Airplane ATPL CPL (Refer to figure 081-16) A rotating propeller blade element produces an aerodynamic force F that may be resolved into two components: - a force T perpendicular to the plane of rotation (thrust) - a force R generating a torque absorbed by engine power The diagram representing a rotating propeller blade element during reverse operation is: A) diagram 1. B) diagram 3. C) diagram 4. D) diagram 2. 232970. Airplane ATPL CPL (Refer to figure 081-16) The diagram representing a feathered propeller is: A) B) C) D)

diagram 3. diagram 1. diagram 4. diagram 2.

232971. Airplane ATPL CPL Which of these statements about propellers is correct or incorrect? I. A cruise propeller has a smaller geometric pitch compared with a climb propeller. II. A coarse pitch propeller is more efficient during takeoff and in the climb, but is less efficient in the cruise, when compared with a fine pitch propeller. A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is incorrect.

1232960 (A) 1232961 (C) 1232962 (0) 1232963 (0) 1232964 (0) 1232965 (C) 1232966 (A) 1232967 (8) 1232968 (C) 1232969 (0) 1 1232970 (A) 1232971 (8) 1

07 Propellers 232972. Airplane ATPL CPL Which of these statements about propellers is correct or incorrect?

232983. Airplane ATPL CPL Which statement is correct when comparing a fixed pitch propeller with a constant speed propeller?

I. A cruise propeller has a smaller geometric pitch compared with a climb propeller. II. A coarse pitch propeller is less efficient during take-off and in the climb, but more efficient in the cruise, when compared with a fine pitch propeller.

I. A constant speed propeller reduces fuel consumption over a range of cruise speeds. II. A coarse fixed pitch propeller is more efficient during take-off.

A) B) C) 0)

I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect. I is incorrect, II is correct.

Airplane ATPL CPL Which of these statements about propellers is correct or incorrect? 232973.

I. A cruise propeller has a greater geometric pitch compared with a climb propeller. II. A coarse pitch propeller is more efficient during take-off and in the climb, but is less efficient in the cruise, when compared with a fine pitch propeller. A) B) C) 0)

I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is correct. I is incorrect, II is incorrect.

232979. Airplane ATPL CPL Which statement is correct?

I. At a given RPM the propeller efficiency of a fixed pitch propeller is maximum at only one value ofTAS. II. A constant speed propeller maintains near maximum efficiency over a wider range of aeroplane speeds than a fixed pitch propeller. A) B) C) 0)

I is correct, II is incorrect. I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is correct.

232980. Airplane ATPL CPL Which statement is correct?

I. At a given RPM-the propeller efficiency of a fixed pitch propeller is maximum at only one value ofTAS. II. A fixed pitch propeller maintains near maximum efficiency over a wider range of aeroplane speeds than a constant speed propeller. A) B) C) 0)

I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct. I is incorrect, II is incorrect.

Airplane ATPL CPL Which statement is correct when comparing a fixed pitch propeller with a constant speed propeller? 232981.

I. A constant speed propeller reduces fuel consumption over a range of cruise speeds. II. A constant speed propeller improves take-off performance as compared with a coarse fixed pitch propeller. A) B) C) 0)

I is incorrect, II is incorrect. I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is correct.

A) B) C) 0)

I is correct, II is correct. I is correct, II is incorrect I is incorrect, II is incorrect. I is incorrect, II is correct.

232984. Airplane ATPL CPL Which statement is correct when comparing a fixed pitch propeller with a constant speed propeller?

I. A fixed pitch propeller improves propeller efficiency over a range of cruise speeds. II. A coarse fixed pitch propeller is more efficient during take-off. A) B) C) 0)

I is correct, II is incorrect. I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct.

232985. Airplane ATPL CPL Which statement is correct when comparing a fixed pitch propeller with a constant speed propeller?

I. A fixed pitch propeller improves propeller efficiency over a range of cruise speeds. II. A constant speed propeller improves take-off performance as compared with a coarse fixed pitch propeller. A) B) C) 0)

I is correct, II is incorrect. I is incorrect, II is incorrect. I is correct, II is correct. I is incorrect, II is correct.

232986. Airplane ATPL CPL (Refer to figure 081-26) The variation of propeller efficiency of a fixed pitch propeller with TAS at a given RPM is shown in:

A) B) C) 0)

figure 3. figure 1. figure 4. figure 2.

232990. Airplane ATPL CPL (Refer to figure 081-25) A typical curve representing propeller efficiency of a fixed pitch propeller versus TAS at constant RPM is:

A) B) C) 0)

figure 4. figure 2. figure 1. figure 3.

232992. Airplane ATPL CPL Which statement about propeller icing is correct?

I. Propeller icing increases blade element drag and reduces blade element lift. II. Propeller icing does not affect propeller efficiency. A) B) C) 0)

I is incorrect, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect. I is correct, II is correct.

1232972(0) 1232973 (A) 1232979(0) 1232980 (A) 1232981 (8) 1232983(8) 1232984 (C) 1232985(0) 1232986 (C) 1232990 (C) 1 1232992 (8) 1

Aviationexam Test Prep Edition 2012

232993. Airplane ATPL CPL Which statement about propeller icing is correct?

I. Propeller icing reduces blade element drag and increases blade element lift. II. Propeller icing reduces propeller efficiency. A) B) C) 0)

A) B) C) 0)

I is correct, II is correct. I is correct, II is incorrect. I is incorrect. II is correct. I is incorrect. II is incorrect.

232995. Airplane ATPL CPL Which statement about propeller icing is correct?

I is incorrect, II is incorrect. I is correct, II is correct. I is correct, II is incorrect. I is incorrect. II is correct.

I. Propeller icing reduces blade element drag and increases blade element lift. II. Propeller icing does not affect propeller efficiency.

Airplane ATPL CPL 232994. Which statement about propeller icing is correct?

I. Propeller icing increases blade element drag and reduces blade element lift. II. Propeller icing reduces propeller efficiency.

A) B) C) 0)

I is incorrect, II is incorrect. I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is correct.

07-02 Engine Failure 3713. Airplane ATPL CPL An engine failure can result in a windmilling (i) propeller and a non rotating (ii) propeller. Which statement about propeller drag is correct? A) B) C) 0)

peller does not produce any thrust.

is absorbing energy to overcome friction and the compression of the engine. The drag of the windmilling propeller is therefore significant.

3735. Airplane ATPL CPL When the blades of a propeller are in the feathered position: A) the windmilling RPM is the maximum. B) the propeller produces an optimal wind milling RPM. C) the drag of the propeller is then minimal. 0) the RPM is then just sufficient to lubricate the engine. (Refer to figure 081-E38) Feathering the propeller means turning the blades to zero angle of attack. The drag is then reduced to a minimum.

3748. Airplane ATPL CPL With a propeller feathered:

For explanation refer to question #3735 on this page.

23623. Airplane ATPL CPL Drag on a windmilling propeller compared to a stationary propeller is:

For explanation refer to question #3713 on this page.

26977. Airplane ATPL CPL The windmilling of a propeller will cause: 1232993 (D) 1232994 (A) 1232995 (A) 1 3713 (C)

26996. Airplane ATPL CPL With the propeller wind milling after an engine failure, the: A) B) C) 0)

ClM will rapidly increase. AlM and ClM will act in the same direction. AlM and ClM will immediately reduce to zero. AlM will rapidly increase.

(Refer to figure 081-E34) CTM (Centrifugal Twisting Moment) is a force that is trying to move the propeller blade (constant speed prop) to a finer pitch (as seen in the illustration on the right - arrows 2 and 3). It is the result of the centrifugal force acting on the propeller. In flight, the ATM (Aerodynamic Twisting Moment) is a force that is trying to move the propeller blade to a coarser pitch angle - it is caused by the fact that the prop blade's center of pressure is located substantially ahead of the blade's center of rotation - the thrust that the blade is generating is trying to pull the blade to a coarser angle. In normal operation the ATM (Aerodynamic Twisting Moment) will oppose the CTM because the pitch change axis will be behind the centre of pressure of the blade thus creating a coarsening moment. It can be expected that the opposition of the ATM will reduce the influence of the CTM, but not completely overcome it. However, when the propeller is windmilling the total reaction on the blade is reversed and as the CP is still in front of the pitch change axis the ATM will also be reversed. Under these circumstances, CTM and ATM are combined and act in the same direction. forcing the prop to a finer angle.

A) the best windmilling speed is achieved. B) the engine will turn over just fast enough to lubricate it. C) there will be minimum lift to drag ratio. 0) there will be minimum drag on the propeller.

greater equal less zero in both cases

drag to be produced instead of thrust. some thrust to be produced. the ClM tend to cause the propeller to move to coarse pitch. the external weights to move the propeller to fine pitch.

A windmilling propeller is absorbing energy to overcome friction and the compression of the engine. The energy absorption is drag, and the windmilling pro-

(ii) is larger than (i). (i) is equal to (ii). (i) is larger than (ii). Impossible to say which one is larger.

A non rotating propeller creates parasite drag, but a windmilling propeller

A) B) C) 0)

A) B) C) 0)

27000. Airplane ATPL CPL The greatest drag produced by the variable pitch propeller on a piston engine will occur when the propeller is:

A) B) C) 0)

stopped in fine pitch. stopped in coarse pitch. windmilling. used during a powered glide.

A non-rotating propeller creates parasite drag, but a windmilling propeller is absorbing energy to overcome friction and the compression of the engine. The drag of the windmilling propeller is therefore significant.

1 3735 (C)

1 3748 (D)

1 23623 (A) 1 26977 (A) 126996 (8) 1 27000 (C) 1

07 Propellers

232957. Airplane ATPL CPL If the propeller pitch of a windmilling propeller is decreased during a glide at constant lAS the propeller drag in the direction of flight will: A) B) C) D)

decrease and the rate of descent will decrease. increase and the rate of descent will decrease. increase and the rate of descent will increase. decrease and the rate of descent will increase.

Airplane ATPL CPL 232958. If the propeller pitch of a windmilling propeller is increased during a glide at constant lAS the propeller drag in the direction of flight will: A) decrease and the rate of descent will decrease. B) increase and the rate of descent will decrease. C) decrease and the rate of descent will increase. D) increase and the rate of descent will increase. Airplane ATPL CPL 232996. A windmilling propeller: A) B) C) D)

produces neither thrust nor drag. improves the glide performance of an aeroplane. has a greater blade angle than a feathered propeller. produces drag instead of thrust.

Airplane ATPL CPL 232999. Which statement is correct regarding a wind milling propeller on a multiengine aeroplane? A) The drag of a windmilling and a feathered propeller is almost the same. B) The windmilling drag is only significant at negative blade angles. C) The windmilling drag is much higher than for a feathered propeller. D) A windmilling propeller hardly affects low speed controllability.

233000. Airplane ATPL CPL Which of these statements concerning propellers is correct? A) The blade angle of a feathered propeller is approximately odegrees. B) The blade angle of a feathered propeller is approximately 90 degrees. C) A windmilling propeller causes less drag than a feathered propeller. D) An unfeathered propeller causes less drag than a feathered propeller. Airplane ATPL CPL 233001. Which of these statements concerning propellers is correct? A) A windmilling propeller causes less drag than a feathered propeller. B) The blade angle of a feathered propeller is approximately odegrees. C) A feathered propeller causes less drag than a windmilling propeller. D) The blade angle of a feathered propeller is approximately 180 degrees. 233002. Airplane ATPL CPL Which of these statements concerning propellers is correct? A) The blade angle of a feathered propeller is approximately 180 degrees. B) The blade angle of a feathered propeller is approximately odegrees. C) A windmilling propeller causes less drag than a feathered propeller. D) When compared with a non-feathered propeller, a feathered propeller improves the handling of a mUlti-engine aeroplane with one engine inoperative.

07-03 Design Features for Power Absorption 3669. Airplane ATPL CPL Which is one of the disadvantages of increasing the number of propeller blades? A) B) C) D)

Decreased propeller efficiency. Increased noise. Less power can be absorbed by the propeller. Higher tip-speed.

Increasing the number ofpropeller blades beyond a certain number (five or six) will reduce overall effiCiency.

3680. Airplane ATPL CPL Increasing the number of propeller blades will: A) decrease the torque in the propeller shaft at maximum power. B) increase the propeller efficiency. C) increase the noise level at maximum power. D) increase the maximum absorption of power. (Refer to figure 081-E03) Power absorption of the propeller depends among other things on the solidity of the propeller. The definition of the solidity is shown in the illustration

(= ratio between total frontal area of the blades to the area of propeller disc). Increasing the number of blades will increase solidity and thus the power absorption.

3684. Airplane ATPL CPL Increasing the camber on propeller blades will, if all else is the same: A) increase the propeller solidity. B) increase the power absorption capability. C) increase the propeller efficiency. D) give the aircraft greater range. A propeller blade is composed of airfoil shapes just like a wing is. Increasing the camber of a propeller blade creates a greater thrust force just like increasing the camber of a wing creates a greater lift force.

3712. Airplane ATPL CPL The number of blades in a propeller would be increased: A) to increase the efficiency of the variable pitch mechanism. B) to increase power absorption capability. C) to reduce noise. D) to enable a longer undercarriage to be fitted.

1232957 (C) 1232958 (A) 1232996 (0) 1232999 (C) 1233000 (8) 1233001 (C) 1233002 (0) 1 3669 (A) 1 3680 (0) 1 3684 (8) 1 1 3712 (8) 1

Aviationexam Test Prep Edition 2012 For explanation refer to question #3680 on page 159.

16703. Airplane ATPL CPL The more blades a propeller has, the more power it is able to absorb. The limitation on blade number from an aerodynamic standpoint is: A) engine speed if the engine is not geared. B) the blade diameter as compared to the maximum width. C) the loss of efficiency of one blade if it follows to the path of the preceding blade too closely. D) the loss of efficiency as the propeller tip approaches sonic speed. From a purely aerodynamic point of view, the only viable answer is C. The vortices from a close preceding blade wifl upset the airflow around the blade and reduce efficiency.

27024. Airplane ATPL CPL The propeller noise can be minimised by: A) B) C) D)

reducing the RPM of the engine. increasing the number of blades. decreasing the angle of attack of the propeller. reducing the propeller area.

A propeller that rotates with relatively high velocity often has tip speeds noise. A propeller with a high load, i.e. each propeller blade has to carry a high thrust load, wifl also produce noise. One solution to lower the propeller noise is to have rather low tip velocity and more shorter blades. Two-blade propellers wifl be more noisy than three or four-blade propellers with a smaller diameter.

232929.

Airplane

ATPL

CPL

The difference between a propeller's blade angle and its angle of attack is called: A) B) C) D)

propeller slip. the helix angle. the effective pitch. the propeller angle.

232935.

Airplane

ATPL

CPL

233003. Airplane ATPL CPL Which statement is correct for a propeller of given diameter and at constant RPM? I. Assuming blade shape does not change power absorption increases if the number of blades increases. II. Power absorption increases if the mean chord of the blades increases. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is correct.

233004. Airplane ATPL CPL Which statement is correct for a propeller of given diameter and at constant RPM? I. Assuming blade shape does not change power absorption is independent of the number of blades. II. Power absorption decreases if the mean chord ofthe blades increases. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct.

233005. Airplane ATPL CPL Which statement is correct for a propeller of given diameter and at constant RPM? I. Assuming blade shape does not change power absorption increases if the number of blades increases. II. Power absorption decreases if the mean chord of the blades increases. A) I is correct, II is correct. B) I is correct, II is incorrect. C) I is incorrect, II is incorrect. D) I is incorrect, II is correct.

The geometric pitch of a propeller is the: A) distance a propeller advances with slippage. B) distance a propeller would have to advance in one revolution to give no thrust. C) the angle between the chord line of a blade element and the propeller plane of rotation. D) theoretical distance a propeller would advance in one revolution at zero blade angle of attack. 232936.

Airplane

ATPL

CPL

The blade angle of a propeller is usually referenced at: A) B) C) D)

25 % of blade radius. 99 % of blade radius. 75 % of blade radius. 50 % of blade radius.

Airplane ATPL CPL 232942. The effective pitch of a propeller is the: A) theoretical distance a propeller would advance in one revolution at zero blqde angle of attack. B) the distance a propeller advances with slippage. C) angle between the chord line of a blade element and the propeller plane of rotation. D) actual distance a propeller advances in one revolution.

233006. Airplane ATPL CPL Which statement is correct for a propeller of given diameter and at constant RPM? I. Assuming blade shape does not change power absorption is independent of the number of blades. II. Power absorption increases if the mean chord ofthe blades increases. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct. I is incorrect II is incorrect.

233007. Airplane ATPL CPL If S is the frontal area of the propeller disc, propeller solidity is the ratio of: A) B) C) D)

the frontal area of one blade to S. the mean chord of one blade to S. 5 to the frontal area of one blade. the total frontal area of all the blades to S.

116703 (C) 1 27024 (8) 1232929 (8) 1232935 (0) 1232936 (C) 1232942 (0) 1233003 (0) 1233004 (A) 1233005 (8) 1233006 (8) 1 1233007 (0) 1

07 Propellers

233008. Airplane ATPL CPL Which statement about propeller noise is correct? I. Propeller noise increases when the blade tip speed increases. II. For a given engine and propeller blade shape, an increase in the number of propeller blades allows for a reduction in propeller noise. A) I is correct, II is correct. B) I is incorrect, II is correct. C) I is incorrect, II is incorrect. D) I is correct, II is incorrect. 233009. Airplane ATPL CPL Which statement about propeller noise is correct? I. Propeller noise decreases when the blade tip speed increases. II. For a given engine and propeller blade shape, a decrease in the number of propeller blades allows for a reduction in propeller noise. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is correct. I is correct, II is correct. I is incorrect, II is incorrect.

233010. Airplane ATPL CPL Which statement about propeller noise is correct? I. Propeller noise increases when the blade tip speed increases. II. For a given engine and propeller blade shape, a decrease in the number of propeller blades allows for a reduction in propeller noise. A) I is incorrect, II is correct. B) I is correct, II is correct. C) J is correct, II is incorrect. D) I is incorrect, II is incorrect. 233011. Airplane ATPL CPL Which statement about propeller noise is correct? I. Propeller noise decreases when the blade tip speed increases. II. For a given engine and propeller blade shape, an increase in the number of propeller blades allows for a reduction in propeller noise.

233013. Airplane ATPL CPL Which statement is correct regarding a propeller? I. Increasing tip speed to supersonic speed increases propeller noise. II. Increasing tip speed to supersonic speed increases propeller efficiency. A) I is correct, II is correct. B) I is incorrect, II is incorrect. C) I is correct, II is incorrect. D) I is incorrect, II is correct. 233014. Airplane ATPL CPL Which statement is correct regarding a propeller? I. Increasing tip speed to supersonic speed does not affect propeller noise. II. Increasing tip speed to supersonic speed decreases propeller efficiency. A) I is correct, II is incorrect. B) I is incorrect, II is incorrect. C) I is correct, II is correct. D) I is incorrect, II is correct. 233015. Airplane ATPL CPL Which statement is correct regarding a propeller? I. Increasing tip speed to supersonic speed does not affect propeller noise. II. Increasing tip speed to supersonic speed increases propeller efficiency. A) B) C) D)

I is correct, II is incorrect. I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is correct.

233016. Airplane ATPL CPL Which statement is correct regarding a propeller? I. Increasing tip speed to supersonic speed increases propeller noise. II. Increasing tip speed to supersonic speed decreases propeller efficiency. A) B) C) D)

I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is correct, II is correct.

A) I is incorrect, II is correct. B) I is incorrect, II is incorrect. C) I is correct, II is correct. D) I is correct, II is incorrect. 233012. Airplane ATPL CPL Which statement about propeller noise is correct? I. Propeller noise remains the same when the blade tip speed increases. II. For a given engine and propeller blade shape, a decrease in the number of propeller blades allows fora reduction in propeller noise. A) I is correct, II is incorrect. B) I is incorrect, II is correct. C) I is incorrect, II is incorrect. D) I is correct, II is correct.

1233008 (A) 1233009 (D) 1233010 (C) 1233011 (A) 1233012 (C) 1233013 (C) 1233014 (D) 1233015 (C) 1233016 (D) 1

Aviationexam Test Prep Edition 2012

07-04 Secondary Effects of Propellers 2643. Airplane ATPL CPL Asymmetric propeller blade effect is mainly induced by: A) B) C) D)

large angles of yaw. large angles of climb. the inclination of the propeller axis to the relative airflow. high speed.

(Refer to figure 081-£07) The asymmetric blade effect is caused by the down-going blade travelling faster than the up-going due to the inclination of the propeller shaft relative to the direction of movement (see illustration). The down-going blade will produce more thrust than the up-going shifting the total thrust towards the downgoing side, in this case the right side. The thrust will therefore produce a yawing moment to the left. The effect is proportional to the inclination which increases with higher angles of attack.

3671. Airplane ATPL CPL A propeller is turning to the right when viewed from behind. The asymmetric blade effect in the climb at low speed will: A) roll the aeroplane to the right. B) roll the aeroplane to the left. C) yaw the aeroplane to the right. D) yaw the aeroplane to the left. For explanation refer to question #2643 on this page.

3677. Airplane ATPL CPL A propeller is turning to the right, seen from behind. The asymmetric thrust effect is mainly induced by: A) B) C) D)

large angles of yaw. high speed. high angles of attack. large angles of climb.

For explanation refer to question #2643 on this page.

3685. Airplane ATPL CPL (Refer to figure 081-09) Using the diagram of the forces affecting a propeller in flight, which arrow represents the torque moment?

A) B B) A

C) C D) D The torque moment is caused by the component of the total reaction of the blade in the plane of rotation, i.e. arrow '/,\".

3688. Airplane ATPL CPL A propeller turns to the right, seen from behind. The torque effect in the takeoff will: A) pitch the aeroplane nose up. B) pitch the aeroplane nose down. C) roll the aeroplane to the right. D) roll the aeroplane to the left. (Refer to figure 081-£06) The torque effect of the propeller is in the opposite direction to the rotation of the propeller. With the propeller turning clockwise seen from behind, the torque effect is a roll to the left.

3708. Airplane ATPL CPL Which of the following would change the magnitude of the gyroscopic precession effect of the propeller?

C) Propeller RPM. D) TAS. The gyroscopic precession depends on the rotating mass and its angular velocity. Increasing the RPM increases the angular velocity of the propeller and therefore also the precession.

3723. Airplane ATPL CPL During the takeoff roll, what affect does torque have on an aircraft with a clockwise rotating propeller? A) Weight on left wheel increased, weight on right decreased. B) Weight on left wheel increased, weight on right remains constant. C) Weight on left wheel decreased, weight on right increased. D) Weight on right wheel increased, weight on left decreased.

wheel wheel wheel wheel

(Refer to figure 081-£06) The torque effect of the propeller is in the opposite direction to the rotation of the propeller. With the propeller turning clockwise seen from behind, the torque effect is a roll moment to the left that will increase the weight on the left wheel and decrease it on the right wheel.

3726. Airplane ATPL CPL A twin-engine aircraft is available in both jet and propeller variants. The engines are mounted on the wings in the same position in both types. In the case of failure of one engine how would the resultant roll effect show itself? A) Jet: roll toward the dead engine; propeller: roll toward the live engine. B) Jet: roll toward the live engine; propeller: roll toward the dead engine. C) Jet: roll away from the live engine; propeller: roll away from the live engine more rapidly. D) Jet: no change but; propeller: roll opposite to direction of rotation of the live engine. In both cases the asymmetric thrust will yaw the aircraft towards the dead engine. The propeller slip stream from the operating engine, having a higher velocity than from the dead engine, will create more lift - in a one-engine-out situation this gives more rolling moment to the propeller aircraft then for a jet powered aircraft.

3752. Airplane ATPL CPL A propeller rotating anti-clockwise when viewed from the front, during the takeoff ground roll will: A) produce an increased load on the left wheel due to torque reaction. B) produce an increased load on the right wheel due to gyroscopic effect. C) produce an increased load on the right wheel due to torque reaction. D) produce an increased load on the left wheel due to gyroscopic effect. (Refer to figure 081-£06) The torque effect of the propeller is in the opposite direction to the rotation of the propeller. With the propeller turning clockwise seen from behind, the torque effect is a roll moment to the left that will increase the weight on the left wheel.

A) Propeller blade angle. B) Rate of roll.

I 2643 (C) 13671 (D) I 3677(C) 13685(8) I 3688 (D) I 3708(C) I 3723(A) I 3726(C) I 3752(A) I

07 Propellers 3753. Airplane ATPL CPL Gyroscopic precession of the propeller is induced by: A) B) C) D)

pitching and rolling. pitching and yawing. increasing RPM and yawing. increasing RPM and rolling.

B) nose up pitch. C) roll to the right. D) nose down pitch. (Refer to figure 081-E06) The torque effect of the propeller is in the opposite direction to the rotation of the propeller. With the propeller turning anti-clockwise (left-prop) seen from behind, the torque effect is a roll to the right.

Gyroscopic precession of the propeller requires a force applied to the propeller perpendicular to the plane of rotation. Only pitching and yawing would do this.

4076. Airplane ATPL CPL What happens during an engine failure with two similar aeroplanes with wing mounted engines, one of them with jet engines, the other one with co-rotating propellers? A) More roll tendency for the propeller aeroplane. B) The same yaw tendency for both aeroplanes regardless of left or right engine failure. C) The same roll tendency for both aeroplanes. D) Less roll tendency for the propeller aeroplane. The propeller slip stream having a higher velocity will create more lift that in a one-engine-out situation gives more roll then for a jet powered aircraft. ((he yaw tendency depends on the critical engine for a propeller aircraft; therefore answer B is incorrect.)

7016. Airplane ATPL CPL In twin-engine aeroplanes with right turning propellers: A) the "minimum control speed" is determined by the failure of the right engine. B) the left engine produces a higher yaw moment if the right engine fails than vice versa. C) the left engine is the critical motor. D) the right engine is the critical motor. (Refer to figure 081-E131) The critical engine of a multi-engine, fixed-wing aircraft is the one whose failure would result in the most adverse effects on the aircraft's handling and performance. In other words - the critical engine is the one that you do not want to loose, because if you do, it is worse than loosing the other one. On typical twin-engine propeller aeroplanes the left engine is the critical one. It arises from the aerodynamic principles. When one of the engines becomes inoperative, a thrust imbalance exists between the operative and inoperative sides of the aircraft and this thrust imbalance tries to yaw the aeroplane towards the dead engine. Now when we involve the "P-factor" - we know that especially at higher angles of attack, the down-going propeller blade produces more thrust than the up-going propeller blade. If we have right-hand props then the right side of each propeller will produce more thrust than the left side of the propeller. If we loose a left engine, the line of thrust of the right (operating) engine will be further out from the aeroplanes longitudinal axis than if we lost the right engine. Therefore the yawing moment produced by an operating right engine will be greater than that of a left operating engine. This issue is eliminated on counter-rotating propeller designs. However, even on these designs we could see a critical engine - not from an aerodynamic point of view, but from a systems point of view - for example an electrical generator could only be installed on 1 engine and thus it becomes a critical engine.

16694. Airplane ATPL CPL Propeller torque is caused by: A) the propeller trying to reduce the pitch angle owing to the centrifugal turning moment. B) the forces caused by the airflow on the propeller. C) the forward thrust on the propeller. D) the backward drag on the propeller. (Refer to figure 081-E35) The torque moment is caused by the component of the total reaction of the blade in the plane of rotation.

16695. Airplane ATPL CPL The torque reaction of a left-hand propeller will cause:

16696. Airplane ATPL CPL For an aircraft with a right hand propeller, the slipstream rotation will cause: A) yaw to the left. B) yaw to the right. C) roll to the left. D) roll to the right. For explanation refer to question #2643 on page 162.

16697. Airplane ATPL CPL To counteract the effect of slipstream on a single engined aircraft: A) B) C) D)

the horizontal stabilizer should be reduced in size. the fin should be placed as far as possible from the propeller. higher setting should be used. frise ailerons should be used.

Of the possible answers, B is the only applicable. Even though there still will be some slipstream effect, the further away from the propeller the fin is placed the lesser is the magnitude of the slipstream is reduced.

16698. Airplane ATPL CPL On a single engine aircraft with a right hand propeller the gyroscopic effect causes: A) B) C) D)

the nose to rise during turn to the left. the nose to fall during turns to the left. roll to the right during turns to the left. roll to the left during turns to the right.

Gyroscopic precession of the propeller causes a force applied to the propeller perpendicular to the plane of rotation to appear to act 90° in the direction of rotation. If the aircraft turns to the left, a force acts on the propeller on the right hand side seen from behind. 90° later in this case will be on bottom of the propeller, so the aircraft would pitch up.

16699. Airplane ATPL CPL Counter rotating propellers have the effect of: A) B) C) D)

increasing the torque but decreasing the gyroscopic effect. decreasing the torque but increasing the gyroscopic effect. increasing the torque and gyroscopic effects. cancelling out the torque and gyroscopic effects.

With the two propellers turning in opposite directions, both the torque reaction and the gyroscopic effects are cancelled out.

21088. Airplane ATPL CPL In twin engine aeroplanes with propellers turning clockwise as seen from behind: A) the left engine produces a higher yaw moment if the right engine fails than vice versa. B) the left engine is the critical engine. C) the minimum control speed is determined by the failure of the right engine. D) the right engine is the critical engine. (Refer to figure 081-E05) With propellers rotating clockwise seen from behind, the asymmetric blade effect (P effect) will shift the thrust to the right of the propeller centre line seen from above. The left engine would thus give a bigger yaw moment than the right engine in case of one engine failing. The left engine is therefore the critical engine.

A) roll to the left.

I

3753 (8)

I

4076 (A)

I

7016 (C)

116694 (8) 116695 (C) 116696 (A) 116697 (8) 116698 (A) 116699 (0) 121088 (8)

I

Aviationexam Test Prep Edition 2012 23557. Airplane ATPL CPL In which of the following lists of flight conditions will torque effect be greatest in a single-engine aeroplane?

233018. Airplane ATPL CPL The torque reaction of a rotating fixed pitch propeller will be greatest at:

A) Low airspeed / high power / high angle of attack. B) High airspeed / high power / high angle of attack. C) Low airspeed / low power / low angle of attack. D) High airspeed / low power / low angle of attack. The torque effect of the propeller is proportional to the engine power output (it is the reaction to the engine power output). At low airspeed the angle of attack is high and the drag on the aircraft is high because of increased induced drag. More power is therefore required. High power on the propeller means larger torque effect.

23567. Airplane ATPL CPL Which of the following would alter the gyroscopic effect of a propeller?

For explanation refer to question #3708 on page 162.

Airplane ATPL CPL Torque effect of a propeller which turns to the right produces 23731.

a:

(Refer to figure 081-E06) The torque effect of the propeller is in the opposite direction to the rotation of the propeller. With the propeller turning clockwise seen from behind, the torque effect is a roll to the left.

ATPL

233019. Airplane ATPL CPL During the take-off roll, when the pilot raises the tail in a tail wheeled propeller driven aeroplane, the additional aeroplane yawing tendency is due to the effect of:

CPL

A propeller rotating clockwise as seen from the rear tends to rotate the aircraft to the: A) right around the vertical axis, and to the right the longitudinal axis. B) right around the vertical axis, and to the left the longitudinal axis. C) left around the vertical axis, and to the right the longitudinal axis. D) left around the vertical axis, and to the left the longitudinal axis.

around around

A) B) C) D)

I is incorrect, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect. I is correct, II is correct.

233021. Airplane ATPL CPL Which statement is correct regarding the gyroscopic effect of a clockwise rotating propeller on a single engine aeroplane?

I. Pitch down produces right yaw. II. Left yaw produces pitch down. A) I is correct, II is incorrect. B) I is incorrect, II is correct. C) I is incorrect, II is incorrect. D) I is correct, II is correct.

around around

The torque reaction will turn the aircraft to the left around the longitudinal axis. The asymmetric blade effect (or P effect) will turn the aircraft to the left about the normal axis.

Airplane ATPL CPL In a single engine Ale with clockwise rotating propeller, a left yaw is generated due to: 27036.

A) the torque effect. B) the slipstream, striking the fin on the left side. C) higher lift on the right wing. D) higher helix angle. The propeller slipstream of a single engine aircraft hitting the fin will cause

a yaw. (None of the other suggested answers produce yaw.) Airplane ATPL CPL Given an aeroplane with a propeller turning clockwise as seen from behind, the torque effect during the take off run will tend to: 233017.

233020. Airplane ATPL CPL Which statement is correct regarding the gyroscopic effect of a clockwise rotating propeller on a single engine aeroplane?

I. Pitch down produces left yaw. II. Left yaw produces pitch up.

A) nose up pitching moment. B) rolling moment to the left. C) nose down pitching moment. D) rolling moment to the right.

Airplane

A) low aeroplane speed and maximum engine power. B) high aeroplane speed and maximum engine power. C) low aeroplane speed and low engine power. D) high aeroplane speed and low engine power.

A) gyroscopic precession. B) slipstream. C) asymmetric blade effect. D) torque reaction.

A) Roll and pitch. B) Pitch and roll. C) Increase RPM. D) Decrease blade angle.

26827.

C) pitch the aeroplane nose down. D) roll the aeroplane to the right.

233022. Airplane ATPL CPL Which statement is correct regarding the gyroscopic effect of a clockwise rotating propeller on a single engine aeroplane?

I. Pitch down produces left yaw. II. Left yaw produces pitch down. A) I is incorrect, II is correct. B) I is correct, II is incorrect. C) I is incorrect, II is incorrect. D) I is correct, II is correct. 233023. Airplane ATPL CPL Which statement is correct regarding the gyroscopic effect of a clockwise rotating propeller on a single engine aeroplane?

I. Pitch down produces right yaw. II. Left yaw produces pitch up. A) I is correct, II is incorrect. B) I is incorrect, II is correct. C) I is incorrect, II is incorrect. D) I is correct, II is correct.

A) pitch the aeroplane nose up. B) roll the aeroplane to the left. 123557 (A) 123567 (C) 123731 (8) 126827 (0) 127036 (8) 1233017 (8) 1233018 (A) 1233019 (A) 1233020 (0) 1233021 (C) 1 1233022 (8) 1233023 (8) 1

07 Propellers 233024. Airplane ATPL CPL Which statement is correct regarding the gyroscopic effect of a clockwise rotating propeller on a single engine aeroplane? I. Pitch up produces right yaw. II. Right yaw produces pitch down. A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct.

233025. Airplane ATPL CPL Which statement is correct regarding the gyroscopic effect of a clockwise rotating propeller on a single engine aeroplane? I. Pitch up produces left yaw. II. Right yaw produces pitch up. A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is incorrect, II is correct.

233027. Airplane ATPL CPL Which statement is correct regarding the gyroscopic effect of a clockwise rotating propeller on a single engine aeroplane? I. Pitch up produces left yaw. II. Right yaw produces pitch down. A) I is correct, II is incorrect. B) I is correct, II is correct. C) I is incorrect, II is correct. D) I is incorrect, II is incorrect. 233028. Airplane ATPL CPL Which statement is correct? I. Propeller gyroscopic effect occurs during aeroplane pitch changes. II. Propeller gyroscopic effect is most noticeable during low speed flight at high propeller RPM. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is correct.

233029. Airplane ATPL CPL Which statement is correct? I. Propeller gyroscopic effect occurs during flight at constant aeroplane attitude. II. Propeller gyroscopic effect is most noticeable during low speed flight at low propeller RPM. A) B) C) D)

I is incorrect, II is correct. I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect.

233031. Airplane ATPL CPL Which statement is correct? I. Propeller gyroscopic effect occurs during flight at constant aeroplane attitude. II. Propeller gyroscopic effect is most noticeable during low speed flight at high propeller RPM. A) B) C) D)

I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is incorrect.

Airplane ATPL CPL 233032. Which statement is correct? I. Propeller gyroscopic effect occurs during aeroplane yaw changes. II. Propeller gyroscopic effect is most noticeable during low speed flight at high propeller RPM. A) B) C) D)

I is incorrect, II is correct. I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect.

Airplane ATPL CPL 233033. Which statement is correct? I. Propeller gyroscopic effect occurs during aeroplane yaw changes. II. Propeller gyroscopic effect is most noticeable during low speed flight at low propeller RPM. A) B) C) D)

I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is correct, II is correct.

Airplane ATPL CPL 233037. The asymmetric blade effect on an single engine aeroplane with a clockwise rotating propeller: A) B) C) D)

produces left yaw. does not produce any yaw. is also called the gyroscopic effect. produces right yaw.

233038. Airplane ATPL CPL Which statement about a propeller is correct? I. Asymmetric blade effect increases when engine power is increased. II. Asymmetric blade effect increases when the angle between the propeller axis and airflow through the propeller disc increases. A) B) C) D)

I is incorrect, II is incorrect. I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is correct.

233030. Airplane ATPL CPL Which statement is correct? I. Propeller gyroscopic effect occurs during aeroplane pitch changes. II. Propeller gyroscopic effect is most noticeable during low speed flight at low propeller RPM. A) B) C) D)

I is incorrect, II is correct. I is correct, II is incorrect. I is incorrect, II is incorrect. I is correct, II is correct.

1233024 (A) 1233025(8) 1233027 (C) 1233028(8) 1233029 (C) 1233030(8) 1233031 (C) 1233032(8) 1233033 (C) 1233037 (A) 1 1233038 (8) 1

L~_

Aviationexam Test Prep Edition 2012

233039. Airplane ATPL CPL Which statement about a propeller is correct?

Airplane ATPL CPL 233044. Which statement about a propeller is correct?

I. Asymmetric blade effect is unaffected when engine power is increased. II. Asymmetric blade effect increases when the angle between the propeller axis and the airflow through the propeller disc increases.

I. Asymmetric blade effect increases when engine power is increased. II. Asymmetric blade effect reduces when the angle between the propeller axis and the airflow through the propeller disc increases.

A) I is correct, II is incorrect. B) I is correct, II is correct. C) I is incorrect, II is incorrect. D) I is incorrect, II is correct.

A) B) C) D)

233040. Airplane ATPL CPL Which statement about a propeller is correct?

I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is correct, II is correct.

Airplane ATPL CPL 233045. Which statement about a propeller is correct?

I. Asymmetric blade effect reduces when engine power is increased. II. Asymmetric blade effect increases when the angle between the propeller axis and the airflow through the propeller disc increases.

I. Asymmetric blade effect is unaffected when engine power is increased. II. Asymmetric blade effect reduces when the angle between the propeller axis and the airflow through the propeller disc increases.

A) B) C) D)

A) B) C) D)

I is incorrect, II is correct. I is correct, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect.

Airplane ATPL CPL 233041. Which statement about a propeller is correct?

I is correct, II is incorrect. I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is correct.

Airplane ATPL CPL 233046. Which statement about a propeller is correct?

I. Asymmetric blade effect increases when engine power is increased. II. Asymmetric blade effect is independent of the angle between the propeller axis and the airflow through the propeller disc.

I. Asymmetric blade effect reduces when engine power is increased. II. Asymmetric blade effect reduces when the angle between the propeller axis and the airflow through the propeller disc increases.

A) B) C) D)

A) I is correct, II is correct. B) I is incorrect, II is correct. C) I is incorrect, II is incorrect. D) I is correct, II is incorrect.

I is correct, II is correct. I is incorrect, II is incorrect. I is incorrect, II is correct. I is correct, II is incorrect.

233042. Airplane ATPL CPL Which statement about a propeller is correct?

I. Asymmetric blade effect is unaffected when engine power is increased. II. Asymmetric blade effect is independent of the angle between the propeller axis and the airflow through the propeller disc. A) B) C) D)

I is incorrect, II is correct. I is incorrect, II is incorrect. I is correct, II is incorrect. I is correct, II is correct.

233123. Airplane ATPL CPL Given two identical aeroplanes with wing mounted engines, one fitted with jet engines and the other with counter rotating propellers, which of these statements is correct about roll behaviour after an engine failure? A) B) C) D)

The propeller aeroplane has less roll tendency. Both aeroplanes have the same roll tendency. The propeller aeroplane has more roll tendency. The roll tendency on the propeller powered aeroplane is more pronounced when the left engine fails than when the right engine fails.

233043. Airplane ATPL CPL Which statement about a propeller is correct?

I. Asymmetric blade effect reduces when engine power is increased. II. Asymmetric blade effect is independent of the angle between the propeller axis and the airflow through the propeller disc. A) B) C) D)

I is correct, II is correct. I is correct, II is incorrect. I is incorrect, II is correct. I is incorrect, II is incorrect.

1233039 (0) 1233040 (A) 1233041 (0) 1233042 (8) 1233043 (0) 1233044 (C) 1233045 (C) 1233046 (C) 1233123 (C) 1

I

08 Flight Mechanics

FLIGHT MECHANICS 08-01 Forces Acting on an Aeroplane 3629. Airplane ATPL CPL An aircraft is in straight, level flight has a Cl of 0,42, and a 1° increase in angle of attack would increase the Cl by 0,1. Following a gust that increases the angle of attack by 3°, what load factor would the aircraft be subject to? A) B) C) D)

N=0,7 N= 1,7 N = 1,4 N =2,4

ward component of weight. This component is the thrust in .the glide, and with a smaller thrust the aircraft wilf decelerate. This in turn wilf reduce lift and drag until the drag balances the forward component of weight. With a reduced speed, the rate of descent decreases since it is equal to Vxsin y.

4094. Airplane ATPL CPL What is the approximate value of the lift of an aeroplane at a gross weight of 50.000 N, in a horizontal coordinated 45° banked turn? A) 50.000 N B) 60.000 N C) 70.000 N D) 80.000 N

Load factor is the ratio between actual lift and weight. In this case the gust increases the lift by increasing C, from 0,42 to C'NEW = (0,42 + 3 x 0,1) = 0,72. The load factor is: L.,. W= (Y2PIf2SC'NEW)'" (Y2pIf2SC,) = C'NEW'" C, = 0,72.,. 0,42 = 7,7143 - 1,7.

3651. Airplane ATPL CPL The lift coefficient (C l ) of an aeroplane in steady horizontal flight is 0,4. Increase of angle of attack of 1° will increase Cl by 0,09. A vertical up-gust instantly changes the angle of attack by S°. The load factor will be: A) 3,18 B) 1,09 C) 2,0

(Refer to figure 081-EI4) As shown in the illustration, the total lift in a turn is greater than the weight. From Leos (/) = W lift is found as L = W.,. cos (/) = 50.000 N .,. cos 45° = 50.000 .,. 0,70711 N = 70.710 N - 70.000 N.

4095. Airplane ATPL CPL Ignoring thrust effects in a steady straight climb at a climb angle "gamma", the lift of an aeroplane with weight W is: A) W x cos (gamma) B) W x (1-sin gamma) C) W x (Han gamma) D) w.,. cos (gamma)

D) 2,13 Load factor is the ratio between actual lift and weight. In this case the gust increases the lift by increasing C, from 0,4 to C, NEW = (0,4 + 5 x 0,09) = 0,85. The load factor is: L .,. W = (Y2PIf2SC'NEW) .,. (Y2pIf2SC,) = C'NEW'" C, = 0,85 .,. 0,4 =2,125-2,13.

3663. Airplane ATPL CPL The lift coefficient (C l ) of an aeroplane in steady horizontal flight is 0,35. Increase in angle of attack of 1° will increase Cl by 0,079. A vertical up-gust instantly changes the angle of attack by 2°. The load factor will be: A) B) C) D)

1,9 0,9 0,45 1,45

(Refer to figure 081-EI6)

4097. Airplane ATPL CPL The turn indicator shows a right turn. The slip indicator is left of neutral. To coordinate the turn: A) B) C) D)

a higher turn rate is required. more right rudder is required. less right bank is required. more right bank is required.

(Refer to figure 081-EI27) A coordinated turn is without Sideslip or skid, so if the slip indicator is to the left of neutral, more right bank is required to centre the ball.

Load factor is the ratio between actual lift and weight. In this case the gust increases the lift by increasing C, from 0,35 to C'NEW = (0,35 + 2 x 0,079) = 0,508. The load factor is: L.,. W = (Y2pIf2SCLNEW) .,. (Y2pIf2SC,) = C'NEW'" C, = 0,508.,. 0,35 = 1,4514 - 1,45.

4107. Airplane ATPL CPL The effect of a headwind is to __ the climb angle and to __ the rate of climb. A) increase; not affect B) increase; decrease C) decrease; increase D) not affect; increase

4083. Airplane ATPL CPL A glider reduces weight by dumping water ballast. A 10% reduction in weight would give:

The climb angle calculated by sin g = (T - 0) .,. W is relative to the air mass. If there is a wind, the climb angle relative to the ground wilf be different. A headwind gives a steeper angle. Although the climb angle relative to the ground is affected by wind, the rate of climb is independent of the wind speed.

A) a decrease in best rate of descent. B) 10% increase in best glide angle. C) 5% reduction in best glide angle. D) no change in best rate of descent. (Refer to figure 081-EI5) The i1fustration shows that a reduction in weight wilf give a smaller for-

I

3629 (8)

I

3651 (D)

I

3663 (D)

I

4083 (A)

I

4094 (C)

I

4095 (A)

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4097 (D)

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4107 (A)

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Aviationexam Test Prep Edition 2012 4108. Airplane ATPL CPL For an aircraft in level flight, if the wing centre of pressure is aft of the centre of gravity and there is no thrust-drag couple, the tailplane load must be:

A) directed upwards.

B) up or down depending on the position of the flight spoilers. C) directed downwards. D) zero at all times. The lift acting through the centre of pressure aft of the centre of gravity will cause a nose down moment about the centre of gravity. To counter this, the tailplane must generate a force downwards.

4111. Airplane In a steady climb:

ATPL

CPL

A) thrust equals drag plus the weight component perpendicular

to the flight path and lift equals the weight component along the flight path. B) thrust equals drag plus the weight component along the flight path and lift equals the weight component perpendicular to the flight path. C) thrust equals the weight component along the flight path and lift equals the sum of the components of drag and weight along the flight path. D) if the angle of climb is 20°, lift equals weight times sin 20°. (Refer to figure 081-EI6) As shown in the illustration, in a climb the thrust equals drag plus the component of weight acting along the flight path, and the lift equals the component of weight perpendicular to the flight path.

4114. Airplane ATPL CPL By what percentage does the lift increase in a steady level turn at 45° angle of bank, compared to straight and level flight?

A) 41% B) 19% C) 31% D) 52% The load factor in a turn is 1 -;- cos C1>, where C1> is the bank angle. The load factor is the ratio between actual lift and weight (= "normal" lift). The lift in the turn is then 1 -;- cos 45° = 1 -;- 0,70711 = 1,41421 or approximately 41% more than in level flight.

Weight always acts vertically downwards, i.e. in the direction of the gravitational force, which - incidentally - is the weight.

4130. Airplane ATPL CPL The maximum glide range of an aircraft will depend on wind and:

A) the ratio to lift to drag which

varies according to angle

of attack. B) speed for minimum power required. C) CLMAX ' D) minimum lift/drag ratio. The glide range equals height loss multiplied by LID. The maximum LID ratio is obtained at a small angle of attack (around 4°).

4140. Airplane ATPL CPL In order to maintain constant speed during a level, co-ordinated turn, compared with straight and level flight, the pilot must:

A) increase thrust/power and decrease angle of attack.

B) increase thrust/power and keep angle of attack unchanged. C) increase thrust/power and angle of attack. D) increase angle of attack and keep thrust/power unchanged. (Refer to figure 081-EI4) Turning requires more lift (= increased angle of attack when the speed is constant) due to the movement of the component of lift away from vertical plane slightly into the horizontal plane - the component of lift is divided into vertical and horizontal components during a turning flight. In order to maintain altitude, the reduced vertical component of lift must be increased to the same value as before commencing the turn => increased angle of attack during the turn is required. This increases induced drag, so to maintain altitude and speed, both the angle of attack and the thrust must be increased.

4142. Airplane ATPL CPL Which statement is correct at the speed for minimum drag (subsonic)?

A) The gliding angle is minimum (assume zero thrust).

B) The CJC o ratio is minimum. C) Induced drag is greater than the parasite drag. D) Propeller aeroplanes fly at that speed at max endurance.

Airplane ATPL CPL The bank angle in a rate-one turn depends on: 4115.

At VMD the lift to drag ratio (LID) is maximum. For the glide angle y, tan y = OIL,

A) wind

so with maximum LID, the glide angle will be minimum.

B) weight C) load factor D) TAS Turn radius Ris (TAS2 -;- (g x tan C1»), where C1> is the bank angle. Since this expression is independent on aircraft weight, the same speed and bank angle gives the same radius. Rewritten, the formula gives: tan C1> = (TAS2 -;- (R x g)), so the bank angle depends on the TAS.

4127. Airplane ATPL CPL An aeroplane performs a steady co-ordinated horizontal turn with 20° of bank and at 150 kt TAS. The same aeroplane with the same bank angle and speed, but at a lower mass will turn with:

A) B) C) D)

A) perpendicular to the chord line. B) parallel to the gravitational force. C) perpendicular to the longitudinal axis. D) perpendicular to the relative airflow.

a higher turn rate. the same turn radius. a larger turn radius. a smaller turn radius.

ATPL

A) B) C) D)

equal to V1MO' slower than V1MO' faster than V1MO' not related to V1MO'

(Refer to figure 081-El06) The speed for minimum sink rate (or minimum rate of descent) is the lAS producing minimum power required, or VMP' As seen in the illustration, V MP is lower than VMD•

4155. Airplane ATPL CPL With a LID ratio of 9:1 and flying at 12.000 ft the glide range in still air would be:

A) 15 NM B) 20 NM C) 14NM D) 18 NM

For explanation refer to question #4115 on this page.

4129. Airplane Weight acts:

4148. Airplane ATPL CPL The speed for minimum sink rate in a glide, compared to the speed for maximum distance V1MO is:

CPL

The glide range equals height loss multiplied by LID, or L1H

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4108 (C) 4155 (0)

4111 (8)

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4114 (A)

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4115 (0)

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4127 (8)

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4129 (8)

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4130 (A)

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4140 (C)

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4142 (A)

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x (UD).

4148 (8)

I

08 Flight Mechanics With the given values: Glide distance = 12.000 ft x 9 = 108.000 ft = 108.000 ft x 0,000165 NMlft = 17,82NM-18NM.

4156. Airplane ATPL CPL An aircraft in flight is affected by loads. These may be classified as: A) B) C) 0)

tensile, shear, twisting and stretching. compressive, tensile, shear and torsional. thrust, drag, lift and weight. compressive, bending, shear and torsional.

Loads are defined as force per area, which renders answer uC' incorrect. The loads on an aircraft are those mentioned in answer uB'~ and combinations of these produce bending and twisting.

4160.

Airplane

ATPL

CPL

A light twin is in a turn at 30° bank and 180 kts TAS. A heavier aeroplane at the same bank and the same speed will: A) B) C) 0)

turn at a smaller turn radius. turn at a bigger turn radius. turn at the same turn radius. turn at a higher turn rate.

Turn radius Ris (TAS2.;. (g x tan (/))), where (/) is the bank angle. Since this expression is independent on aircraft weight, the same speed and bank angle gives the same radius.

4165. Airplane ATPL CPL During a correctly balanced turn: A) the thrust is a component of the centrifugal force. B) the centrifugal force directly balances the weight of the aircraft. C) the lift force balances the aircraft weight. 0) the lift force provides a centripetal force and a force that opposes the weight of the aircraft. (Refer to figure 081-EI4) As shown in the illustration the lift provides both centripetal force and a force equal to and opposite the weight.

4166. Airplane ATPL CPL The angle of climb of an aircraft is proportional to __ and __ as weight increases. A) excess power; decreases B) excess thrust; increases C) excess thrust; decreases 0) excess power; increases Sinus to the angle of climb y is sin y = (T - D) .;. W. The angle of climb is therefore proportional to the excess thrust. Increasing weight means more drag, and thus less excess thrust and a decrease in climb angle.

4167.

Airplane

ATPL

CPL

At a true airspeed of 300 kts and in a 45° bank level turn, the radius of turn would be (assume a value of 10 m/sec 2 for g):

Airplane

ATPL

CPL

A) B) C) 0)

the turn radius of A is greater than that of B. the load factor of A is greater than that of B. the rate of turn of A is greater than that of B. the lift coefficient of A is less than that of B.

Turn radius is \P.;.(g x tg(/)), where (/) is the bank angle. As the speed is higher for B, the turn radius is greater for B. Rate of turn is TAS .;. Turn radius. Since the bank angle is the same, the rate of turn can be expressed as TAS .;. TAS2 = I.;. TAS.As the TAS forA is lower, the rate of turn forA will be larger than forB.

15615. Airplane ATPL CPL What factors determine the distance travelled over the ground of an aeroplane in a glide? A) The wind and the lift/drag ratio, which changes with angle of attack. B) The wind and the aeroplane s mass. C) The wind and CLMAX ' 0) The wind and weight together with power loading, which is the ratio of power output to the weight. The distance travelled over ground in a glide is determined by the UD ratio (glide ratio), but wind also affects the distance; headwind reducing it, and tailwind increasing it.

15711. Airplane ATPL CPL The value of the induced drag of an aeroplane in straight and level flight at constant weight varies linearly with: A) B) C) 0)

V 1.;- V 1.;- V2 V2

Drag varies with the square of the speed. Induced drag, however, decreases with increasing speed, so the variation is with I .;. \P.

15723. Airplane ATPL CPL In a turn, the load factor "n" and the stalling speed Vs will be: A) "n" greater than B) un" smaller than C) un" greater than 0) "n" smaller than

1, Vs higher than in straight and level flight. 1, Vs lower than in straight and level flight. 1, Vs lower than in straight and level flight. 1, Vs higher than in straight and level flight.

(Refer to figure 081-EI4) As shown in the illustration the lift provides both centripetal force and a force equal to and opposite the weight. The load factor (UW) is therefore greater than I. Stall speed in a turn is VS,g x ,fn, where n is the load factor, and since n is greater than one, the stall speed is higher than in straight and level flight.

Airplane

ATPL

CPL

The greatest gliding range would be obtained from a wing at:

Turn radius R is (TAS2 .;. (g x tan (/))), where (/) is the bank angle. With the given values: R = (300 kts x 0,5144 mlslktsJ2 .;. (10 mls2 x tan 45°) = (154,32 mlsY .;. (10 mls2x 1,0) =2381 m.

Airplane

7903.

Two identical aeroplanes A and B, with the same mass, are flying steady level co-ordinated 20° bank turns. If the TAS of A is 130 kts and the TAS of B is 200 kts:

16652.

A) 2.381 m B) 4.743 m C) 3.354m 0) 23.780 m

4172.

0) weight is greater than lift. Because the aeroplane descents, the weight is greater than the lift.

ATPL

CPL

A) a high angle of attack at maximum lift/drag ratio. B) a small angle of attack at maximum lift/drag ratio. C) a small angle of attack at minimum lift/drag ratio. 0) a high angle of attack at minimum lift/drag ratio. The gliding range equals height loss multiplied by UD. The maximum UD ratio is obtained at a small angle of attack (around 4°).

An aeroplane performs a continuous descent with 160 kts lAS and 1.000 ft/min vertical speed. In this condition: A) drag is less than the combined forces the aeroplane forward. B) lift is equal to weight. C) lift is less than drag. 1 4156 (8) 1 4160 (C) 116652 (8) 1

that

1 4165 (0) 1 4166 (C) 1 4167 (A)

move

1 4172 (0) 1 7903 (C) 1 15615 (A) 1 15711 (C) 115723 (A) 1

Aviationexam Test Prep Edition 2012

16662. Airplane ATPL CPL In a steady banked turn the lift will: A) equal the weight. B) equal the centripetal force. e) equal the resultant of weight and centripetal force. D) equal the centripetal force minus the weight. (Refer to figure 081-EI4) As shown in the illustration the lift provides both centripetal force and a force equal to and opposite the weight, so it is the resultant ofweight and centripetal force.

16667. Airplane ATPL CPL During the glide, the forces acting on an aircraft are: A) thrust, lift and drag. B) lift, weight and thrust. C) lift, drag and weight. D) drag, thrust and weight. (Refer to figure 081-EI5) In a glide the thrust is a component of weight; see illustration. Consequently, the forces acting on the aircraft are: weight, lift and drag.

16668. Airplane ATPL CPL To cover the greatest distance when gliding, the gliding speed must be: A) near to the stalling speed. B) as high as possible within V limits. C) minimum control speed. D) the one that gives the lowest total drag. The gliding distance equals height loss multiplied by UD. The maximum gliding distance is obtained at the lowest value ofD.

21018. Airplane ATPL CPL An aeroplane climbs to cruising level with a constant pitch attitude and maximum climb thrust (assume no supercharger). How do the following variables change during the climb? (gamma flight path angle)

=

A) gamma decreases, angle of attack increases, lAS remains constant. B) gamma decreases, angle of attack increases, lAS decreases. e) gamma decreases, angle of attack remains constant, lAS decreases. D) gamma remains constant, angle of attack remains constant, lAS decreases. With increased altitude the power available decreases whilst power required increases. The excess power is therefore reduced and the climb angle smaller. The density decreases, so to produce the required lift, the angle of attack must be increased. The increased angle of attack causes increased drag, and with decreased power, the speed decreases.

21026. Airplane ATPL CPL An aeroplane is in a steady horizontal turn at a TAS of 194 kts. The turn radius is 1.000 m. The bank angle is (assume g 10 m/s2 )?

=

A) 45° B) 30° e) 50° D) 60° Turn radius R is (TAS2 + (g x tan ([»), where ([> is the bank angle. The bank angle is derived from: tan ([> = (TAS2 + (g x R)). With the given values: tan ([> =(194 kts x 0,S144 m/s/kts1 + (10 m/s2 x 1.000 m) =(99,79 m/s1 + (10.000 ni/S2) =0,996I. An angle with tangent I is 45~

21028. Airplane ATPL CPL An aeroplane performs a right turn, the slip indicator is left of neutral. One way to co-ordinate the turn is to apply: A) a higher turn rate. B) more right rudder. e) less right bank. D) more left rudder. (Refer to figure 081-EI27) A coordinated turn is without sideslip or skid, so if the" slip indicator in a right turn is to the left of neutral, more right bank is required to centre the ball. One way of doing that is more left rudder.

21029. Airplane ATPL CPL If an aeroplane performs a steady co-ordinated horizontal turn at a TAS of 200 kt and a turn radius of 2000 m, the load factor (n) will be approximately: A) 2,0

B) 1,4 e) 1,1

D) 1,8 The load factor in a turn is I+cos ([>, where ([> is the bank angle. Turn radius R is (TAS2 + (g x tan ([»). The bank angle is derived from: tan ([> = (TAS2 + (g x R)). With the given values: tan ([> = (200 kts x 0,5144 m/s/kts1+(9,81 m/s2 x 2.000 m) = (102,88 m/s1+(19.620 m/s2) = 0,53946. This equals an angle of28,35°. Cosine of this angle =0,88006. The load factor is then n = 1+0,88006= 1,1363-1.1.

21032. Airplane ATPL CPL Approximately how long does it take to fly a complete circle during a horizontal steady co-ordinated turn with a bank angie of 45° and a TAS of 200 kts? A) 65 seconds B) 95 seconds e) 125 seconds D) 650 seconds The distance of a complete circle is 27TR. The turn radius R is (TAS2+(gxtan ([»), where ([> is the bank angle. With the given values: R = (200 kts x 0,5144 m/s/kts1+(9,81 m/s2 x tan 45°) = (102,88 m/s1+(9,81 x I m/s2) = 1.078,93 m. The complete circle is then S =27T x 1.078,93 m =6.779,11 m. To fly this distance at 200 kts: time =S+TAS =6.779, 11 m + (200 kts x 0,5144 m/s/kts) =65,9 s - 63 s.

21042. Airplane ATPL CPL Dividing lift by weight gives: A) wing loading. B) lift/drag ratio. e) load factor. D) aspect ratio. Definition.

21044. Airplane ATPL CPL During a climbing turn to the right the: A) angle of attack of the left wing is larger than the angle of attack of the right wing. B) angle of attack of the left wing is smaller than the angle of attack of the right wing. e) angle of attack of both wings is the same. D) stall angle of attack of the left wing will be larger than the corresponding angle for the right wing. In a climbing turn the inner wing describes a steeper spiral than the outer wing, and the spiral is an upward spiral. The air comes down to meet the inner wing at a steeper angle than on the outer wing, thus reducing the angle of attack more on the inner wing.

116662 (C) 116667 (C) 116668 (0) 1 21018 (8) 121026 (A) 121028 (0) 121029 (C) 121032 (A) 121042 (C) 121044 (A) 1

08 Flight Mechanics

Airplane ATPL CPL During a straight steady climb: 1) Lift is less than weight. 2) Lift is greater than weight. 3) Load factor is less than 1. 4) Load factor is greater than 1. 5) Lift is equal to weight. 6) Load factor is equal to 1. Which of the following lists all the correct answers? 21047.

A) 1,3

B) 2,4

C) 5,6 D) 1,6 (Refer to figure 081-EI6) The illustration shows that the lift in a steady climb is less than the weight (L x cos V). The load factor, being the actual lift divided by the weight, is therefore less than 1.

Airplane ATPL CPL For shallow flight path angles in straight and steady flight, the following formula can be used: 21054.

A) sin(gamma) = WIT - C/CL B) sin(gamma) =TIW - C/CL C) sin(gamma) = WIT - CJCD D) sin(gamma) = TIW - CJCD (Refer to figure 081-EI6) From the illustration one can derive: sin y = (T - D) + W = (T + W) - (0 + W) = T + W - (YipV>SCD) + (V2pV>SC, x cos y) = T + W - CD/(C, x cos V). For small angles cosine is nearly 1, so the formula can be reduced to sin y =T + W - C/C, .

21058.

Airplane

ATPL

CPL

Given: Aeroplane mass: 50.000 kg Lift/Drag ratio: 10 Thrust per engine: 60.000N Assumedg: 10 m/s2 For a straight, steady, wings level climb of a twin engine aeroplane, the all engines climb gradient will be:

the tangent to the climb angle y. For small angles, sin y'" tan y =climb gradient. From the illustration one can deriveHin y = (T - D) + W = (T + W) - (0 + W) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) (1 + (LID x cos V)). For small angles cosine is nearly 1, so the formula can be reduced to Climb gradient = T + (m x g) - (1 + LID). With the given values: Climb gradient = (4 x 20.000 N) + (50.000 kg x 10m/s2) - 1+10=0,16-0,1 = 0,06 or 6%.

21060. Airplane ATPL CPL Given: Aeroplane mass: 50.000 kg Lift/Drag ratio: 10 Thrust per engine: 30.000N 10 m/s2 Assumedg: For a straight, steady, wings level climb of a three-engine aeroplane, the all engines climb gradient will be: A) 8,5% B) 9,7%

C) 2,9% D) 8,0% (Refer to figure 081-EI6) Climb gradient is the ratio of height gained to distance travelled, and therefore the tangent to the climb angle y. For small angles, sin y'" tan y = climb gradient. From the illustration one can derive: sin y = (T - D) + W = (T + W) - (0 + W) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) (1 + (LID x cos V)). For small angles cosine is nearly 1, so the formula can be reduced to Climb gradient = T + (m x g) - (1 + LID). With the given values: Climb gradient = (3 x 30.000 N) + (50.000 kg x 10 m/s2) - 1+10 = 0,18 - 0,1 = 0,08 or 8%.

21061. Airplane ATPL CPL Given: 50.000 kg Aeroplane mass: Lift/Drag ratio: 12 Thrust per engine: 20.000N 10 m/s2 Assumedg: For a straight, steady, wings level climb of a four-engine aeroplane, the all engines climb gradient will be: A) 4,3%

A) 3,7%

B) 7,7%

B) 14% C) 15,7% D) 11,7%

C) 6,0%

D) 8,5%

(Refer to figure 081-EI6) Climb gradient is the ratio of height gained to distance travelled, and therefore the tangent to the climb angle y. For small angles, sin y'" tan y = climb gradient. From the illustration one can derive: sin y =(T-o)+W = (T+W)-(o+W) = T+(mxg)-(o+(Lxcos V)) =T+(mxg)-(o+(Lxcos V)) =T+(mxg)-(1+(Lloxcos V)).

(Refer to figure 081-EI6) Climb gradient is the ratio of height gained to distance travelled, and therefore the tangent to the climb angle y. For small angles, sin y'" tan y = climb gradient. From the illustration one can derive: sin y = (T - D) + W = (T + W) - (0 + W) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) (1 + (LID x cos V)).

For small angles cosine is nearly 1, so the formula can be reduced to Climb gradient =T+(mxg)-(1+Llo). With the given values: Climb gradient =(2 x 60.000 N) + (50.000 kg x 10m/s2)-1+10=0,24-0,1 =0,140rI4%.

For small angles cosine is nearly 1, so the formula can be reduced to Climb gradient = T + (m x g) - (1 + LID). With the given values: Climb gradient = (4 x 20.000 N) + (50.000 kg x 10 m/s2) - 1+12 = 0,16 - 0,083 = 0,077 or 7,7%.

21059.

Airplane

ATPL

CPL

Given: Aeroplane mass: 50.000 kg Lift/Drag ratio: 10 Thrust per engine: 20.000N Assumedg: 10 m/s 2 For a straight, steady, wings level climb of a four-engine aeroplane, the all engines climb gradient will be: A) B) C) D)

8,5% 4,3% 7,7% 6,0%

(Refer to figure 081-EI6) Climb gradient is the ratio of height gained to distance travelled, and therefore

21062. Airplane ATPL CPL Given: Aeroplane mass: 50.000 kg Lift/Drag ratio: 12 Thrust per engine: 21.000 N 10 m/s2 Assumedg: For a straight, steady, wings level climb of a four-engine aeroplane, the all engines climb gradient will be:

A) B) C) D)

8,5% 4,3% 7,7% 6,0%

(Refer to figure 081-EI6) Climb gradient is the ratio ofheight gained to distance travelled, and therefore

121047 (A) 121054 (8) 121058 (8) 121059 (D) 121060 (D) 1 21061 (8) 121062 (A) 1

Aviationexam Test Prep Edition 2012 the tangent to the climb angle y. For small angles, sin y'" tan y = climb gradient. From the illustration one can derive: sin y =(T - D) + W =(T + W) - (0 + W) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) (1 + (LID x cos V)). For small angles cosine is nearly 1, so the formula can be reduced to Climb gradient = T + (m x g) - (1 + LID). With the given values: Climb gradient = (4 x 21.000 N) + (50.000 kg x 10mls2)~ 1+12 =0,168-0,083 =0,085 or 8,5%.

21063. Airplane ATPL CPL Given: Aeroplane mass: 50.000 kg Lift/Drag ratio: 12 Thrust per engine: 21.000 N 10 m/s2 Assumedg: For a straight, steady, wings level climb of a four-engine aeroplane, the one-engine-inoperative climb gradient will be:

A) 6,0% B) 7,7% C) 4,3% D) 8,5% (Refer to figure 081-EI6) Climb gradient is the ratio of height gained to distance travelled, and therefore the tangent to the climb angle y. For small angles, sin y", tan y = climb gradient. From the illustration one can derive: sin y = (T - D) + W", (T + W) - (0 + W) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) (1 + (LID x cos V)). For small angles cosine is nearly 1, so the formula can be reduced to Climb gradient= T + (m x g) - (1 + LID). With the given values (note it is an one engine inoperative climb): Climb gradient = (3 x 21.000 N) + (50.000 kg x 70 mls2) - 1+ 12 =0,126 - 0,083 =0,043 or 4,3%.

21064. Airplane ATPL CPL Given: Aeroplane mass: 50.000 kg Lift/Drag ratio: 12 Thrust per engine: 28.000N 10 m/s2 Assumedg: For a straight, steady, wings level climb of a four-engine aeroplane, the one-engine-inoperative climb gradient will be: A) 8,5%

B) 8,0% C) 9,7% D) 2,9%

21065.

Airplane

ATPL

CPL

Given: Aeroplane mass: 50.000 kg Lift/Drag ratio: 12 Thrust per engine: 28.000N 10 m/s2 Assumedg: For a straight, steady, wings level climb of a three-engine aeroplane, the one-engine-inoperative climb gradient will be: A) 8,0%

B) 9,7% C) 2,9% D) 8,5% (Refer to figure 081-EI6) Climb gradient is the ratio of height gained to distance travelled, and therefore the tangent to the climb angle y. For small angles, sin y'" tan y = climb gradient. From the illustration one can derive: sin y = (T - D) + W = (T + W) - (0 + W) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) (1 + (LID x cos V)). For small angles cosine is nearly 1, so the formula can be reduced to Climb gradient = T + (m x g) - (1 + LID). With the given values (note it is an one engine inoperative climb): Climb gradient = (2 x 28.000 N) + (50.000 kg x 70 mls2) - 1 + 12 = 0,112 - 0,083 = 0,029 or 2,9%.

21066. Airplane ATPL CPL Given: Aeroplane mass: 50.000 kg Lift/Drag ratio: 12 Thrust per engine: 30.000N 10 m/s2 Assumedg: For a straight, steady, wings level climb of a three-engine aeroplane, the all engines climb gradient will be: A) 2,9%

B) 9,7% C) 8,0% D) 8,5% (Refer to figure 081-EI6) Climb gradient is the ratio of height gained to distance travelled, and therefore the tangent to the climb angle y. For small angles, sin y '" tan y = climb gradient. From the illustration one can derive: sin y = (T-O)+W = (T+W)-(O+W) = T+(mxg)-(O+(Lxcos V)) = T+(mxg)-(O+(Lxcos V)) = T+(mxg)-(1+(LlOxcos V)). For small angles cosine is nearly 1, so the formula can be reduced to Climb gradient= T+(mxg)-(1+LlO). With the given values: Climb gradient = (3 x 30.000 N) + (50.000 kg x 70 mls2) - 1 + 12 =0,18 - 0,083 =0,097 or 9.7%.

(Refer to figure 081-EI6) Climb gradient is the ratio of height gained to distance travelled, and therefore the tangent to the climb angle y. For small angles, sin y'" tan y = climb gradient. From the illustration one can derive: sin y = (T - D) + W = (T + W) - (0 + W) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) (1 + (LID x cos V)). For small angles cosine is nearly 1, so the formula can be reduced to Climb gradient = T + (m x g) - (1 + LID). With the given values: Climb gradient (all engines) = (4 x 28.000 N) + (50.000 kg x 10 mls2) - 1+12 = 0,224 - 0,083 = 0,141 or 14,1%. Climb gradient (one engine out) = (3 x 28.000 N) + (50.000 kg x 70 mls2) - 1+12 =0,168 - 0,083 =0,085 or 8,5%.

21067. Airplane ATPL CPL Given: 50.000 kg Aeroplane mass: Lift/Drag ratio: 12 Thrust per engine: 50.000N Assumedg: 10 m/s2 For a straight, steady, wings level climb of a twin engine aeroplane, the all engines climb gradient will be: A) 15,7% B) 3,7% C) 14%

D) 11,7% (Refer to figure 081-EI6) Climb gradient is the ratio of height gained to distance travelled, and therefore the tangent to the climb angle y. For small angles, sin y'" tan y = climb gradient. From the illustration one can derive: sin y =(T - D) + W =(T + W) - (0 + W) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) (1 + (LID x cos V)). For small angles cosine is nearly 1, so the formula can be reduced to Climb gradient = T + (m x g) - (1 + LID). With the given values: Climb gradient = (2 x 50.000 N) + (50.000 kg x 10 mls2) - 1 + 12 = 0,2 - 0,083 = 0,117 or 11,7%.

121063 (C) 121064 (A) 121065 (C) 121066 (8) 121067 (0) 1

08 Flight Mechanics 21068.

Airplane

ATPL

Consequently, the load factor being LID is less than one.

CPL

Given: Aeroplane mass: Lift/Drag ratio: Thrust per engine: Assumedg:

50.000 kg 12

60.000N 10 m/s2

For a straight, steady, wings level climb of a twin engine aeroplane, the all engines climb gradient will be: A) 14%

B) 3,7%

(Refer to figure 081-£16) Climb gradient is the ratio of height gained to distance travelled, and therefore the tangent to the climb angle y. For small angles, sin y'" tan y = climb gradient. From the illustration one can derive: sin y = (T - D) + W = (T + W) - (0 + W) =T + (m x g) - (0 + (L x cos V)) = T + (m x g) - (0 + (L x cos V)) = T + (m x g) (1 + (LID x cos V)). For small angles cosine is nearly 1, so the formula can be reduced to Climb gradient = T + (m x g) - (1 + LID). With the given values: Climb gradient = (2 x 60.000 N) + (50.000 kg x 10 mls2) - 1 + 12 = 0,24 - 0,083 = 0,157 or 15,7%.

Airplane

ATPL

Aeroplane mass: Lift/Drag ratio: Thrust per engine: Assumedg:

21121. Airplane ATPL CPL The forces of lift and drag on an aerofoil are, respectively, normal and parallel to the:

A) relative wind/airflow. B) chord line. C) longitudinal axis. D) horizon. Drag acts opposite to the motion, that is in the same direction as the relative wind on the aircraft. Lift (defined as the force opposing the weight) acts perpendicular to the drag.

CPL

Given: 50.000 kg 12

60.000N 10 m/s2

For a straight, steady, wings level climb of a twin engine aeroplane, the one-engine-inoperative climb gradient will be: A) 3,7% B) 15,7% C) 14%

D) 11,7% (Refer to figure 081-£16) Climb gradient is the ratio ofheight gained to distance travelled, and therefore the tangent to the climb angle y. For small angles, sin y'" tan y = climb gradient. From the illustration one can derive: sin y = (T - D) + W = (T + W) - (0 + W) = T + (m x g) - (0 + (L x cos V)) =T + (m x g) - (0 + (L x cos V)) =T + (m x g) (1 + (LID x cosy)). For small angles cosine is nearly 1, so the formula can be reduced to Climb gradient = T + (m x g) - (1 + LID). With the given values (note it is an one engine inoperative climb): Climb gradient = (60.000N) + (50.000 kg x 10 mls2) -1 + 12 =0,12 - 0,083 =0,037 or 3,7%.

21082. Airplane ATPL CPL In a slipping turn (nose pointing outwards), compared with a co-ordinated turn, the bank angle (i) and the "ball" or slip indicator (ii) are respectively:

A) (i) too large; (ii) displaced towards the high wing. B) (i) too small; (ii) displaced towards the low wing. C) (i) too large; (ii) displaced towards the low wing. D) (i) too small; (ii) displaced towards the high wing. (Refer to figure 081-£127) Side-slip in a turn is caused by overbanking. The bank angle is too big causing the slip indicator to show the side-slip by the ball displaced towards the low wing.

21084. Airplane ATPL CPL In a straight steady descent, which of the following statements is correct?

A) B) C) D)

A) configuration and angle of attack. B) mass and altitude. C) altitude and configuration. D) configuration and mass. The gliding angle is only dependent of the lift to drag ratio (LID). Of the given possibilities, the only set of relevant factors is configuration (influence on D) and angle of attack (influence on L).

C) 15,7% D) 11,7%

21069.

21115. Airplane ATPL CPL The descent angle of a given aeroplane in a steady wings level glide has a fixed value for a certain combination of: (ignore compressibility effects and assume zero thrust)

21132. Airplane ATPL CPL The speed for minimum glide angle occurs at an angle of attack that corresponds to (assume zero thrust): A) (C/C 02)MAX

B) CLMAX C) (C/CO)MAX D) (CL3/C02)MAX The gliding angle is only dependent of the lift to drag ratio (LID). The minimum glide angle is obtained at (LlD)MAJ( or (C/CJMA)(,

21142. Airplane ATPL CPL What decreases the maximum ground distance during a glide with zero thrust?

A) B) C) D)

A decrease in aeroplane mass with zero wind. A tailwind with constant aeroplane mass. An increase in aeroplane mass with zero wind. A headwind with constant aeroplane mass.

The glide distance equals height loss multiplied by LID and is therefore independent of the weight. However, this only applies in still air. If there is a wind the ground speed changes, and so the distance over the ground changes. A headwind will decrease the distance.

21143. Airplane ATPL CPL What increases the maximum ground distance during a glide with zero thrust?

A) B) C) D)

A decrease in aeroplane mass with zero wind. A headwind with constant aeroplane mass. An increase in aeroplane mass with zero wind. A tailwind with constant aeroplane mass.

The glide distance equals height loss multiplied by LID and is therefore independent of the weight. However, this only applies in still air. If there is a wind the ground speed changes, and so the distance over the ground changes. A tailwind will increase the distance.

Lift is equal to weight, load factor is equal to 1. Lift is less than weight, load factor is equal to 1. Lift is less than weight, load factor is less than 1. Lift is equal to weight, load factor is less than 1.

Because the aeroplane descents, the weight is greater than the lift.

121068 (e) 121069 (A) 121082 (C) 121084 (e) 1 21115 (A) 1 21121 (A) 1 21132 (e) 1 21142 (D) 1 21143 (D) 1

Aviationexam Test Prep Edition 2012 21144. Airplane ATPL CPL What is the approximate diameter of a steady, level, co-ordinated turn with a bank angle of 30° and a speed (TAS) of 500 kts?

A) 13 km B) 17 km C) 23 km D) 7km Turn radius R is (TAS2+(gxtan (/))), where (/) is the bank angle. With the given values: R = (500 kts x 0,5744 mlslktsl + (9,87 mls2 x tan 30°) = (275,2 mlsl + (9,87 x 0,57735 mls2) = 77.679,76 m. The diameter is 2R =23.359,5 m - 23 km.

21145. Airplane ATPL CPL What is the approximate radius of a steady horizontal co-ordinated turn at a bank angle of 45° and a TAS of 200 kts?

23273.

Airplane

ATPL

CPL

Side slip is: A) that which occurs when an aircraft loses adhesion when taxiing. B) the motion that will occur if trailing edge flaps deploy asymmetrically. C) the out of balance which occurs when an engine fails and thrust is asymmetric. D) motion of an aircraft, relative to the relative airflow, which has a component of velocity along the lateral axis. In the sideslip condition, the airplane's longitudinal axis remains parallel to the original flightpath, but the airplane no longer flies straight along its original track. Now, the horizontal component of lift forces the airplane to move sideways toward the low wing.

23291. Airplane ATPL CPL In steady level flight the load factor is:

A) 1 km B) 10 km C) 2km D) 1,5 km

A) zero

Turn radius R is (TAS2+(gxtan (/))), where (/) is the bank angle. With the given values: R = (200 kts x 0,5744 mlslktsl + (9,87 mls2 x tan 45°) = (702,88 mlsl + (9,87 x 7 mls2) = 7.078,93 m - 7 km.

21146. Airplane ATPL CPL What is the correct relationship between the true airspeed for (i) minimum sink rate and (ii) minimum glide angle, at a given altitude?

A) (i) is equal to (ii). B) (i) is less than (ii). C) (i) is greater than (ii). 0) (i) can be greater than or less than (ii) depending on the type of aeroplane. Tangent to the glide angle is tan y = OIL. Minimum glide angel is obtained ata speed where UD is maximum, i.e. VMD • Minimum rate ofdescent is obtained when V x sin y is minimum. For small angles, sin y = tan y, so minimum ratio of descent at a speed where Vx tan y is minimum, and this speed is below VMD •

Airplane ATPL CPL When an aeroplane performs a straight steady climb with a 20% climb gradient, the load factor is equal to: 21155.

A) 0,83 B) 1,02

B) 1,0 C) 1,5 D) 2,0 Load factor is defined as actual load divided by weight. In steady level flight the lift equals the weight, so the load factor is 7.

23326. Airplane ATPL CPL To maintain level flight at a steady speed:

A) B) C) D)

thrust must be exactly equal to drag. thrust must be slightly greater than drag. thrust must be much greater than drag. thrust must be less than drag.

To maintain level flight at steady speed the sum of forces in the direction

of movement must be zero, i.e. Thrust = Drag. 23375. Airplane ATPL CPL Which statement is true, if during a level coordinated turn the load factor was kept constant?

A) B) C) D)

A decrease in airspeed results in an increase in radius. An increase in airspeed results in an increase in radius. An increase in airspeed results in a decrease in radius. An increase in airspeed would result in the same radius.

The load factor in a turn is 7 + cos (/), where (/) is the bank angle. Turn radius R is (TAS2 + (g x tan (/))). An increase in speed with the same bank angle (to main-

C) 1

tain the load factor) means a larger turn radius.

D) 0,98 (Refer to figure 087-£76) From the illustration: L W x cos y. Load factor is n L + W (W x cos y) + W = cos y. The climb gradient is equal to tan y. With the given value, tan y = 0,20 means the climb angle is 71,32". The load factor is n =cos 71,32° =0,987.

=

=

=

21183. Airplane ATPL CPL The lift to drag ratio determines the:

A) B) C) D)

horizontal distance in the climb up to a given altitude. maximum rate of climb. endurance speed. horizontal glide distance from a given altitude at zero wind and zero thrust.

Airplane ATPL CPL For a given TAS and bank angle, a heavy aircraft: 23378.

A) will have a larger radius of turn than a lighter one. B) will have a smaller radius of turn than a lighter one. C) will have the same radius of turn as a lighter one, but at a higher G load. D) will have the same radius of turn as a lighter one, and the same G load. Turn radius R is (TAS2+(gxtan (/))), where (/) is the bank angle. None of the factors differ for the two aircraft, so the turn radius is constant. The load factor in a turn is 7+cos (/), which is independent of the weight, so the load factor also remain unchanged.

The gliding distance in still air equals height loss multiplied by UD.

Airplane ATPL CPL What action is necessary to make an aircraft turn? 23380.

Airplane What is load factor? 23222.

A) B) C) D)

ATPL

CPL

Lift multiplied by the total weight. Lift divided by the total weight. Lift subtracted by the total weight. The total weight divided by the wing area.

Load factor is defined as actual load divided by weight.

A) Change the direction of lift. B) Change the direction ofthrust. C) Yaw the aircraft. D) Roll the aircraft. (Refer to figure 087-£74)

As shown in the illustration, in a turn the lift provides both centripetal force

1 21144 (C) 1 21145 (A) 1 21146 (8) 1 21155 (D) 1 21183 (D) 123222 (8) 123273 (D) 123291 (8) 123326 (A) 123375 (8) 1 1 23378 (D) 1 23380 (A) 1

08 Flight Mechanics and a force equal to and opposite the weight. This is obtained by changing the direction of the lift.

23401. Airplane ATPL CPL When an aircraft is climbing the requirements to mainta in equilibrium are: A) thrust equals the sum of drag and the weight component along the flight path, and lift equals the weight component perpendicular to the flight path. B) thrust equals the weight component along the flight path, and lift equals the sum of the drag and weight component perpendicular to the flight path. C) thrust equals the weight component perpendicular to the flight path, and lift equals the weight component along the flight path. D) lift equals weight, and thrust equals drag.

of turn. B) For a specific angle of bank and airspeed the rate and radius of turn will not vary. C) The faster the true airspeed, the faster the rate and larger radius of turn regardless of the angle of bank. D) To maintain a steady rate of turn, the angle of bank must be increased as the airspeed is decreased. Rate of turn is (g x tan (/») 7 V, where (/) is the bank angle. Turn radius R is (1fI7 (g x tan (/»)). With given values of speed (V) and bank angle, both rate and radius of turn is constant.

23408. Airplane ATPL CPL If an aircraft maintains a constant radius of turn but the speed is increased: A) the bank angle must be increased. B) the bank angle must be decreased.

For explanation refer to question #4111 on page 168.

C) the bank angle will remain constant and the G load will be

23403. Airplane ATPL CPL When climbing into a headwind, compared to still air, the climb gradient relative to the ground will be:

D) the bank angle will remain constant but the G load will

constant.

A) steeper, and the rate of climb increased. B) steeper, and the rate of climb unchanged. C) less steep, and the rate of climb increased. D) the same, and the rate of climb unchanged. Although the climb angle relative to the ground is affected by wind - larger in headwind, smaller in tailwind - the rate of climb is independent of the wind speed.

23404. Airplane ATPL CPL A glider has a LID ratio of25:1. For every 1.000 ft of height lost it would cover a distance in still air of: A) B) C) D)

4NM 2,5 NM 25 NM 40NM

The LID ratio equals the glide ratio (distance over ground 7 height loss). The glide distance therefore equals height loss multiplied by LID. In this case: Distance = 1.000 ft x 25 =25.000 ft =25.000 x 0,000165 NM =4, 125 NM - 4 NM.

23405. Airplane ATPL CPL In a glide the line of action of the total reaction will be: A) B) C) D)

behind that of lift and ahead that of weight. ahead that of lift and directly opposite that of weight. behind that of lift and directly opposite that of weight. ahead that of lift and weight.

(Refer to figure 081-E15)

As can be seen in the illustration the sum oflift and drag equals weight.

23406. Airplane ATPL CPL The force which causes an aircraft to turn is given by: A) B) C) D)

the rudder. the ailerons. the wing lift. the weight.

(Refer to figure 081-E14) As shown in the illustration, in a turn the lift provides both centripetal force and a force equal to and opposite the weight.

23407. Airplane ATPL CPL Which statement is correct with respect to rate and radius of turn for an aeroplane flown in a coordinated turn at a constant altitude?

increase. Turn radius R is (TAS2 7 (g x tan (/»)), where (/) is the bank angle. Hence, if the radius should stay constant at an increasing speed, the tangent to the bank angle, and thus the angle, must be increased.

23409. Airplane ATPL CPL In coordinated flight for any specific bank, the faster the speed of the aircraft the: A) smaller the radius and slower rate of turn. B) greater the radius and faster rate of turn. C) smaller the radius and faster rate of turn. D) greater the radius and slower rate of turn. Turn radius R is (TAS27 (g x tan (/»)), where (/) is the bank angle. Increasing speed ata given bank angle means a greaterradius. Rate of turn is (g x tan (/») 7 TAS, showing an increase in speed will give slower rate ofturn.

23410. Airplane ATPL CPL While holding the angle of bank constant, if the rate of turn is varied the load factor would: A) vary depending upon the resultant lift vector. B) remain constant regardless of air density and the resultant lift vector. C) vary depending upon speed and air density provided the resultant lift vector varies proportionally. D) increase at an increasing rate. The load factor in a turn is hcos (/), where (/) is the bank angle. It is therefore independent of anything but the bank angle.

23411. Airplane ATPL CPL For an aircraft to make a rate 1 turn: A) there is only 1 correct speed and one corresponding bank angle. B) it may be done at any speed but there is only 1 correct bank angle. C) there is only 1 correct speed but any bank angle may be chosen. D) it may be done at any speed but the higher the speed the greater the bank angle. Rate 1 turn is a turn with a fixed turn rate (three degrees per second). Rate of turn is (g x tan (/») 7 V, where (/) is the bank angle. Thus, ata given speed a certain bank angle is required. If the speed is increased, the bank angle must also be increased to keep the rate of turn constant.

A) For any specific angle of bank and airspeed, the lighter the aeroplane the faster the rate and the smaller the radius 123401 (A) 123403 (8) 123404 (A) 123405 (C) 123406 (C) 123407 (8) 123408 (A) 123409 (0) 123410 (8)

I 23411

(0)

I

Aviationexam Test Prep Edition 2012 23466.

Airplane

ATPL

CPL

Which statement is true, regarding the opposing forces acting on an aeroplane in steady state level flight? A) Thrust is greater than drag and weight and lift are equal. B) Thrust is greater than drag and lift is greater than weight. C) Thrust is less than drag and lift is less than weight. D) The opposing forces are equal. To maintain level flight at steady speed the sum of forces on the aircraft must be zero, i.e. Lift = Weight, and Thrust = Drag.

23468.

Airplane

ATPL

A) less. B) greater. C) the same. D) it depends on the exact CG location. The lift acting through the centre of pressure aft of the centre of gravity will cause a nose down moment about the centre of gravity. To counter this, the tailplane must generate a force downwards, and the wing must therefore produce more lift than the weight. If the centre of gravity moves to its aft limit it is closer to the centre of pressure; the nose down moment from the wing lift is decreased, and the tailplane's downwards force is smaller. This reduces the total wing lift if level flight is to be maintained.

Airplane

ATPL

CPL

Which is true regarding the forces acting on an aircraft in a steady-state descent? A) The sum of all rearward forces is greater than the sum of all forward forces. B) The sum of all forward forces is equal to the sum of all rearward forces. C) The sum of all upward forces is less than the sum of all downward forces. D) The sum of all upward forces is greater than the sum of all downward forces. (Refer to figure 081-E75) In a descent the flight path is declined downwards, but the sum of forces acting in the direction of and perpendicular to the movement must be zero in a steady state descent.

23476.

Airplane

ATPL

CPL

If, during a level turn the rate of turn is kept constant, an increase in airspeed will result in a: A) decrease in centrifugal force. B) constant load factor regardless of changes in bank angle. C) need to decrease angle of bank to maintain the same radius of turn. D) need to increase angle of bank to maintain the same radius of turn. Rate of turn is (g x tan cD) -;- II, where cD is the bank angle. With an increase in speed, to maintain the same rate of turn tan cD and thus the bank angle must be increased.

23477.

Airplane

ATPL

CPL

If no corrective action is taken by the pilot as angle of bank is increased, how is the vertical component of lift and sink rate affected? A) B) C) D)

Airplane

ATPL

CPL

A) Rate will increase and radius will decrease. B) Rate will decrease and radius will increase. C) Rate and radius will increase. D) Rate and radius will decrease. Rate of turn is (g x tan cD) -;- II, where cD is the bank angle. Turn radius R is (IP -;(g x tan cD)). With a given value of bank angle and increasing speed, rate of turn will decrease and radius of turn increase.

CPL

With the CG on the aft limit, compared to the forward limit, the wing lift required for level flight will be:

23475.

23478.

What is the relationship of the rate of turn with the radius of turn with a constant angle of bank but increasing airspeed?

Lift increases and sink rate increases. Lift decreases and sink rate decreases. Lift increases and sink rate decreases. Lift decreases and sink rate increases.

(Refer to figure 081-E74) As seen in the illustration, if the bank angle is increased without othe; corrections, the vertical component of lift will decrease and therefore the sink rate will increase.

23479.

Airplane

ATPL

CPL

If an aircraft with a gross weight of 2.000 kg was subjected to a 60 degree bank turn, what would the total load be? A) B) C) D)

3.000 kg 12.000 kg 1.000 kg 4.000 kg

The load factor in a turn is 7-;-cos cD, where cD is the bank angle. Cos 60° = 0,5, so the load factor is 2. The total load is then: mxn = 2.000 kg x 2 = 4.000 kg.

23492.

Airplane

ATPL

CPL

For an aircraft at high weight, the minimum possible radius of turn will be: A) less than when at low weight. B) the same as when at a low weight. C) more than when at a low weight. D) unable to solve without additional information. (Refer to figure 087-E74) As shown in the illustration, in a turn the lift provides both centripetal force and a force equal to and opposite the weight. With a higher weight it would not be possible to bank the aircraft as much as with a low weight to avoid a stall. Turn radius R is (TAS2 -;- (g x tan cD)), where cD is the bank angle. With a lower bank angle (and thus tangent), the minimum turn radius is larger.

23497.

Airplane

ATPL

CPL

What effect does an increase in airspeed have on a co-ordinated turn while maintaining a constant angle of bank and altitude? A) The rate of turn will decrease resulting in a decreased load factor. B) The rate of turn will decrease resulting in no change in the load factor. C) The rate of turn will increase resulting in an increased load factor. D) The rate of turn will increase resulting in a decreased load factor. Rate of turn is (g x tan cD) -;- V, where cD is the bank angle. Increasing the speed whilst the bank angle is constant results in a smaller rate of turn. The load factor in a tum is 7 -;- cos cD; with a constant bank angle, the load factor does not change.

23498.

Airplane

ATPL

CPL

Upon which factor does wing loading during a level co-ordinated turn in smooth air depend? A) Angle of bahk. B) TAS. C) Rate of turn. D) lAS. Wing loading is the lift divided by the wing area. In a level turn the lift is increased to provide both a vertical force to counter weight and a centripetal force to execute the turn. The magnitude of the total lift is expressed in the load factor, and in a turn the load factor is 7 -;- cos cD, where cD is the bank angle.

I 23466 (0) I 23468 (A) I 23475 (8) I 23476 (0) I 23477 (0) I 23478 (8) I 23479 (0) I 23492 (C) I 23497 (8) I 23498 (A) I

08 Flight Mechanics 23499. Airplane ATPL CPL To obtain the best possible gliding distance an aircraft should:

A) be as light as possible. B) have a wing that will give high lift. C) have the highest possible lift/drag ratio.

0) be as heavy as possible. Maximum gliding distance is obtained when UD is maximum.

Airplane ATPL CPL In a climb the weight component along the flight path is balanced by: 23500.

A) thrust B) lift

C) drag 0) gravity (Refer to figure 087-E76) As shown in the illustration, in a climb the component of weight acting along the flight path is balanced by the thrust.

23534. Airplane ATPL CPL If a twin engine aircraft with a LID ratio of 8:1 is in straight and level flight and the engines are each developing 16.000 N of thrust, what is the weight of the aircraft?

A) B) C) 0)

4.000 N 8.000 N 256.000 N 32.000 N

In straight and level flight thrust equals drag. From the lift to drag ratio UD, the lift can be found as L =(UD) x 0, or L =(UD) x T. With the given values: L=8x2x 76.000 N =256.000 N.

23548. Airplane ATPL CPL A glide ratio of 14:1 with respect to the air mass will be:

A) B) C) 0)

7:1 in a headwind and 28:1 in a tailwind. 7:1 in a tailwind and 28:1 in a headwind. 14:1 in a tailwind and 7:1 in a headwind. 14:1 regardless of wind direction and speed.

The air mass as a whole may be moving over the ground due to wind, but this will have no effect on the glide ratio with respect to the air mass. This will always be 74:7 in this case.

23549. Airplane ATPL CPL For a given angle of bank, the load factor imposed on both the aircraft and pilot in a co-ordinated constant altitude turn:

A) is constant, but the stall speed is higher than in straight and level flight. B) varies with the rate of turn. C) is directly related to the aeroplane's gross weight. 0) is inversely proportional to the bank angle. The load factor in a turn is 7+cos , where is the bank angle. Cosine decreases with increasing angle, so the load factor varies proportionately with the bank angle. With a given bank angle the load factor is constant, but stall speed in a turn increases with a factor vn, or v(7+cos

10

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\\%

~

, ,:>==

'0

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'':.9 ,

:\~

,,'

,, \

\.~ \

250 300 350 Indicated Airspeed - kts

,

\

400

450

FIGURE 081-02

.50 .55

.60 .65 .70

.75

.80

INDICATED MACH NUMBER

1

1.5

2

2.5

LOAD FACTOR

EXAMPLE

Data Weight: Load factor: Level: Mach Nr.: Level: Weight:

Results

0.84

0.80 350 120 t

®

At Mach 0.80 Buffeting takes place at 48° bank or 1.5g

120t

19

Buffet Onset Boundary Chart - Clean Configuration

Aviationexam Test Prep Edition 2012

FIGURE 081-03

, ,, ,

BUFFET ONSET clean configuration

,,

NOTE: FOR MACH NUMBERS ABOVE OR EQUAL TO 0.82 THERE IS NO CG VARIATION EFFECT FROM REFERENCE VALUE

I

"

, ,, , ,

REF

! I

, ,,

,, .,

FUGHTLEVEL

,,

140

, ,

",

, i

,,

! ;

,, ,

80

!

130

"

,,, ,,

, ,,

120

, !

,

100

110 !

,

I "' I'

120

I I I

, ,

I

100

, ! ;

140

,! ' ;

160

,i ,

,. ,i :

"

:!

I

,

,

, ,

i

,

:

; ;

! I

,

.

;

,, ,' , I ;,

,. ,

,, ,

,,

,

,; .; ;

:.

:

:; ; ; ;;

; ; I

,

;

; ;

,

iW~IG~T(t)=

I I! ,I'

i

270 290 310 330 350 370 390 410 .50

i

.!

200 220 240 250

90 80

,

i;

180

,, ,

I;

• J"

, i

i

,

,, BANK ANGLE (0)_ 3P

.55

.60

.65

.70

.75

MACH NUMBER

.so

.~515

t

4556~5;:J6prn6~==

20 25 30 35 40 45 50 1 1.21.41.61.8 2 2.22.4

CG%

LOAD FACTOR

MMO

FIGURE 081-04

FIGURE 081-05

x

TAS

Picture Supplements - Questions

FIGURE 081-07

FIGURE 081-06

-

time

FIGURE 081-09 FIGURE 081-08

Relative wind V ~

=Stagnation point

FIGURE 081-10 A)

V

---.

8)

V

---.

FIGURE 081-11

r> I

2

C) V 0)

V

---.

e

FIGURE 081-12

c .

Fixed surface

~ +

c;;,""". q;::::s-

FIGURE 081-13

/

variablJ linkage

Tab

Aviationexam Test Prep Edition 2012

FIGURE 081-14

FIGURE 081-15

'" '"

propeller axis

'" '"

'"

"Hinge

plane of rotation

FIGURE 081-16

o =rotational velocity propeller axis

N

propeller axis

Diagram 1

____________________________________________ ~

propeller axis

________

Diagram 2

____________________________________ _

propeller axis

TAS

TAS

o

plane of rotation

Diagram 3

Diagram 4

FIGURE 081-17

FIGURE 081-18

plane of rotation

Picture Supplements - QuestiQns

FIGURE 081-20

FIGURE 081-19 y

x

z

x

I

I

D

l111 y'

x'

y

sequence 1 x , f _

y,f_ y

sequence 2 x'_~

x

z

z'~ __

y

x

_______ sequence 3 x,~ x

z

y'£

z'L ___

Y'~

sequence 4 x'_/?:_

J) y'

x'

z z , f __

,p:? y------y

z'~

Z

l111

z'

x

y

z __

FIGURE 081-21

z'

x

y z z'~_

,~ y------y

sequence 1 x , f _

,p:?

x sequence 2 x'_~ y------Y x x _______ sequence 3 ,~ y------x y,£y sequence 4 x ' _ f .

z

z'~_ z

,p:?

z'L ___ z z ' £__

FIGURE 081-22 x

¥

I

z

x

I

I

})

l111 y'

x' x sequence 1 x , f _ x

y-------

sequence 2 x , f _

Y'~ x

_______ sequence 3 x,~

x

sequence 4 x,~

J) y'

z'

p:?y y' _______

z'~_

x' z

z,f_

x

sequence 1

x'~

x

y z z'~__

,p:?y

z z'L ___

y-------

z'~_

z

,p?y

z z ' £ __

sequence 2 x ' _ P y------x y sequence 3 x'

z

Y'./:y

I

l111

z'

,p:?y

z

¥

sequence 4

_R

y'

~y

z

z'

X'_4;::;;:;:;~?/ y , L

line 2

em + pitch up line 1

line 2

a line 3

a line 4

line 3 line 4

z

z , f __

FIGURE 081-24

FIGURE 081-23

~-

Aviationexam Test Prep Edition 2012

FIGURE 081-25

FIGURE 081-26

Propeller efficiency

Propeller efficiency

Propeller efficiency

Propeller efficiency

____________

TAS

1

OL-__________

TAS

2

Propeller efficiency

~

~~

~

____________

O

o~

TAS

~

TAS

TAS

2

1 Propeller efficiency

Propeller efficiency

~~

Propeller efficiency

~

____________

TAS

~

~~

~

OL-__________

O

TAS

O~

~

________

~~

TAS

4

3

TAS

4

3

FIGURE 081-27

FIGURE 081-28 line 1

C

kE~________________~line2

o

__

TAS

0

a

- pitch down A

FIGURE 081-29 Cm + pitch up

o - pitch down

1

point 2

a

·Picture Supplements Explanations

Picture Supplements - Explanations

FIGURE 081-EOl

Propel\eJ hub

a

FIGURE 081-E03

FIGURE 081-E02

Slip /

r

Geometric pitch

Effective pitch

FIGURE 081-E05

FIGURE 081-E04 L

Critical engine

Centre of Gravity

w

Greater ' - - - - thrust arm

Aviationexam Test Prep Edition 2012

FIGURE OSl-E06

FIGURE OSl-E07 Down-going blade has higher relative velocity - more thrust

Flightpath ~---

Distance travelled by down-going blade in one-half revolution

FIGURE OSl-EOS Induced flow . / fr9m propeller "7'" slipstream Vertical component_ of thrust

FIGURE OSl-E09

FIGURE OSl-El0 Lift

I!II Rolling friction

Weight Decreased effective sweep

Picture Supplements - Explanations

FIGURE 081-Ell

--r v

T

(?,=

0°

Thrust yawing moment

L

Sideways component ~-~~~ of lift

\w \ \

_),J'J~~~~

~~ ~~W

Rudder yawing ~moment

Ball rests at base of tube

FIGURE 081-E12 Change in tail lift

TAS ~

~ Relative airflow from angular rotation Pitching velocity

Increase in tail angle of attack due to pitching velocity

FIGURE 081-E13 Reduced arm

Aviationexam Test Prep Edition 2012

FIGURE 081-E14

Centre of turn

t,,

Centripetal force

,, ,, ,, , ,,

",

)'

tW

FIGURE 081-E15 Total reaction ~ __ _

/

'"

",, , , , --- -t 1/_. . . . . . . , r-V

I

I

",

, \

1

I

I

I I I I I I I

!!

\

I

\

\\ I

I

\

\

L=~cosV

I i I I

/

\ \

I

I I , I , I " I " I

"

Flight path

I I

/ /

/

"" /

I

/

Forward component

"'\\..._W_-_-_-_-_--__/e;9ht fIN cos yl FIGURE 081-E16

/

'" "" ""

//

Aerodynamic drag

__ - - - - - - Thrust required to balance aerodynamic drag

,

/

\ Flight path

~\~ \ \

\ \

I I I I I

\

\

\--WCOSV

I

V\

/ \

, '.....

W

............

Backwards component of weight - - W

_--

)VJfC!

-----.I V

Sin

\

/

\

\ ...... .,..,.""

",,'" '"

/

Extra thrust required to balance backwards component of weight

Picture Supplements - Explanations

FIGURE 081-E17 Lateral axis Positive pitching moment, M

Longitudal axis

Normal axis

FIGURE 081-E18

~

...... =

Weight

FIGURE 081-E19

••••••••'fJ

Aviationexam Test Prep Edition 2012

FIGURE 081-E20

oor-"

J

~~n

-::::=::~====::::::::=iiiiiii~~~~~-iiiii=:::::::::==~=:== _ __

Dihedral angle -----'---_______

A

Velocity component due to sideslip

Weight

~\ ~\

l

Velocity component due to sideslip Component of weight

-'----../ acting to cause sideslip

8

/ / / / / / Total relative freestream (main component along longitudinal axis)

c

/ / /

Dihedral angle

Picture Supplements - Explanations

FIGURE 08l-E2l

..

c Normal flight

Deep stall condition - T-tail in "shadow" of wing

FIGURE 08l-E22

The various chords on the planform of the swept-wing of an aircraft Tip chord \\ \ \

Root chord

Tip chord

\ \

\

Root chord \ \ \

Aviationexam Test Prep Edition 2012

FIGURE 081-E23

I

FIGURE 081-E24

Flapperons

FIGURE 081-E25 Maximum local flow . / velocity is less than Mach 1 « sonic)

/

Flight at critical mach number (eg. M 0.77)

...•

~

Normal shock wave /

Flight above critical mach number (eg. M 0.80)

Normal shock wave

Flight above critical mach number (eg. M 0.82)

Possible flow separation

Picture Supplements - Explanations

FIGURE 081-E26 ~

::l

~

'"'"~ ""0 0

"Ct. "- "0 0 Q)

Q) Q)

'"

0

c 0

~

ro

L..

0,2

(/)1

I

°

I

I

I

I I I

I

!J12rr'~'2t ~2.e.!f!..C~lJtjl!l2.ul aerraYiam'i cerre 4° 8° Angle of attack

}

)r ./

~ P·osition of aerodynamic centre

_4°

/

]l

~sslIre Quarter-chord position 1

Leading edge

~I =1

'Kent .;; reOf

0,4

u..

ffil

\

.c

-

0)1

--

+0,1 OeM

'"" .... .... I

- 0,1

-0,2 20°

1

12°

FIGURE 081-E48

Lateral axis

•

CP

~,

,,

'.

Picture Supplements - Explanations

FIGURE 081-E49

1.5 B

Cf

1.0

CL

1.0

.5 Spanwise lift distribution

Root

Tip

Elliptical

A

Rectangular, ;'=1.0

/~ ~

B~

.... - - -----Stall

progreSSion~

High taper, ;'=0.25

O

~::-'

[P /

.--.--:: ""-

Moderate taper, ;'=0.5

]

c~

Pointed tip, ;'=0

E

Sweepback

F

FIGURE 081-E50 Tailplane

Wing

Downwash

-=::::.

__________ c

~ Increased

~Sh c---::::...~.CP

Nose down pitching moment

u

Nose up pitching moment

Aviationexam Test Prep Edition 2012

FIGURE 081-E51 Effect of CG Position CG position 10% MAC Pull

Trim speed

/

30% MAC

/ /

40% MAC

o

/

----50% MAC

_--

-

EAS

.....-'

Push Manoeuvre margin

L

.'

L

,

1~~4----

x

----~-----r----~~~.------------

y

K::::::::::::==>

,

,, Fwd CG limit high stick force

,,

, ,,

,,

Aft CG limit low stick force Neutra! point Manoeuvre point

FIGURE 081-E52 Static margin

/::.L

.'

,

L

y

Lt Lt

,,

,

, ,,

,~

Aft CG limit Neutral point

Picture Supplements - Explanations

FIGURE 081-E53

FIGURE 081-E54

~I --7

Flapper switch (activated by movement of stagnation point)

=

-p;:J -------=---

No Slat

With Slat

Stagnation point (has moved downwards and backwards around leading edge)

FIGURE 081-E55

n

~

Hinge

,

"

,

"

~,

'"

~" vv. "

Flap extended

w

Flap extended '\

""

Split flap

',

'\

"

Fowler flap

Slotted flap

Slat - In or Up

Slat - Out or Down

Leading edge slat

FIGURE 081-E56 Slat \

CLmax wing (given adverse pressure grandient)

Krueger flap

Slat open - boundary layer re - energised (same adverse pressure grandient)

Aviationexam Test Prep Edition 2012

FIGURE 081-E57

FIGURE 081-E58

~o~ V=====-

FIGURE 081-E59 Rigid wing

Elastic wing

~C:::::::==========~

Aileron effectiveness

1.01-------_~

CL elastic

CL rigid

---Or---------------------------------~--------~~

Equivalent airspeed

FIGURE 081-E60

--

--

FIGURE 081-E62

FIGURE 081-E61 Large upward movement

r

Small downward movement

Hinge ,. .; line

Picture Supplements - Explanations

FIGURE 081-E63 Effect of Trim Tab Setting

Pull

EAS

o~-------------.--------~-------.~--------~~ CG@20%MAC Push

'""''=>.... C___ J

'""'z:::::::::>r ...._ _ _J

FIGURE 081-E64 Horn free to Pivot on hinge axis / Pilot input ......... [:2===-~::;::::;

~g c:_-----_-_-_--=---=--=--=--===C ~

+

FIGURE 081-E65 Tab force

Pilot input .....·C=~

Control force

FIGURE 081-E66 Pilotinput .....c:::2==~A

c:::_---'--'--?lf~~Tab 0~

force

Control force

FIGURE 081-E67 Pilot input ......... '------,.-1

Control "horn" free to pivot on hinge axis

c:=-____________~\~----V FIGURE 081-E68 Effect of Bobweight

Bobweight

~!11

8. ?/<

Aviationexam Test Prep Edition 2012

FIGURE 081-E69

c __~~ c

~

FIGURE 081-E70 Screw jack

NC structure

FIGURE 081-E71 Yawing moment coefficient, Cn

.....

.....

r

..... ..... ..... ..... .....

Neutral Sideslip angle, P.,

--------------............ - - - - - - -

\

~

-P.,

.....

+P.,

Unstab:

-cn

FIGURE 081-E72

v

'! . .

I

It

~

Picture Supplements - Explanations

FIGURE 081-E73 M 1.5

... --- ... "","............ ... ... , ..... .::',-....... ..., \

4i~II'?'

0IIII{ ~"

,

I(

.....'....

...

,

M 1.0

I

I

,

I

....... .,::-.... ... ' , " '""'----

I

MO.5

...,.~

---_ ...

FIGURE 081-E74 Supersonic Wave Characteristics Type of wave

OBLIQUE Shock wave

NORMAL Shock wave

EXPANSION wave

,

-

~

-

= a>

-'

"i a>

(j)o 0

'(3

Basic wing section

IE: a>

0 0

~ C 0

na> (j)

a ..... ., .... , , ,, , ,

2.0 -10

-5

0

5

10

15

Section angle of attack a 0 degrees

20

/

Wing plus slats

I

CL

/Wing

1.5

1.0

.5

5

10

15

20

25

Angle of attack

30

Aviationexam Test Prep Edition 2012

FIGURE OSl-El05

FIGURE OSl-El06 WHOLE AIRCRAFT L1FT:DRAG RATIO POLAR DIAGRAM

Total drag

D I I

1 1

D

Best angle of climb speed Vx (Prop) - -

CLMAX

'D P 1 1

Stalling speed

VMP

\

Best prop endurance speed Best glide endurance speed V MDR

\ \ \ \ \ \ \

,,

,. ;

;;

.

; ;"'

, ,,

,

....... Best rate of climb speed V y (Prop)

.... ....

....

VMD Best Best Best Best Best

v

prop range speed glide range speed VMGA L:D ratio endurance (Jet) angle of climb speed Vx (Jet)

A Best rate of climb speed Vy (Jet) Best range (Jet)

. . . .1----- Increasing airspeed FIGURE OSl-El07 CG position % MAC Low altitude \

,/

,/ ,/ ,/ ,/

,/

,/

,/

,/ '---- High altitude

,/

Y' Load factor

Load factor

FIGURE OSl-El0S

Flaps up

Flaps up

Landing

Takeoff

Angle of attack

Angle of attack

Picture Supplements - Explanations

FIGURE 081-El09 velocity

~

component parallel to leading edge

Free stream velocity

/ Sweep angle

Velocity component perpendicular to leading edge

II I

I

/ V

V

~ ~A ~

~

1

./

I/'

:::;;;;;0

....-

-'1

~

........

:0-

I

12

1

U---

I,) ~

I

14

116

I

1

I 18

2~0

I

I

/

V VI

~

I

I 1~

V

V

V

22 I

!M i

wing shapes drag

FIGURE 081-Ell0 60 Percent reduction in induced drag coefficient

50 40

CL constant

30 20 10 +--t--t---If---t--""-k--+-

0~~~-+--~+-~~-4~~*=~----

o

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 Ratio of wing height to span (h/b)

Aviationexam Test Prep Edition 2012

FIGURE 081-E111

1.4 Wing

CL

1.2 1.0 0.8 0.6 0.4 0.2

\

Basic section AR infin'te 1

\(

-

I

I

A~; 18

I

I

AR=~

I AR=5

A, =112

\

:..---

/: / V // / 1/ / / fl/ //

~

/

~

y--

---

~

~

~

V

(Low Mach number)

til

"

0 0.05

0.10

0.15

0.20

0.25

Wing drag coefficient CD

FIGURE 081-E112 1.4--

1.4

1.2

1.2

1.0 1···············;·······,,.·····;···/'····,·············+···········\-,··············+··········_··,·····--···1 0.8

CL 1.0-1 ..............,. . ............,. . . .--.'0......,..········_·+············,·············1

o.8--1···············,·············/:..···_·,·········_..;.·····_···..;.·······__ ··+·····_······1

=

0.6···· 0.4 ...

0·~··7 ~Dpm;n o

0.2 O~~~--~~~--~~~

0.05

0.10

0.15

o

0.05

0.10

0.15

Picture Supplements - Explanations

FIGURE 081-E113 1.4

I

I

1

I

1

I:

Ordinary angle of flight

I I

1,2

V

/

0,8 'E 0) "(3

Ii: 0) 0

¢:!

,I '

J

1,0

(.l

~

/

/

0,6

\\

I

V

I I

1\

I I I

\

I

L

0)1 0>1

C I (\).l.

c'l

/

:.:J

;

=1 ]§I (j)

/

0.4

V

/

0,2

II

/ 40

80

20°

Angle of attack

FIGURE 081-E114 28 1.1 1 I Ordinary

24

I I

L~l\.

I I I

"'\

I I

0)1

L

~

c'

"".""~

(\)

'E' 0)

gJ (\)1 0> I "~ I .$II (j)1

~

I

: I

i'\

"(3

Ii: 0)

8

l

I I

II

I

I

I I

I

20

I

angles of flight

1ii

\ 1\

0 ~

~ ~

4

\

40 80 Angle of attack

1

20°

Aviationexam Test Prep Edition 2012

FIGURE 081-El15 45

~

,""-

1'1

I

1\ ~

1.0 G level flight and no turbulence ,

40

U

1\

\. ~

t5

~

!"

,

35 I"\:

"" I

30

I FL290

I

~,

II

I

~W

\.

\

§ o o

I

25

r-

"T

I

.\

~

20

"T

\.1

I

c

-

~I ~

~

15

10 150

r

I'

200

250 215

300

Indicated airspeed - kt

350 337

11 1I

II

400

I" 45o

Picture Supplements - Explanations

I; [tlll il ,.1:1 e§'@ BUFFET ONSET j

j

I

I-

I

FLIGHT LEVEL l/ !

,

II , I III I

clean configuration I

I

/1

I

I

I

I

I

I

I

I

v

I I

I

VMoLiMIT 1\.1

VI

I

v

II

I

II

I

j/

, V II

V

1/

60

I I

V- 1r~

t71~d / 130

j/

1\

!--'

\

1/

1/

/

80

, ,

NOTE: FOR MACH NUMBERS ABOVE OR EQUAL TO I .82 THERE IS NO C.G. VARIATION EFFECT FROM REFERENCE VALUE

I

I

/

, , , ,

,

'

REF

/ 20

/ j/

V

I

II

100

V-

I

1\

II

I 110

1/

/

120

$ffi

I

1/

1/

V

/

\

/

I

II 1/

1M

1\

140 160

II I

I I

/

90

1/

180

/

V

-

/

f-

200 220

-

f-

II

260

/

l/

....

v

V

v

/ /

f-

270

I

WEIGHT(t)

II ,

I

liE J

j/

v

30

410 .50

,

I

/11'

350 370 390

80

VI/

310 330

.

V /

I

\

/

290

I

L III

1/

240

100

/

.55

DATA:

.60

.65 .70 MACH NUMBER

M =.80 FL = 350 WEIGHT = 11 Otons CG = 30%

.75

.80

.8515 20 25 30 3540 CG%

1

I BANK ANGLE (0) 45 50 ~5,--t 60 6,5tfj-

RESULTS: BUFFET ONSET AT: M = 0.80 WITH 54° BANK ANGLE, OR AT 1.7 g LOW SPEED (1g): M = 0.555 HIGH SPEED: ABOVE MO.84 (MMo) 1.3G ALTITUDE = FL 405

m

1.2 1.4 1.6 1.8 2 2.2 2.4 LOAD FACTOR

Picture Supplements - Explanations

FIGURE 08l-E119 ,

I I

,

I

I

I I I

I I I I

I I

,

100

I

,

,,

120

I

I I'

I

I

I

, I" 1

I I I I I

I I I I I I 1

I I 1

180

I 1

1

200 1 I ' I 220 1 ' I I 240 ' ,I I II I 250 i : I 270 I ,I I 290 I I I 310 I' 'I I I 330 I 'I , , 350 I ! 370 380

, I

'

1

,

I I

.50

,I

1

I

,

,I I I 1 , I I ' I I I I I 1 I

I I I

I I , 1 1 I I I

,,

, I

I I

,

, I I I

.55

I I I

1

, ,

I I, I I I, I I 1 I I I I I , I I I II I I I I, I I I , I I

.

I .

.60

65

,

I I II I I I I ,

!

III

I I I

1

I I I I I I 1 I I

I I

I I I I I I I 1 I I

-H+ +H+

, I

I I I II I I I III I I I

I I I

.70

I I I

I I I I I I I I I I I I I I I I

.75

, ,

I

I

,

I I

I

,

:

,

I

,

I I I

I 1 1 1

I I

I I I

,

I

1

I 1

I

I

Fun

i

*,

I I

i

1

l-

I 1 III I I I ' I I I I I I 1 I I I I I I I I

.80 84

I

~ I I I

I I I

I I

I

1 1 I

I I I

I

,

1

I I

I

I I 1

I I

I I

I

I I 1

,

I I I 1 1 I I I I

I I

I

• I

,,

·, I

I 1 . ' 1 • I . ' 1

I I

,

I

1

I

I ,

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LOAD FACTOR

CG%

MACH NUMBER

FIGURE 08l-E120

120 ,

100:

140 '

90

160 ' 80

180 200 220 : 240 260 280 , 300 : 320 340 360 , , 380 : .50 .55

Weight (t)

, ,., 3045 50 ' 55 ~ 61i:R:i:i65

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INDICATED MACH NUMBER

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LOAD FACTOR

Buffet Onset Boundary Chart - Clean Configuration

Aviationexam Test Prep Edition 2012

FIGURE 081-E121 Low and High Speed Buffer Onset Boundary Aircraft weights in Ibs x 1000 45 r7\----,,~---..-----._----_,------._----_,

\

Level Flight 1g No Turbulence

\

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25

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450

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FIGURE 081-E122

Increased total drag

Drag

, ,,

,

, ,,

,

Increased parasite drag (e,g flaps , undercarraige or speed-brakes)

Decreased V mdbecause of increased parasite drag

lAS

Picture Supplements - Explanations

FIGURE 081-E123

/

, , , /

/ /

Drag

/ /

Decreased total drag at lower weight

...

"

,-

,,

,

,-

-,-","" ~ '" '"

"

Parasite drag

~---- ---

Decreased V md because of lower weight

lAS

FIGURE 081-E124

.;::

::i

o

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'13 tEO Q)

Center of Pressure (CP)

flaps extended

o

U

Coefficient of Drag CD

Aviationexam Test Prep Edition 2012

liI@ll;J:(.1:5e§Eli 1 st Mode or Phugoid Angle of attack at each instant along the flight patch is essentially

~

constant

c:P

~

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Q)

Time "~£ --~----~~----~--------~~------------~~--------~------~~ C::"C

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Motion occurs at essentially constant speed

Time to damp to half amplitude Time

/'

/'

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III:"f'!'r.'II IIIiIIaiIIiiI

Picture Supplements - Explanations

FIGURE 081-E126 STATIC STABILITY Static stability is defined as the capability of a body to return to its original condition after a diturbance (tendency of an aircraftto return to its original condition of flight after a disturbance).

t

POSITIVE STATIC STABILITY

--NEUTRAL STATIC STABILITY

t

--- -------J NEGATIVE STATIC STABILITY

t

----__

--I

DYNAMIC STABILITY The dynamic stability of an aircraft is how the motion of an aircraft behaves after it has been disturbed from steady non-oscillating flight.

POSITIVE DYNAMIC STABILITY

~- -~E~T~DYNAMlcs~~~rY .

~

O;sturbance

-_~

Equal period - constant amplitude

NEGATIVE DYNAMIC STABILITY

/ /

,,

/

,, Disturbance

/

,

/

Equal period - increasing amplitude

Aviationexam Test Prep Edition 2012

FIGURE 081-E127 COORDINATED FLIGHT

Coordinated right turn

Skidding right turn

Slipping right turn

SLIPPING TURN If not properly manoeuvred, the aircraft is said to be slipping into the turn, because when the force is not correctly balanced, the aircraft sideslips into the turn. The ball in the slip indicator moves to the inner side of the turn and you feel the effect as if you wanted to slip to the lower side of the aircraft. This condition is caused by insufficient rudder application for the amount of bank. To correctly balance the forces you must increase rudder input in the same direction as the turn in order to counteract the adverse yaw. Then the aircraft's longitudinal axis becomes tangential to the turn. The ball in the slip indicator moves to the centre and you feel comfortable in the seat. The aircraft is said to be in a balanced turn. To correct the slipping turn as shown in the picture above, you must add more right rudder or decrease the right bank.

SKIDDING TURN If the aircraft is not properly manoeuvred and the aircraft tail tends to skid out of the turn, the aircraft is said to be skidding into the turn. The ball in the slip indicator moves to the outside of the turn and you are pushed towards the outside. It is caused by too much rudder in the direction of the turn or not enough bank for the amount of rudder used. To correct, you must change rudder input in the direction opposite to the turn, so that the ball in the turn indicator moves to the centre and you feel comfortable in the seat. Again, the aircraft is said to be in a balanced turn. To correct a skidding turn as shown in the picture above, you must use less right rudder or bank more to the right.

Picture Supplements - Explanations

FIGURE 081-E128 AIRSPEEDS Airspeed is the speed of an aircraft relative to the air. There are several different measures of airspeed: indicated airspeed, calibrated airspeed, equivalent airspeed and true airspeed. It is measured within the flying aircraft with an airspeed indicator - it connects to ram air pressure from outside the aircraft and compares it to non-moving air pressure outside the aircraft. The ram pressure is sampled by a pitot tube, carefully located clear of the propeller blast and other airflow distortions. There is also typically one or more static ports carefully located on the outside of the aircraft. Indicated airspeed (lAS) ... is the airspeed indicator reading (ASIR) uncorrected for instrument, position, and other errors. From current EASA definitions: Indicated airspeed means the speed of an aircraft as shown on its pitot static airspeed indicator calibrated to reflect standard atmosphere adiabatic compressible flow at sea level uncorrected for airspeed system errors. Most airspeed indicators show the speed in knots i.e. nautical miles per hour.

An airspeed indicator is a differential pressure gauge with the pressure reading expressed in units of speed, rather than pressure. The airspeed is derived from the difference between the ram air pressure from the pitot tube, or stagnation pressure, and the static pressure. The pitot tube is mounted facing forward; the static pressure is frequently detected at static ports on one or both sides of the aircraft. Sometimes both pressure sources are combined in a single probe, a pitot-static tube. The static pressure measurement is subject to error due to inability to place the static ports at positions where the pressure is true static pressure at all airspeeds and attitudes. The correction for this error is the position error correction (PEC) and varies for different aircraft and airspeeds. Further errors of 10% or more are common if the airplane in flown in "uncoordinated" flight. Calibrated airspeed (CAS) ... is the speed shown by a conventional airspeed indicator after correction for instrument error and position error. Most EFIS displays also show CAS. At high speeds and altitudes, calibrated airspeed is further corrected for compressibility errors and becomes equivalent airspeed (EAS). CAS has two primary applications in aviation: - for navigation, CAS is traditionally calculated as one of the steps between indicated airspeed and true airspeed; - for aircraft control, CAS (and EAS) are the primary reference points, since they describe the dynamic pressure acting on aircraft surfaces regardless of density altitude, wind, and other conditions. EAS is used as a reference by aircraft designers, but EAS cannot be displayed correctly at varying altitudes by a simple (single capsule) airspeed indicator. CAS is therefore a standard for calibrating the airspeed indicator such that CAS equals EAS at sea level pressure and approximates EAS at higher altitudes. Equivalent airspeed (EAS) ... is defined as the speed at sea level that would produce the same incompressible dynamic pressure as the true airspeed at the altitude at which the vehicle is flying. An aircraft in forward flight is subject to the effects of compressibility. Likewise, the calibrated airspeed is a function of the compressible impact pressure. EAS, on the other hand, is a measure of airspeed that is a function of incompressible dynamic pressure. Structural analysis is often in terms of incompressible dynamic pressure, so that equivalent airspeed is a useful speed for structural testing. At sea level, standard day, calibrated airspeed and equivalent airspeed are equal (or equivalent), but only at that condition. For the performance engineer, there is no practical reason to use equivalent airspeed for anything. However, structural analysis is often performed in terms of equivalent airspeed (since it is a direct function of the incompressible dynamic pressure).

EAS may be obtained from CAS by correcting for compressibility error. EAS = TAS x "(Actual Air Density'" Standard Air Density). The difference between calibrated airspeed and equivalent airspeed is negligible at low Mach numbers rising to 3% at Mach 0.5 and 13% at Mach 1 depending on altitude. True airspeed (TAS) ... of an aircraft is the speed ofthe aircraft relative to the air mass in which it is flying. True airspeed is important information for accurate navigation of an aircraft.

Indicated airspeed will differ from true airspeed whenever the aircraft is flying in air whose density differs from the density at sea level and 15° Celsius. Air density is affected by temperature, moisture content, and altitude. Indicated airspeed is used in aircraft operation as the aircraft stalling speed and structural limiting speeds are dependent on indicated airspeed, irrespective of true airspeed. However, proper navigation via dead reckoning (without constant ground reference) requires the use of true airspeed and wind corrections. For a low-speed flight True airspeed (TAS) can be calculated as a function of indicated airspeed (or equivalent airspeed) and air density: TAS = lAS x "(Standard Air Density'" Actual Air Density)

Aviationexam Test Prep Edition 2012

FIGURE 081-E129 WING DESIGN PARAMETERS SPAN Selecting the wing span is one of the most basic decisions to made in the design of a wing. The span is sometimes constrained by contest rules, hangar size, or ground facilities, but when it is not, we might decide to use the largest span consistent with structural dynamic constraints (flutter). This would reduce the induced drag directly. However, as the span is increased, the wing structural weight also increases and at some point the weight increase offsets the induced drag savings. This point is rarely reached, though, for several reasons.

Ctip •

t~______________~s~p~a~n~,b~____________~

S

=wing area 2

AR 1 1\

b b =aspect ratio. =-=-S C Ctip =taper ratio =-croat •

A = swept of cf4 line

e =wing twist angle

1. The optimum is quite flat and one must stretch the span a great deal to reach the actual optimum. 2. Concerns about wing bending as it affects stability and flutter mount as span is increased. 3. The cost of the wing itself increases as the structural weight increases. This must be included so that we do not spend 10% more on the wing in order to save .001% in fuel consumption. 4. The volume of the wing in which fuel can be stored is reduced. 5. It is more difficult to locate the main landing gear at the root of the wing. On the other hand, span sometimes has a much greater benefit than one might predict based on an analysis of cruise drag. When an aircraft is constrained by a second segment climb requirement, extra span may help a great deal as the induced drag can be 70-80% of the total drag. The selection of optimum wing span thus requires an analysis of much more than just cruise drag and structural weight. Once a reasonable choice has been made on the basis of all of these considerations, however, the sensitivities to changes in span can be assessed. AREA The wing area, like the. span, is chosen based on a wide variety of considerations including:

1. 2. 3. 4.

Cruise drag Stalling speed f field length requirements Wing structural weight Fuel volume

These considerations often lead to a wing with the smallest area allowed by the constraints. But this is not always true; sometimes the wing area must be increased to obtain a reasonable C L at the selected cruise conditions. Selecting cruise conditions is also an integral part of the wing design process. It should not be dictated a priori because the wing design parameters will be strongly affected by the selection, and an appropriate selection cannot be made without knowing some of these parameters. But the wing designer does not have complete freedom to choose these, either. Cruise altitude affects the fuselage structural design and the engine performance as well as the aircraft aerodynamics. The best CL for the wing is not the best for the aircraft as a whole. An example of this is seen by considering a fixed CL, fixed Mach design. If we fly higher, the wing area must be increased by the wing drag is nearly constant. The fuselage drag decreases, though; so we can minimize drag by flying very high with very large wings. This is not feasible because of considerations such as engine performance. SWEEP Wing sweep is chosen almost exclusively for its desirable effect on transonic wave drag. (Sometimes for other reasons such as a c.g. problem or to move winglets back for greater directional stability.)

1. It permits higher cruise Mach number, or greater thickness or C L at a given Mach number without drag divergence. 2. It increases the additional loading at the tip and causes spanwise boundary layer flow, exacerbating the problem of tip stall and either reducing CLmax or increasing the required taper ratio for good stall. 3. It increases the structural weight - both because of the increased tip loading, and because of the increased structural span. 4. It stabilizes the wing aeroelastically but is destabilizing to the airplane. 5. Too much sweep makes it difficult to accommodate the main gear in the wing. Much of the effect of sweep varies as the cosine of the sweep angle, making forward and aft-swept wings similar. There are important differences, though in other characteristics.

Picture Supplements - Explanations

FIGURE 081-E130 WING DESIGN PARAMETERS ... continued

THICKNESS The distribution of thickness from wing root to tip is selected as follows: 1. We would like to make the tic as large as possible to reduce wing weight (thereby permitting larger span, for example). 2. Greater tic tends to increase CLmax up to a point, depending on the high lift system, but gains above about 12% are small if there at all. 3. Greater tic increases fuel volume and wing stiffness. 4. Increasing tic increases drag slightly by increasing the velocities and the adversity of the pressure gradients. 5. The main trouble with thick airfoils at high speeds is the transonic drag rise which limits the speed and CL at which the airplane may fly efficiently.

TAPER The wing taper ratio (or in general, the planform shape) is determined from the following considerations: 1. The planform shape should not give rise to an additional lift distribution that is so far from elliptical that the required twist for low cruise drag results in large off-design penalties. 2. The chord distribution should be such that with the cruise lift distribution, the distribution of lift coefficient is compatible with the section performance. Avoid high CL which may lead to buffet or drag rise or separation. 3. The chord distribution should produce an additional load distribution which is compatible with the high lift system and desired stalling characteristics. 4. Lower taper ratios lead to lower wing weight. 5. Lower taper ratios result in increased fuel volume. 6. The tip chord should not be too small as Reynolds number effects cause reduced CL capability. 7. Larger root chords more easily accommodate landing gear. Here, again, a diverse set of considerations are important. The major design goal is to keep the taper ratio as small as possible (to keep the wing weight down) without excessive C L variation or unacceptable stalling characteristics. Since the lift distribution is nearly elliptical, the chord distribution should be nearly elliptical for uniform CL . Reduced lift or tic outboard would permit lower taper ratios. Evaluating the stalling characteristics is not so easy. In the low speed configuration we must know something about the high lift system: the flap type, span, and deflections. However, the flaps-retracted stalling characteristics are also important.

TWIST The wing twist distribution is perhaps the least controversial design parameter to be selected. The twist must be chosen so that the cruise drag is not excessive. Extra washout helps the stalling characteristics and improves the induced drag at higher CL for wings with additional load distributions too highly weighted at the tips. Twist also changes the structural weight by modifying the moment distribution over the wing. Twist on swept-back wings also produces a positive pitching moment which has a small effect on trimmed drag. The selection of wing twist is therefore accomplished by examining the trades between cruise drag, drag in second segment climb, and the wing structural weight. The selected washout is then just a bit higher to improve stall.

FIGURE 081-E131

----.to

p' caIN,

engine

(Critical engine)

Aviationexam Test Prep Edition 2012

FIGURE 082-EOl

FIGURE 082-E02

4 ""11 - - -

Downwash ---+t

) J -

-- -

~,," ,,"~

- -#---=-..-...- -

- ....

~ ............

-- --

'-----

..-/

... The relative airflow meets the forward and rearwards blades at different angles.

Pressure build-up ?pposing induced flow

FIGURE 082-E03

Flare changes the flow relative to the disc.

FIGURE 082-E04

Normal - Blades are balanced. - The resultant center of pressure is situated at the rotor hub.

Ground resonance - Blades are out of phase. - The resultant center of pressure is offset from the rotormast - When ground contact is made, destructive vibrations occur.

FIGURE 082-E06

Pitch Control Rod Control

FIGURE 082-E05 Equilibrium Rotor Thrust I --. I I I _-

)I

Stabilizer

Weight

Flapping Hinge Axis

Direction of Rotation

Picture Su pplements - Explanations

I; Mll;1 :CII:,}! gIlA ..

Blade Span

~_==== 1 ..:::....:..:.:..:.:.:.:.:.:.:.:::..::. .::. .:.:.:..:.==..:. .: :.-.:.:-.:._ed~Tu~ic~pe~(~ ac~p: ~:)r-d-a-t~tl ~ Root Cho,d

/ Blade Root

•

R __

.................................... ..........:

Blade Tip

URE082-E Normal Axis (Yaw) I

Total reaction

Longitudinal Axis (Roll)

Axis ofI 'rotat'Ion I

I I

I

Lateral Axis (Pitch) _

Total rotor thrust

I

A

Rotor drag

Axis of 'rotation \

\

Total reaction

B ?\3"e 0\

{0'l.3~'!.."- -

--

~--Relative airfloW

URE082-

IDisc Levell

Plane of

Rotationa·I·Ahf f .. ·· · ... .. Rate of ow " ... Descent Flow

~_-:..::.:::.:..:.:~_135~.t.9tion ------

L-----~~~~--~

RE 082-

Plane of

~~~~~~~::::;::::::===~~~_~t~_t~~~ __ Rate of Descent Flow

'" ".

Profile Drag

URE082-

r----

Increased Ind uced Flow Induced Flow

-- - --- -

.. ...

---------Rotat;onal~~~~?3>.

_

Relative A"rf/ - - - - - - - -I ow

a . . .. ..

Aviationexam Test Prep Edition 2012

FIGURE 082-E13 Propeller

Autorotative

Stall I I I

Rotor RPM Increasing

Rotor RPM Decreasing ar--------------------,-------~

Induced Rotor RPM Really LOW

~

Flow

_____ .---R.esult. Airflow

____________~______~F= FIGURE 082-E14 Axis of Rotation

I

Rotor Thrust Induced Airflow Plane of Rotation

Rotational Airflow

Rotor Drag

FIGURE 082-E16

FIGURE 082-E15 ... ... . Angle of attack

Angle of attack .... . close to blade root

......~

al blade lip____

FIGURE 082-E17

;

[

Induced Flow

Vr close to blade root

Vr at blade tip

Rotational Ai ow

FIGURE 082-E18 Axis of rotation

... /

...

I

Pitch angle ,/ Plane of rotation

Rotational flow

. . -----------.

:-------+-------...:...."""T"-----~~

Rate of descent flow

a = Angle of attack

.

Pro-Autorotatlve

Picture Supplements - Explanations

FIGURE 082-E19 I

Rotor Thrust

I l ....................•

f

2

I I

Vi

2

Ii I I

I

~

; '

Total Reaction

~~~~---------I Rotor Drag

---------.----------Vr

I

----::. ______ ~_lI _________ _ Pitch Operating Arm -

---------t---------I

=====~====

Swash Plate

1I

I

FIGURE 082-E20

FIGURE 082-E21

Recirculation Air Flow

Flow Induced

l

..

l __=::~~~======~~~~ Rotational Airflow

l

Induced Flow Velocity During Hovering Flight

FIGURE 082-E22

Axis of Rotation

Induced Airflow

-1- 1 - + - - - - - - - - - - - - - - - 1 - - - - - - Plane of

Rotational Airflow

Rotation

FIGURE 082-E23

Axis of advancing blade at 90°

cyclic movement

Lateral cyclic movement

Aviationexam Test Prep Edition 2012

FIGURE 082-E25

FIGURE 082-E24 Centrifugal Turning Moment Centrifugal force keeps some blades stiff as they rotate as the Centre Of Gyration is removed from the Centre of Rotation, it produces a pulling force that emanates from all points, rather than just along the length of the blade: A

This elbow moves away from the mast as the rotor is tilted

Because of the angles involved, the resultant of centrifugal force at the trailing edge of a blade (B) is longer than the one on the leading edge (A). Because one is lower than the other in flight (they are not in the same plane), a couple is created that will tend to feather the blade (decrease the pitch angle) and move the controls for you.

This elbow moves toward the mast as the rotor is tilted

Because of the underslung rotor, the center of mass remains approximately the same distance from the mast after the rotor is tilted.

FIGURE 082-E26 -{light Path

Relative Wind.

210 ... 190 Q)

~

Q.

170

Q)

~ 150

I

130

""

110

o

20

""

"

40 60 80 100 True airspeed (kt)

FIGURE 082-E27 CHANGE IN PRESSURE

\\

Velocity Increases

11

Pressure = Ambient

\

Pressure Less Than Ambient \======3:;-)======":::) Energy Added By Rotor Pressure Greater Than Ambient

\1++1 j ,o

n

Maximum Velocity Pressure = Ambient

Ambient Pressure

Picture Supplements - Explanations

FIGURE 082-E28 Total Rate of Descent

Endurance Speed

Rate of Descent Required

.... ;....

Range Speed

True Air Speed

FIGURE 082-E29 Total Power Required

Parasite Power Power Rotor Profile Power

Induced Power TAS

FIGURE 082-E30 Power Required

Power Available

•

: Maximum I Rate of : Climb I Speed I I I I

Power

...........

.... ....

....

..-

......... ........

.... ....

.... ....

.... ....

........

I I

~------~~--~\--------f~ThS Endurance speed (Piston)

Range speed (Piston)

Maximum speed

Aviationexam Test Prep Edition 2012

FIGURE 082-E31

Z'

Parasite drag rate of descent

..... C C