Part 66 Aerodynamics

Module 8

 Aerodynamics Exam Number:-1. 1.

If the wing tips stall before the root root on a swept wing aircraft, the aircraft will a) roll b) pitch nose up c)

pitch nose down

2) ngle of attac! .

a) increases with an increased angle of incidence "angle of attac!) b) decreases with an increase in angle of incidence "angle of attac!) c)

#.

does not change with a change in angle of incidence "angle of attac!)

$n a straight wing aircraft, stall commences at the

a) root on a high thic!ness ratio wing b) tip on a high thic!ness ratio wing c)

tip on a low thic!ness ratio wing

%.

$n a high wing aircraft in a turn a) the up-going wing loses lift causing a de-stabilising e&ect b) the down-going wing gains lift causing a stabilising e&ect c)

'.

the down-going wing loses lift causing a de-stabilising de-stabilis ing e&ect

(or the same angle of attac!, the lift on a delta wing a) is greater than the lift on a high aspect ratio wing b) is lower than the lift on a high aspect ratio wing

c)

.

is the same as the lift on a high aspect ratio wing

*he I+ a) is ta!en from the euator b) is ta!en from %' degrees latitude c)

/.

assumes a standard da

s altitude increases, pressure a) decreases decreases at constant constant rate b) increases exponentiall c)

decreases exponentiall

0. *he thrust-drag couple oercomes the lift-weight couple. hat direction of force is reuired to be produced b the tail of the aircraft to maintain straight and leel 3ight a) upwards b) downwards c)

4.

sidewas

hen the pressure pressure is half of that at sea leel, what is the altitude a) 12,555 ft b) 0,555 ft c)

15.

10,555 ft

6uring a turn, the stalling angle a) increases b) decreases c)

remains the same

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ans819 7 b; ans829 7 a; ans8#9 7 a; ans8%9 7 b; ans8'9 7 b; ans89 7 b; ans8/9 7 c; ans809 7 a; ans849 7 c; ans8159 7 c;

explain8197rst read. ll wing tpes "straight, swept, delta etc.) increase lift with an increase in angle of attac! "up to the stall angle).; explain8#97*hic!ness explain8#97*hic! ness ratio is a red herring. ?ut ou must learn the stall points for di&erent tpes of wing platforms - the di&er greatl.; explain8%97*he down-going wing has an increased lift due to an increas in angle of attac! "due to the up 3ow of air). *his opposes the roll which is a stabili@ing e&ect.; explain8'97 long slender wing "i.e. high spect Aatio) has a higher lift than a short stubb wing "low spect Aatio).  delta wing is about as low spect Aatio as ou can get "about 1:1 for concord for example).; explain897*he properties of a standard da are related to sea leel at latitude %' degrees with absolutel dr air.; explain8/97le and total drag. s aircraft weight increases, it must produce more lift to support it. Hore lift 7 more induced drag. Now s!etch the induced drag cure higher, and see where the intersection with pro>le drag moes to.; explain8497*his ma surprise ou.  glider conerts potential energ "ie height) into !inetic energ "ie speed) and thus lift. Hore weight 7 more speed 7 more lift. *he glide angles of a hea glider is exactl the same as a light glider. "?ut the increased speed means it coers the distance faster).; explain81597*he high pressure under the wing 3ows around the tip to the low pressure on top of the wing. *he resulting ortex is what causes induced drag. +ince air is iscous it drags the

air underneath the wing towards the tip, and pushes the air on top of the wing towards the root.;

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Exam Number:-#. --------------------------------------------------------------------------------

1.

t stall, the wingtip stagnation point a) moes toward the lower surface of the wing b) moes toward the upper surface of the wing c)

2.

doesnt moe

Jow does I+ at the point of stall ar with height a) It is practicall constant b) It increases c)

#.

It decreases

*he rigging angle of incidence of an eleator is a) the angle between the mean chord line and the hori@ontal in the rigging position

b) the angle between the bottom surface of the eleator and the hori@ontal in the rigging position c)

%.

the angle between the bottom surface of the eleator and the longitudinal datum

hat is the lapse rate with regard to temperature a) 1.40oC per 1555 ft b) 1.40o( per 1555 ft c)

'.

%oC per 1555 ft

hat happens to load factor as ou decrease turn radius a) It increases b) It decreases c)

It remains constant

. If ou steepen the angle of a ban!ed turn without increasing airspeed or angle of attac!, what will the aircraft do a) It will remain at the same height b) It will sideslip with attendant loss of height c)

/.

It will stall

n aircraft wing tends to stall >rst at a) the tip due to a higher ratio thic!nessKchord b) the tip due to a lower ratio thic!nessKchord c)

0.

the root due to a higher ratio thic!nessKchord

6ihedral wings combat instabilit in a) pitch b) aw c)

4.

sideslip

*o stop aircraft decreasing in height during a sideslip, the pilot can a) adance the throttle b) pull bac! on the control column c)

adFust the rudder position

15. hat control surface moements will ma!e an aircraft >tted with rudderators aw to the left a) =eft rudderator lowered, right rudderator raised b) Aight rudderator lowered, left rudderator raised c)

?oth rudderators raised

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ans819 7 a; ans829 7 a; ans8#9 7 a; ans8%9 7 a; ans8'9 7 b; ans89 7 b; ans8/9 7 c; ans809 7 c; ans849 7 a; ans8159 7 a;

explain8197t stall the angle of attac! is high "all along the wing) is positioned towards the lower surface of the wing..; explain8297*he true airspeed at which an aircraft stalls increases with height due to a drop in densit. Joweer the Indicated irspeed decreases with height due to the same drop in densit. *herefore there is practicall no change in stall speed with height..; explain8#97*he angle of incidence of an surface is measured from the mean chord line.; explain8%97*he lapse rate is approximatel 2 degrees Centigrate per 1555 feet.; explain8'97+ince the load factor increases in a turn, if ou decrease the turn rate the load factor decreases.; explain897Increasing the angle of a ban!ed turn without increasing the airspeed or angle of attac!, the aircraft will sideslip and lose height.; explain8/97*he boundar laer separates at a lower angle of attac! with a higher thic!nessKchord atio. *herefore it will stall >rst at the root..; explain8097s the aircraft sideslips, there is a greater angle of attac! on the lower wing which increases lift, straightens the aircraft and stops the sideslip.; explain84976uring a turn, extra speed is reuired to stop the aircraft sideslipping and decreasing in height.; explain81597*o ma!e the aircraft aw to the left, the left rudderator is lowered, the right rudderator is raised.;

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Exam Number:-%. --------------------------------------------------------------------------------

1.

hen a leading edge slat opens, there is a gap between the slat and the wing. *his is a) to allow it to retract bac! into the wing b) to allow air through to re-energi@e the boundar laer on top of the wing c)

2.

to !eep the area of the wing the same

hich of the following is true a) =ift acts at right angles to the wing chord line and weight acts erticall down b) =ift acts at right angles to the relatie air3ow and weight acts erticall down

c) =ift acts at right angles to the relatie air 3ow and weight acts at right angles to the aircraft centre line

#.

If the wing tips stall before the root on a swept wing aircraft, the aircraft will a) roll b) pitch nose up c)

%.

pitch nose down

=ift on a delta wing aircraft a) increases with an increased angle of incidence "angle of attac!) b) decreases with an increase in angle of incidence "angle of attac!) c)

'.

does not change with a change in angle of incidence "angle of attac!)

$n a straight wing aircraft, stall commences at the a) root on a high thic!ness ratio wing b) tip on a high thic!ness ratio wing c)

.

tip on a low thic!ness ratio wing

$n a high wing aircraft in a turn

a) the up-going wing loses lift causing a de-stabili@ing e&ect b) the down-going wing gains lift causing a stabili@ing e&ect c)

/.

the down-going wing loses lift causing a de-stabili@ing e&ect

(or the same angle of attac!, the lift on a delta wing a) is greater than the lift on a high aspect ratio wing b) is lower than the lift on a high aspect ratio wing c)

0.

is the same as the lift on a high aspect ratio wing

*he I+ a) is ta!en from the euator b) is ta!en from %' degrees latitude c)

4.

assumes a standard da

s altitude increases, pressure a) decreases at constant rate b) increases exponentiall c)

decreases exponentiall

15. *he thrust-drag couple oercomes the lift-weight couple. hat direction of force is reuired to be produced b the tail of the aircraft to maintain straight and leel 3ight a) Gpwards b) 6ownwards c)

+idewas

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ans819 7 b; ans829 7 b; ans8#9 7 b; ans8%9 7 a; ans8'9 7 a; ans89 7 b; ans8/9 7 b; ans809 7 b; ans849 7 c; ans8159 7 a;

explain8197*he gap between the wing and the slat is to allow air from the lower surface through to the upper surface to re-nergise it at high angles of attac!.; explain8297=ift acts at right angles to the relatie air3ow and weight acts erticall down.; explain8#97If the tips of a swept wing aircraft stall, the lift still acting at the roots, will pull the aircraft up..; explain8%97=ift "on an tpe of wing) increases with an increased angle of attac!.; explain8'97+tall commences on a straight wing at the root "on an thic!ness ratio wing).; explain897*he down going wing gains lift due to the upl3ow, which stops the aircraft ban!ing. *his is the basic mechanism of dnamic stabilit.; explain8/97(or the same angle of attac!, the lift on a delta wing is lower than the lift on a delta wing.; explain8097*he I+ is ta!en from %' degrees latitude as an aerage of the orldLs atmospheric data.; explain8497s altitude increases, pressure decreases exponentiall. +ince pressure is gien b densit x grait x height, both densit and height decreases "that is, height aboe the point ou are measuring) so the decrease in pressure is exponential; explain81597+ince the thrust-drag couple is usuall a nose-up couple "on low engined aircraft) then if the thrust-drag couple oercomes the lift weight couple, the aircraft will pitch nose-up.  *he tail of the aircraft would hae to produce an upward force to counteract this..;

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Exam Number:-'. --------------------------------------------------------------------------------

1.

hen the pressure is half of that at sea leel, what is the altitude a) 12,555 ft b) 0,555 ft c)

2.

10,555 ft

6uring a turn, the stalling angle a) increases b) decreases c)

#.

remains the same

*he ertical >n of a single engined aircraft is a) parallel with both the longitudinal axis and ertical axis b) parallel with the longitudinal axis but not the ertical axis c)

%.

parallel with the ertical axis but not the longitudinal axis

ircraft 3ing in the transonic range most often utili@e a) sweptbac! wings b) adanced supercritical airfoils c)

'.

high wings

hich tpe of 3ap changes the area of the wing a) (owler b) +plit c)

+lotted

. (orward swept wings tend to stall at the root >rst so the aircraft retains lateral control, so wh are the neer used on passenger aircraft

a) ?ecause the wing tips wash in at high wing loads b) ?ecause the wing tips wash out at high wing loads c) ?ecause at high loads their angle of incidence increases and the loads imposed on the wing can increase until the destro it

/.

hat happens to air 3owing at the speed of sound when it enters a conerging duct a) Melocit decreases, pressure and densit increase b) Melocit increases, pressure and densit decreases c)

0.

Melocit, pressure and densit increase

s the angle of attac! of an airfoil increases the centre of pressure a) moes forward b) moes aft c)

remains stationar

4. n aircraft, which is longitudinall stable, will tend to return to leel 3ight after a moement about which axis a) tted forward of the ailerons

+tall strips a) cause the wing root to stall b) cause the wing tip to stall c)

cause the wings to stall smmetricall

4. 6ue to the interference of the air3ow on a high wing aircraft between the fuselage and the wings, the lateral stabilit of the aircraft in a gust wind situation will cause a) the upper wing to increase its lift b) the upper wing to decrease its lift c)

15.

the lower wing to decrease its lift

+lats

a) reduce the stall speed b) reduce the tendenc of the aircraft to aw c)

decrease the aerofoil drag at high speeds

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ans819 7 c; ans829 7 a; ans8#9 7 a; ans8%9 7 a; ans8'9 7 c; ans89 7 b; ans8/9 7 b; ans809 7 a; ans849 7 b; ans8159 7 a;

explain8197Mortex generators on the wing are designed to re-energise the boundar laer at high angles of attac! and help preent separation of the air3ow; explain8297*he chord line is a +*AIDJ* line which goes from the leading edge of the wing to the trailing edge of the wing.; explain8#97*he angle of incidence is the angle between the chord line and the longitudinal axis.; explain8%97*he centre of pressure is positioned roughl #5 - %5 O of the chord line ?CP from the leading edge.; explain8'97Compressibilit e&ect is associated with an increase in drag during the transonic 3ight stage.; explain897t high angles of attac!, the air3ow oer the ailerons can be separated from the surface. Mortex generators, positioned Fust forward of the ailerons, are designed to re-energise the boundar laer and help to preent this separation. *his ma!es the ailerons more e&ectie at high angles of attac!.; explain8/97+tall strips are >tted at the leading edge of the wing to ensure that the root of the wing stalls before the tips.; explain8097+tall strips are >tted at the leading edge of the wing to ensure that the root of the wing stalls before the tips.; explain8497In a gust, the aircraft ma be forced to roll and sideslip awa from the gust. In such a slideslip, the fuselage shields the upper wing from some of the air3ow. *his reduces the lift on the upper wing which drops and opposes the gust.; explain81597+lats are designed to increase the lift at low speed, and hence decrease the stall speed.;

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Exam Number:-/. --------------------------------------------------------------------------------

1.

hat is the temperature lapse rate for aircraft 3ing below #,555 feet altitude

a) 1QC per 1555 feet b) #QC per 1555 feet c)

2.

2QC per 1555 feet

(or a pressure of 2'lbsKinR at sea leel, what is the absolute pressure a) #4./ lbsKinR b) %4./ lbsKinR c)

15.# lbsKin

#. n aircraft ban!s into a turn. No change is made to the airspeed or angle of attac!. hat will happen a) *he aircraft enters a side slip and begins to lose altitude b) *he aircraft turns with no loss of height c)

%.

*he aircraft aws and slows down

*he relationship between induced drag and airspeed is a) directl proportional to the suare of the speed b) inersel proportional to the suare of the speed c)

'.

directl proportional to speed

hat is the de>nition of ngle of Incidence a) *he angle the underside of the mainplane or tailplane ma!es with the hori@ontal

b) *he angle the underside of the mainplane or tailplane ma!es with the longitudinal datum line c)

*he angle the chord of the mainplane or tailplane ma!es with the hori@ontal

.

hat is ?oundar =aer a) +eparated laer of air forming a boundar at the leading edge b) *urbulent air moing from the leading edge to trailing edge

c) +luggish low energ air that stic!s to the wing surface and graduall gets faster until it  Foins the free stream 3ow of air

/.

*he normal axis of an aircraft passes through a) the centre of grait b) a point at the center of the wings c)

0.

at the centre of pressure

$n a high winged aircraft, what e&ect will the fuselage hae on the up-going wing a) *he up-going wing will hae a decrease in angle of attac! and therefore a decrease in lift b) *he down-going will hae a decrease in angle of attac! and therefore a decrease in lift

c) lift

*he up-going wing will hae an increase in angle of attac! and therefore a decrease in

4. hat is the collectie term for the >n and rudder and other surfaces aft of the centre of grait that helps directional stabilit a) E&ectie !eel surface b) Empennage c)

15.

(uselage surfaces

*emperature aboe #,555 feet will a) decrease exponentiall

b) remain constant c)

increase exponentiall

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ans819 7 c; ans829 7 a; ans8#9 7 a; ans8%9 7 b; ans8'9 7 c; ans89 7 c; ans8/9 7 a; ans809 7 a; ans849 7 a; ans8159 7 b;

explain8197*emperature lapse rate up to #,555 feet "the tropopause) is approximatel 2 degress centigrade per 1555 feet. boe the tropopause it is constant.; explain8297bsolute pressure 7 gauge pressure S atmospheric pressure. tmospheric pressure 7 1%./ psi.; explain8#97hen an aircraft ban!s and turns, some of the lift ector is used to turn the aircraft, therefore the aircraft will lose altitude.; explain8%97Induced drag decreases proportionall with the suare of the speed.; explain8'97ngle of incidence is the Lwing setting angleL. *hat is the angle of the chord of the mainplane or tailplane with the hori@ontal - or aircraft centre line when in the rigging position.; explain897*he boundar laer is the laer of air immediatel in contact with the aircraft s!in which is slowed down b the s!in friction.; explain8/97ll the axis of the aircraft "normal, longitudinal and lateral) pass through the centre of grait.; explain8097*he up-going wing of an aircraft in a turn or ban! has a down-3ow of air due to its moement. It therefore has a decrease in angle of attac! and a decrease in lift. *his is the basic mechanism of dnamic stabilit.; explain8497ll the side surfaces aft of the centre of grait which aid the directional stabilit are collectiel called the E((EC*IME PEE= +GA(CE.; explain81597*emperature lapse rate up to #,555 feet "the tropopause) is approximatel 2 degress centigrade per 1555 feet. boe the tropopause it is constant.;

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Exam Number:-0. -------------------------------------------------------------------------------1.

 decrease in incidence toward the wing tip ma be proided to

a) preent aderse aw in a turn b) preent spanwise 3ow in maneuers c)

2.

retain lateral control e&ectieness at high angles of attac!

*he angle of attac! which gies the best =K6 ratio

a) decreases with a decrease in densit b) in una&ected b densit changes c)

#.

increases with a decrease in densit

(or a gien aerofoil production lift, where

< 7 pressure and M 7 elocit:

a) le drag

a) increases b) decreases c)

#.

decreases at >rst then increase

*he stagnation point on an aerofoil is the point where

a) the suction pressure reaches a maximum b) the boundar laer changes from laminar to turbulent c)

%.

the air3ow is brought completel to rest

fter a disturbance in pitch, an aircraft continues to oscillate at constant amplitude. It is

a) longitudinall unstable b) longitudinall neutrall stable c)

'.

laterall unstable

$n an aircraft with an all-moing tailplane nose up pitch is caused b

a) increasing tailplane incidence b) decreasing tailplane incidence c)

.

up moement of the trim tab

*he stalling of an aerofoil is a&ected b the

a) airspeed b) angle of attac! c)

/.

transition speed

hat gies the aircraft directional stabilit a) Mertical stabiliser b) Jori@ontal stabiliser c)

0.

Eleators

*he most fuel eTcient of the following tpes of engine is the

a) roc!et b) turbo-Fet engine c)

4.

turbo-fan engine

*he uietest of the following tpes of engine is the

a) roc!et b) turbo-Fet engine c)

15.

turbo-fan engine

(orward motion of a glider is proided b

a) the engine b) the weight c)

the drag

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ans819 7 c; ans829 7 a; ans8#9 7 c; ans8%9 7 b; ans8'9 7 b; ans89 7 b; ans8/9 7 a; ans809 7 c; ans849 7 c; ans8159 7 b;

explain8197Induced drag decreases with increasing speed.; explain8297le drag increases with increasing speed.; explain8#97*he stagnation point on the aerofoil is the point where the air3ow is brought completel to rest on the leading edge.; explain8%97If an aircraft oscillates in pitch without the oscillations increasing or decreasing it is longitudinall neutrall stable.; explain8'97*o ma!e the nose pitch up, the tailplane down load must be increased. *his is done b decreasing its incidence "or increasing its negatie incidence).; explain897*he stall position of an aerofoil is determined b its angle of attac! onl.; explain8/97*he ertical stabiliser gies the aircraft directional stabilit.; explain8097*he turbo fan is the most fuel eTcient engine.; explain8497*he turbo fan is the uietest engine.; explain81597*he weight proides forward motion of a glider.;

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Exam Number:-2%. --------------------------------------------------------------------------------

1.

le drag consists of what drag tpes

a) (orm, s!in friction and interference b) (orm, induced and s!in friction c)

2.

(orm, induced and interference

n aircraft in straight and leel 3ight is subFect to

a) @ero load factor b) a load factor of 1 c)

a load factor of Y

#.

spect ratio is gien b the formula

a) Hean Chord +pan b) +pan2 rea c)

+pan2

Hean Chord

%.

$n a high wing aircraft in a turn

a) the up going wing loses lift which has a de-stabili@ing e&ect b) the down going wing gains lift causing a stabili@ing e&ect c)

the down going wing loses lift causing a de-stabili@ing e&ect

'.

hich condition is the actual amount of water apour in a mixture of air and water

a) Aelatie humidit b) 6ew point c)

.

bsolute humidit

n aspect ratio of 0 means a) the span is 0 times the mean chord b) the mean chord is 0 times the span c)

/.

the area is 0 times the span

*he I+ a) is ta!en from the euator b) is ta!en from %' degrees latitude c)

0.

assumes a standard da

hich will weigh the least a) 40 parts of dr air and 2 parts of water apour b) #' parts of dr air and ' parts of water apour c)

4.

'5 parts of dr air and '5 parts of water apour

 high aspect ratio wing a) is sti&er than a low aspect ratio wing b) has less induced drag than a low aspect ratio wing c)

has a higher stall angle than a low aspect ratio wing

15. *he thrust-drag couple oercomes the lift-weight couple. hat force must the tail of the aircraft exert to maintain the aircraft in a leel attitude a) 6own

b) Gp c)

+idewas

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ans819 7 a; ans829 7 b; ans8#9 7 b; ans8%9 7 b; ans8'9 7 c; ans89 7 a; ans8/9 7 b; ans809 7 a; ans849 7 b; ans8159 7 b;

explain8197le consists of (orm 6rag, +!in (riction 6rag and Interference 6rag.; explain8297n aircraft in straight and leel 3ight is subFect to a load factor of 1 "i.e. 1g).; explain8#97spect Aatio is span K mean chord. Hultipl top and bottom b span and ou get span suared K area.; explain8%97hen an aircraft roles, the downgoing wing gains lift "due to the up3ow of air causing an increased angle of attac!). *his opposes the role.; explain8'97bsolute humidit is the LactualL amount of water in a mixture of air and water.; explain897n spect Aatio of 0 means the span is 0 times the chord.; explain8/97*he I+ is ta!en from %' degrees latitude.; explain80976r air is heaier than water apour.; explain8497 long slender wing "high aspect ratio) has less induced drag than a short stubb wing.; explain81597ssuming the thrust-drag couple is a nose up couple "low engined aircraft) then if  the thrust-drag couple oercomes the lift-weight couple, the aircraft will pitch up. *he tail of the aircraft needs to exert an upwards force to maintain leel 3ight.;

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Exam Number:-2'. --------------------------------------------------------------------------------

1.

Induced downwash

a) reduces the e&ectie angle of attac! of the wing b) increases the e&ectie angle of attac! of the wing c)

2.

has no e&ect on the angle of attac! of the wing

6uring a turn, the stalling angle

a) increases b) decreases c)

remains the same

#. hich is the ratio of the water apour actuall present in the atmosphere to the amount that would be present if the air were saturated at the preailing temperature and pressure a) bsolute humidit b) Aelatie humidit. c)

%.

6ew point

 straight rectangular wing, without an twist, will

a) hae greater angle of attac! at the tip b) hae the same angle of attac! at all points along the span c)

'.

hae less angle of attac! at the tip

If gauge pressure on a standard da is 2' le drag cure. Increasing the weight eleates the induced drag "lift dependant drag) and therefore the intersection is shifted to the right "greater Mmd).; explain8#97*emperature is a measure of the !inetic energ of the molecules of a substance. Jeat is a form of energ exchange.; explain8%97Aelatie humidit is the ratio of the water apour actuall present to the water apour that the air would hold if it were saturated.; explain8'97Induced drag causes air to 3ow under the wing spanwise towards the tip and on top of the wing spanwise towards the root.; explain897Aelatie humidit is the ratio of the water apour actuall present to the water apour that the air would hold if it were saturated.; explain8/97Jigh temperature and high humidit are the worst conditions for aircraft performance.; explain8097*he stall strip is to ma!e the root of the wing stall before the tip so at the stall point, full aileron control is maintained.; explain8497*he gap which opens up when the leading edge slat opens is to allow high pressure through from beneath the wing and re-energise the boundar laer on top of the wing.; explain81597*he wing is designed to produce lift resulting from relatiel positie air pressure below the wing surface and negatie air pressure aboe the wing surface.;

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Exam Number:-2/. --------------------------------------------------------------------------------

1.

spect ratio of a wing is de>ned as the ratio of the

a) wingspan to the wing root b) suare of the chord to the wingspan c)

2.

wingspan to the mean chord

hich of the following is true

a) =ift acts at right angles to the wing chord line and weight acts erticall down b) =ift acts at right angles to the relatie air3ow and weight acts erticall down c) =ift acts at right angles to the relatie air 3ow and weight acts at right angles to the aircraft centre line

#. *he temperature to which humid air must be cooled at constant pressure to become saturated is called

a) dewpoint b) absolute humidit c)

%.

relatie humidit

*he air3ow oer the upper surface of a cambered wing

a) increases in elocit and pressure b) increases in elocit and reduces in pressure c)

'.

reduces in elocit and increases in pressure

hich tpe of 3ap increases the area of the wing

a) cant part of a stall strip is missing on an aeroplane wing, a li!el result will

a) increased lift in the area of installation on the opposite wing at high angles of attac! b) asmmetrical aileron control at low angles of attac! c)

/.

asmmetrical aileron control at or near stall angles of attac!

ith increased speed in leel 3ight

a) induced drag increases b) pro>le drag increases c)

0.

pro>le drag remains constant

6eploment of 3aps will result in

a) a decrease in stall angle b) an increase in stall angle c)

4.

a decrease in angle of attac!

n aeroplane wing is designed to produce lift resulting from relatiel a) positie air pressure below and aboe the wingLs surface.

b) negatie air pressure below the wingLs surface and positie air pressure aboe the wingLs surface. c) positie air pressure below the wingLs surface and negatie air pressure aboe the wingLs surface.

15.

*he angle of attac! of an aerofoil section is the angle between the

a) chord line and the relatie air3ow b) underside of the wing surface and the mean air3ow c)

chord line and the centre line of the fuselage

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ans819 7 c; ans829 7 b; ans8#9 7 a; ans8%9 7 b; ans8'9 7 b; ans89 7 c; ans8/9 7 b; ans809 7 a; ans849 7 c; ans8159 7 a;

explain8197spect ratio is de>ned as the ratio of the wing span to mean chord.; explain8297=ift acts at right angles to the relatie air3ow and weight acts erticall down.; explain8#97*he temperature to which humid air must be cooled to become saturated is called the Ldue pointL.; explain8%97ir3ow 3owing oer the upper surface of an aerofoil increases in elocit and decreases in pressure.; explain8'97 fowler 3ap increases the wing area as well as increasing the wing camber.; explain897*he stall strip is to ma!e the root of the wing stall before the tip so at the stall point, full aileron control is maintained.; explain8/97ith increased speed in leel 3ight, the pro>le drag increases and the induced drag decreases.; explain80976eploment of 3aps increases camber and decreases stall angle.; explain8497*he wing is designed to produce lift resulting from relatiel positie air pressure below the wing surface and negatie air pressure aboe the wing surface.; explain81597ngle of attac! of an aerofoil is the angle between the chord line and the relatie air 3ow.;

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Exam Number:-20. --------------------------------------------------------------------------------

1.

 swept wing tends to stall >rst at the

a) root b) tip c)

2.

centre section

Preuger (laps are normall >tted to

a) the trailing edge of the wings b) the tips of the wings c)

#.

the leading edge of the wings

spect ratio of a wing is de>ned as the ratio of the

a) wingspan to the wing root. b) suare of the chord to the wingspan. c)

%.

wingspan to the mean chord

*he trailing ortex on a pointed wing "taper ratio 7 5) is

a) at the root b) at the tip c)

'.

euall all along the wing span

 high wing aircraft will be more

a) laterall stable than a low wing aircraft b) longitudinall stable than a low wing aircraft c)

.

directionall stable than a low wing aircraft

 wing with a er high aspect ratio "in comparison with a low aspect ratio wing) will hae

a) increased drag at high angles of attac!. b) a low stall speed. c)

/.

poor control ualities at low airspeeds.

*he lift cure for a delta wing is

a) more steep than that of a high aspect ratio wing b) less steep than that of a high aspect ratio wing c)

the same as that of a high aspect ratio wing

0. fter an aircraft has been disturbed from its straight and leel 3ight, it returns to its original attitude with a small amount of decreasing oscillation. *he aircraft is

a) staticall stable but dnamicall unstable b) staticall unstable but dnamicall stable c)

staticall stable and dnamicall stable

4. n increase in the speed at which an aerofoil passes through the air increases lift because a) the increased speed of the air3ow creates a greater pressure di&erential between the upper and lower surfaces. b) the increased speed of the air3ow creates a lesser pressure di&erential between the upper and lower surfaces. c)

the increased elocit of the relatie wind increases the angle of attac!

15.

 delta wing has a) a higher stall angle than a straight wing

b) a lower stall angle than a straight wing c)

the same stall angle than a straight wing

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ans819 7 b; ans829 7 c; ans8#9 7 c; ans8%9 7 c; ans8'9 7 a; ans89 7 a; ans8/9 7 b; ans809 7 c; ans849 7 a; ans8159 7 a;

explain8197 swept wing tends to stall >rst at the tip.; explain8297Preuger (laps are normall >tted to the leading edge of the wings "ref: /#/155,255 etc.).; explain8#97spect ratio is de>ned as the ratio of the wingspan to the mean chord.; explain8%97*railing ortex of a pointed wing is spread euall along the trailing edge.; explain8'976ue to pendulum e&ect of the fuselage, a high wing aircraft will be more laterall stable than a low wing aircraft.; explain897 er high aspect ratio wing will hae increased drag at high angles of attac!.; explain8/97 delta wing produces less lift for an gien angle of attac! than an other tpe of wing.; explain8097+tatic stabilit is the abilit of the aircraft to return to its untrimmed position. 6namic stabilit is the abilit of the aircraft to not oscillate about the trimmed position.; explain8497Increasing the speed of an aerofoil increases the pressure di&erential between the upper and lower surface.; explain81597 delta wing has a much higher stall angle than a normal wing.;

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Exam Number:-24. --------------------------------------------------------------------------------

1.

*he =iftK6rag ratio of a wing at the stalling angle is

a) of a negatie alue b) low c)

2.

high

*he air3ow oer the upper surface of a cambered wing a) increases in elocit and pressure b) increases in elocit and reduces in pressure c)

#.

reduces in elocit and increases in pressure

*he speed of air oer a swept wing which contributes to the lift is

a) less than the aircraft speed b) more than the aircraft speed c)

%.

the same as the aircraft speed

(or a gien angle of attac! induced drag is

a) greater on a high aspect ratio wing b) greater towards the wing root c)

'.

greater on a low aspect ratio wing

In straight and leel 3ight, the angle of attac! of a swept wing is

a) the same as the aircraft angle to the hori@ontal

b) more than the aircraft angle to the hori@ontal c)

.

less than the aircraft angle to the hori@ontal

Induced drag

a) is neer eual to the pro>le drag b) is eual to the pro>le drag at the stalling speed c)

is eual to the pro>le drag at Mmd

/.  delta wing aircraft 3ing at the same speed "subsonic) and angle of attac! as a swept wing aircraft of similar wing area will produce

a) the same lift b) more lift c)

0.

less lift

*he stagnation point is

a) static pressure plus dnamic pressure b) static pressure minus dnamic pressure c)

dnamic pressure onl

4. $n a swept wing aircraft, due to the aderse pressure gradient, the boundar laer on the upper surface of the wing tends to 3ow a) directl from leading edge to trailing edge b) towards the tip c)

15.

towards the root

ith increased speed in leel 3ight a) induced drag increases

b) pro>le drag increases c)

pro>le drag remains constant

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ans819 7 b; ans829 7 b; ans8#9 7 b; ans8%9 7 c; ans8'9 7 b; ans89 7 c; ans8/9 7 c; ans809 7 a; ans849 7 b; ans8159 7 b;

explain8197t stall the lift drops rapidl and the drag increases rapidl. =iftK6rag ratio therefore decreases.; explain8297ir3ow oer the upper surface of a cambered surface of the wing increases in elocit and decreases in pressure.; explain8#97ir3ow oer the upper surface of a cambered surface of the wing has a greater elocit than the aircraft speed.; explain8%97 low aspect ratio wing "short-stubb wing) has a greater induced drag.; explain8'97ngle of attac! in straight and leel 3ight is eual toi the angle of incidence which is more than the angle of the aircraft "swept wing or not).; explain897Induced drag is eual to pro>le drag at Mmd.; explain8/97 delta wing aircraft at an gien angle of attac! and speed will produce less lift than an other tpe of wing.; explain8097t stagnation, the pressure is total "static plus dnamic).; explain84976ue to aderse pressure gradient on a swept wing, the boundar laer slides towards the tip and thic!ens at the tip.; explain81597le drag increases with speed, induced drag decreases with speed.;

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Exam Number:-#5. -------------------------------------------------------------------------------1.

If a swept wing stalls at the tips >rst, the aircraft will

a) pitch nose up b) pitch nose down c)

2.

roll

*he thic!nessKchord ratio of the wing is also !nown as

a) aspect ratio b) mean chord ratio c)

#.

>neness ratio

(lexure of a rearward swept wing will

a) increase the lift and hence increase the 3exure b) decrease the lift and hence decrease the 3exure c)

%.

increase the lift and hence decrease the 3exure

 Jigh spect Aatio wing is a wing with

a) long span, long chord b) long span, short chord c)

'.

short span, long chord

+tall commencing at the root is preferred because

a) the ailerons become ine&ectie

b) it proides the pilot with a warning of complete loss of lift c)

.

it will cause the aircraft to pitch nose up

n aircraft 3ing in Wground e&ectX will produce

a) more lift than a similar aircraft outside of ground e&ect b) less lift than a similar aircraft outside of ground e&ect c)

/.

the same lift as a similar aircraft outside of ground e&ect

If the angle of attac! of a wing is increased in 3ight, the

a) C of < will moe forward b) C of D will moe aft c)

0.

C of < will moe aft

*he Aams Jorn Mortex on a forward swept wing will be

a) the same as a rearward swept wing b) more than a rearward swept wing c)

4.

less than a rearward swept wing

hen maintaining leel 3ight an increase in speed will

a) cause the C of < to moe aft b) cause the C of < to moe forward c)

15.

hae no a&ect on the position of the C of <

(or a cambered wing section the @ero lift angle of attac! will be

a) @ero b) % degrees c)

negatie

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