Low Visibility Operations
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EMBRAER 170/175/190/195 LOW VISIBILITY OPERATIONS EMPRESA BRASILEIRA DE AERONÁUTICA S.A.
THIS DOCUMENT INCLUDES DEFINITIONS, SYSTEM LOGIC AND OPERATIONAL PHILOSOPHY REGARDING LOW VISIBILITY OPERATIONS. THIS MANUAL IS APPLICABLE TO EMBRAER 170/175/190/195 FAMILY AIRPLANES.
GP–2603 JUNE 30, 2006 REVISION 3 – NOVEMBER 27, 2009 Copyright 2009 by EMBRAER - Empresa Brasileira de Aeronáutica S.A.. All rights reserved. This document shall not be copied or reproduced, whether in whole or in part, in any form or by any means without the express written authorization of Embraer. The information, technical data, designs and drawings disclosed in this document are property information of Embraer or third parties and shall not be used or disclosed to any third party without permission of Embraer.
GENERAL PUBLICATION
LOW VISIBILITY OPERATIONS
LIST OF EFFECTIVE PAGES ORIGINAL ............0 ........... JUN 30, 2006 REVISION ............1 ............ JUL 23, 2007 REVISION ............2 ........... SEP 01, 2008 REVISION ............3 ...........NOV 27, 2009
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TABLE OF CONTENTS
LOW VISIBILITY OPERATIONS TABLE OF CONTENTS
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SECTION I – GENERAL ...................................................................... 1 INTRODUCTION ............................................................................. 1 SECTION II – DEFINITIONS AND CERTIFICATION .......................... 3 AWO ................................................................................................ 3 PRECISION APPROACH CATEGORIES....................................... 3 RUNWAY VISUAL RANGE (RVR).................................................. 6 SLANT VISUAL RANGE (SVR) ...................................................... 7 DECISION HEIGHT....................................................................... 10 LOW VISIBILITY APPROACH MINIMA ........................................ 11 FAIL PASSIVE LANDING SYSTEM.............................................. 12 LOW VISIBILITY TAKEOFF (LVTO) ............................................. 12 SECTION III – AUTOLAND SYSTEM ................................................ 14 GENERAL ..................................................................................... 14 SYSTEM ARCHITECTURE .......................................................... 15 SYSTEM OPERATION.................................................................. 21 SECTION IV – HGS SYSTEM............................................................ 34 GENERAL ..................................................................................... 34 SYSTEM ARCHITECTURE .......................................................... 36 SYSTEM OPERATION.................................................................. 41 LVTO MODE ................................................................................. 44 HUD A3 APPROACHES ............................................................... 50 NON-HUD A3 APPROACHES ...................................................... 65
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LOW VISIBILITY OPERATIONS
SECTION I – GENERAL INTRODUCTION Gone are the days where airlines could order extra equipment they fancied because 10% to 20% difference in the price of the airplane was not much of a concern. Presently profit margins in the Air Transport industry are tight, especially in the regional and short/medium haul segments. Equipment associated with Low Visibility Operations may represent significant investments for airlines. The only way to justify their price is to prove that they are the most effective way to maintain schedule reliability without diversions and delays due to reduced operations minima. Although in average less than 2% of operations are performed under CAT II/III conditions worldwide, depending on operator’s profile at a given airport (frequency of flights, type of airport, time for arrivals/departures, etc..), reduced weather minima may be significantly present in daily operations. Investments on low visibility equipment may then be justified. This General Publication provides information for operators regarding Low Visibility equipment certified onboard EMBRAER 170/175/190/195 family. Two systems are covered: •
AFCS equipped with Autoland.
•
Head Up Guidance System (HGS).
The main focus of this publication is provide operational guidelines of such systems as predicted in All Weather Operations (AWO) regulations, specifically related to CAT IIIa/b and Low Visibility Takeoff (LVTO) capabilities.
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Other information such as limitations and system descriptions are covered by the Airplane Flight Manual and/or Airplane Operations Manual.
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LOW VISIBILITY ON TAKEOFF Low visibility conditions limit airplane departures and require departure alternates. Additional awareness about the remaining runway length is necessary, since risk of overruns after rejected takeoffs are three times higher than during clear visibility conditions. LOW VISIBILITY ON APPROACH AND LANDING The most critical phase of a low visibility landing is the transition from instrument to visual conditions, when the crew looks for clues to understand the real situation of the airplane related to the runway. Events happen in a quickly and minor momentary distractions at this moment may result in demanding situations or even a missed approach or a balked landing. Operational techniques and special systems were developed to improve the rate of successful approaches, mitigating human errors. Extending the landing capability to CAT III minima requires pilots to have visual references only a few seconds before touchdown. This requires total crew awareness at all times and demands systems that either: Allow the pilot to see both the landscape ahead and the relevant instrument indications while hand flying the airplane so that the transition is not required. This can be performed using HGS.
•
Does not require the pilot to hand fly the airplane, but instead uses Autoland capabilities.
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SECTION II – DEFINITIONS AND CERTIFICATION AWO All Weather Operations is the operational concept established by ICAO in Doc.9365 where recommendations for low visibility operations on takeoffs, landings and taxi are established. It includes guidelines for CAT I, CAT II, CAT III (a, b, and c), Taxi under low visibility (LVTO), as well as airport, airplane and crew requirements. Based on this document, low visibility regulations were established worldwide, defining specific requirements for each kind of low visibility operation. Some examples are: •
EASA-CS-AWO/JAR-AWO (EASA).
•
AC 120-28D “Criteria For Approval Of Category III Weather Minima For Takeoff, Landing, and Rollout” (FAA).
•
AC 120-29 “Criteria For Approval Of Category I and Category II Weather Minima For Approach” (FAA).
Based on these documents, some definitions provided may offer improved systems understanding.
PRECISION APPROACH CATEGORIES ICAO defines precision approach as “an instrument approach and landing using precision azimuth and glide guidance with minima as determined by the category of operations”. There categories of approach operations are set and definitions may vary throughout the regulations. They are: CATEGORY I (CAT I): A precision instrument approach and landing with: •
Decision height: DH >= 200 ft
•
RVR >= 550 m
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Autopilot coupled approaches may be performed down to 50 ft or minimum autopilot use height (whichever is higher) defined by the manufacturer.
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CATEGORY II (CAT II): A precision instrument approach and landing with: •
Decision height: 100 ft 300 m
Comments for CAT I and II Operations: •
CAT I and II minima are designed to provide suitable visual references at DH in order to permit a safe manual landing or go around.
•
For CAT I, the Autoland or HGS feature is not required for the approach, but may be used if available.
CATEGORY IIIa: A precision instrument approach and landing with: •
Decision height: - DH < 100 ft
•
RVR >= 200 m
CATEGORY IIIb: A precision instrument approach and landing with: •
Decision height: DH < 50 ft or no decision height.
•
50 m < RVR < 200 m – ICAO/FAA
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75 m < RVR < 200 m – EASA
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CATEGORY IIIc: A precision instrument approach and landing with no decision height and no RVR limitation. Once zero RVR and ceiling is possible, this kind of operation requires both rollout and taxi guidance on ground. Comments for CAT III Operations: •
CAT III weather minima do not provide visual references to allow safe manual landings and go arounds. The visual contact at minimum RVR is usually done just a few seconds before touchdown, over the touchdown zone of the runway.
•
Special systems are required to aid or enhance the pilot’s performance during landing, flare and rollout. Therefore Autoland feature or HGS guidance is mandatory for CAT III.
•
Special systems certified to CAT IIIa minima are designed to guide the airplane safely to the touchdown zone or go around. Within the EMBRAER 170/175/190/195 family, this can be performed with either Autoland or HGS guidance.
•
Special systems certified to CAT IIIb minima are designed to guide the airplane safely to the touchdown zone or go around, and also provide rollout guidance down to taxi speed using ILS beam signal. Within the EMBRAER 170, this may be performed with the Autoland 2.
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NOTE: Some configurations may not be approved in certifications. Refer to the AFM for further information.
all
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RUNWAY VISUAL RANGE (RVR) According to ICAO: “The Runway Visual Range (RVR) is the range over which a pilot of an airplane on the centerline of the runway can see: •
The runway surface markings or;
•
The lights delineating the runway or;
•
Centerline is identified”.
The RVR is essential information for pilots under low visibility conditions, since it reflects the horizontal visibility in the touchdown area and along the runway extension. The RVR is measured by three transmissometers located side parallel along the runway extension located at: •
Touchdown zone – required for CAT II and CAT III.
•
Middle of Runway – required for CAT III.
•
Rollout Point or End of Runway.
Generally the three RVR values are specified in the meteorological codes. When only one RVR value is provided, it refers to the touchdown zone. Some specific requirements are: FAA CAT III Operations: All the RVR measuring points are required when operating under the weather minima for each category.
•
EASA CAT III Operations: JAR OPS1 requires only one RVR measuring point, if DH is not used.
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SLANT VISUAL RANGE (SVR) When low visibility moisture is homogeneous it may be expected that the RVR value near the threshold to be very similar to the visibility expected at DH. But in most of situations what pilots see is not a horizontal range at DH, but a Slant Visual Range (SVR) defined by: “A straight line between pilot’s eyes and the farthest point in front the airplane, where he can see the runway surface from his seat position in the cockpit”. The angle defined by the SVR line and the pitch line called “down vision angle”. In fact, what pilots actually see on the ground at DH is a visual segment that is defined from the angle between the SVR line and the cockpit cutoff angle (down vision angle minus approach pitch angle). An obscured segment is also created, where the pilot cannot see any surface portion due to airplane geometry.
PITCH
PILOT EYES
HORIZONTAL REFERENCE
SVR 100 ft (30 m)
W
VISUAL SEGMENT
SEGMENT OBSCURED
EM170AOM980003B.DGN
W DOWN VISION ANGLE
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SLANT VISUAL RANGE
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The SVR value is geometrically determined from pilot’s eyes height above the runway related to each kind of airplane, calculated as follows:
SVR =
(VS + [h * cot an( w)])2 + h 2
Where:
VS = Visual Segment. = Pilot Eyes Height.
h
NOTE: Pilot Eyes Height = Wheel Ht + Eye-to-Wheel Ht + (Eyeto-Wheel length)*sin(Θ).
w = Cockpit Cutoff Angle. The SVR is a geometrical value and reflects the opacity of a horizontal sample of the atmosphere at low heights. It is known that fog density decreases with height above the ground, therefore the SVR will generally be less than the reported RVR. At lower altitudes, below 50 ft, the SVR will be nearly the same of RVR. A model for a deep stable fog was set by the UK CAA in order to determine the relation between RVR and SVR and is widely used in aeronautical industry. This is shown in the figure below: SVR/RVR CAA UK EVALUATION 1.00 0.95 0.90 SVR/RVR
0.85 0.80 0.75 0.70 0.65 0.60 0.55 0.50 0
20
40
60
80
100
120
140
160
180
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Pilot´s Eyes Height (ft)
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As an example, for a typical EMBRAER 170 geometry, it is possible to estimate the required RVR for a CAT III operation. As geometrically demonstrated, the optimum visual segment is attained when the pilot’s eye position is as high as possible. Therefore the correct pilot’s seat position and adjustment is essential for a good recognition of runway surface at DH. Section 14-01-10 of the Airplane Operations Manual shows the correct way for pilots adjust their seats for all operations.
LI NE O F SI G HT
BLACK
WHITE
WHITE
FRONT VIEW
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EM170AOM140008.DGN
LOWER VIEW
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DECISION HEIGHT According to ICAO, FAA and EASA the Decision Height (DH) is defined as: “The wheel height above the runway elevation which a go-around procedure must be initiated unless adequate visual reference has been established and the airplane position and approach path have been accessed as satisfactory to continue the approach and landing in safety”. Some remarks about this definition are suitable: •
Runway elevation means the highest point in the touchdown zone.
•
DH is primarily recognized by radio altimeter on all certifications , but;
•
FAA also allows this to be done through barometric altitude (Decision altitude - DA) or INNER MARKER if radio altimeter measurements are not reliable due to terrain irregularities.
•
EASA defines some references at DH:
o
about
adequate
visual
For CAT II/IIIa approaches visual references are considered not less than:
3 light segments of centerline on approach lights or;
Runway centerline or;
Touchdown zone lights or;
Runway edge lights.
For CAT IIIb approaches the visual reference must contain at least one centerline light.
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criterion
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LOW VISIBILITY APPROACH MINIMA Minimum values for DH and RVR are commonly referred to on regulations minima. These specifically apply to the airport and are related to ground equipment accuracy and reliability. The quality of signal of the ILS beam is related to the category of operations and consequently defines the procedure minima. The localizer and glide path accuracy must remain inside the following tolerances:
ILS Category
Maximum Lateral Deviation at Reference Point
Maximum Vertical Deviation at Reference Point
CAT I
±10.5 m
±10 ft
CAT II
±7.5 m
+10 ft / - 0 ft
CAT III
±3 m
+10 ft / - 0 ft
The Reference Point is set over the threshold at a certain height depending on GS angle and category (CAT I = 40 to 60 ft , CAT II/III = 47 to 60 ft , 50 ft is recommended by ICAO). Operators may be subject to other minima determined by other considerations such as: Operational approvals (operational minima).
•
Crew qualification determined training aspects (crew minima).
•
Limitations referred in AFM (airplane minima).
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determined
by
local
authorities
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FAIL PASSIVE LANDING SYSTEM According to ICAO: “A automatic landing system is fail passive if, in event of a failure, there is no significant deviation to autopilot trim, flight path or attitude, but the landing will not be completed automatically”. For this kind of system the pilot must take the controls of the airplane after a system failure and perform a manual landing or go-around. The “Fail Passive System” is defined as: “A system which, in the event of a failure, causes no significant deviation of airplane flight path or attitude”. The Autoland system and the HGS for the EMBRAER 170/175/190/195 family are certified with the fail-passive concept. ICAO also defines a “Fail Passive Hybrid Landing System” that consists of: “…a fail passive automatic landing system with a monitored head up display which provides guidance to enable the pilot to complete the landing manually after a failure of the automatic landing system”. Although some airplanes may have a combination of HGS and Autoland, the EMBRAER 170/175/190/195 family is not certified for hybrid operations.
LOW VISIBILITY TAKEOFF (LVTO) For European operators, JAR OPS 1 defines a Low Visibility Takeoff (LVTO) if RVR is below 400 m. This requires a takeoff alternate airport within one hour range with one engine inoperative. For RVR between 400 m and 150 m the following airport equipment are required: RVR (m)
Airport Equipment Required
250
Runway Edge Lighting or centerline markings
200
Runway Edge Lighting and centerline markings
150
Runway Edge Lighting, centerline markings and multiple RVR information.
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Takeoff RVR may be reduced below 150 m using HGS, under local operational approval.
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Embraer has demonstrated the LVTO rollout guidance for a ILS beam CAT III with RVR down to 75 m using HGS. During the takeoff the RVR and the SVR are the same. The visual segments for take-off with reported RVR of 125 m are shown in the table below for EMBRAER 170/175/190/195 models:
EMBRAER model
Visual Segment
EMBRAER 170
110 m
EMBRAER 175
111 m
EMBRAER 190
109 m
EMBRAER 195
109 m
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Consequently, all EMBRAER 170/175/190/195 models have the capability to be operated with 125 m RVR at takeoff.
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SECTION III – AUTOLAND SYSTEM GENERAL
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As aviation technology evolves, commercial airplanes incorporate more automation which helps the pilot by performing computations, obtaining data, and completing tasks. It is widely known that humans have many extraordinary abilities that no computer can match like pattern recognition, ability to self adapt and so on. However, humans are very bad at multitasking. The Autoland feature is probably the most effective way to reduce crew workload during the approach and landing phases. When performing an Autoland approach the pilot and the autopilot share authority over the control of the airplane. The interface between them is designed to contain enough information so that the pilot can correctly predict the airplane's behavior, while not overloading him with unnecessary information. This allows heightened confidence that the system will perform as desired. AUTOLAND 1 is disengaged 5 seconds after touchdown. AUTOLAND 2 remains engaged until 12 kt of groundspeed. The fail-passive Autoland system available for the E-jets allows CAT IIIa operations with decision heights not less then 50 ft. The mode AUTOLAND 1 allows CATIIIa operations with a RVR not less than 200 m (656 ft). The mode AUTOLAND 2 allows CATIIIb operations with a RVR not less than 400 ft (FAA/ICAO)/150 m (EASA).
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SYSTEM ARCHITECTURE As there are many capabilities and system requirements that must be met by an airplane certified for automatic landings, and many of those are already met on the standard configuration of the E-jets, only a brief description of the architecture related to the Autoland system is found below. For additional information refer to the AOM. PRIMUS EPIC AFCS The AFCS is hosted in the Primus Epic MAU, and is comprised of two channels designated as AFCS1 and AFCS2. They work on an active/standby configuration, the priority being determined based on system/function availability requirements and capability. If both channels are equally capable, the priority is selectable by the pilot via the MCDU menu. In case of failure of the active channel, the priority is automatically transferred to the standby channel. Only the Hi-Priority AFCS channel commands the AP/YD system, as it does for all AFCS functions. Although disturbance to the airplane due to channel transfer will be minimal, to minimize exposure of the Autoland system to latent failures, the AFCS swaps the active channel at the beginning of each new flight. YAW AXIS SYSTEM
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The Yaw axis system provides turn coordination and yaw damper functions. These functions operate independent of the automatic pilot and flight guidance system, but are also controlled by the AFCS. The commands are sent directly to the rudder primary actuator control electronics (P-ACE) via the flight control modules (FCM) in the MAU. The Yaw Damper is required in order for the system to Arm/Engage Autoland. In Autoland-equipped airplanes, yaw axis control is provided also through a parallel rudder servo. This servo engages at Autoland engage and at coupled Go-around. Its failure while Autoland or Go-around modes are active will disengage the autopilot. Upon Autoland engagement, the parallel rudder servo is tested by commanding a small and slow movement of the pedals in both directions. This pedal command does not cause any surface movement; it only serves the purpose of verifying the proper function of the parallel rudder servo.
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AP PITCH TRIM SYSTEM Also computed by the AFCS, the AP pitch trim system positions the horizontal stabilizer surface to off-load the aerodynamic force held by the elevator to maintain a particular flight condition, hence minimizing transient responses after AP disengagements, reducing the control column force maintained by the Autopilot servo, and improving airplane cruise performance. During Autoland operations the automatic pitch trim adds a nose up trim bias into the horizontal stabilizer trim command at 800 ft radio altitude, in order to prevent a nose down transient in the event of an autopilot disconnect during flare. Pitch trim commands are also inhibited during flare, de-rotation or rollout modes (i.e, below 50 ft radio altitude). THRUST MANAGEMENT SYSTEM The thrust management system is configured in a dual redundant architecture designed for increased system availability and is comprised of thrust rating selection (TRS), Electronic Thrust Trim System (ETTS) and Autothrottle (AT) functions. Like in the AFCS only one channel of the TMS operates at a given time and in case of a failure in the active channel, the priority will be automatically transferred to the other channel. The AT, ETTS and TRS priority channel can be selected via the MCDU. There is no change or specific configuration of the TMS functions for Autoland operations. RADIO NAVIGATION SYSTEM The radio navigation system required for Autoland operations is basically the same installed on the standard airplanes, with the exception of the ILS receivers and radio altimeters.
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Dual radio altimeters are required for Autoland operations. In additional to its normal functions, the signal from the radio altimeter is used by the AFCS to define the gain of the autopilot when Autoland is engaged. This means that when the airplane comes closer to the ground, the amplitude of the commands to track the glideslope become smaller.
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Dual ILS receivers are normally installed, but for Autoland operations, to ensure signal separation and integrity, second GS antenna and localizer are installed for safety and reliability reasons. Also the related software (VIDL) installed on standard airplanes needs to be updated in order to perform automatic landings.
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To improve safety, a Radio Tune inhibit does not allow the pilot or other airplane systems to change the Nav Radio frequency while the Autoland mode is engaged. The Autoland system also monitors the Nav Radio frequency to identify faults, which could result in a change of the Nav Radio frequency.
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SYSTEM CONTROLS Although there are no additional controls for Autoland operations, some of the buttons have new functions and/or behaviors. These differences are described below. The approach pushbutton (APP) is used to engage the highest available approach mode, for CAT I, CAT II and AUTOLAND. A second press will disarm or deactivate the mode. When the AUTOLAND mode is already engaged, a second press will not deactivate the mode. Autoland will only disengage if: • The autopilot (AP), yaw damper (YD), TOGA or autopilot quick disconnect buttons are pressed, • Pitch trim is actuated, • The flap/slat lever is moved to a position other than 5, • The control column is forced, through the forward and after movement. The following controls are also inhibited when AUTOLAND is engaged: • The pushbuttons for source selection, lateral modes, speed modes and vertical modes, including SRC, NAV, HDG, BANK, VNAV, FLCH, ALT, VS, FPA, IASMACH and APP pushbuttons. • The course selection knob, • The FD buttons,
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• Touch control steering handle.
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DISPLAYS AND ANUNCIATIONS Autoland mode has specific FMA annunciations, EICAS messages and aural warnings. Below is a brief description of these annunciations. For more details refer to the AOM. FMA Indications for AUTOLAND follow the same philosophy of other modes of operation and are exemplified in the picture below. AUTOLAND ARMED
ACTIVE AT MODE ARMED AT MODE
SOURCE
AUTOLAND 1 AP SPD T AT ENGAGE STATUS
ACTIVE LATERAL FD MODE
AUTOLAND ENGAGED
AUTOLAND 1 ALIGN
FLARE
RLOUT
D-ROT
ARMED LATERAL FD MODE
ACTICE FD MODE EM170AOM980015A.DGN
PFD
ARMED VERTICAL FD MODE
An aural alert “NO AUTOLAND” will be issued together with the NO AUTOLAND FMA indication in case of system failure. The EICAS messages related to Autoland system are the following: • AUTOLAND 1 NOT AVAIL - displayed to indicate that Autoland 1 is not available due to the lack of a required system element. • AUTOLAND 2 NOT AVAIL - displayed to indicate that Autoland 2 is not available due to the lack of a required system element. • AP RUDDER NOT AVAIL - displayed to indicate that autopilot rudder control is not available.
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• AUTOLAND OFF - displayed to indicate that Autoland was disabled via the MCDU.
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SYSTEM OPERATION Although Autoland systems are a great advance that allows the airplane to literally “land itself”, conducting an Autoland is far more complex than pressing a button labeled “LAND”. The pilot must be prepared to monitor the system performance, identify any abnormal behavior and if necessary take control of the airplane. This requires specific training, use of appropriate procedures and knowledge of the airplane system. AUTOLAND OPERATIONAL MODES There are six FGCS modes that can be active during Autoland operations. Localizer and Glideslope modes are basically the same as in APPR 1 or APPR 2 operations. There are only four additional FGCS modes related to Autoland operations: Flare, Derotation, Align and Rollout. VERTICAL MODES 1) Glideslope Mode The glideslope mode provides glideslope beam capture and tracking until the transition to the flare mode at approximately 50 ft radio altitude. Prior to flare mode engagement, the control law is the same as that for APPR 1/2 approach. Below 100 ft radio altitude, guidance is based solely on inertial data, and the dependence on the glideslope deviation is reduced to zero after 2 seconds and a 3 degree flight path angle will be maintained. In case a valid radio altimeter signal is not present, the glideslope control law will continue to track beam deviation. 2) Flare
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The Flare mode provides vertical guidance and control for the transition from glideslope control (-3 degrees flight path angle) to main gear touchdown during Autoland operations, and includes landing the airplane within the longitudinal runway dispersion requirements. This mode is automatically armed, when Glideslope engages, and engaged, at 50 ft radio altitude, for Autoland operations only.
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3) Derotation (D-ROT) The Derotation mode is a vertical guidance mode, and automatically arms during Autoland operations. When active, it commands a nose down pitch rate to bring the nose gear into contact with the runway. Derotation arms when Flare mode is engaged, and engages at main gear touchdown, together with rollout mode, and disengages when the autopilot disengages (manually or automatically). LATERAL MODES 1) Align The Align mode utilizes aileron control in conjunction with rudder control to align the airplane with the runway prior to touchdown. Rudder control is used to align the airplane heading with the runway heading in crosswinds, and aileron control is used to arrest the resultant drift to allow the airplane to continue to track the localizer centerline. The maneuver is sometimes referred to as cross control since the rudder and aileron commands are in opposing directions for coordinated flight. Align mode arms when Localizer mode is engaged, and engages at 150 ft radio altitude, remaining engaged until main gear touchdown. 2) Rollout (RLOUT) Rollout mode uses pedal control to maintain the airplane on the runway centerline while the nose is lowered and after the nose gear touches the ground. During this mode, the ailerons are gently moved toward neutral. Rollout arms when Align mode is engaged, and engages at main gear touchdown, together with Derotation mode. It disengages when the autopilot is manually or automatically disconnected. 3) Localizer Mode
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The localizer mode provides localizer beam capture and tracking to the point at which the align mode engages, which occurs at 150 ft radio altitude. This mode uses the same control law as that for APPR 1/2 approach.
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REVISION 3
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION AUTOLAND NORMAL OPERATION
While performing an automatic landing, the pilot must monitor the system behavior, maintain hand and feet on the controls for the entire approach and be prepared to take any corrective action if necessary. Below is a step-by-step example of the scenario that will pass during normal approach with Autoland and autothrottle engaged. It considers that Autoland is available and was not deselected by the pilot on the MCDU. 1) AUTOLAND arm
AUTOLAND 1 AP SPD T AT
LOC
GS
arm.
EM170AOM980018A.DGN
APPR PUSHBUTTON ............................................. PRESS The highest integrity approach mode available will Considering AUTOLAND 1/2 is available it will arm.
If not already set, IAS mode is set automatically by EDS at Autoland Arm. When AUTOLAND 1/2 arms, glideslope and localizer (GS/LOC) modes arm or activate. Glideslope and Localizer mode capture and track requirements are the same as for APPR 2 operation.
GP-2603
It is possible to terminate Autoland 1/2 Arm using the same means available for APPR 1/2 Arm. In case AUTOLAND 1/2 does not arm, check the following conditions: • Autoland is enabled via the MCDU, • AP and YD are engaged, • RA/BARO set to RA, • Minimums set at 50 ft or above, • LOC 1 on left PFD and LOC 2 on right PFD, • Both NAV set to the same correct LOC frequency, • Both PFDs set to correct LOC inbound course (V/L), • No miscompares on PFDs, • Autobrake set at any landing mode (Autoland 2 only).
GP REVISION 2
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LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
2) AUTOLAND engage AUTOLAND 1/2 will transition to Engaged when the following set of conditions is satisfied: • Autoland 1/2, is Armed, • Radio altitude is less than or equal to 1500 ft (referred to as the Autoland engage height) and greater than 800 ft, • Flaps are in position 5, • LOC/GS modes captured. With the conditions satisfied the Align and Flare modes will arm.
SPD
T
AP AT
LOC
GS
ALIGN
FLARE
AUTOLAND 1 SPD
AP AT
T
LOC
GS
ALIGN
FLARE
EM170AOM980021A.DGN
AUTOLAND 1
Switching the Minimums from RA to Baro, or dialing the Minimums to any value is allowed after Autoland engages. While Autoland is engaged prior to align mode, the parallel rudder provides commands to hold zero degrees of sideslip angle. 3) ALIGN mode engage At 150 ft radio altitude, the align mode automatically engages and the rollout mode arms.
T
AP AT
ALIGN
GS
RLOUT
FLARE
AUTOLAND 1 T
AP AT
ALIGN
GS
RLOUT
FLARE
GP-2603
SPD
EM170AOM980039A.DGN
AUTOLAND 1 SPD
GP Page 24
REVISION 3
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION 4) FLARE mode engage
At 50 ft radio altitude, the Flare mode automatically engages and Derotation mode arms.
SPD
T
AP AT
ALIGN
FLARE
RLOUT
D-ROT
AUTOLAND 1 SPD
T
AP AT
ALIGN
FLARE
RLOUT
D-ROT
EM170AOM980040A.DGN
AUTOLAND 1
5) Retard mode engage (Autothrottle engaged only) At 30 ft radio altitude, the Retard mode engages retarding the thrust levers to idle.
AP AT
ALIGN
FLARE
RLOUT
D-ROT
AUTOLAND 1 RETD
AP AT
ALIGN
FLARE
RLOUT
D-ROT
EM170AOM980041A.DGN
AUTOLAND 1 RETD
6) ROLLOUT and DEROTATION modes engage At main gear touchdown, Rollout and Derotation engage. Runway centerline is maintained while the nose is lowered. The autothrottle also disengages normally (annunciation in green, no aural alert). AUTOLAND 1 RLOUT
D-ROT
AUTOLAND 1
GP-2603
AP AT
RLOUT
D-ROT
GP REVISION 2
Page 25
EM170AOM980042A.DGN
AP AT
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
The flashing AT disconnect annunciation may be cancelled by pressing the AT quick disconnect pushbuttons on either throttle lever.
RLOUT
EM170AOM980043A.DGN
AUTOLAND 1 AP
D-ROT
7) Autopilot disconnection The autopilot automatic disconnection logic is different in both Autoland modes: Autoland 1 will disconnect automatically 5 seconds after transitioning to RLOUT and D-ROT; Autoland 2 will disconnect automatically once the ground speed is at or below 12 kt. After Autopilot disconnection the AUTOLAND 1/2 status is removed and the flight director modes and cues are removed. The autopilot visual and aural warnings are initiated. The pilot must then take control of the airplane. AUTOLAND 1
AUTOLAND 1
GP-2603
AP
GP Page 26
EM170AOM980044A.DGN
AP
REVISION 2
GENERAL PUBLICATION
LOW VISIBILITY OPERATIONS
EM170AOM980045A.DGN
After the pilot presses the quick disconnect button, the visual and aural warnings cease.
When operating with crosswind the airplane may not touch the runway parallel to the centerline, and correction of the autopilot may cause passenger discomfort. The flight crew may elect to manually disengage the Autopilot at nosewheel touchdown, in order to make smoother corrections. MODE PROMOTION FROM APPR 1/2 TO AUTOLAND Promotion to AUTOLAND 1/2 from the APPR 1/2 Arm or Engage state is possible when the airplane is above 800 ft RA provided the criteria to arm or engage AUTOLAND is met. The crew is advised of the promotion from either APPR 1 or APPR 2 to AUTOLAND 1/2 by flashing the new, active state for 5 seconds. Transition from APPR 1 Arm or Engage to APPR 2 Arm or Engage state will occur per the normal course of events. MODE PROMOTION FROM AUTOLAND 1 TO AUTOLAND 2 Promotion to AUTOLAND 2 from AUTOLAND 1 Arm state is possible when the airplane is above 800 ft RA provided the criteria to arm Autoland 2 is met and Autoland 2 is available. FAILURE TO ENGAGE AUTOLAND If Autoland is armed but unable to engage because the flaps are not set to 5, Autoland will continue to be armed until either the flaps are set to 5 or the airplane descends below 800 ft RA.
GP-2603
In the case where Autoland is armed and the airplane descends below 800 ft RA the following events occur:
GP REVISION 2
Page 27
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
• AUTOLAND 1/2 disarms and the annunciation is removed. • APPR 1 engages and is displayed at the top right side of the FMA, and flashes inverse video for 5 seconds. • APPR 1 ONLY is displayed at the top left side of the FMA, and flashes amber, inverse video for 5 seconds and then steady. • The Minimum digits on the PFD flash amber inverse video for 5 seconds and then steady. If weather conditions permit, the pilot may continue the approach and perform a CAT I landing. FAILURES DURING AUTOLAND ENGAGE When Autoland is engaged, the AFCS reacts differently to failures, in part as a function of height above terrain. • Above 800 ft – automatic priority transfers may allow AP and Autoland to stay engaged, • Below 800 ft and above 200 ft – automatic priority transfers result in loss of AP or Autoland depending on the nature of the failure, • Below 200 ft – transfer of control always results in loss of autopilot and Autoland Engage. In any case the autopilot remains engaged, loss of Autoland engage results in a red “NO AUTOLAND” annunciation displayed at the top left side of the FMA and a single “NO AUTOLAND” aural alert. This will cause the Autoland unique modes (ALIGN, FLARE, D-ROT and RLOUT) to be removed from the armed/active FMA fields. When appropriate, an amber flashing “DH” setting on the PFD will also be displayed. The visual warnings can be canceled by pressing, the AP quick disconnect button.
GP-2603
Any reversion from Autoland will degrade to the highest capable category/flight director mode. Localizer and Glideslope miscompares will cause the reversion from LOC/GS to FPA/ROLL. Below are two examples of failures during Autoland operations. Note that they are only examples, and different modes of failures could result in different reversions.
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REVISION 3
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
•
Example 1 : Autoland reversion to APPR 2. In this particular example, a radio altimeter failure will cause the reversion to APPR 2 and the AP will remain engaged. a) The scenario starts with AUTOLAND 1 engaged with LOC/GS modes active. The minimums are set to RA for a 50 ft DH.
SPD
T
AP AT
ALIGN
GS
ALIGN
FLARE
EM170AOM980046A.DGN
AUTOLAND 1
b) One of the radio altimeters fails. The red "NO AUTOLAND" annunciation flashes inverse video for 5 seconds at the top, left side of the FMA and a single aural warning “NO AUTOLAND” will be given. As the minimums were set to 50 ft, they will also flash amber inverse video for 5 seconds, because it is not possible to perform an APPR 2 with a 50 ft DH. AUTOLAND 1 engaged is replaced by APPR 2 engaged and the modes ALIGN and FLARE are removed. APPR 2 LOC
GS
GP-2603
NO AUTOLAND SPD T AP AT
APPR 2 LOC
GS
EM170AOM980047A.DGN
NO AUTOLAND SPD T AP AT
GP REVISION 2
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LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
After 5 seconds the red “NO AUTOLAND” is replaced by amber “APPR 2 ONLY” annunciation.
APPR 2 LOC
GS
EM170AOM980048A.DGN
APPR 2 ONLY SPD T AP AT
In this moment the crew must decide if it is safe to continue the approach of if a go around is required. c) First possibility - Continuing the approach. In order to continue the approach, the crew must reset either of the displayed PFD minimums to a CAT II range (> 80 ft). With this action the aural alert and the “APPR 2 ONLY” annunciations are canceled, and the color of the minimums on the PFD return to normal.
T
AP AT
LOC
GS
GP-2603
SPD
EM170AOM980049A.DGN
APPR 2
GP Page 30
REVISION 2
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
d) Second possibility - Aborting the approach. If the crew decides to abort the approach, the pilot must press the TOGA button or move the thrust lever to TO/GA. This will cancel the aural alert and the “APPR 2 ONLY” annunciations, and the color of the minimums on the PFD will return to normal.
AP AT
TRK
GA
GP-2603
GA
AP AT
TRK
GA
EM170AOM980050A.DGN
GA
GP REVISION 2
Page 31
LOW VISIBILITY OPERATIONS
•
GENERAL PUBLICATION
Example 2: Autoland Fail Scenario Resulting In Loss of AP. This example shows the annunciation sequence following failure of the parallel rudder. a) The scenario starts with Autoland 1 engaged with ALIGN/FLARE modes active. The minimums are set to RA for a 50 ft DH.
T
AP AT
ALIGN
FLARE
RLOUT
D-ROT
EM170AOM980051A.DGN
AUTOLAND 1 SPD
b) The parallel rudder servo fails. This will result in loss of autopilot. The red "AP" annunciation flashes on the FMA and the aural "Autopilot" is annunciated continuously until canceled by the crew. The active modes ALIGN and FLARE are replaced by FPA/ROLL which flash for 5 seconds before going steady. The armed modes RLOUT and D-ROT are removed.
T
AP AT
FPA
ROLL
SPD
T
AP AT
FPA
ROLL
EM170AOM980052A.DGN
SPD
GP-2603
The AP visual and aural alerts are cancelled by pressing the AP quick disconnect. If visual conditions permit, the crew may consider continuing the approach, otherwise a go-around is required.
GP Page 32
REVISION 2
GENERAL PUBLICATION
LOW VISIBILITY OPERATIONS
ENGINE FAILURE In the absence of other system failures, the operational state of the engines does not adversely affect Autoland availability. Steady state asymmetric thrust compensation will be applied via the parallel rudder servo allowing the airplane to perform successful automatic lands with one engine inoperative. AUTOBRAKE FAILURE
GP-2603
If the Autobrake fails during airplane rollout the Autoland 2 mode will not disengage and the crew is responsible for brakes application. The aural “AUTOBRAKE” is issued.
GP REVISION 3
Page 33
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
SECTION IV – HGS SYSTEM GENERAL The Head Up Guidance System (HGS) is primarily a display device, which provides attitude, speed, flight path, and optionally low visibility takeoff, landing and rollout guidance to the pilot in symbolic format, among others. All information is shown in the pilot’s forward field of view eliminating transitions from head-down to head-up flying. Conformal display of flight path and acceleration allows the crew to precisely fly the airplane in all phases of flight from takeoff through enroute and terminal area maneuvering to a precision landing with enhanced operational safety. All displayed information is derived from airplane equipment and sensor data. The image produced by the HGS is generated by a holographic device that generates symbols which are optically at a focal distance compatible with the outside landscape seen through the windshield. The system has been designed with human factors considerations such as:
•
There is no need for the pilots to adapt eye focus when switching from landscape to symbology. Aiming and touchdown points on the runway do not move with head movement.
GP-2603
•
GP Page 34
REVISION 2
LOW VISIBILITY OPERATIONS
GP-2603
EM170AOM980053A.DGN
GENERAL PUBLICATION
GP REVISION 2
Page 35
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
SYSTEM ARCHITECTURE Each HGS set is composed of three basic Line Replaceable Units (LRUs): •
HGS computer: central processor unit, providing pixilated image and control data.
•
Overhead Unit: generates the display image on a micro Liquid Crystal Display (LCD), illuminated with a green light.
•
Combiner (HUD – Head-up display): provide conformal display on a projection screen image at optical infinity.
The HGS may be implemented in a Dual or Single configuration: SINGLE CONFIGURATION One set designed to support Low Visibility Takeoff guidance (LVTO) and CAT III approaches down to 50 ft DH, including landing and rollout guidance. The system architecture is the following:
IRU 1
MAU 1
OHU
HUD COMPUTER
COMBINER
MAU 1
IRU 2
MCDU 1
RALT 2
MCDU 2
EM170AOM980054A.DGN
RALT 1
MAU 2
GP-2603
The HGS computer will drive annunciations for both PFDs 1 and 2.
GP Page 36
REVISION 2
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
DUAL CONFIGURATION Two sets designed to support Low Visibility Takeoff guidance (LVTO) and CAT III approaches down to 50 ft DH, including landing and rollout guidance. The system architecture is the following: IRU 1 RALT 1 OHU 1 MAU 1
HUD COMPUTER 1
IRU 2
COMBINER 1
MAU 1 MCDU 1
RALT 2
MAU 2
HUD COMPUTER 2
MAU 2 MCDU 2
COMBINER 2 EM170AOM980055A.DGN
OHU 2
GP-2603
The left HGS computer will drive annunciations on PFD 2, while the right HGS will drive the annunciations on PFD 1. If one combiner is stowed or one HGS is failed, the remaining HGS operates as a single HGS.
GP REVISION 2
Page 37
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
MCDU INTERFACE The MCDU can be used by the flight crew to enter runway data, select symbology features and enable HUD A3 approach mode (dual installation). On ground it is used to perform maintenance operations. The link to access the HGS page on the MCDU is available on the “MENU” page, which is accessed pressing the “MENU” key on the MCDU keyboard.
HGS RWY LENGTH
11000 FEET RWY ELEVATION
22 FEET CONBINER MODE AUTO DECLUTTER FULL HUD A3 ON OFF
EM170AOM980056A.DGN
MAINT
The HGS page presents 4 different options: • RWY Length
GP-2603
The runway length information is displayed in green numbers underneath the inscription “RWY LENGTH”. It is automatically set by the FMS, however can be manually modified by entering the new value on the scratch pad – using the alphanumeric keyboard of the MCDU – and pressing the LSK at the side of the RWY Length value.
GP Page 38
REVISION 2
GENERAL PUBLICATION
LOW VISIBILITY OPERATIONS
• RWY Elevation The runway TDZE information in feet is displayed in green numbers underneath the inscription “RWY ELEVATION”. It is automatically set by the FMS, however can be manually modified by entering the new value with the appropriate signal (+ or -) on the scratch pad – using the alphanumeric keyboard of the MCDU – and pressing the LSK at the side of the RWY Elevation value. • Combiner Mode The removal and re-appearance (Declutter) of the HGS Airspeed and Altitude Tapes and HGS information can be controlled by the flight crew thought the display control option. The following options can be selected by pressing the LSK correspondent to the “Display Control” indication. The functions of the three Combiner Mode settings are: • AUTO The HGS automatically removes the airspeed and altitude tapes and the Horizontal Situation Indicator (HSI) during the approach phase. • DECLUTTER Pilots may manually declutter the Combiner display during any phase of flight if the presentation of the tapes and HSI are not critical. • FULL Pilots may manually choose to maintain or restore the full symbology on the Combiner display after an automatic or manual removal of the tapes and HIS. • HUD A3
GP-2603
Enable or disable the HUD A3 approach mode.
GP REVISION 2
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LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
HGS SYMBOLOGY The HGS is considered the PFD when the pilot is flying "head-up". The HGS presents information to the pilot in a form similar to a head-down PFD. In fact, where practical, the individual HGS symbols form and function are customized to be similar to those of the airplane's heads down PFD. This is done to allow easy recognition by the pilot while causing no confusion due to ambiguity with similar information presented on other cockpit displays. Information is positioned on the HGS to conform to the "basic T" instrument conventions unless it is shown that conventions other than the basic T are safe (no loss of basic information – listed below) and provide some advantage in the interpretation and use of information on the HGS. For instance, certain compromises to the basic T may be made in order to optimize the HGS use in conditions such as crosswinds where large crab angles may be encountered. The basic information provided on the HGS includes: 1. Attitude. 2. Heading. 3. Airspeed. 4. Altitude. 5. Vertical Speed. 6. Navigation and Position. 7. Flight Guidance. 8. Guidance Mode and Status. 9. Angle of Attack.
GP-2603
For detailed information on HGS symbology, refer to the AOM.
GP Page 40
REVISION 2
GENERAL PUBLICATION
LOW VISIBILITY OPERATIONS
SYSTEM OPERATION Regardless of the configuration, the HGS system is designed to be a supplementary display of primary flight data displayed on PFDs: attitude, altitude, airspeed and Flight Mode Annunciation (FMA). Therefore it may be operated in all flight phases. Additionally, a declutter feature can be used to reduce the symbology to the minimum necessary for the associated phase of flight. During normal operations, Embraer suggests the Pilot Flying (PF) use head up guidance, while the Pilot not Flying (PNF) monitors flight parameters either on HGS or PFD. TAKEOFF GUIDANCE LVTO mode is available at every takeoff from a runway with a tuned localizer signal. If this signal is not present, the LVTO feature is not available. The HGS is certified for LVTO operations, considering the following specifications: RVR
≥ 300 ft
Runway length
4000 to 18000 ft
Operation
Single/Dual Engine Operation
In the LVTO mode, the HGS derived ground guidance cue provides:
GP-2603
• Appropriate steering guidance and additional symbology; • Ground Roll Reference symbol; • Takeoff Mode Annunciation; • Runway Remaining readout; • Excessive Deviation symbology.
GP REVISION 2
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LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
APPROACH GUIDANCE It is statistically proven that HGS guidance significantly enhances pilot’s skills and provides better accuracy for ILS approaches, reducing the possibility of unstabilized approaches. • HUD A3 approaches The HGS uses its own calculation guidance, which is different from Flight Director information. Pilots must be aware that the ILS signal and sensibility displayed on PFDs may not reflect the pictorial information on the HGS. The HUD A3 guidance can be used to perform CAT I, II or III approaches. It is mandatory to disengage the autopilot after the landing configuration is achieved but above 500 ft. • Non HUD A3 approaches The HGS it is a repeater of the PFD and therefore can be used to perform CAT I or II approaches only. The airplane may be flown manually or with autopilot engaged for CAT I flight director approaches. For CAT II approaches only autopilot coupled approaches may be flown. Manually flown approaches are not authorized. Below DA/DH, the landing maneuver may be done manually in visual conditions. In this case, the flare cue on the HGS shall not be used as a main driver for the flare due to the quality of the localizer and glide slope signal. CAT III with Autoland is allowed. GO AROUND GUIDANCE
GP-2603
In case of go-around complete guidance will be provided to accomplish the maneuver, using the Initial Climb symbology.
GP Page 42
REVISION 3
GENERAL PUBLICATION
LOW VISIBILITY OPERATIONS
TAIL STRIKE ALERTING: TAKEOFF AND APPROACH The HGS includes a tail strike alerting function that is active during takeoff and approach operations. The takeoff symbol is displayed above the Airplane Reference symbol and will settle toward the Airplane symbol as the tail strike becomes probable. • Takeoff The Tail Strike Pitch Limit symbol is displayed during liftoff, rotation, and initial climb if the attitude of the airplane is such that a tail strike is likely to occur. The Tail Strike Pitch Limit symbol is enabled during the takeoff roll and uses pitch angle, pitch rate and altitude to provide sufficient warning for the pilot to recognize and prevent a potential tail strike. This symbol is used with the Airplane Reference symbol to show when the pitch limit is reached. • Approach On approach, a potential tail strike event due to an improperly configured airplane or low-altitude go-around operation shows as the symbol “LDG ATT” on the Combiner display. This will be displayed above the Zero Degree Pitch Line and under the Airplane Reference symbol. The symbol will be displayed as long as the approach is in a possible tail strike configuration. OTHER GUIDANCES Other suitable guidance and alerts are also available in the HGS system such as: • EGPWS messages. • AOA limit and stick shaker symbol. • Windshear alert messages and escape guidance. • TCAS symbology with fly-to or stay-clear zones. CERTIFICATION REQUIREMENTS Even if not used for CAT III approaches, HGS requires flight simulator training for operational approval.
GP-2603
The use of HGS for CAT III approaches requires operational approval by the Civil Aviation Authorities. Specific training programs must be approved in this case.
GP REVISION 2
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LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
LVTO MODE LVTO Mode is available at every takeoff from a runway with a tuned localizer signal, to be used when appropriate operational conditions are met. HGS evaluates the ability of the overall takeoff system to successfully complete the takeoff. The takeoff function capability is presented to the pilot on the HGS and repeated on the pilot not flying PFD. On Dual HGS configuration, the HGS takeoff function capability is also presented on the pilot not flying Combiner. The HGS determines whether the pilot is following the commands presented on the HGS accurately enough to assure that the airplane will remain within the required takeoff (lateral) limits of the runway. Takeoff "excessive deviation" monitoring is active from the initiation of the takeoff roll until airplane rotation or until the airplane decelerates to below a safe taxi speed during an aborted takeoff. Takeoff monitoring status is presented to the pilot in the form of an excessive deviation symbol which indicates the direction to correct in order to again, attain and remain within the required takeoff limits. To maintain proficiency, it is recommended that the HGS low-visibility takeoff procedures be used for takeoffs where conditions allow. This is generally anytime the departing runway has a localizer beam and traffic allows for the proper execution of the procedure. NORMAL OPERATION During normal LVTO operations, HGS provides lateral and vertical guidance for rollout and rotation to takeoff pitch angle maneuvers. In addition, PFD guidance is also available with some differences from the normal takeoff flight director guidance: •
Vertical cross bar guidance is removed.
•
An expanded lateral scale remains displayed in order to assist the rollout.
In case of HUD fail, reversion to PFD guidance is recommended.
GP-2603
Below is a step-by-step example of the takeoff LVTO Mode engaging sequence:
GP Page 44
REVISION 2
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION 1) LVTO armed
When the airplane senses the necessary takeoff configuration and a valid ILS signal, the LVTO takeoff mode is automatically armed and the “LVTO” annunciation is shown in white color at the first row and first column of the PFD FMA section. The necessary operational conditions for LVTO to be armed are: •
Same Localizer frequency tuned and valid signal on both sides.
•
Runway length between 4000 ft to 18000 ft.
ROLL
EM170AOM980057B.DGN
LVTO TO
2) LVTO engages After sensing ILS localizer locked, the LVTO mode is engaged. The “LVTO” annunciation in green color will flash in inverse video for 5 seconds. LVTO TO
LVTO ROLL
TO
GP-2603
“LVTO” shows on the upper right part of the Combiner display. It also flashes on the Combiner display for the first 5 seconds and then is steady.
GP REVISION 2
Page 45
EM170AOM980058B.DGN
ROLL
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
3) Initial Climb Guidance
EM170AOM980062A.DGN
After liftoff, and while the flight director is still in TO mode, the display appears as shown in the figure below. The correct pitch attitude is established by positioning the Airplane Reference Symbol over the TO Pitch Reference Line. This satisfies the flight director vertical command. This line is in view on the display until 3 seconds after the airplane passes through 50 ft or a new vertical mode is selected. Speed control is achieved by observing the CAS value on the Airspeed Tape. The Speed Error Tape (referenced to V2) is also displayed.
The Flight Path Acceleration symbol is useful in determining a positive climb gradient and optimizing climb performance. The airplane is accelerating when the Flight Path Acceleration symbol is above the Flight Path wing and is decelerating when the symbol is below the wing. When the desired pitch attitude and airspeed are achieved, placing the Flight Path Acceleration at the “wing” of the Flight Path symbol maintains the optimal initial climb performance.
GP-2603
No Guidance Cue is displayed after takeoff until the airplane is at 50 ft or a vertical mode change occurs.
GP Page 46
REVISION 2
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
ABNORMAL OPERATION There are two failure possibilities during LVTO operation and they can be monitored through FMA annunciations on the PFD. •
Example 1: Failure between 40 and 80 kt. If the LVTO mode fails while IAS is between 40 and 80 kt, the “LVTO” annunciation in red color will flash in inverse video for 5 seconds in the first row and second column of the PFD FMA, then it stays in red color. NO LVTO TO EM170AOM980059B.DGN
ROLL
NO LVTO ROLL
TO
In this case of LVTO Mode disengagement (also occurs during failure to engage), the annunciation LVTO WRN will be displayed on the PFD. Also the “LVTO WRN” annunciations are displayed in both HGS & PFDs even if only one HUD detects this condition.
1O
1O
LVTO WRN
RWY XXXX
1O
GP-2603
EM170AOM980060A.DGN
1O
GP REVISION 2
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LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
In this case, as the airplane is accelerating through speeds in the low energy phase of takeoff run (below 80 kt), Embraer recommends to abort the takeoff. The Expanded Lateral Deviation guidance is demonstrated to be a very useful tool in order to steer the airplane during the RTO maneuver. •
Example 2: Failure below 49 kt or above 80 kt.
An amber “LVTO” is displayed on the PFD to indicate LVTO has lost capability below 40 kt or above 80 kt. This allows the pilot to safely abort the takeoff at low speeds or continue the takeoff at his discretion for speeds approaching V1. The annunciation is on the right side of the top mode line of the PFD. The annunciation flashes inverse video for the first 5 seconds on the PFD and then is steady on its usual background (“NO LVTO” shows on the Combiner display). NO LVTO TO
NO LVTO TO
GP-2603
ROLL
EM170AOM980061B.DGN
ROLL
GP Page 48
REVISION 2
GENERAL PUBLICATION
LOW VISIBILITY OPERATIONS
LVTO OPERATIONAL LIMITATIONS Runway remaining is advisory information only and must not be used for performance monitoring purposes. Embraer recommends not attempting rolling takeoffs during LVTO operations. The following equipment and instruments must be installed and operative: - 1 Multi Control Display Unit (MCDU). - 1 Flight Management System (FMS). - 2 Inertial Reference Systems (IRS). - 2 Navigation Radios.
GP-2603
PERFORMANCE For maximum demonstrated wind components for HGS LVTO operations refer to the AFM.
GP REVISION 2
Page 49
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
HUD A3 APPROACHES
GP-2603
The HGS is configured to provide the functions required to allow manual airplane approach, landing, and rollout operations in reduced visibility conditions to Category III minima, providing sufficient information to the flight crew. Information provided during CAT III operations includes the basic information of an optimized PFD (declutter function active) for the approach, landing, and rollout along with special information required to perform reduced visibility operations. Approach, landing, and rollout capabilities are presented to the pilot on the HUD and repeated on the pilot not flying's head down display (PFD). The HGS computer evaluates the ability of the overall approach, landing, and rollout systems (including the pilot) to successfully complete a CAT III approach, landing, and rollout and also determines whether the pilot is flying the commands presented on the HUD accurately enough to assure that the airplane will safely touchdown within the required touchdown zone. Similar to the capability status, the HGS approach and landing status is presented to the pilot on the HUD and repeated to the pilot not flying. An approach monitoring algorithm is active from 500 ft AGL until airplane touchdown. An approach warning is indicated if any of the approach monitors detect a problem during the approach and landing. Once on the ground, the HGS determines whether the pilot is controlling the airplane to the ground roll commands presented on the HUD accurately enough to assure that the airplane will safely remain within the required rollout zone. Rollout monitoring is also active from rollout start until the rollout guidance is removed from HGS display. Since the pilot can only respond to a HGS rollout monitor indication by continuing the rollout with more awareness of the appropriate rollout control, only an excessive deviation indication (arrow) is provided to the pilot.
GP Page 50
REVISION 2
GENERAL PUBLICATION
LOW VISIBILITY OPERATIONS
The legend “HUD A3” is shown on the Combiner while providing HGS CAT III Guidance. In addition, the following supplementary symbology is presented on the Combiner for the CAT III feature: 1. Flare Command 2. HGS Guidance cue
2
GP-2603
EM170AOM980063A.DGN
1
GP REVISION 2
Page 51
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
When the airplane is equipped in dual HGS configuration, all FMA annunciations will be driven to cross-side PFDs: •
HUD 1 will drive annunciations to PFD 2.
•
HUD 2 will drive annunciations to PDF 1.
HUD 1
HUD 2
ALERTINGS
ALERTINGS
VAPP FLARE
AP B AT B
236
VOR
ASEL
1
26O
247 OO
4OOO
VAPP FLARE
AP B AT B
236
VOR
ASEL
1
26O
255OO
247 OO
4OOO
255OO
4
4
R
24O
R 1O
2
2 1
1O
5.O
22 O
24O
25O OO
E
1OOO
22 O
OM
25O OO
E
1OOO
RF
AP
2OO
2 1
1O
5.O
OM
RF
1 2
1O
1O
AP
2OO
19O
1 2
1O
1O
4
4
18O
18O
GSPD
HDG
O79
33O
3OO 1O
FMS1
KT
DTK
6
CHR O7:12
GSPD
HDG
O79
33O
KT
DTK
6
APP WPT VPTH MSG HDGINT
KPHX 5OO NM 23 MIN
NAV1 118 O3 119 O3
N
3
OO5
H VOR1 VOR2 VHF1 118 O25 119 O25
33
N
W
3O
VHF1 118 O25 119 O25
33
H VOR1 VOR2
3OO 1O
FMS1
3
OO5
29.92 IN
M
3O
CHR O7:12
555
29.92 IN
M
W
555
PFD 2
19O
APP WPT VPTH MSG HDGINT
KPHX 5OO NM 23 MIN
NAV1 118 O3 119 O3
EM170AOM980064A.DGN
PFD 1
1O
2
GP-2603
In case of single HGS configuration, the annunciations will be displayed on both PFDs.
GP Page 52
REVISION 2
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION NORMAL OPERATIONS
HUD A3 SPD T AT
HDG
ALT
LOC
GS
EM170AOM980065A.DGN
The HUD A3 Mode engagement and related FMA annunciations on PFDs are shown throughout the approach sequence. The following steps are displayed: 1) HUD A3 armed: When APPR button is pressed a white HUD A3 armed annunciation is displayed along with armed LOC and GS modes.
2) At localizer intercept, LOC engages and flashes inverse video for 5 seconds:
LOC
AT
ALT
GS
HUD A3 GA
LOC
AT
ALT
GS
EM170AOM980066A.DGN
HUD A3 SPD T
3) After LOC capture, glide slope engages. The HUD A3 remains armed until the airplane flies below the minimum HUD A3 engagement height (1500 ft RA).
LOC
GS
AT
HUD A3 GA
LOC
GP-2603
AT
GS
EM170AOM980067A.DGN
HUD A3 SPD T
GP REVISION 2
Page 53
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
4) Provided all HUD A3 engage requirements are met, when radio altitude is below 1500 ft, the green HUD A3 engaged annunciation appears at the top right side of the FMA and flashes in inverse video for 5 seconds. At the same time, RLOUT arms in the lateral and FLARE arms in the vertical FMA.
SPD
T
AT
RETD
LOC
GS
RLOUT
FLARE
HUD A3 SPD
T
AT
RETD
LOC
GS
RLOUT
FLARE
EM170AOM980068A.DGN
HUD A3
5) Upon HGS command (at 50 ft RA), FLARE mode engages and flashes in inverse video for 2 seconds. The flight director cue is removed in the PFD when FLARE is active.
HUD A3 RETD
LOC
T
AT
FLARE
RLOUT
HUD A3 SPD RETD
LOC
T
AT
RLOUT
FLARE
EM170AOM980069A.DGN
SPD
GP-2603
Starting at an altitude of 100 ft, the Flare Command Symbol, consisting of a single plus sign (“+”), rises from the bottom of the display and joins the guidance cue at the point where the flare maneuver should be initiated.
GP Page 54
REVISION 2
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
HUD A3 FLARE LOC RLOUT
SPD 125
ASEL 122O 5
5
31
3O
32
-3.O
-3.O
IDLE 25
GSPD 114
125O B MIN
HDG 3OO
CRS 31O -1O
RA 6O
VS -6OO
EM170AOM980105A.DGN
124
-1O
DME 1 1.5 NM
LOC1 1O
FLARE COMMAND SYMBOL 6) At 30 ft, Autothrotle RETD mode engages and flashes in inverse video for 2 seconds. HUD A3 LOC
AT
FLARE
RLOUT
HUD A3 RETD
LOC
GP-2603
AT
RLOUT
FLARE
EM170AOM980070A.DGN
RETD
GP REVISION 2
Page 55
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
7) At main gear touchdown, RLOUT mode engages and flashes in inverse video for 2 seconds. The Autothrotle disengages (annunciation in green, no aural alert) and the flashing AT disconnect annunciation is cancelled by pressing the AT quick disconnect pushbuttons on either throttle lever: HUD A3 RLOUT
HUD A3 RLOUT
EM170AOM980071A.DGN
AT
GP-2603
EM170AOM980073A.DGN
Following touchdown, the display declutter removes unnecessary symbology to assist with the landing rollout. This includes changing the localizer symbol to the Ground Localizer Scale and Pointer. The centerline is tracked while the airplane is decelerated to exit the runway. A Deceleration Scale is displayed which shows the inertial deceleration of the airplane during rollout and includes the effect of braking, reverse thrust, runway friction, etc.
GP Page 56
REVISION 2
GENERAL PUBLICATION
LOW VISIBILITY OPERATIONS
GP-2603
EM170AOM980045A.DGN
8) RLOUT and HUD A3 are removed when the airplane reaches safety speed (groundspeed ≤ 20 kt) or turning off the runway. The PFD annunciation is then removed.
GP REVISION 2
Page 57
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
ABNORMAL OPERATIONS •
HUD failure on single configuration If a HUD failure occurs during the approach, the pilot not flying PFD receives and displays annunciations from the off-side system. The advisory EICAS message HUD FAIL will be displayed and the pilot must use PFD guidance.
•
HUD failures on dual configuration
In case of failure of one HUD, the PFD of the failed side receives the off-side system information. The messages HUD 1(2) FAIL or HUD 1(2) A3 NOT AVAIL will be displayed as applicable. Below are 6 examples of the failures that may occur during HUD operations. •
Example 1: HUD 3A Armed WITH Autopilot engaged above 500 ft. 1) Crossing 650 ft, HUD A3 will flash in white inverse video until HUD A3 engages.
AP AT
LOC
GS
HUD A3 AP SPD T AT
LOC
GS
EM170AOM980074A.DGN
HUD A3 SPD T
2) Crew disengages AP FMA AP annunciation toggles red inverse video for a minimum of 5 seconds until the pilot acknowledgement with the AP quick disconnect button.
T
AP AT
LOC
GS
RLOUT
FLARE
HUD A3 T
AT
LOC
GS
RLOUT
FLARE
GP-2603
SPD
EM170AOM980075A.DGN
HUD A3 SPD
GP Page 58
REVISION 2
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
•
Example 2: HUD A3 Armed WITH Autopilot engaged below 500 ft. 1) Crossing 500 ft, HUD A3 white is removed and NO HUD A3 flashes red in reverse video for 5 seconds when first displayed and then goes steady. NO HUD A3 T
AP AT
GS
LOC
NO HUD A3 SPD
LOC
T
AT
GS
EM170AOM980076A.DGN
SPD
Approach warning annunciation (APPR WRN) is displayed on PFDs.
1O
1O
1O
1O
GP-2603
EM170AOM980077A.DGN
APPR WRN
GP REVISION 2
Page 59
LOW VISIBILITY OPERATIONS
Example 3: HUD A3 Failure Above 500 ft. 1) Consider that HUD A3 is engaged with LOC and GS modes active. The minimums are set to RA for a 50 ft DH.
HUD A3 SPD
T
AT
LOC
GS
RLOUT
FLARE
EM170AOM980078A.DGN
•
GENERAL PUBLICATION
2) If the Radar Altimeter 2 fails, an amber "NO HUD A3" annunciation will be displayed and flashes in inverse video continuously until the APPR button is pressed.
SPD
LOC
T
GS
AT
EM170AOM980079A.DGN
NO HUD A3
ROLL
T
AT
FPA
GP-2603
SPD
EM170AOM980080A.DGN
3) When the APPR button is pressed: - Armed modes RLOUT and FLARE are removed. - CAS message HUD 1(2) A3 NOT AVAIL is shown. - No aural warning is given. - Pressing the APPR button cancels the LOC and GS modes and the FD reverts to basic modes (FPA, ROLL) and the NO HUD A3 amber annunciation is removed:
GP Page 60
REVISION 2
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
In this moment the crew must decide if it is safe to continue the approach or if a go around is required. a) Continue on Approach: Pressing the APPR button again arms a lower approach capability (CAT II or CAT I). The pilot must set a new DH, according to the new approach type.
SPD
T
EM170AOM980081A.DGN
APPR 2 LOC
GS
AT
b) Go-Around: Pressing either of the G/A pushbuttons on the throttle levers remove the NO HUD A3 caution visual alert and reset the color of the Minimums displayed on the PFD to normal:
TRACK
GA
AT
TRACK
GA
GA
GP-2603
AT
GP REVISION 2
Page 61
EM170AOM980082A.DGN
GA
LOW VISIBILITY OPERATIONS
•
GENERAL PUBLICATION
Example 4: HUD A3 Failure below 500 ft.
HUD A3 SPD
T
AT
LOC
GS
RLOUT
FLARE
EM170AOM980083A.DGN
1) Consider that HUD A3 is engaged with LOC and GS modes active. The minimums are set to RA for a 50 ft DH.
2) If the Radar Altimeter 2 fails a red "NO HUD A3" annunciation will be displayed, flashing in inverse video for 5 seconds and then remains steady.
T
AP AT
LOC
GS
EM170AOM980084A.DGN
NO HUD A3 SPD
In this case, a go-around shall be executed. Additionally, the following announcements will be displayed: Armed modes RLOUT and FLARE are removed. APPR WARN is annunciated in the PFD. CAS message HUD 1(2) A3 NOT AVAIL is shown. No aural warning is given. Visual annunciations and alerts are removed only after crew starts a Go-around or crossing 500 ft.
GP-2603
-
GP Page 62
REVISION 2
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION •
Example 5: HUD A3 Failure during Rollout. 1) Upon HGS command at main gear touchdown, RLOUT mode engages and flashes in inverse video for 2 seconds. Autothrotle also disengages normally (annunciation in green, no aural alert). HUD A3 RLOUT
HUD A3 RLOUT
AT
EM170AOM980085A.DGN
AT
2) In case of rollout guidance failure, RLOUT annunciation is removed and NO HUD A3 amber is displayed in inverse video for 2 seconds and then goes steady. NO HUD A3 GS
AT
NO HUD A3 LOC
GP-2603
AT
GS
EM170AOM980086A.DGN
LOC
GP REVISION 2
Page 63
LOW VISIBILITY OPERATIONS
•
GENERAL PUBLICATION
Example 6: Approach Limit Exceedance. 1) During final approach, below 500 ft, if the approach conditions exceed HGS preset tolerances or localizer/glide slope signal loss, the APPR WARN is annunciated in the PFD and HUD A3 remains green in the FMA.
LOC
GS
RLOUT
FLARE
T
AT
EM170AOM980087A.DGN
HUD A3 SPD
GP-2603
Even if the approach conditions turns into HGS preset tolerances, the APPR WARN annunciation continues to be displayed on the PFD. In this case, the MISSED APPROACH procedure must be performed unless the approach is continued under visual conditions and the airplane position and attitude assure a safe landing. If the approach is continued the HUD A3 guidance must not be followed.
GP Page 64
REVISION 2
GENERAL PUBLICATION
LOW VISIBILITY OPERATIONS
NON-HUD A3 APPROACHES
GP-2603
During approach, if the Combiner mode is set to AUTO on the MCDU, the display will automatically declutter by removing the Airspeed and Altitude Tapes and the HSI. Altitude and airspeed data are then displayed as digital values near the Flight Path, and ILS data is also displayed. The Guidance Cue is derived from the FGCS and is removed from he display at 50 ft (CAT II) or 150 ft (CAT I). • Flight director modes are displayed. • Between 55 ft and 10 ft, Flare Cue symbols, consisting of two plus signs (“+ +”), are displayed above the wings of the Flight. Path symbol to alert the pilot that the flare maneuver should be initiated. However, no approach monitoring or flare guidance is provided by the HGS. Although the Flare Cue indicates that flare should be initiated, the symbol does not provide any guidance to perform the flare maneuver. Flight director guidance is displayed when pitch and roll command inputs to the HGS Computer are valid.
GP REVISION 2
Page 65
LOW VISIBILITY OPERATIONS
GENERAL PUBLICATION
GP-2603
INTENTIONALLY BLANK
GP Page 66
REVISION 2
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