CH9 FLIGHT CONTROLS Flashcards
What does the PRIMARY FLIGHT COMPUTERS Disconnect Switch do?
Disconnects the primary flight computers from the flight control system and puts the flight control system in direct mode
The AUTO option can be reselected to attempt restoration of secondary or normal mode operation.
What happens when the PRIMARY FLIGHT COMPUTERS Disconnect Switch is set to AUTO?
Attempts restoration of secondary or normal mode operation
When the system operates in normal mode, it can switch to secondary or direct modes due to system faults.
What does the DISC light indicate when illuminated?
The primary flight computers are disconnected and the system is in direct mode
The light appears amber when this condition occurs, either automatically or manually.
What are the modes of operation for the flight control system?
Normal mode, secondary mode, direct mode
Fill in the blank: The primary flight computers can be disconnected from the flight control system using the _______.
[PRIMARY FLIGHT COMPUTERS Disconnect Switch]
What is the role of the Pitch and Stabilizer Trim Systems in the flight control?
Control the aircraft’s pitch and stabilizer trim adjustments
What is the function of the pitch trim switches?
They are spring-loaded to neutral and can directly move the stabilizer on the ground or change the trim reference airspeed in the air.
In secondary and direct modes, they also directly move the stabilizer.
What happens when the control wheel is rotated?
It deflects the ailerons, flaperons, and spoilers in the desired direction.
What is the purpose of the control column?
It commands the airplane to pitch in the desired direction by pushing or pulling.
In normal mode, it deflects the elevator and horizontal stabilizer; in secondary and direct modes, it deflects the elevator.
In normal mode, what does pushing or pulling the control column deflect?
Elevator and horizontal stabilizer.
In secondary and direct modes, what does the control column deflect?
Elevator.
What does the FMC Stabilizer Takeoff Setting display?
Displays the FMC calculated stabilizer takeoff setting in units of trim
The display is shown in magenta color.
What happens when FMC data is not present or is invalid?
The digital readout is not shown
What does the Stabilizer Position Indicator show?
Displays actual stabilizer position in 0.25 increments from 0.25 to 16.75 units of trim
When does the digital readout and pointer show white on the Stabilizer Position Indicator?
When the trim pointer is outside the green band
What color indicates that the trim pointer is within the green band?
Green
This occurs when FMC performance data is entered.
What does it indicate when the stabilizer signal is not present or invalid?
The digital readout and pointer are not shown
What is shown on the digital readout when the stabilizer trim is inoperative?
An ‘X’ replaces the digital readout
The box, the ‘X’, and the pointer show amber.
What does the green band indicate?
The allowable takeoff trim range
This is based on V1, gross weight, and CG information from the FMC.
What is the default green band range before performance data is entered into the FMC?
From 4 to 9 units of trim
This range is established prior to entering specific performance data.
What happens when the green band signal is not present or is invalid?
The green band is not shown
What is the function of the Alternate (ALTN) PITCH TRIM Switches on the B787?
Spring-loaded to neutral, they directly move the stabilizer on the ground and change the trim reference airspeed in the air in normal mode.
In secondary and direct modes, they also directly move the stabilizer.
What happens when both Alternate (ALTN) PITCH TRIM Switches are pushed on the ground?
Directly moves the stabilizer.
What is the NORM position of the Stabilizer (STAB) Cutout Switches?
Electrical power is supplied to the related stabilizer control unit.
This includes power from the left and right 235 Vac buses.
What occurs if unscheduled stabilizer motion is detected?
Electrical power to the related stabilizer control unit is automatically shut off.
What does the CUTOUT position of the Stabilizer (STAB) Cutout Switches do?
Shuts off electrical power to the related stabilizer control unit.
Fill in the blank: The Stabilizer Trim System is associated with _______.
Pitch and Stabilizer Trim Systems.
What does the RUDDER TRIM Indicator display?
Digital readout displays rudder position in 0.2 increments from 0.0 to 1.0 unit and in 0.5 increments between 1.0 and 17.0 units of trim.
An L or R is displayed to indicate non-zero rudder trim.
What happens when the rudder signal is not present or is invalid?
The digital readout, left/right indication, and pointer are not shown on the rudder position indicator.
What is displayed when the rudder trim is inoperative?
The digital readout is replaced with an ‘X’, and the box, the ‘X’, and the pointer show amber. The pointer remains on the scale at the last known trim position.
What is the function of the RUDDER Trim Selector?
It is spring-loaded to neutral and trims the rudder in the desired direction.
Rotating to the detent runs at low speed, while rotating past the detent runs at high speed.
What effect does rotating the RUDDER Trim Selector have during normal flight control mode?
It disables the transfer of any steady state lateral control to the rudder, potentially causing increased drag and fuel consumption for the remainder of the flight.
How do the rudder pedals react during rudder trim operation?
The rudder pedals move with rudder trim operation.
What is the function of the rudder pedals?
Push - deflects the rudder in the desired direction.
For additional information, refer to Brake System, Chapter 14, Section 20 and Nosewheel Steering, Chapter 14, Section 20.
What happens to the speedbrake lever when thrust lever is advanced to the takeoff thrust position?
The speedbrake lever moves to DOWN and all spoiler panels retract.
What occurs when both reverse thrust levers are raised to the reverse idle detent?
The speedbrake lever moves to UP and all spoiler panels extend.
Fill in the blank: The speedbrake lever moves to _______ when the thrust lever is advanced.
DOWN
Fill in the blank: The speedbrake lever moves to _______ when both reverse thrust levers are raised.
UP
What is the position of the speedbrake lever when all spoiler panels are retracted?
DOWN (detent)
What does the ‘ARMED’ position of the speedbrake lever indicate?
The auto speedbrake system is armed
What happens when the speedbrake lever is in the UP position?
Required spoiler panels extend to their maximum in-flight or on-ground position
Intermediate positions can also be selected for specific aerodynamic needs.
What is the primary mode of the Flap Lever?
Positions the slats and flaps hydraulically
What does the secondary mode of the Flap Lever do?
Positions the slats and flaps hydraulically and/or electrically when the primary mode fails
What does the Flap Gate at position 1 prevent?
Inadvertent retraction of the slats
What does the Flap Gate at position 20 prevent?
Inadvertent retraction of the flaps past the go-around position
What happens when the Alternate Flaps Arm (ALTN FLAPS ARM) Switch is pushed?
Arms the alternate flap control mode and disables primary and secondary flap/slat mode operation
What protections are not available when the Alternate Flaps Arm Switch is activated?
Asymmetry/skew and uncommanded motion protection, slat autogap, and flap/slat load relief
FLAP LEVER INOP
What is the function of the Alternate Flaps Selector in the RET position?
Retraction is accomplished electrically and sequenced so that full flap retraction occurs before the slats begin to retract
What does the OFF position of the Alternate Flaps Selector do?
Deactivates alternate flaps
What occurs when the Alternate Flaps Selector is in the EXT position?
The slats and flaps are electrically extended, with maximum extension at flaps 20 and slats at midrange position
What does the Flap Limit Placard indicate?
Flap extended speed limits for the aircraft
Speed limits are specified for various flap positions.
What does the Normal Flap Position Indication display?
Combined flap and slat positions
This occurs when all surfaces are operating normally.
When is the flap position indication removed?
10 seconds after slat retraction
What mode must the control be in for the Normal Flap Position Indication to function?
Primary (hydraulic) mode
True or False: The indicator shows continuous motion when all surfaces are operating normally.
True
Continuous motion indicates normal operation.
What does the EICAS display show when the flaps are UP?
The slats and flaps are retracted
This indicates that the aircraft is in a clean configuration.
What position do the slats extend to when the flap position is 1?
The slats extend to the midrange position
The flaps are not extended in this position.
What are the flap positions associated with the slats remaining in the midrange position?
5, 10, 15, 17, 18, and 20
In these positions, the flaps extend to the commanded position.
What happens when the flap position is 25?
The slats extend to the fully extended position. The flaps do not move.
What does the flap position of 30 indicate?
The flaps extend to the commanded position
What color indicates that the slats or flaps are in transit to the commanded position?
Magenta
What color indicates that the slats or flaps are in the commanded position?
Green
Fill in the blank: The flap lever position is indicated by a line and number that changes color to ______ when the slats or flaps are in transit.
Magenta
What does the EICAS display indicate for flap/slat load relief?
LOAD RELIEF
What does the Flap/Slat LOAD RELIEF Indication display when retracting the flaps?
Displayed (white) - flap load relief is retracting the flaps, or inhibiting extension, as required to prevent air load damage due to excessive airspeed.
This indication is crucial for preventing structural damage to the aircraft.
What happens to flap and slat position indications if any flap/slat is non-normal?
Slat and flap positions are shown independently. Each wing is also shown separately.
How is indicator motion represented between flap detents?
Indicator motion is continuous.
This provides real-time feedback on flap and slat positions.
What indication color is used when operating in secondary mode?
White.
This color indicates that the system is not in its normal operational mode.
What color indicates an issue with FLAPS DRIVE or SLATS DRIVE EICAS?
Amber.
What do the slat and flap position indications show during extension?
The slat indication fills up (forward) and the flap indication fills down (aft)
This indicates the current position of slats and flaps during extension.
How is loss of position information displayed in the flap and slat indicators?
White outline with no fill and no flap lever position indication
This indicates that the system is unable to provide position data.
What is the limitation of flap and slat extension in alternate mode?
Extension is limited to slats midrange and flaps 20
This mode is activated when the alternate control mode is armed.
What do the flap position index marks reference?
Flaps UP, 5, and 20
How is loss of position information indicated in alternate mode?
White outline with no fill and no position index marks or numbers
How can the flight controls synoptic be displayed?
By pushing the systems (SYS) display switch, then selecting the FCTL synoptic key from the menu page
What indicates an unknown aileron position?
A gray scale and no pointer
How are failed control surfaces or trim functions indicated?
An amber border with an ‘X’ inside
What does a blanked spoiler display indicate?
Unknown position or failed electric spoilers
This applies to the affected spoiler.
What color indicates a normally functioning hydraulic system?
Green
This indicates that the associated hydraulic system is functioning normally.
What color indicates a failed hydraulic system?
Amber
This indicates that the associated hydraulic system has failed.
What does green indicate in electrical systems?
The associated electrical system is functioning normally
What does amber indicate in electrical systems?
The associated electrical system has failed
What does the FLT CTRL MODE indication show when flight controls revert to secondary or direct modes?
Amber SECONDARY or DIRECT
Green text shows for NORMAL mode.
What color indicates that an Actuator Control Electronic (ACE) is functioning normally?
Green
What color indicates a failed Actuator Control Electronic (ACE)?
Amber
What does the NORM position indicate for flight control surfaces?
The respective flight control surfaces are unlocked.
NORM is the standard operational mode for the flight control surfaces.
What does the LOCK position indicate for flight control surfaces?
The respective flight control surfaces are electronically locked and the EICAS advisory message FLT CONTROL LOCKED is displayed.
LOCK is indicated by an illuminated amber light.
What does the Flight Control Surfaces Lock FAIL Light indicate when illuminated white?
A flight control surfaces lock switch is selected and any of the respective flight control surfaces are not locked.
What inputs does the primary flight control system use to command the flight control surfaces?
Conventional control wheel, column, and pedal inputs from the pilot.
These inputs are electronically processed to control the flight surfaces.
What are the three operating modes of the primary flight control system?
Normal mode, secondary mode, direct mode
The system is highly redundant.
What components make up the pilot controls?
- Alternate flap switches
- Alternate pitch trim switches
- Control wheel pitch trim switches
- Rudder trim selector
- Stabilizer cutout switches
- Flap lever
- Speedbrake lever
- Two control columns
- Two control wheels
- Two pairs of rudder pedals
What happens when multiple ACE and/or hydraulic system failures occur?
The EICAS caution message FLIGHT CONTROLS is displayed
This indicates loss of a significant number of control surfaces or other significant faults.
How do ACEs interact with pilot control inputs?
They can transmit inputs directly to the control surfaces or to the PFCs
ACEs also receive control commands back from the PFCs.
What types of data do PFCs use to compute control surface commands?
- Air data
- Inertial data
- Flap and slat position
- Engine thrust
- Radio altitude
True or False: The autopilot sends commands directly to the flight control surfaces.
False
The autopilot sends commands to the PFCs, which then produce control surface commands.
Fill in the blank: The secondary flight controls consist of _______.
[high lift devices consisting of flaps and slats]
These are hydraulically powered with an electrically powered backup system.
What mechanisms allow pilots to maintain control during a jam?
Jam override mechanisms
Pilots can apply force to the other column, wheel, or rudder pedals.
What allows pilot control of pitch and roll in the event of a loss of all hydraulic power?
Electrically actuated stabilizer and two spoiler pairs allow pilot control using primary pitch trim switches, alternate pitch trim switches, and the control wheel.
This system ensures that pilots can maintain control even in the unlikely scenario of hydraulic failure.
In case of a complete loss of flight control signaling, what enables pilot control of pitch and roll?
Direct wiring from the flight deck to the stabilizer and a spoiler pair allows control using alternate pitch trim switches and the control wheel.
This backup system is crucial for maintaining control under extreme failure conditions.
What flight control surfaces provide pitch control?
- Two elevators
- A movable horizontal stabilizer
What flight control surfaces are responsible for roll control?
- Two flaperons
- Two ailerons
- Fourteen spoilers
What is the role of the single rudder in flight control?
Yaw control.
Where are the flaperons located on the aircraft?
Between the inboard and outboard flaps on both wings.
Flaperons enhance roll control and improve slow speed performance.
What happens to the ailerons during high-speed flight?
The ailerons are locked out.
In high-speed conditions, flaperons and spoilers provide sufficient roll control.
At what speed does the rudder become aerodynamically effective during takeoff?
Approximately 60 knots.
This speed is crucial for effective yaw control during the critical takeoff phase.
What assists the flaperons and ailerons in roll control during low-speed flight?
The ailerons operate to augment roll control.
This feature is especially important for maintaining control at lower speeds.
What is the primary function of the spoilers in roll control?
Assisted roll control through asymmetry.
What is the primary function of flaps and slats?
Provide high lift for takeoff, approach, and landing
What type of spoilers are used as speedbrakes?
Symmetric spoilers
Where are the flight control surfaces lock switches located?
On the overhead panel
What is the purpose of the flight control lock switches?
To lock out the flight control surfaces on the tail and wings for maintenance
What advisory message is displayed when a flight control surface is locked?
FLT CONTROL LOCKED
At what groundspeed do flight control surfaces automatically unlock?
40 knots
What does the flight control lock FAIL light indicate?
A lock switch is in the LOCK position and associated surfaces do not lock
List the flight control surface locations.
- Aileron (1 per side)
- Flaps (2 per side)
- Rudder
- Elevator
- Spoilers (7 per side)
- Krueger Flaps (1 per side)
- Stabilizer
- Flaperon (1 per side)
In normal mode, how do pilot control inputs get processed?
Four ACEs receive inputs, send signals to three PFCs, which compute control surface commands.
What happens to pilot controls when the autopilot is engaged in normal mode?
The autopilot system sends control surface commands to PFCs, backdriving the pilot controls.
What is the condition for autopilot operation?
Autopilot is only available during normal mode operation.
What is required for the first series of flight control self-tests after landing?
Flaps and speedbrakes retracted, all hydraulic power on, groundspeed below 20 knots for 5 seconds.
How long do the first series of self-tests take to complete?
Approximately 90 seconds.
What conditions must be met during the second series of flight control self-tests?
Hydraulics must remain unpowered and flaps/speedbrakes must not be moved.
How long do the second series of self-tests take to complete?
Approximately 55 seconds.
What conditions are required for the third series of self-tests?
Both engines shut down and PMG power off.
How long do the third series of self-tests take to complete?
Approximately 90 seconds.
What could cause a fault condition in flight control self-tests?
Skipping tests, interrupting tests, or failing to accomplish hydraulic power-off tests on consecutive flights.
What is the purpose of the fault condition in the flight control system?
It may affect dispatch and require maintenance tests.
What happens during the self-tests in the Primary Flight Control System?
EICAS alert and status messages display, and various failures display on the flight controls synoptic page.
Once self-tests are complete, the EICAS messages are removed, and the display returns to normal.
Fill in the blank: In Normal Mode, the PFCs generate __________ commands.
control surface
Control surface commands are essential for flight maneuverability.
What is the role of Actuator Control Electronics (ACES) in the flight control system?
Provide redundant control in each axis
ACES enhances the reliability of control inputs.
What does the primary flight control system provide during manual flight?
Flight envelope protection
What are the methods used by flight envelope protection to provide crew awareness?
Tactile, aural, and visual cues
These cues help pilots maintain awareness of envelope margins.
Does envelope protection reduce pilot control authority?
No
List the protection functions included in flight envelope protection.
- Bank angle protection
- Overspeed protection
- Stall protection
When does the PFC automatically revert to secondary mode?
When inertial or air data is insufficient or when slat and flap position data is unavailable
What do the PFCs do in secondary mode?
Use simplified computations to generate flight control surface commands
What is the status of elevator and rudder sensitivity in secondary mode?
More sensitive at some airspeeds
This sensitivity can affect handling characteristics.
What functions are not available in secondary mode? (List at least three)
- Autopilot
- Auto speedbrakes
- Envelope protection
- Gust suppression
- Pitch compensation
- Roll/yaw asymmetry compensation
- Tail strike protection
The lack of these functions can impact flight safety and control.
What does the EICAS caution message FLIGHT CONTROL MODE indicate?
The primary flight control system is in the secondary mode
The secondary mode cannot be manually selected.
What triggers the transition to the direct mode in the Flight Control System?
Failure of all three PFCs or loss of communication with the PFCs
The direct mode can also be manually selected.
MOVE PRIMARY FLT COMPUTERS DISC SW TO DISC
Fill in the blank: The direct mode can be manually selected by moving the PRIMARY FLIGHT COMPUTERS disconnect switch to _______.
DISC
This action allows pilots to override the current control mode.
What happens in the direct mode of the flight control system?
Pilot inputs are sent directly to the control surface actuators without PFC command generation.
What caution message is displayed when the system is in direct mode?
PRI FLIGHT COMPUTERS.
This indicates the flight control system is operating in direct mode.
List the functions that are not available in direct mode.
- autopilot
- auto speedbrakes
- envelope protection
- gust suppression
- pitch compensation
- roll/yaw asymmetry compensation
- tail strike protection
These functions are disabled to allow for direct pilot control.
True or False: The airplane handling qualities in direct mode are significantly different from the secondary mode.
False.
Handling qualities are almost the same as in secondary mode.
In direct mode, how is yaw damping affected?
Yaw damping is degraded.
What is the function of the Primary Flight Control System in Direct Mode?
Provides redundant control in each axis
The system includes various control surfaces such as spoilers, ailerons, flaperons, elevators, and rudder.
In Normal Mode, how do pilot control inputs affect pitch control?
Control column input commands the PFCs to generate a pitch maneuver based on column displacement
The PFCs automatically position the elevator and stabilizer to achieve the commanded maneuver.
What do PFCs do in response to pilot commands?
Constantly monitor airplane response and reposition the elevator and stabilizer accordingly
Fill in the blank: In Normal Mode, the control characteristics are similar to _______.
[conventional airplanes]
What do the PFCs provide to minimize airplane pitch responses?
Pitch compensation
PFCs utilize control surface commands to minimize pitch responses to thrust changes, configuration changes, turbulence, and turns.
What is the function of PFCs during turns up to 30° of bank?
Maintain altitude without additional column back pressure
The pilot does not need to add additional column back pressure for turns up to 30° of bank.
What happens when the bank angle exceeds 30°?
Pilot needs to add column back pressure
For turns of more than 30° of bank, additional column back pressure is required.
How do PFCs behave as airspeed changes?
Require pilot control column inputs or trim changes
What command do PFCs issue during a manual landing flare?
Slight nose down pitch command
This allows the pilot to apply normal aft column force during the landing flare.
How is primary pitch trim controlled?
By dual pitch trim switches on each control wheel
Both switches must be moved to command trim changes.
What happens to primary pitch trim switches when the autopilot is engaged?
They are inhibited
Pitch trim does not move the control column.
How does primary pitch trim operate differently on the ground compared to in flight?
On the ground, the stabilizer is directly positioned; in flight, it makes inputs to the PFCs
The trim reference speed is the speed at which the airplane stabilizes without control column inputs.
What is the trim reference speed?
The speed at which the airplane stabilizes with no control column inputs
Once trimmed to zero, the airplane maintains a constant speed.
What do the PFCs do when pilot trim inputs are made?
Automatically move the elevators and stabilizer
This is to achieve the trim change and streamline the elevator.
What is the function of alternate pitch trim?
Controlled by dual pitch trim switches on the control stand
Both switches must be moved to command trim changes.
What is the priority of alternate pitch trim over primary pitch trim?
Alternate pitch trim commands have priority
This applies in all flight control modes.
How does alternate pitch trim operate in flight compared to on the ground?
On the ground, stabilizer is directly positioned; in flight, changes to trim reference speed
This is similar to the operation of primary pitch trim switches.
What operates the stabilizer in alternate pitch trim mode?
The pilot uses the alternate pitch trim switches
What are the functions of pitch envelope protection?
- Overspeed protection
- Stall protection
These functions enhance crew awareness of approaching overspeed or stall conditions.
What does overspeed protection do?
Reduces the likelihood of exceeding VMO or MMO
It enhances crew awareness of approaching an overspeed condition and limits speed trimming.
How does overspeed protection limit the airplane’s speed?
By inhibiting trim in the nose down direction at VMO/MMO
The pilot must apply continuous forward column pressure at twice the normal force to maintain airspeed.
What is the purpose of stall protection?
Reduces the likelihood of exceeding the stall angle of attack
It provides enhanced awareness of the approach to a stall condition.
At what speed does stall protection inhibit trim in the nose up direction?
Approximately the minimum manoeuvring speed
This speed is at the top of the amber band at lower altitudes and can be 10 to 20 knots lower at higher altitudes.
What must the pilot do to maintain airspeed below trim inhibit?
Apply continuous aft column pressure at higher than normal force
This is necessary when the airplane slows to a speed where manoeuvre margin is limited.
What do PFCs calculate based on airspeed?
Feel commands
Control column forces generally increase as airspeed increases for a given column displacement.
What happens during takeoff or landing regarding Tail Strike Protection?
PFCs calculate if a tail strike is imminent and decrease elevator deflection to reduce potential tail contact with the ground.
Activation does not provide feedback to the control column, does not degrade takeoff performance, and is compatible with the autoland system.
Can the pilot override the tail strike protection?
Yes, with continued column input.
How does pitch control in secondary and direct flight control modes differ from normal mode?
Uses simplified computations to generate flight control surface commands.
Control columns command a proportional elevator deflection instead of a manoeuvre command.
What automatic compensations are not provided in secondary and direct modes?
- Flap and speedbrake configuration changes
- Gear configuration changes
- Turns to 30° bank angle
- Turbulence
- Thrust changes
What does the elevator variable feel system provide in secondary and direct modes?
Two feel force levels based on flap position.
With the flaps up, there is a single manoeuvre force level used over a large speed range.
How does pitch control sensitivity change with airspeed in secondary mode?
Can become as much as twice as sensitive compared to normal mode.
What does the feel system provide when the flaps are out of up?
A reduced force level appropriate for approach and landing.
Is there a trim reference speed in secondary and direct modes?
No, there is no trim reference speed.
How do both the primary and alternate pitch trim switches function in secondary and direct modes?
They move the stabilizer directly.
How are stabilizer position commands processed?
Through two independent channels within the flight control system.
Commands come from the primary or alternate pitch trim switches and move the stabilizer using an electric control unit powered by the L2 and R2 AC buses.
What happens if uncommanded stabilizer motion is sensed?
The stabilizer channel that caused the motion is automatically shut down
In normal and secondary modes, an EICAS advisory message is displayed if a channel is inoperative.
What EICAS advisory messages are displayed if a stabilizer channel is inoperative?
STABILIZER L2 or STABILIZER R2
These messages indicate which stabilizer channel is affected.
What occurs in secondary mode if both stabilizer channels cannot be isolated?
Both channels are shut down
The EICAS warning message STABILIZER is inhibited in this mode.
What EICAS warning message is displayed if both stabilizer channels automatically shut down or fail in normal mode?
STABILIZER
This warning is also displayed if automatic shutdown fails to stop uncommanded motion.
Where are the L2 and R2 stabilizer cutout switches located?
On the aisle stand
These switches control electric power to the independent stabilizer channels.
What happens when both stabilizer cutout switches are placed in the CUTOUT position?
Stabilizer operation is disabled and the EICAS advisory message STABILIZER CUTOUT is displayed
The STABILIZER warning message is not displayed in this case.
Does placing both stabilizer cutout switches in CUTOUT clear the STABILIZER warning message if both channels are shut down?
No, it does not clear the warning message
The STABILIZER CUTOUT advisory message is also not displayed.
What remains available for pitch trim if the stabilizer is manually shut down or has failed?
Pitch trim through the elevators
Commands from primary or alternate pitch trim switches change the trim reference speed.
What is the function of the column cutout?
To stop the effects of uncommanded pitch trim input from jammed or failed pitch trim switches
It disables specific pitch trim switch commands if opposed by control column input for more than 2 seconds.
What happens if the column cutout function remains active for more than 20 seconds?
The STABILIZER L2/R2 EICAS advisory is displayed and uncommanded input is removed by system shutdown
This indicates a jammed or failed trim switch.
Is the column cutout function active while on the ground?
No, it is not active while on the ground
This allows trimming nose down stabilizer with aft column input during a touch-and-go.
Where is stabilizer position indicated?
On EICAS and the flight controls synoptic
The EICAS indication includes a takeoff green band.
When does the EICAS stabilizer position indication blank?
When gear is up for 10 seconds or 60 seconds after liftoff
What conditions cause the EICAS stabilizer position indication to automatically display?
The EICAS stabilizer position indication displays if any of the following conditions are satisfied:
* After landing and any pair of pitch trim switches are used
* After landing and groundspeed is less than 40 knots
* In the air with specific EICAS messages active
What EICAS messages can trigger the stabilizer position indication in the air?
The following EICAS messages can trigger the stabilizer position indication in the air:
* FLIGHT CONTROL MODE
* PITCH DOWN AUTHORITY
* PITCH UP AUTHORITY
* PRI FLIGHT COMPUTERS
* STABILIZER
* STABILIZER CUTOUT
What is the purpose of the stabilizer green band monitor?
The stabilizer green band monitor confirms that the green band displayed on the stabilizer position indicator is correct based on the actual takeoff weight and CG. BASED ON ENTRIES IN FMC
How does the stabilizer green band monitor determine actual airplane gross weight and CG?
Two nose gear pressure transducers provide actual airplane gross weight and CG information.
What triggers the EICAS advisory message STAB GREENBAND?
The STAB GREENBAND advisory message is displayed if:
* Computed green band disagrees with pressure transducer data
* The two transducer values are not within set tolerance
* Either transducer has failed
What is the function of the Hybrid Laminar Flow Control (HLFC) system?
The HLFC system reduces aerodynamic drag on the vertical stabilizer.
How does the HLFC system operate?
The HLFC system uses two external door assemblies to automatically provide negative pressure to the leading edges in flight.
Are there any crew procedures or monitoring requirements for the HLFC system?
There are no crew procedures or monitoring requirements for the HLFC system.
Fill in the blank: The stabilizer green band is based on the gross weight and CG entries in the _______.
[FMC]
What are the roll control characteristics in normal mode for the airplane?
Similar to conventional airplanes, but the control wheel commands a roll maneuver dependent on wheel displacement.
The flight control system automatically positions the ailerons, flaperons, and spoilers to achieve the commanded maneuver.
What feature minimizes airplane roll response to turbulence?
Automatic control surface commands.
This feature helps maintain stability during turbulent conditions.
What is the status of ailerons at high speeds?
Ailerons are locked out.
This is a safety feature to prevent excessive roll rates at high airspeeds.
What is incorporated into the flight control laws for roll control?
Aileron trim.
No pilot input is required for aileron trim adjustments.
What does bank angle protection do?
Reduces likelihood of exceeding the bank angle boundary due to disturbances or pilot actions.
It provides roll control inputs when bank angle exceeds approximately 35°.
What occurs if the bank angle exceeds the protection boundary?
Control wheel force rolls the airplane back within 30° of bank.
This command can be overridden by the pilot.
How is excessive bank angle indicated to the pilot?
Changes color to amber on the PFD bank indicator.
This occurs when bank angles exceed 35°.
What is the difference in roll control between secondary/direct modes and normal mode?
In secondary/direct modes, the control wheel commands proportional roll surface deflection instead of a roll rate command.
Roll envelope bank angle protection is not available in these modes.
What are the yaw control characteristics in normal mode for the airplane?
Similar to conventional airplanes, but rudder pedals command a sideslip maneuver.
The airplane sideslip angle is dependent on pedal displacement.
How does the flight control system respond to pilot inputs for yaw control in normal mode?
It automatically positions the rudder to generate the commanded maneuver.
The system continuously monitors the airplane’s response to pilot inputs.
What minimizes the airplane sideslip response to turbulence?
Automatic control surface commands.
What happens to pedal forces as pedal displacement increases?
Pedal forces increase as pedal displacement increases.
Do pedal forces change with airspeed changes?
No, pedal forces do not change with airspeed changes.
What does the rudder ratio changer do as airspeed increases?
It automatically reduces the sideslip command for a given pedal input.
Is sufficient rudder authority provided at all airspeeds to maintain airplane control during engine failure?
Yes, sufficient rudder authority is provided at all airspeeds.
What does the flight control system do during reverse thrust asymmetry conditions?
It attempts to maintain a zero yaw rate by automatically adding rudder corrections.
Do the rudder pedals move during reverse thrust asymmetry conditions?
No, the rudder pedals do not move.
Above what groundspeed does the flight control system attempt to maintain a yaw rate near zero?
Above 60 knots groundspeed.
What cue can the pilot recognize during the initial onset of an engine failure?
The airplane yaw cue.
What happens in flight when a roll or yaw asymmetry condition exists?
The flight control system attempts to maintain zero roll rate and sideslip.
What does the flight control system do after initial inputs during roll or yaw asymmetry?
It transfers any steady state lateral control input to the rudder.
What indication is automatically shown on the EICAS display when the flight control system transfers lateral control to the rudder?
The resulting rudder trim indication.
What happens when the Rudder Trim Selector is rotated in normal flight control mode?
It disables the transfer of any steady state lateral control to the rudder.
What are the potential consequences of disabling the transfer of steady state lateral control to the rudder?
Increased drag and fuel consumption for the remainder of the flight.
What caution message is displayed for large asymmetry conditions?
EICAS caution message ROLL/YAW ASYMMETRY.
What caution message is shown for severe asymmetric conditions with limited roll control?
EICAS caution message ROLL LEFT/RIGHT AUTHORITY.
In which flight control modes are automatic lateral and rudder inputs available?
Only in the normal flight control mode.
What is the function of the wheel to rudder cross-tie?
It reduces maximum sideslip and vertical fin loads.
Is wheel to rudder cross-tie required in normal mode?
No, it is not required; the flight control system automatically controls sideslip and fin loads.
What is Yaw Damping?
The roll/yaw control laws that provide turn coordination and Dutch roll damping.
What does vertical gust suppression do?
Enhances ride quality in the presence of vertical gusts and turbulence by utilizing symmetric deflection of the flaperons and elevators.
This function is active only with the autopilot engaged in Altitude Hold or VNAV level flight modes.
What is the purpose of lateral gust suppression?
Improves ride quality and reduces pilot workload on approach by applying discrete yaw commands in response to lateral gusts and turbulence.
This system helps maintain stability during turbulent conditions.
How many static pressure ports are involved in lateral gust suppression?
Four static pressure ports (two on each side of the vertical stabilizer).
These ports provide necessary inputs for the lateral gust suppression function.
What happens to the control surfaces during the operation of vertical and lateral gust suppression?
There is no movement of the control wheel, control column, or rudder pedal.
This indicates that the system operates autonomously without pilot intervention.
What is the primary mode in which vertical and lateral gust suppression is available?
Normal mode
What manual rudder trim operation is provided in all three flight control modes?
Rudder trim selector located on the aft aisle stand
How many rudder trim rates are available?
Two
What command is given when the rudder trim selector is rotated to the detent?
Low rate
What command is given when the rudder trim selector is rotated past the detent?
High rate
Under what condition are manual trim inputs automatically zeroed during takeoff?
When groundspeed exceeds 30 knots
When are further manual trim inputs inhibited after takeoff?
Until in the air
What inhibits manual rudder trim when the autopilot yaw is engaged?
Autopilot yaw engaged (LAND 3) on approach
What provides pilot awareness of the amount of manual rudder trim applied?
Pedals move to reflect the amount of manual rudder trim
In which flight control mode is automatic rudder trim provided?
Normal flight control mode
What does the system do to reflect any asymmetric condition on the ground or in the air?
Automatically moves the rudder pedals
What prevents running the trim for normal situations like coordinating a turn?
Rudder deflection remains minimal, keeping trim centered
What happens to automatic and manual rudder trim inputs on landing?
They are zeroed
What is displayed on EICAS regarding rudder trim?
Rudder trim indication
When does the EICAS indication blank for rudder trim?
When gear is up for 10 seconds or 60 seconds after liftoff
When does the EICAS rudder trim indication automatically display?
After landing and groundspeed is less than 40 knots
What EICAS messages will activate the rudder trim indication in the air?
- ENG FAIL L (or R)
- ENG SHUTDOWN L (or R)
- ENG THRUST L (or R)
- FLIGHT CONTROL MODE
- PRI FLIGHT COMPUTERS
How does yaw control in secondary and direct flight control modes differ from normal mode?
The flight control system uses simplified computations to generate flight control surface commands and the rudder pedals command a proportional rudder deflection.
In normal mode, the system employs more complex calculations for maneuver commands.
What happens to pedal feel forces in secondary and direct modes?
Pedal feel forces are unchanged from normal mode.
This ensures pilot familiarity and control feel remains consistent.
What is the effect of flap position on rudder response in secondary and direct modes?
With flaps up, the rudder response to pedal inputs is less than when the flaps are not up.
This means that pilot inputs may result in less yaw control when flaps are extended.
List the functions that are inoperative in secondary and direct modes.
- Asymmetry compensation
- Automatic rudder trim
- Flight envelope protection
- Gust suppression
- Yaw damping
These functions are typically available in normal mode to enhance safety and control.
How many sets of spoilers are on each wing and how are they arranged?
There are 7 sets of spoilers, 4 outboard and 3 inboard of the flaperons, numbered from left to right, 1 through 14.
Spoilers on opposing wings are symmetrically paired for balanced performance.
What are the primary functions of spoiler panels?
- Increase drag
- Reduce lift
- Supplement roll control
How are the spoilers powered and what is the purpose of this system?
Each hydraulic system supplies 5 pairs of spoilers, dedicated to different sets for isolation and symmetric operation during hydraulic failure.
This design enhances safety by ensuring that not all spoilers fail simultaneously.
What happens during engine start and taxi regarding spoiler operation?
The flight control system automatically biases the spoilers up to prevent spoiler trailing edges from contacting the flaps.
This prevents potential damage to the flaps during ground operations.
What EICAS advisory message is displayed for the failure of one or two spoiler panels in the air?
The EICAS advisory message ‘SPOILERS’ is displayed.
What EICAS advisory message is displayed when three or more spoiler panels fail?
The EICAS advisory message ‘SPOILER PAIRS’ is displayed.
What are the 14 spoiler panels used for?
Speedbrakes
What are the three marked positions of the speedbrake lever?
- DOWN
- ARMED
- UP
The lever can also be placed in intermediate positions between ARMED and UP.
What happens when the speedbrake lever is in the ARMED position?
Spoilers extend and the speedbrake lever is driven aft to the UP position on landing
This occurs when the main gear trucks untilt and both thrust levers are not in the takeoff range.
Under what conditions do spoilers automatically extend when the speedbrake lever is not in the ARMED position?
- On ground with groundspeed above 85 knots and thrust levers moved to idle
- On ground with both thrust reverse levers moved to reverse idle detent
When do the spoilers automatically retract and the speedbrake lever move to the DOWN position?
- On ground, if either thrust lever is moved to the takeoff range
- On ground, if there is a transition to in the air
- In the air, when either thrust lever is approximately 70% of full travel
In what mode are automatic speedbrakes available?
Normal mode
What does the autodrag function do?
Deflects ailerons upward and raises outboard spoilers to assist in glideslope/glidepath capture
When does autodrag function activate?
When the airplane is on or above the vertical path or in approach mode (V/S or FPA)
Autodrag is specifically designed to aid during landing.
What is the function of Autodrag?
The autodrag function operates by deflecting the ailerons upward and raising the two most outboard spoilers to assist in glideslope/glidepath capture
Autodrag functions only in landing configuration with flaps 25 or 30 and thrust levers at idle.
When does Autodrag function activate?
Autodrag activates during automatic or manual approaches when the airplane is on or above the vertical path
It functions in V/S or FPA mode.
What happens to autodrag surface deflection below 500 feet AGL?
The autodrag surface deflection is gradually removed below 500 feet AGL
This is to ensure flare and touchdown are not affected.
What does the Landing Attitude Modifier (LAM) do?
LAM increases pitch attitude and nose gear height when landing flaps are selected at higher speeds
It increases pitch attitude by partially raising selected lateral control surfaces.
What are the main components of flaps and slats?
The airplane has an inboard and an outboard flap on the trailing edge of each wing, and one inboard and five outboard slats on the leading edge
A two-position Krueger flap seals the inboard slat and the engine nacelle.
What flap positions are designated for takeoff?
Flaps 5, 10, 15, 17, 18 are takeoff flap positions
Flaps 25 and 30 are designated for landing.
What is inhibited to protect against inadvertent flap deployment during cruise?
Flap and slat extension from the UP position is inhibited when speed is more than 260 KIAS or altitude is above approximately 20,000 feet
This inhibit is available only in primary and secondary flap and slat modes.
What is the sequencing of flaps and slats when the flap lever is moved?
Slats extend first and retract last
Fill in the blank: In the flaps 1 position, only the _______ move.
slats
How many hydraulic systems must be pressurized for flaps to move on the ground?
All three hydraulic systems must be pressurized
This is to avoid contact with an unpowered (drooping) spoiler.
What happens when the flap lever is in the UP detent?
All flaps and slats are commanded to the retracted position
What happens when flaps 5, 10, 15, 17, 18, and 20 are selected?
The flaps move to the selected position and the slats remain in the middle position.
What occurs when flaps 25 are selected?
The slats move to the fully extended position and the flaps do not move.
What is commanded when flaps 30 are selected?
The flaps extend to the primary landing position.
What happens during flap retraction?
Flap and slat sequencing is reversed.
What is the function of the mechanical gate at the flaps 20 detent?
It prevents inadvertent retraction of the flaps past the go-around flap setting.
What does the mechanical gate at flaps I prevent?
It prevents inadvertent retraction of the slats past the middle position.
What are the three modes of flap and slat operation?
- primary
- secondary
- alternate
How are flaps and slats controlled in the primary mode?
They are controlled together and positioned using center hydraulic system motors.
What operations occur in the primary mode?
- Autogap
- Flap load relief
What automatically selects the secondary mode?
Any of the following conditions occur:
* Center hydraulic system failure
* Control surfaces travel at less than 50% of normal hydraulic rate
* Flap or slat disagree detected
* Flap or slat primary control failure
* Primary mode fails to move flaps or slats to selected position
* Uncommanded flap or slat motion detected
In secondary mode, how are the slats and flaps controlled?
They are controlled separately and can be positioned by hydraulic or electric motors.
If the slats hydraulic control fails, how are the flaps and slats powered?
Flaps are driven hydraulically and slats are powered electrically.
How is pilot control achieved in secondary mode?
Pilot control is through the flap lever, but operation is limited to flaps 20 by non-normal procedures.
What does the three-position alternate flaps selector do?
Extends and retracts the flaps and slats
The flaps and slats extend simultaneously, but slat retraction is inhibited until the flaps are up.
What is the limitation of flap and slat extension in alternate mode?
Limited to the slats middle position and flaps 20
Asymmetry and uncommanded motion protection, slat autogap and pregap, and flap and slat load relief are not available in alternate mode.
How must the alternate mode be selected?
Manually
Slat and flap operation time in the secondary and alternate modes is greatly increased.
What does the flap load relief system do in primary mode?
Protects the flaps from excessive air loads
If flap airspeed placard limits are exceeded, the flaps automatically retract to a safe position.
What happens when airspeed is reduced after flap load relief has activated?
Flaps automatically re-extend as airspeed allows
Re-extension is limited to the commanded flap position.
What is the maximum flap position during load relief retraction?
Limited to flaps 5
Load relief is available only in the primary mode.
What does the EICAS flap display indicate?
An in-transit flap condition and shows actual flap position
The flap lever does not move during flap load relief operation.
What is the condition for slat load relief activation in the secondary mode?
Airspeed exceeds 240 KIAS with the slats fully extended
They retract to the middle position and LOAD RELIEF is displayed.
What is the function of the slat autogap?
Fully extends the slats to increase wing camber
This improves lift and margin to stall at a high angle of attack.
In what mode is the slat autogap function available?
Primary mode
It is active when airspeed is below 240 KIAS and slats are in the middle position.
What is the purpose of the pregap function in secondary mode?
Moves the slats to the fully extended position from the middle position
This occurs when the flap lever is not UP and airspeed is less than 240 KIAS.
What do cruise flaps optimize?
Performance in cruise by varying the camber of the wing
This reduces drag based on airplane parameters such as weight, airspeed, and altitude.
What happens if the cruise flaps system fails?
EICAS advisory message CRUISE FLAPS SYS is displayed
This occurs with the flaps in an increased drag condition.
Under what conditions are cruise flaps available?
In normal mode, above 25,000 feet, between 0.54 and 0.87 Mach
Control surface movements are minor and no pilot interaction is required.
What happens when a skew condition or asymmetric deployment is detected in the flap and slat systems?
The systems are designed to shutdown and the EICAS caution message FLAPS DRIVE and/or SLATS DRIVE is annunciated.
What are the conditions that indicate uncommanded motion of flaps or slats?
Uncommanded motion is detected when the flaps or slats:
* move away from the commanded position
* continue to move after reaching a commanded position
* move in a direction opposite to that commanded.
What occurs in the flap or slat system when uncommanded motion is detected in primary mode?
An automatic transfer to the secondary mode occurs and the EICAS caution message FLAPS PRIMARY FAIL and/or SLATS PRIMARY FAIL is displayed.
If the motion continues, the system shuts down, and the EICAS caution message FLAPS DRIVE and/or SLATS DRIVE is displayed.
What does ‘flap or slat disagree’ mean?
A disagree is detected when the flaps or slats do not move or move too slowly after a commanded input.
What happens when the rate of motion for flaps or slats is less than half the normal rate?
An automatic transfer to the secondary mode occurs, and the EICAS caution message FLAPS PRIMARY FAIL and/or SLATS PRIMARY FAIL is displayed.
Where are flap position indications displayed?
Flap position indications are displayed on the primary EICAS display.
What happens to flap/slat control indications in secondary or alternate mode?
An expanded flap indication is displayed automatically, showing the position of the left and right flaps and slats separately.
This provides detailed information for the pilot during non-normal conditions.
In alternate mode, what replaces the position commanded by the flap lever?
Flap position index marks at all flap and slat positions, and numbers at flaps 5 and flaps 20.
The index marks serve as a guide for positioning the flaps.
