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.