Flight Controls - Complete Flashcards
The ailerons are commanded by… ?
Conventional control cables
How are the ailerons controlled?
Via control cables that run from each control wheel to a pair of hydro-mechanical actuators: PCU’s
The primary control electronics include what two complimentary parts?
The PACE - Primary Actuator Control ElectonicsFCM - Flight Control Module
The Pitch Trim Switch on the yoke will be deactivated under what circumstances?
If only half the switch is activated for longer than 7 seconds
Maual pilot trims are limited to… ?
3 seconds
The AP/TRIM DISCONNECT button on the yoke does what?
It disables both the HS-ACE channels while pressed. Once released the channels are active.
The guarded PITCH TRIM SYS 1/2 CUTOUT button accommplishes what?
Disables the respective HS-ACE channels.
Pushing the guarded FLIGHT CONTROL MODE BUTTON
Places the associated system into direct mode.
What does a white dashed box represent on the flight controls page?
A white dashed box is shown only for suface position greater than 50% of its deflection.
What does a surface line and the surface with green stripes represent on the flight controls page?
Deployed
What does an amber line, a white dashed box and an amber cross represent on the flight controls page?
Failed retracted
What does a white dashed box, surface amber stripes and amber cross represent?
Failed deployed.
If the value of the PBIT remaining time is higher or equal to _____ the value is shown in _____
5 , green
If the value of the PBIT remaining time is lower than ____ the value is shown in ____
lower than 5, cyan
The cyan pointers on the SLAT/FLAP position show what?
Show the commanded position
Tick marks at the end of the SLAT scale represent what?
positions at 0 and 25
Tick marks at the end of the FLAP sacle represent what?
positions at 0 and 35
In the case of a SLAT/FLAP jamming what indications are there?
There is an additional box displayed in amber, as well as the readout.
There are 5 tic marks on the ROLL and YAW trim indicator representing what?
0-50-100% each side
How many ACE - Actuator Control Electronics are there?
9
How many FCM’s are there?
4
How many primary ACEs are there?
3 Primary ACE ( P-ACE)
What do the P-ACE do?
Control the rudder and elevator surfaces
Each P-ACE has how many channels
Each P-ACE has two channels, one is active the other is standby
How many SF-ACEs are there? What are they for?
Two SF-ACEs. They are for the SLAT/FLAP
How many different types of ACE’s are there and what are they?
4 ACEs - Actuator Control Electronics P-ACE - Primary SF-ACE - Slat / Flap HS-ACE - Horizontal Stabilizer S-ACE - Spoiler
How many FCM’s are there?
Four
The SF-ACEs reside within… ??
The FCM’s
What do the ACE unites do?
They connect the control column electronically to the respective flight control surfaces
What do the FCMs do?
Provide software-based assistance to the P-ACE and is required for normal - mode operation. Provides high - level functions such as AOA limiting to the P-ACE units
FCM 1 and 2 are located in?
MAU #1
FCM 3 and 4 are located in?
MAU #3
What connects the FCMs to the P-ACE?
The Controller Area Network Bus ( CAN BUS )
What are the modes of operation for the FBW system?
Normal Mode and Direct Mode
What does Normal Mode include to limit the P-ACE?
Takes into account airspeed, elevator control laws, auto thrust compensation, AOA, rudder airspeed gain and limiting, yaw damper, rudder authority, configuration gain compensation.
In Direct Mode what changes are there to the FBW system
The FCMs are removed from the control loop.
When the FCM’s are removed what mode is that and what happens?
Direct Mode: control limits default to fixed control laws, values set by the hardware in the P-ACE
If air data is lost what happens.
The FBW defaults to Direct Mode
When in Direct Mode explain how control input affects the flight controls.
Control Input provided by either control yoke is sent directly to the surface, bypassing the FCM.
What is the communication link between the P-ACE and the FCM?
The Controller Area Network BUS - CAN BUS
The IRS provides attitude and acceleration information to the … ?
… to the FCM’s for AOA limiting.
What Modes of Operation are there under Normal Mode?
Elevator Control Laws scheduling with airspeed
Auto-Thrust Compensation with Elevator
Rudder Airspeed Gain Scheduling and Stroke Limiting
Yaw Damper and turn coordination via the AFCS
Rudder Flight Authority
Roll Spoiler Scheduling with Airspeed and Speed Brake Deployment
What are some sources of information for the Flight Control Systems
Smart probe and Air Data Application modules IRS Proximity Sensors BCM - Brake Control Module FADEC
The Electrical PBIT expires when
After 50 hours
What interrupts the Electrical PBIT
if any ACMP - Electric Hydraulic Pump is turned on
if the FCP switches are cycled
if AC power is interrupted
When is the Electrical PBIT completed
Automatically performed with the power up of any AC source
How long does the Electrical PBIT take to accomplish?
3 minutes
What does the electric PBIT accomplish?
Tests the FCMs, P-ACEs, and SF-ACEs for failures and out of tolerance conditions
What is displayed while the Electrical PBIT is in progress
FLT CTRL TEST IN PROG status message ( White )
What does the Hydraulic PBIT do?
Provides functional test of the flight control actuators
When is the Hydraulic PBIT accomplished
Automatically on the ground when all 3 hydraulic systems are pressurized.
How long does the Hydraulic PBIT take to complete
One minute
What will interrupt the Hydraulic PBIT?
If any flight control surface is moved
What are the conditions when the Hydraulic PBIT is not automatically completed?
If the temperature of the Hydraulic Reservoir is lower than 10 deg C ( 50 deg F )
How do is the Hydraulic PBIT re-run if interrupted
All 3 hydraulic systems must be completely depressurized then pressurized.
If the hydraulic reservoir temperature is lower than 10 degrees will the Hydraulic PBIT run automatically?
NO… unless it is expired indicated by the EICAS message: FLT CTRL BIT EXPIRED
Where can you find the time remaining for each PBIT?
On the flight control page
How many control channels are there for the elevator, rudder and horizontal stabilizer
There are 2 each
Which channels are active on the elevator, rudder and horizontal stabilizer?
1 of 2. They alternate based on Odd-Even Day Logic to allow for even wear.
If the Odd - Even day logic results in a different configuration, does it require a write up and can the aircraft depart?
No write up is required unless it is accompanied by an EICAS message. YES the aircraft can depart.
In the case of loss of all electrical, what back up is there for the FBW system?
There is a DEDICATED battery charged by DC ESS 3 that provides power to keep the elevator and rudder actuarors operating for 15 minutes.
What keeps the FBW back up battery functional?
There is an internal heater to insure proper temperatures and protected from powering back to the DC ESS BUS via an internal rectifier.
Explain the FBW Pitch Control
Electro-Hydraulic Elevators
Electro-Mechanical Horizontal Stabilizer
How many PCU’s are there on the Elevator
Total of 4 and they are independently controlled by the four P-ACE channels.
How is the Elevator Control System effected with the loss of the FCM
Loss of gain scheduling as a function of airspeed, elevator thrust compensation, and AOA limiting.
With the loss of the Elevator FCM what is lost?
Elevator High Level Functions as well as the AUTO PILOT
What will cause the loss of Auto Pilot
In Direct Mode when the FCM is removed from the control loop
How many PCUs on the elevator?
Total of 4 with the actuators on each surface alternating between active and standby every time the system is powered up.
What causes the standby PCU to become active?
The loss of hydraulic supply to the other, forces the standby PCU to become active.
What happens if there is a jam detected in the elevator?q
The respective elevator surface will remain fixed in that position, allowing the pilot to control the pitch with the remaining elevator.
If the Elevator FBW system defaulted to Direct Mode how is it reset?
By pressing the dedicated “ELEVATORS” on the FLIGHT CONTROLS MODE panel
What happens when the ELEVATORS button is pressed on the FLIGHT CONTROLS MODE panel?
All 4 FCM Elevator channels to change from Normal to Direct Mode. In addition, the active elevator channels transition to standby.
On the horizontal stabilizer, how many actuators are there?
One - A single electrical mechanical actuator with 2 DC motors to drive the actuator.
How many degrees is the elevator command limited to under the FCM guided ELEVATOR THRUST COMPENSATION FUNCTION
5 degrees.
What is the ETC - Elevator Thrust Compensation OFF LOAD function.
For long term control, the ETC commands are off loaded to the stabilizer.
What is the time limit of the split trim switches when activated seperately
7 seconds… If only one half is activated for 7 seconds, that switch is then deactivated.
Manual trim inputs are limited to …
3 seconds.
What is the Stabilizer Trim Priority Logic
Backup Switches
Captain
FO
FCM commands
Is there a mechanical connection between the control column and the elevator control surfaces?
NO - FBW
How many Artificial Feel Units are there?
2 - one for each torque tube incase a disconnect, the remaining elevator surface will retain artificial feel.
Can the elevator disconnect mechanism be reconnected if pushed in?
NO
Aileron Control is accomplished through… ?
Conventional cable system
If the RAT is powering the aircraft during an electrical failure, how is the trim effected?
It operates at half speed.
If there is an aileron jam on the right side, does the captain retain artificial feel?
Yes… the captain retains control of the left aileron and the pair #5 multi function spoilers with artificial feel
If there is an aileron jam on the left side, what control remains.
The FO retains control of the right aileron with #4 multi function pair… yet WITHOUT artificial feel.
Horizontal Stabilizer is …
Electro Mechanical
What else besides the pilot’s input via the trim switches affect the control of the electro mechanical servo motor couples to the Horizontal Stabilizer Actuator - HSA
the FCM for autopilot trim and speed brake auto trim
What moves the Horizontal Stabilizer
HS-ACE and one HSA - Horizontal Stabilizer Actuator
What control surface are you moving with the horizontal trim switches?
The Forward Surface - Horizontal Stabilizer.
How many PCU actuators are there on the rudder
2
The upper Rudder PCU is commanded by who?
The captain commands the upper PCU
The Lower Rudder PCU is commanded by who?
The FO commands the lower PCU
In the event of electrical emergency how is the Horizontal Stabilizer effected?
Only the HS-ACE channel 2 is operational at half rate.
The lateral roll system is controlled by what?
Conventional cable controls for the ailerons and FBW multi function spoilers.
In the event of the captains side aileron jam, can the FO trim the ailerons?
NO… he loses both artificial feel and roll trim.
Why? Because the AFU is attached to the captains side of the system.
If one aileron PCU is lost… what happens?
It will be disconnected and the other will provide control. yet the force authority will be halved as they share force authority. If the FCM detects this an EICAS message will be displayed.
How many Multi Function Spoiler Panels are there?
6 panels numbered from inboard to outboard.
L3-4-5
R3-4-5
In the event of Spoiler FCM failure what happens?
The FCM associated with the failure turns to Direct Mode. Yet the rest of the spoilers remain in Normal Mode.
The rudder has how many PCU’s
2 PCUs
The upper actuator is controlled by Hydraulic 1
The lower actuator is controlled by Hydraulic 3
The Rudder is controlled by how many P-ACE modules and how many FCM units?
Two independent P-ACE modules drive the upper and lower PCU’s
Four independent FCM units provide high level control such as yaw damping, turn coordination, as well as gain scheduling as a function of airspeed.
How many Direct Modes are there in relation to YAW?
There are Two
Low Speed Fixed Gain
High Speed Fixed Gain
What is the Direct Mode HIGH SPEED FIXED GAIN in YAW
In DIRECT MODE it is automatically selected when the slats and flaps are extended. It ensures rudder movement is limited at high speeds, providing structural protection
What is the Direct Mode LOW SPEED FIXED GAIN in YAW
In DIRECT MODE it is automatically selected with the slats and flaps extended. It ensures there is enough rudder authority to control the aircraft in the approach and landing.
If the Rudder is jammed due to a jammed PCU what happens?
The rudder will be hydraulically locked at the current position.
If the Rudder pedals become jammed what happens?
The rudder remains active and will be actuated by high level functions ( yaw damping and turn coordination )
What are the high level functions for YAW
Yaw damping and turn coordination
How many slat surfaces are there?
Four per wing - total of Eight
How many SF-ACES are used to control the Slats and Flsps
Two
The SF-ACES command what??
Power Drive Units - PDUs that are electrically operated
How many flap actuators are there per side
Four flap actuators per side
Do the SLATS operate normally in the case of a FLAP FAIL Caution EICAS Message?
Yes
Do the FLAPS operate normally in the case of a SLAT FAIL Caution EICAS Message?
Yes
Explain the Higher Functions in Normal Mode for the Rudder
With increasing airspeed, rudder gain is reduced by the FCM in order to compensate for the rudder effectiveness and maintain structural protection.
Also there is Yaw Damping and Turn Coordination.
Do you lose yaw damping if pushing the RUDDER button and going into Direct Mode for Rudder?
…. ?? … I don’t know the answer to this question
What are the 7 NORMAL MODES of operation
Elevator Control Laws Auto Thrust Compensation AOA Limiting Rudder Airspeed Gain Yaw Damper and Turn Coordination Rudder Flight Authority Roll Spoiler Scheduling with AS and Speed Brakes Configuration Change Compensation
Can you move the Flaps / Slats when you have a FLAP FAIL or SLAT FAIL message on the EICAS
NO… the system is shut down as there is a differing movement of a panel
What drives the flaps?
PDUs - Power Drive Units
Are the flaps electric or hydraulic?
Electric via PDUs commanded by the SF-ACE
What does the EICAS message SLAT-FLAP LEVER DISAG mean?
If the respective surface has not reached the selected position.
With the EICAS message SLAT-FLAP LEVER DISAG what happens to the SLAT - FLAP system?
The other system can still be operated normally.
What is going on when you have both
FLAP / SLAT FAIL
SLAT / FLAP LEVER DISAG
Strike Protection. Can reselect flaps / slats back to the previous position and try again… it can then be commanded in both directions up to 2 more times. After that, if a excessive load is detected, the affected surface is de-energized.
If on emergency power via the RAT are the slats and flaps available?
YES… yet only at half speed
AND
The SF-ACE prevents deployment of slats and flaps beyond position THREE
On the ground, when are the Multi Function Spoilers deployed?
Weight On Wheels
Wheel Speed is above 45 KT or Airspeed is above 60 KIAS
Thrust Lever Angle is below 26 degrees
After landing the Multi-Function Spoilers will retract when?
Wheel speed is below 45 KTS for 5 seconds
If the throttles are moved beyond 35 TLA
Do the ground spoilers deploy on a bounce landing?
The on ground signal is held for 5 seconds after the “In Air” WOW signal is sensed. If the TLA is greater than 24 degrees, the ground spoilers are retracted
What is the multi function spoiler deploy limit on the ground and in flight
Full deflection on the ground 40 degrees
In flight limited to 30 degrees
Are Speed Brakes available in Direct Mode
NO
If Speed Brakes are extended on approach, when will they retract automatically?
When Flaps 2 selected
Below 180 KIAS - won’t deploy either
When the TLA is 70 degrees
AOM and Notes Complete
Complete
