Flight Controls Flashcards
Describe the Pitch Feel Unit
2 units that artificially generate control feel.
The units use HYD fluid from the L + C system
What are the 3 types of trim?
Electric Trim – Stab
Alternate Trim
Autopilot – Auto trim
What does pushing APP do with respect to the electrical bus systems?
Separates the electrical system.
Uses static inverted to convert DC to AC for the Centre Autopilot
How is trim moved?
2 motors
How does the PES control trim?
R HYD system has a motor that uses trapped line fluid.
¼ rate movement
At what rate does the Autopilot trim?
Half
When does aileron lockout happen?
Outboard = High speed
Inboard = works at all ranges
How are the spoilers controlled?
Electrically controlled
Hydraulically actuated
Aileron droop occurs when?
Take off flap settings
What does a spoiler light indicate?
Spoiler fault
Spoilers fail in pairs
What does an Auto Speedbrake light indicate?
Fault
Do not arm speed brake
450’ penalty applied to LDR (QRH non normal)
What does the speed brake light indicate?
Speed brakes extended below 800’ or landing flap extended
When does the Yaw Damper INOP light extinguish on power up?
1 IRU aligned
How many Flap drive units are there?
3 each wing
Elec control
HYD Actuated
How many fuel quantity probes are there?
- 1 in each of the L and R
2 C probes
How is the gear held down?
Mechanical Down locks
Which hydraulic system is responsible for actuating the landing gear?
C HYD
How is the gear controlled?
Electrically controlled, HYD actuated
What does the Lever lock over ride switch do?
Manually releases the lever lock
If there is no C HYD pressure, can the gear be retracted?
No
How much pressure is required to move the landing gear?
3000psi
Gear handle goes up, what happens?
Doors open
How are the main gear doors held up?
Mechanical uplocks
What does moving the gear handle from UP to Off do?
Slowly releases the HYD pressure from the gear system. Main Gear comes to rest on the doors
Nose wheel held up by mechanical uplocks
If the C HYD system fails in flight, how do we extend the gear?
Call for the checklist
Alternate gear extension
How do the main and nose gear extend?
3000psi from C HYD. Held down with downlocks
What does alternate gear extension do?
Uses electricity to open door uplocks, opens doors (never to close again)
Door light will be displayed because doors don’t close after gear extension
If gear disagree light remains after running checklist, how else can you check if the gear is down?
Set landing flap, and wait for landing configuration warning
When does the main gear logic switch to ground mode?
Tilt is less than 1 degree
Rudder pedal provide a maximum deflection of?
7 degrees
The tiller provides a deflection of?
65 degrees
What is the turn radius?
146’
The parking brake is part of which HYD system?
The normal
If the parking brake valve is off what does that mean?
Parking brake valve is closed. Brakes set
Which fluid is used to set the park brake?
Anti skid return fluid
If the parking brake light is on, what does that mean?
Parking brake valve is open either partially or fully
On taxi, if the parking brake light comes on, what does that mean?
Anti skid not operative. TLR information no longer valid
If the parking brake is set with 1050/1100psi, what happens?
Parking brake will set, but may not hold for very long
Which HYD system do normal brakes require?
Right HYD
If you have normal brakes, what other system do you generally have?
Auto brakes
How do Auto brakes decelerate?
Deceleration rate
Auto brakes 3 selected, how do you transition to manual braking for taxi. How can you disarm auto brakes 3?
Press on the toe brakes
Move thrust levers to TO range
Speed brake handle moved back to down
Select disarm on auto brakes
In flight what could cause auto brake selection to move to disarm?
A fault in the system
R HYD failure
Anti skid failure
Air/Ground logic
When’s does the auto brakes light illuminate
Any time autobrakes disarmed due to normal functions or system faults
With loss of R HYD pressure light, and switching between normal and alternate brakes, what moves the brake valve?
Brake valve will reposition with loss of pressure, not quantity.
How do you know you have successfully transitioned from normal to alternate brakes?
Brake source light is OFF
Alternate brakes, what anti skid do we have?
Alternate anti skid, tandem wheel pairs. No autobrakes
What’s the purpose of the C HYD resevoir standpipe?
Trap fluid from reserve brakes in the event of loss of HYD fluid
What does the brake source light mean?
Loss of C + R HYD
When using accumulator brakes, what are the considerations?
Long dry runway – anti skid with contaminated will depleat brake pressure
Normal brakes and anti skid available
1 steady application of brakes
If the brake source light comes on and goes out by itself, what has happened?
Boeing has met the logic to turn the light off. Follow the checklist
What happens when turning on Reserve brakes and steering?
Boeing forces 2 ISLN valve’s to correct position
C1 HYD pump powered, no matter the position of the switch
Brake source light should go out (if logic met)
What does the Reserve BKS & STRG light mean?
Valve(s) hasn’t gone to correct position
What Anti skid is available with the different modes of braking?
Normal Brakes - Normal
Alternate Brakes - Alternate
Accumulator Brakes - Normal
Reserve Brakes - Alternate
Brake temp warning on EICAS displays when?
5 and above
What attitude will cause a tail strike?
+9.6
What’s the purpose of the tail skid?
Protect from strike and protect pressure
How does the tail skid extend/retract?
With the gear
C HYD only
What does the tail skid light mean?
Disagreement of position with position of gear
Not always in same position as a gear
What are the available positions of the leading edge slats?
Up
Mid
Full (Used with landing flap)
How does alternate flap extension extend flaps?
Electricity – longer extension
How are the flaps moved?
Input
3 flap drive units – they command flap position
HYD/Electric
When is assymetry protection provided for flaps?
LE – in normal and alternated flap
TE – in normal
When does flap load relief work?
Only TE
Flap 25 and 30 only
Load relief retracts flap directly to 20
What brings on a LE Flap Light?
Detected assymetry
Flap disagree
What brings on a TE Flap Light?
Assymetry detected
Flap position disagree
Load relief FAILURE
When would alternate flap extension be used?
No HYD
Handle wont work
When is the PRV closed?
Onb take off, the engines are producing 150+psi, PSV closes to limit duct pressure to approx 42psi
When does the HPSOV open?
HPSOV opens at any low power setting
When there isn’t enough pressure in the ducts
Electrically controlled
Pneumatically operated
What does the PRV do?
Partner of the bleed air value to regulate the bleed air pressure to approximately 42%
Variable position valves
On start up what is the position of the PRV/Bleed valve?
Open
On take off roll what is the position of the PRV/Bleed valve?
Closed
What does the fan air pre cooler do?
Uses outside air to cool down air coming from the engine
What kind of valve is HPSOV?
Non variable
How does the Master Trim air system work?
Takes duct air and warms it for distribution through individual zone control valves
How many recirculation fans are there?
1 FWD
1 AFT
They capture conditioned air for redistribution to the cabin, decreasing Pack workload
Why is the centre isolation valve always open?
When centre isolation valve isn’t open in flight you can’t get air to the ADP, that’s why we don’t ever close it in normal operation
What could bring the bleed light on?
Too much pressure in the valve
What could cause too much pressure in the duct?
HPSOV fully open when not required
PRV stuck open
All isolation valves need to be open for start, why?
So APU can reach all 4 ducts.
1 way check valves mean air has to travel through the ISLN valves.
What could cause too much pressure in the duct?
HPSOV fully open when not required
PRV stuck open
All isolation valves need to be open for start, why?
So APU can reach all 4 ducts.
1 way check valves mean air has to travel through the ISLN valves.
WHat are the 3 pneumatically powered items on the R Duct system?
R Pack
R Wing anti ice
R HYD Resevoir positive pressure
What are the 3 pneumatically powered items on the L Duct system?
L Pack
L Wing Anti Ice
L HYD Resevoir positive pressure
What is pneumatically powered items on the C Duct system?
F Cargo Heat
What are the pneumatically powered items on the Body Duct system?
AFT Cargo Heat
ADP
C HYD REsevoir positive pressure
Bulk Cargo Heat
What do the one way check valves do?
One way check valves before the ISLN valves prevent cross side bleed air with the ISLN valves open.
What are the bleed air valves?
Pressure regulating and shut off valves
Where is bleed pressure and OVHT temperature sensed?
Within the duct
What closes the bleed valve automatically (by Boeing logic)?
OVHT light
What is happening with the display of the OVHT light?
OVHT > Bleed valve closes > associated duct pressure decreases > associated pack off light > matching switch with where the valve already is
