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Flashcards in Flight Controls Deck (25):

What is the maximum rudder deflection.....

0° flaps?

5° flaps?

What system prevents this?



Rudder input restrict or mechanism. The flap lever is mechanically linked to the co-pilots forward quadrant.

*Aft rudder 2x deflection


How are controls locked?

Ailerons: Mechanical control lock

Elevator and rudder: Hydraulic dampening


How does flap auto trim work?

Between 15° and 35° both ways


What happens if 1 pcu fails on the rudder?

Operating pressure on other PCU doubles


When do outboard spoilers get disabled?


What controls this?

Airspeed >170 kts

Airspeed thru 165k



What is the purpose of the Rudder Feel Trim and Summing Unit?

Where does it get inputs from?

Provides artificial feedback forces to the rudder pedals.

Receives input from rudder pedals and the yaw damper. It takes the two and transmits as a single input.


How does hydraulic pressure to the rudder PCU vary with airspeed?

It decreases as airspeed increases. Rudder authority is limited as a function of airspeed by the FCECU which gets an input from the ADC. The reduced hydraulic pressure causes less rudder deflection.


What is the indication of rudder trim indication failure?

An off scale deflection of the needle.


Where does the yaw damper get it's inputs from?

What if one fails?

2 FGMs. If one fails you lose the yaw damper.


How do spoilers work on touchdown?

WOW and power leavers (PLA < 12°) send signal to FCECU and PSEU and the lift dump valves are energized.


How is aileron trim activated?

Electrically. Done by deflecting both ailerons.


What is the purpose of the tab on the ailerons

It's a gear tab and assists in aileron movement.


What is the purpose of the pitch feel and trim units (PFTU)

How many?

-Provide artificial feel (provided by the right pitch feel actuator.



How many pitch feel actuators on each PFTU?

What happens if one fails?


FCECU detects failed pitch feel actuator and holds it at its last valid position. The other pitch feel actuator operates normally but with reduced artificial feel. T.he ELEVATOR FEEL caution light will come on.


Where does the FCECU get it's info from?

Both ADCs


What controls elevator trim rate and how does it vary?


Below 150 kts: High speed mode
Above 250 kts: Low speed mode.

Basically higher trim speed rates are required for lower airspeeds.


What is the purpose of the Flap Control Unit (FCU)?

What is an advantage of having an FCU

If the FCU fails which caution lights come on?

Monitors and controls flap movements through the Flap Power Unit (FPU).

It minimizes non-selected flap movements,flap asymmetry if the flap drive line fails.

FLAP POWER or FLAP DRIVE caution lights.


How does the Flap Power Unit drive the flaps?

Converts hydraulic power to rotary motion to operate the flap actuators.


How are the flaps controlled and operated?

Electronically controlled and hydraulically operated.


Which control column is connected to the spoilers?


Capt: Spoilers

FO: Ailerons


What happens if both rudder PUSH OFFs are pressed at the same time?

Nothing! Lights come on but PCUs don't depressurize.


How does the yaw damper work?

It's an actuator that supplies automatic compensation for minor yaw acceleration. It requires an input from both FGMs and improves directional stability and turn co-ordination.


What happens if you push either the SPLR 1 or SPLR 2 switchlight?

ROLL SPLR INBD HYD or ROLL SPLR OUTBD HYD (<165 kts) caution lights will illuminate. SPLR OUTBD caution light also comes on when you push SPLR 2 switch-light.


What happens if you attempt to takeoff with the flight/taxi switch in taxi?

The switch will automatically spring to flight once the power leavers pas FI + 12 degrees. Spoilers will stay retracted and advisory lights will go out.


How many static wicks on the bullet fairing, rudder, and each ailerons and elevators?

Bullet fairing 2

Ailerons 6

Elevators 4

Rudder 3

Ref: AOM 3.3 pg. 3-19 to 3-20