Flight Controls

Question 1

What is the only primary flight control that is not FBW (Fly-By-Wire)?

Answer 1

Ailerons.

Note: The Primary Flight Controls are the Rudder, Elevator, Ailerons, MFS (roll control)

Secondary Flight Controls are the Horizontal Stabilizer, MFS (speed brakes), Slats/Flaps, Dedicated GND Spoilers.

Question 2

What is the difference between normal mode and direct mode?

Answer 2

There are no higher level functions in direct mode.

Note: Normal Mode – FBW (Fly-By-Wire) uses electrical signals from the cockpit control, modifies it according to flight conditions to provide the most optimum signal to flight control surface.

Question 3

What are the higher level functions associated with Pitch?

Answer 3

• Gain on airspeed: as airspeed increases, pitch decreases.
• Elevator thrust compensation: provides pitch control during thrust changes.
• AOA limiting: does not allow the aircraft to stall.

Question 4

What are the higher level functions associated with Yaw?

Answer 4

• Yaw damp
• Turn coordination
• Gain on Airspeed: as airspeed increases, rudder deflection decreases.

Question 5

What is the priority for the pitch trim system?

Answer 5

1. Back-up (Switches)
2. Captain (LH Pitch trim)
3. First Officer (RH Pitch trim)
4. Autopilot - FCM (auto trim commands)

Question 6

How is roll controlled?

Answer 6

Ailerons are mechanically controlled through cables, NO FBW, hydraulically actuated through PCU (Power Control Unit) and MFS (Multi-Function Spoilers) which are the outer 3 spoilers on each wing providing roll assist)

Question 7

How many spoilers are on each wing? What are their functions?

Answer 7

Five: 3 outboard multi-function spoilers are used to assist in roll control, as speed brakes, and as ground spoilers. 2 inboard spoilers are only used as ground spoilers.

Question 8

When will the speed brakes automatically close even if the lever shows deployed?

Answer 8

• Slat/Flaps selected to 2 or greater
• Airspeed less than 180 knots
• TLA greater than 70 degrees

Question 9

What is the flap/slat extension/retraction sequence?

Answer 9

Slats extend first
Flaps retract first

Question 10

Will loss of airspeed data cause the flight controls to go into ‘DIRECT’ mode?

Answer 10

Yes

Question 11

Can a FCM override pilot input?

Answer 11

No, the pilot has priority control.

Question 12

What happens to artificial feel if flight controls are disconnected?

Answer 12

Artificial feel is felt at 1/2 the normal rate.

Question 13

How are the flight controls trimmed?

Answer 13

Roll and Yaw - Ailerons and Rudder surface repositioned to anew ‘neutral position’.

Pitch - Horizontal Stabilizer

Question 14

Will the multi-function spoilers function in ‘DIRECT’ mode?

Answer 14

Yes, for roll only and at a default fixed gain.

Question 15

Will the speed brakes/ground spoilers function in ‘DIRECT” mode?

Answer 15

No

Question 16

What happens to the flight control system when the RAT is the only AC power source?

Answer 16

• Horizontal stab trim operates at LO SPEED
• Slat/Flap system operates at LO SPEED
• Slat/Flap position is limited to ‘3’ to allow adequate airspeed for the RAT (The only difference between positions 3 and 4/5 are the slats are left more retracted