Flight Controls - Question Bank

Question 1

Describe the function of the Stabilizer (STAB) Trim Cutout Switches, AUTO position.

Answer 1

• Supplies hydraulic power for stabilizer trim

- Shuts off related system hydraulic power if unscheduled trim detected.

Question 2

What surface component is moved when stabilizer trim inputs are made?

Answer 2

• Leading edge of the movable horizontal stabilizer

- Stabilizer trim varies the angle of incidence of the horizontal stabilizer.

Question 3

State what occurs when the Stabilizer Trim CUTOUT switches are in CUTOUT.

Answer 3

Shuts off related hydraulic power to stabilizer trim.

Question 4

Describe the function of the alternate trim switches.

Answer 4

• Trim commands through a separate control channel

- Increased range of stabilizer trim travel

Question 5

How do the FMCs calculate correct stabilizer trim greenband?

Answer 5

They use:

• Calculated CG
• calculated gross weight
• Takeoff thrust de-rate selection

Question 6

How does the aircraft provide a crosscheck to ensure the correct greenband has been displayed?

Answer 6

Nose gear oleo pressure switch position is compared to the calculated greenband

Question 7

What is the effect on stabilizer trim if the control wheel stabilizer trim switches are used while the autopilot is engaged?

Answer 7

• Single autopilot engaged: the autopilot will disengage and the stabilizer trim will move in the desired direction
• Multiple autopilots engaged: the control wheel stabilizer trim switches are inhibited

Question 8

State the effect on the autopilots and stabilizer trim, if the alternate trim switches are used with any number of autopilots engaged.

Answer 8

Alternate trim switches:

• override autopilot trim commands
• do not cause autopilot disengagement

Question 9

How many spoiler panels are provided?

Answer 9

6 panels on each upper wing

Question 10

Which spoiler panel does not function as a flight spoiler?

Answer 10

Inboard spoiler on each wing

Question 11

Which spoiler panels function as speedbrakes in flight?

Answer 11

4 inboard spoilers on each wing

Question 12

Which spoiler panels function as ground spoilers when on the ground?

Answer 12

All 6 spoilers on each wing

Question 13

Which spoiler panel is displayed on the EICAS status display?

Answer 13

• 4th panel from the left wingtip on the left wing (flight spoiler, speedbrake, and gnd spoiler)
• R outermost panel (flight and gnd spoiler only - speedbrake extension is not displayed on the right wing spoiler indicator)

Question 14

Which spoiler panels are extended with the speedbrake lever in the flight detent position?

Answer 14

• 2 inboard spoilers on each wing extended to mid-travel

- 2 mid-span spoiler panels on each wing extend to full travel

Question 15

When do spoiler panels extend to the UP position during landing, if the speedbrake lever is ARMED?

Answer 15

• Main landing gear touchdown

- Thrust levers 1 AND 3 near idel

Question 16

When do the spoiler panels extend to the UP position during landing if the speedbrake lever is NOT Armed?

Answer 16

• Main landing gear touch down
• Thrust levers 1 AND 3 near idle
• Reverse thrust levers 2 OR 4 pulled up to the idle detent

Question 17

Since the speedbrake lever is in the DN position during takeoff, what action provides an automatic spoiler function for RTO?

Answer 17

Reverse thrust levers 2 OR 4 pulled to idle

Question 18

For go-around protection, what action drives the speedbrake lever to the DN position?

Answer 18

Thrust lever 1 OR 3 advanced from idle (regardless of whether ground spoilers were automatically or manually selected)

Question 19

Which elevator panels are displayed on the Surface Position Indicator?

Answer 19

Left and right outboard elevator positions

Question 20

What can you do if you lose elevator control due to a jam?

Answer 20

When significant manual force is applied to the control column, shear outs between the inboard and outboard elevators allow elevator control to be regained

Question 21

Describe the elevator feel system.

Answer 21

• Mechanism provides artificial feel at control columns
• Force increases as airspeed increases
• If both Hyd Sys 2 & 3 fail- mechanical springs provide feel force (feel force is not longer a function of airspeed).

Question 22

How does the aileron lockout system work?

What is its purpose?

Answer 22

Works: Locks the outboard ailerons in the neutral position at 238 knots

Purpose:

• Permits full travel of the outboard ailerons at low airspeeds
• Prevents over-controlling at high airspeeds
• Provides the required roll authority at low airspeeds

Question 23

What would happen if you use aileron trim with the autopilot engaged?

Answer 23

• Aileron neutral point is repositioned
• When A/P disengaged- the wheel and ailerons move to the repositioned aileron neutral point
• Airplane responds with roll proportional to the amount of aileron trim input

Question 24

How do the rudder ratio changers work?

Answer 24

• Gradually reduce each rudder surface’s response to pedal inputs as airspeed increases
• Protects vertical tail from stresses caused by large rudder surface deflections at high airspeeds

Question 25

What is the purpose of the yaw dampers?

Answer 25

• Improve airplane directional stability

- Provide turn coordination