Flight Controls

Question 1

Electric PBIT

Hydraulic PBIT

Answer 1

Power up built in test
Good for 50 hours (powered up time)

Electronic: FFOD item - takes 3 minutes
Tests electronic components of the fly by wire system
Hydraulic: (done on originating flow as needed) - takes 1 minute
tests the hydraulic components of fly by wire

Electric test interrupted if
AC power disrupted
Flight control Mode buttons cycled
Any hydraulic pump is turned on

Hydraulic test interrupted if
Any flight control surface is moved.

Question 2

How many actuators do the rudder and left/right elevators have?

Answer 2

2 each. each powered by two different hydraulic systems. One actuator used at a time usually alternating each day.

Question 3

Flight control Modes

Answer 3

Normal - FCM - flight control modules provide high level functions like AOA limiting

If directed by QRH - Direct - FCM is bypassed and high level functions not available

Fail - when hydraulic system not pressurized.

Question 4

Eicas indications of slats and flaps

Answer 4

shows position. if amber, the system has failed. if dashed lines, position is unknown.

Question 5

Slat and Flap protection

Answer 5

Skew protection: for asymmetric flap or slat movement

Strike protection - stops extension if force required is too great.

Question 6

Flight control mode guarded button. Elevators

Answer 6

Out - normal mode - uses high level functions:
Elevators:
1. AOA limiting with elevator offset to prevent stalls

2. Thrust compensation for thrust changes
3. Elevator control laws to reduce deflections at higher airspeeds
4. Config change compensation
   stabilizes pitch when using speed breaks.

Pressed in (striped) - direct mode - non of the above functions- control input direct to surface.

Question 7

Flight control mode normal: High level functions of Rudder

Answer 7

Rudder flight authority

Yaw damper and autopilot control coordination via AFCS

Question 8

Flight control mode normal: High level functions of Spoilers

Answer 8

Roll spoiler scheduling based on airspeed and speed brakes to give more control at low speeds.

Ground spoiler automatic deployment on landing- stowed if thrust added for go around.

Direct mode! Note: Ground spoilers not available (not even if the spoiler lever is actuated)

Question 9

ACE

FCM

Answer 9

ACE (Actuator Control Electronics) connects the control column to the PTUs electronically
FCM (Flight Control Module) brain that allows high level functions. Conceded to ACE .. controls multifunction spoilers to aid in roll

Question 10

Pitch trim

Answer 10

Manual trim commands are limited to 3 seconds (then aural “TRIM” is announced).

If half the switch is actuated for more than 7 seconds, the switch is disabled.

The red button is the AP/TRIM DISC (disconnect) button. disables both pitch trim channels.

Question 11

Speedbrakes will automatically retract if:

Answer 11

• •
Airspeed is slower than 180 kts,
or Thrust near TOGA (70⁰ TLA), or
Flaps 2 or greater

Question 12

Stabilizer trim priority

Answer 12

1. Back up switches (shown here)
2. Captain
3. First Officer
4. FCM(auto-trim) commands)

Question 13

Yaw trim

Answer 13

Yaw Trim is NOTautomatically accomplished when the autopilot is on.

Question 14

Flap speeds and go around settings

Answer 14

Max Flap Speeds 
Flaps 1: 230 kts 
Flaps 2: 215 kts 
Flaps 3: 200 kts 
Flaps 4 or 5: 180 kts 
Flaps FULL: 165 kts

If approaching Flaps 5, go-around Flaps 2
If approaching Flaps FULL, go-around Flaps 4

Question 15

If pitch trim is outside of green for takeoff

Answer 15

“No takeoff Trim”will be heard when advancing thrust