FLIGHT CONTROLS

Question 1

How many groups of leading edge flaps are provided, and how are they
normally powered?

Answer 1

•Three groups on each wing: outboard, midspan, and inboard sections.
•Normally pneumatically powered from the bleed air duct.

FCOM, VOL 2; 9.20.13

Question 2

What are the two groups of trailing edge flaps, and how are they powered?

Answer 2

•Inboard and outboard
•Inboard powered by hydraulic system 1
•Outboard by system 4

FCOM, VOL 2; 9.20.13

Question 3

Is there any asymmetry protection in alternate flap mode?

Answer 3

•NO, there is no protection provided by the FCUs in alternate mode.

FCOM, VOL 2; 9.20.14

Question 4

How are the trailing edge flaps driven in primary mode?

Answer 4

•Hydraulically

FCOM, VOL 2; 9.20.13

Question 5

How long does the flap indication on primary EICAS remain
displayed after all flaps are up?

Answer 5

10 seconds

FCOM, VOL 2; 9.20.15

Question 6

What protection features do FCUs provide for trailing edge flaps in primary mode?

Answer 6

•Asymmetry protection
•Flap load relief
•Flap position information to EICAS and other systems

FCOM, VOL 2; 9.20.13

Question 7

How many Flap Control Units (FCUs) are provided?

Answer 7

Three

FCOM, VOL 2; 9.20.13

Question 8

What is the maximum extension of the trailing edge flaps in
alternate mode?

Answer 8

•Flaps 25

FCOM, VOL 2; 9.20.15

Question 9

What EICAS Advisory message displays if all three FCUs fail in their control function?

Answer 9

FLAPS CONTROL

FCOM, VOL 2; 9.30.1 & QRH 9.4

Question 10

How does the Flap Alternate Control mode work?

Answer 10

•Bypasses the FCUs
•Can be manually selected
•All flaps are extended or retracted by electric motors

FCOM, VOL 2; 9.20.14

Question 11

Is there any asymmetry protection in alternate flap mode?

Answer 11

•NO
- The FCU provide asymmetry protection in normal mode.

Question 12

What happens if a primary control failure occurs in either the inboard or midspan leading edge flap group?

Answer 12

•Both groups switch to secondary mode

FCOM, VOL 2; 9.20.14

Question 13

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

Answer 13

•Thrust levers 1 and 3 near idle position.
•Main landing gear on the ground
•Reverse thrust levers 2 or 4 pulled up to the idle detent

FCOM, VOL 2; 9.20.11

Question 14

747-8, To improve takeoff performance and reduce noise, outboard ailerons
deflected down* at which flap settings?
They return to the neutral position at which flap settings?
Inboard ailerons droop in which flap settings?

Answer 14

•10 or 20
•25 or 30
•10 or greater
*The downward deflection is removed if the angle of attack
is above the stick shaker

FCOM, VOL 2; 9.20.11

Question 15

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

Answer 15

•Supplies hydraulic power for stabilizer trim
•Shuts off related system hydraulic power if unscheduled
trim detected.

FCOM, VOL 2; 9.10.2

Question 16

What is the affect on the flap system during engine reverse thrust operation?

Answer 16

Inboard and midspan leading edge flaps retract automatically

FCOM, VOL 2; 9.20.15

Question 17

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

Answer 17

•Leading edge of the movable horizontal stabilizer
•Stabilizer trim varies the angle of incidence of the
horizontal stabilizer

FCOM, VOL 2; 9.20.3

Question 18

What is the purpose of the yaw dampers?

Answer 18

To improve airplane lateral and directional stability and
provide turn coordination.

FCOM, VOL 2; 9.20.10 & QRH 9.20

Question 19

How does the aileron lockout system work, and what is its purpose?

Answer 19

Locks outboard ailerons in the neutral position at high airspeeds.
Additional information;
- Permits full travel of the outboard ailerons at low airspeeds
- Prevents over‐controlling at high airspeeds

FCOM, VOL 2; 9.20.7

Question 20

What system assists the 747-8 in pitch stability and landing flare?

Answer 20

Pitch augmentation control system (PACS)
Additional Information
- During the landing flare, this system provides a small amount of nose up
elevator as the airplane approaches the runway, without moving the
control column

FCOM, VOL 2 747-8; 9.20.3

Question 21

When does the 747-8 takeoff and landing tail strike protection activate?

Answer 21

•PACS senses imminent tail strike Decreasing elevator deflection
Additional Information
- Activation of tail strike protection does not move the
control column

FCOM, VOL 2 747-8; 9.20.3

Question 22

Takeoff trim setting is calculated based on__?

Answer 22

FMC calculated:
- gross weight
- center of gravity
- takeoff thrust derate selection
- takeoff flap selection (747-8 only)

FCOM, VOL 2; 9.20.4, 747-8, 9.20.5

Question 23

Will pushing control wheel Stabilizer Trim switches, with multiple
autopilots engaged, cause the autopilot to disconnect?

Answer 23

No Stabilizer trim switches are inhibited with multiple
autopilots engaged

FCOM, VOL 2; 9.20.5, 747-8 9.20.6