Flight Controls

Question 1

How many Flap Control Units (FCU’s) are provided?

Answer 1

3

9.20.13

Question 2

What are the basic functions of the FCU’s?

Answer 2

Primary control
Secondary control
Indication and annunciation

9.20.13

Question 3

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

Answer 3

3

Pneumatically

9.20.13

Question 4

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

Answer 4

2

Hydraulically 1 & 4

Question 5

How are opposite trailing edge flaps connected?

Answer 5

Mechanically

9.20.13

Question 6

What protection features do FCU’s provide for trailing edge flaps in primary mode?

Answer 6

FCU’s shut down Primary and Secondary Modes for the failed group.

Question 7

Describe the function of the FCU’s in primary mode

Answer 7

Drive LE Pneumatically
Drive TE Hydraulically
Detect Asymmetry
Load Relief

9.20.13

Question 8

Describe the function of the FCU’s in secondary mode

Answer 8

If primary fails, secondary activates in symmetrical groups.
Driven by electric motors.
TE Flaps can upgrade to HYD when pressure is restored or fully UP if in secondary for other reasons.

9.20.13

Question 9

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

Answer 9

Both groups switch to secondary

9.20.13

Question 10

What happens if a failure occurs in a leading-edge flap group on one wing?

Answer 10

Both switch to secondary after a short delay.

9.20.14

Question 11

What happens immediately if a trailing edge asymmetry is detected?

Answer 11

Primary mode is immediately shut down and secondary mode is not used for the failed group.

9.20.13

Question 12

What EICAS advisory message displays if all three FCU’s fail in their control function?

Answer 12

FLAPS CONTROL

9.20.13

Question 13

How does the Flap Alternate Control mode work?

Answer 13

FCU’s are bypassed for a simplified control system on electric motors with no protection.

9.20.13

Question 14

Is there any asymmetry protection in alternate mode?

Answer 14

No

9.20.13

Question 15

State the actions that occur when the Alternate (ALTN) Flaps Arm switch is pushed

Answer 15

FCU’s are bypassed.
Alternate Flaps selector is armed.

9.20.13

Question 16

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

Answer 16

25*

9.10.18

Question 17

Describe the secondary mode or non-normal expanded flap position indication for leading edge flaps

Answer 17

6 boxes indicate LE flap extension
4 sliders show TE flap extension

9.10.12

Question 18

Describe the secondary mode or non-normal expanded flap position indication for leading edge flaps

Answer 18

6 boxes indicate LE flap extension
Can be: 
White box outline
White Crosshatch
Solid Green
Amber Border
Amber Solid Box
Amber Crosshatch

9.10.12

Question 19

Describe the secondary mode or non-normal expanded flap position indication for trailing edge flaps

Answer 19

4 sliders show TE flap extension

9.10.11

Question 20

What does an amber “X” mean on an expanded flap display?

Answer 20

Position sensor for the respective flap has failed.

9.10.11

Question 21

Describe the Alternate Mode Expanded Flap Position Indicator

Answer 21

6 boxes indicate LE flap extension
4 sliders show TE flap extension

9.10.12