Flight Controls - GENERAL

Question 1

Flight Controls

What is the flight control system powered by ?

Answer 1

• The Hydraulic system,
• The Electrical system
• The RAT

Question 2

Flight Controls

What are individual flight surfaces controlled by ?

Answer 2

Individual flight surfaces are controlled by 4 Actuator Control Electronics (ACEs).

Question 3

Flight Controls

How many Actuator Control Electronics (ACEs) are there ?

Answer 3

4

Question 4

Flight Controls

What is the purpose of the 4 Actuator Control Electronics (ACEs) ?

Answer 4

They control individual flight surfaces.

Question 5

Flight Controls

Can pitch and roll still be controlled in the event of the loss of ALL hydraulic power ?

Answer 5

YES, through the electrically actuated stabilizer and 2 spoiler pairs:
• Pitch control ➔ primary and alternate pitch trim switches
• Roll control ➔ control wheel

Question 6

Flight Controls

Can pitch and roll still be controlled in the event of the complete loss of flight control signaling ?

Answer 6

YES, through direct wiring from the flight deck to the stabilizer and one spoiler pair.
• Pitch control ➔ alternate pitch trim switches
• Roll control ➔ control wheel

Question 7

Flight Controls

Can flight control surfaces be LOCKED ?

Answer 7

YES, through 2 flight control lock switches on the overhead panel.
TAIL and WINGS.

Question 8

Flight Controls

What does the FAIL light indicate on the flight control surfaces lock panel ?

Answer 8

A lock switch is in the lock position and one or more of the associated surfaces does not lock.

Question 9

Flight Controls

Can flight control surfaces be locked in flight through the lock switches on the overhead panel ?

Answer 9

NO, flight control surfaces automatically unlock when ground speed > 40 kts.

Question 10

Flight Controls

What happens if a jam occurs in the column, wheel or rudder pedals on one side ?

Answer 10

The pilots can maintain control by applying force to the other column, wheel or rudder pedals to overcome the jam.

Question 11

Flight Controls

How many modes does the Primary Flight Control system have ?

Answer 11

3

• Normal
• Secondary
• Direct

All three modes use the same pilot controls and flight control surfaces.

Question 12

Flight Controls

When are flight controls tested ?

Answer 12

1- After landing a 1st series of flight control self-tests are run when :
• Flaps and Speedbrakes are retracted,
• Ground speed is < 30 kts,
• Hydraulic power is on.

2- An additional series of flight control self-tests are run when:
• First series of tests are complete,
• All hydraulic systems are depressurized.

Question 13

Flight Controls

What happens during each series of the flight control self-tests ?

Answer 13

• Various EICAS alert and status messages display
• the trim indication blinks
• various failures display on the flight controls synoptic page

Question 14

Flight Controls

What happens if the flight control self-tests are not accomplished on two consecutive flights ?

Answer 14

A fault condition may be set.

Question 15

Flight Controls

After landing, what are the conditions to be met for the first series of flight control self-tests to start ?

Answer 15

• Flaps and Speedbrakes are retracted,
• Ground speed < 30 kts,
• Hydraulic power is on.

Question 16

Flight Controls

What are the conditions to be met for the second series of flight control self-tests to start ?

Answer 16

• The first series of tests are complete,

* All hydraulic systems are depressurized.

Question 17

Flight Controls

Approximately how long does the first series of flight control self-tests take ?

Answer 17

90 seconds

Question 18

Flight Controls

Approximately how long does the second series of flight control self-tests take ?

Answer 18

70 seconds

Question 19

Flight Controls

When do the PFCs (Primary Flight Computers) automatically revert to secondary mode ?

Answer 19

• When Inertial or Air Data is insufficient to support normal mode or,
• When all Flap and Slat position data is unavailable.

Question 20

Flight Controls

Can the secondary flight control mode be manually selected ?

Answer 20

NO

Question 21

Flight Controls

What functions are lost in SECONDARY mode ?

Answer 21

• autopilot
• gust suppression
• auto speedbrakes
• envelope protection
• pitch compensation
• roll/yaw asymmetry compensation
• tail strike protection
  (same as direct mode)

Question 22

Flight Controls

When do the ACEs (Actuator Control Electronics ) automatically revert to direct mode ?

Answer 22

• they detect the failure of all three PFCs

- or they lose communication with the PFCs

Question 23

Flight Controls

What functions are lost in DIRECT mode ?

Answer 23

• autopilot
• gust suppression
• auto speedbrakes
• envelope protection
• pitch compensation
• roll/yaw asymmetry compensation
• tail strike protection
  (same as secondary mode)

Question 24

Flight Controls

What is the main difference between secondary mode and direct mode ?

Answer 24

In secondary mode, the PFCs send simplified signals to the ACEs to be sent to the flight control surfaces.
In direct mode, the ACEs directly send signals to the flight control surfaces.

Question 25

Flight Controls

On the ground, what provides actual airplane gross weight and CG information ?

Answer 25

2 nose gear pressure transducers.

Question 26

Flight Controls

What power source provides backup power for the Flight Control Electronics during temporary power interruptions ?

Answer 26

2 dedicated FCE batteries .