Flight Controls

Question 1

Primary flight control system

Answer 1

Ailerons, elevator, rudder and Multifunction Spoilers
 Mid and Outboard panels

Question 2

Secondary flight control system

Answer 2

Flaps, horizontal stabiliser and inboard spoilers

Question 3

FSC structure

Answer 3

FCCs convert control input to electronic signals which are sent to the REUs, these then command their respective hydraulic actuators to move the control surface

Question 4

Primary controls have how many HA’s

Answer 4

Aileron, elevator and rudder have 2 hydraulic actuators, driven by the left and right hydraulic system

Question 5

Spoilers have how many HA’s

Answer 5

Spoiler has a single hydraulic actuator driven by Either the left or right hydraulic system
Midboard Left

Question 6

16 REUs

Answer 6

o Aileron (4)
o Elevator (4)
o Rudder (2)
o Spoiler (6)
* Controls actuators and Horizontal Stabiliser Trim Actuators (HSTA) on FCC commands
* Report control surface positions back to FCCs
* Each REU has 2 DC power supplies for redundancy

Question 7

16 Flight Control Actuators

Answer 7

o Aileron (4)
o Elevator (4)
o Rudder (2)
o Spoiler (6)
2 types HA and EBHA

Question 8

HAs 9

Answer 8

 One for each primary control surface (5)
 One for each inboard and midboard spoiler (4)
 Uses Left or Right hydraulic system pressure
 Commanded by an REU

Question 9

EBHAs

Answer 9

 One for each primary control surface (5)
 One for each outboard spoiler (2)
 Normally uses Left or Right hydraulic system pressure
 Normally Commanded by an REU
* If normal pressure lost
o Reverts to EB mode
o Uses electric power to drive a pump at the actuator
 Each EHBA has an Motor Control Electronics (MCE) with dual roles for that actuator
* Powers the pump
* Is a Backup REU
o Able to receive FCC commands but unable to report back

Question 10

HA and EBHA Modes

Answer 10

Active - HA and EBHA
Damped - HA and EBHA
Electric Backup - EB

Question 11

Damped Bypass Mode

Answer 11

If actuator fails (Hyd loss, REU fail etc)
* Reverts to a Damped condition
o Hyd pressure damped within actuator to supress surface movement and avoid flutter
* For primary flight controls the Damped actuator will passively follow the working one

Question 12

Electric Backup Mode

Answer 12

When normal hydraulic pressure not available for that surface uses electric power to drive a pump at the actuator

Question 13

FCC power sources

Answer 13

UPS
 FCC 1A and FCC 2B
 BFCU
Left ESS - FCC 1B
Right ESS - FCC 2A

Question 14

Spoilers power

Answer 14

Electrically controlled, hydraulically actuated
o Inboards - Right Hyd
o Midboards - Left Hyd
o Outboards - Right and EBHA

Question 15

Flight control spoilers

Answer 15

Midboard and Outboard work in conjunction with ailerons
Roll spoiler extension 55 degreee max

Question 16

Speed brakes

Answer 16

Max extension
 In-flight up to 30 deg
 On ground 55 deg