Primary Flight Controls

Question 1

How many elevators are there?

Answer 1

2

Question 2

Which flight computers control the elevators and what is the redundancy sequence?

Answer 2

ELAC 2
ELAC 1
SEC 2
SEC 1

Question 3

Which HYD sources power the elevators and what redundancy is there?

Answer 3

elevator 1: Green, Blue backup
elevator 2: Yellow, Blue backup

Question 4

When will backup hydraulic sys become active with regards elevator control?

Answer 4

If primary HYD sys fails, or ELAC 2 fails.

Question 5

How does the THS move and what hyd systems actuate it?

Answer 5

THS mounted on a screw jack which rotates to move THS. Powered by two HYD motors G+Y.

Question 6

Which flight computers control the hydraulic motors of the THS?

Answer 6

ELAC 2 > motor 1
ELAC 1 > motor 2
SEC 2 > motor 3
SEC 1 > motor 2

Question 7

Can the THS be moved manually, what is the effect?

Answer 7

Yes, manual inputs have priority

Question 8

How many ailerons are there?

Answer 8

2

Question 9

Which HYD sys actuate the ailerons?

Answer 9

Hydraulically actuated by jacks, G+B.
Left Blue, Green backup
Right Green, Blue backup

Question 10

Which flight computers control the ailerons, redundancy sequence?

Answer 10

ELAC 1
ELAC 2
then SECs provide roll control via spoilers

Question 11

Which spoilers make up the ground lift dump?

Answer 11

All 5

Question 12

Which spoilers make up the speedbrakes?

Answer 12

middle 3 (2/3/4)

Question 13

Which spoilers make up the roll control spoilers?

Answer 13

outboard 4 (2/3/4/5)

Question 14

Which flight computers control which pairs of spoilers?

Answer 14

SEC 2/1/1/3/3 () 3/3/1/1/2

Question 15

When will the spoilers automatically deploy (lift dump) during the landing phase?

Answer 15

Both MLG on ground.

Armed: both thrust levers at or below idle, or rev selected on at least one eng (other below MCT)

Not armed: rev selected on at least one eng (other below MCT)

Question 16

If a spoiler is deployed ad associated SEC fails, what happens to spoiler?

Answer 16

retracts

Question 17

If a spoiler is deployed and an associated HYD sys failed, what happens?

Answer 17

Remains in position at time of failure. Aerodynamic forces may provide blowback.

Question 18

How is the rudder hydraulically actuated in normal conditions, and what is the redundancy sequence?

Answer 18

Three independent hydraulic servojacks, operating in parallel.
Automatic op (yaw damping, turn coordination) green servo drives all 3 servojacks.
Yellow servo remains sync and takes over if there’s a failure.
If that fails, auto rudder not avail, AP drops out. Rudder can be moved by blue sys via rudder pedals.

Question 19

Which Hyd sources power which SECs?

Answer 19

GYBYG () GYBYG

Question 20

Which flight computers control rudder movement?

Answer 20

ELAC calculates in auto mode and send to FAC which controls rudder movement

Question 21

If only the blue system is actuating the rudder, what is the implication on rudder operation?

Answer 21

Automatic rudder is inoperative.

Question 22

Describe how the rudder travel limiter functions?

Answer 22

At high speeds the rudder travel limiter prevents large rudder movements which could put excess strain on the fuselage by restricting the movement range.

Question 23

At high aircraft speeds, what happens if you apply a full manual rudder input?

Answer 23

You will get full rudder deflection.

Question 24

If the rudder travel limiter fails in flight, what are the consequences?

Answer 24

Rudder deflection limit stops at the last value reached. At slats extension, full rudder travel authority is recovered.

Question 25

How does the rudder trim function operate, and what components make it up?

Answer 25

Two electric motors.
FAC 1 = motor 1
FAC 2 = motor 2
With AP engaged, rudder trim rotary switch and rudder trim reset pb are not active.

Question 26

What conditions will cause a speed brake inhibition?

Answer 26

1. SEC 1 and SEC 3 FAULTS
2. ELEVATOR (L/R) FAULT
3. AOA PROT active
4. Flaps in config FULL
5. THR above MCT
6. aFLOOR active

Question 27

Above what speed will spoilers deploy in event of RTO?

Answer 27

72kts

Question 28

What is phased lift dump? And when will full lift dump occur?

Answer 28

Partial spoiler extension

Speed brake lever not retracted/ground spoilers armed:
- one MLG on ground
- both the levers at/below idle

Speed brake lever retracted/ground spoilers not armed:
- one MLG on ground
- rev on at least one engine (other thrust lever below MCT)

Question 29

How many slats and flaps are there on the A320?

Answer 29

5 leading edge slats
2 trailing edge flaps

Question 30

Which HYD sys actuates the slats and flaps, and which computers control movement?

Answer 30

Movement calculated by SFCCs
Flaps hydraulically powered by Y and G
Slats hydraulically powered by G and B

Question 31

If one of the hydraulic inputs or associated comp fail, what is the effect on surface deployment?

Answer 31

If one SFCC is inop, slats and flaps at half speed.
If one HYD sys inop, slats or flaps at half speed.

Question 32

What happens behind the scenes when the flap handle is moved?

Answer 32

SFCCs check current posn of surfaces at gearbox
SFCC energises PCU (both had pumps) to drive gearbox
Position pick off sensors will indicate when at desired posn
Pressure off brake interrupts hydraulic supply to motors and surface travel stops.

Question 33

What happens if a flap mechanism failure occurs?

Answer 33

Flap disconnection system detects excessive differential movement, and inhibits flap operation to prevent damage.

Question 34

What happens if the flaps or slats deploy unevenly?

Answer 34

APPU measures asymmetry between L/R wings. WTB activates. Cannot be released in flight.