Flight Controls

Question 1

Flight control computers

Answer 1

2 ELAC’s function as primary flight control computer. Sends the need for spoiler roll to the SEC’s and rudder movement to the FAC’s
3 SEC’s Direct control of the spoilers and backup of elevator and trimmable horizontal stabilizer. SEC 3 does not provide any backup control
2 FAC’s Provide control of the rudder and associated rudder functions. Compute flight envelope limits. Only one active at a time while the other acts as a backup. Not depicted on F/CTL page. If both lost a mechanical connection to rudders is used

Question 2

Normal to Alternate to Direct Law

Answer 2

Normal to Alternate:
Both ELAC’s fail or
All 3 SEC’s fail or
Both FAC’s fail
Alternate to Direct:
More significant failures

Question 3

Pitch control

Answer 3

Autopilot or stick movement to ELAC’s to servos on elevator

Servos operate in one of three different modes:
Active
Damping
Centering

F/CTL page elevator indicator turns amber when both associated hydraulic systems are unable to provide pressure and changes to amber xx when position cannot be determined caused by both ELAC’s and SEC’s 1&2 have failed or turned off

Question 4

Pitch Trim on F/CTL page

Answer 4

The word PITCH is normally white and turns amber when trim jams
And the numbers change from green to amber if hydraulic pressure is low.
With the loss of both G and Y systems THS movement is not possible

Question 5

Flight control overview

Answer 5

AP or side stick to
ELAC’s to
Aileron servo and SEC’s and FAC’s and elevator servos

Question 6

Roll Control

Answer 6

ELAC’s to aileron servos
On F/CTL page normally white and turns to amber if hydraulic systems G and B cannot provide pressure.
If both ELAC’s have failed or been turned off they’re two amber xx’s

Question 7

Spoilers

Answer 7

On F/CTL page:
Green: normal
Amber: fault arrow while extended and failed spoiler number if failed when retracted

Question 8

Rudder control

Answer 8

Side stick to FAC’s (one is active at a time)
FAC’s to servos. 3 separate hydraulic servos each powered by separate system.
Dual FAC failure rudder peddles mechanically move rudder with at least one hydraulic system required
F/CTL page turns amber when all three hydraulic systems are unavailable
Amber xx indicates loss of both FAC’s and total loss of rudder trim
Rudder trim automatic with autopilot on

Question 9

Speed Brakes/Spoilers

Answer 9

A320 limited to 1/2 with auto brake
Partial extension when only one landing gear compressed and at least one thrust lever REV

Amber SPEED BRK on E/WD indicates brakes are deployed with engines above idle

Question 10

Flaps/Slats

Answer 10

SFCC receive input from handle then they signal slat/flap motors
SFCC also control WTB (wing tip brake) in the event of assemetric

Two motors for slats B and G and two motors for flaps Y and G. 1/2 speed if one system is lost.
Slats move independently of flaps

Question 11

Position 1 flap handle

Answer 11

T/O: 1+F which is first slat and flap position
Landing: position 1 give slat 1 only
Inflight: Position 1 from position 2 or greater gives 1+F

Question 12

Slat/Flap indicators

Answer 12

Provide info to E/WD
If these sensors fails amber x’s appear on E/WD
Since they are separate from the SFCC’s function of the slat/flaps is still normal and position is verified from cabin and pylon labels

Question 13

Slat/Flap abnormal

Answer 13

Hydraulic failure or both SFCC results in amber indications on E/WD
Amber F-LOCKED or S-LOCKED on E/WD means asymmetrical or runaway

Question 14

Slat/Flap protections

Answer 14

With slats/flaps extended and speed exceeds 210kts the flaps auto retract but slats remain.

Slat Alpha/Speed Lock:
Prevents slats/flaps from retracting during slow speed or high angle of attack

Question 15

Mechanical Backup and Abnormal Law

Answer 15

Mechanical Backup: rudder peddles, thrust levers, and pitch trim wheels
Abnormal Law:
Provides sufficient control for recovery from an unusual attitude

Question 16

Pitch Trim Normal Law

Answer 16

Automatic with or w/o autopilot with less than 33 degrees bank

Question 17

Normal Law Protections

Answer 17

Maneuver: +2.5G’s up to -1G down flaps up. +2G’s to 0G flaps down

Pitch Attitude: 30 degrees up to 15 degrees down

Overspeed: ELAC’s automatically pitch aircraft up (will not protect against exceeding vmo/mmo

Alpha (ALPHA PROT): VLS lowest safe speed. (Amber hook on airspeed indicator

Alpha Prot changes logic to load factor to alpha demand so the side stick controls alpha directly. Top of amber and black band on a/s indicator

Alpha max: top of solid red band. The a/c will descend if not sufficient thrust available

Alpha Floor: TOGA power applied approximately half way between alpha prot and alpha max regardless if auto thrust is on (as long as it’s functional)

Reminder all these available in NORMAL LAW

Question 18

Roll Normal Law

Answer 18

Max bank 67 degrees. 45 degrees in alpha or high speed protections

Bank angle hold: <33 degrees bank a/c will hold bank angle and introduce the required level of back pressure to maintain level flight called automatic pitch

Positive spiral stability: 67>33 degrees bank if you let go the side stick automatically returns to 33 degrees bank. Additionally PSS becomes active at any bank angle if overspeed or Alpha protections are active. In this case it will bring the a/c to 0 degrees bank if the side stick is neutral

Question 19

Flight control Ground mode

Answer 19

No load control and roll rate required so side stick and control surfaces directly related and proportional. Enables a flight control test and to rotate o. Take off

Question 20

Landing Mode

Answer 20

Gives conventional feel to the landing. Radar altimeter required

Unavailable in alternate law so you wouldn’t get that conventional feel so if in alternate law when the landing gear is lowered flight control reverts to direct law

Question 21

Alternate Law Indications

Answer 21

Amber x’s replace the green = symbols on PFD. Alpha prot and alpha max symbols are replaced by stall warning indicator which is red and black barber pole.
Also abnormals in the E/WD

Pitch control is identical to normal law however ground and landing modes are not available and pitch protection is greatly reduced. No 30 degrees up to 15 degrees down and high speed protection replaced by high speed stability…still nose up protection but can push thru with the side stick.
Alpha protection is replaced by low speed stability…adds gentle nose down but can be overridden and cause a stall

No automatic turn coordination

Question 22

Alternate law roll

Answer 22

No protections (max bank, bank angle hold, automatic pitch trim, positive spiral stability)

Now have ROLL DIRECT which results in roll response varying with a/s similar to conventional a/c. Could be up to twice the roll rate

Question 23

Direct Law

Answer 23

Side stick has direct relationship with flight controls
No protections and stability
No auto trim
No yaw damp