Flight Controls Flashcards
What are primary flight controls ?
They perform roll, pitch and yaw
What are secondary flight controls ?
They enhance aerodynamic performances. This includes : flaps/slats, speed brakes and ground spoilers
How are the flight surfaces controlled/operated ?
All surfaces are electrically controlled and hydraulically operated.
Stabilizer and rudder can also be mechanically controlled.
How is roll achieved ?
By 1 aileron and 4 roll spoilers on each wing
How is pitch achieved ?
By 2 elevators hinged to the Trimmable Horizontal Stabilizer (THS).
THS can be controlled manually from a cable running from the THS wheel on the pedestal
How is yaw achieved ?
By a rudder
How many slats sections are there ?
Each wing is equipped with 5 slats sections
How many spoilers on each wing are there ?
5 spoilers on each wing numbered 1 to 5 (starting inboard).
Spoilers are used to assist roll with spoilers 2-3-4-5.
Spoilers 2-3-4 are also used as speedbrakes.
On touchdown (or RTO), all spoilers 1-2-3-4-5 are used as ground spoilers
How many flight control computers are there ?
11 flight control computers :
- 2 ELAC
- 3 SEC
- 2 FAC
- 2 SFCC
- 2 FCDC
What is the ELAC ?
Control the normal elevator, stabilizer and ailerons
What is the SEC ?
Control the spoilers and remain on SBY for elevator or stabilizer control
What is the FAC ?
They control the rudder, rudder trim amd yaw damping. They also compute flight enveloppe parameters (minimum speed, low energy warning, windshear…)
What is the SFCC ?
They control the flaps and slats
What is the FCDC ?
They acquire the data from the ELAC and SEC and transmit it to the ECAM
What is the maximum deflection for the elevator ?
30° nose up - 17° nose down
What is the maximum deflection for the stabilizer ?
13,5° nose up - 4° nose down
Which ELAC normally controls the elevator and THS ?
ELAC 2
Which hydraulic jacks normally control the elevator ?
GREEN for left elevator and YELLOW for right elevator
Which electric motor normally drives the THS ?
Electric motor n°1
What happens if ELAC 2 failure or hydraulic jacks failure on the elevator ?
ELAC 1 takes over and the outer servojack supplied by the BLUE hydraulic system become active
What happens if both ELAC fail on the elevator ?
The elevator is controlled by either SEC 1 or SEC 2 and THS motor n°2 or 3
Is mechanical control of the THS is available anytime ?
Yes, if either the GREEN or YELLOW hydraulic system are available.
How many control modes the servojacks on the elevator have ?
They have 3 modes :
- Active (jack is electrically controlled)
- Damping (the jack follows the surface movement)
- Centering (the jack is hydraulically retained in neutral position)
What happens if both servojack fail on the elevator ? (regarding the control mode)
They automatically switch to damping mode
What happens if neither servojack is electrically controlled on the elevator ? (regarding the control mode)
Both servojacks are switched to centering mode
What happens if neither servojack is hydraulically controlled on the elevator ? (regarding the control mode)
Both servojacks are switched to damping mode
How many hydraulic motor for the THS ?
2 hydraulic motors
Does the deflection of the elevator remain the same after a failure of one elevator ?
No, it is limited to avoid excessive asymetric loads
How are the THS hydraulic motors controlled ?
By one of the three electric motors
By the mechanical trim wheel
Is hydraulic power required to move the THS ?
YES, hydraulic power is always required to move the THS. The three electric motors can only control the two hydraulic motors.
What is the maximum deflection of the ailerons ?
25°
What is the maximum deflection of the spoilers ?
35°
What is the aileron droop ?
The ailerons extend 5° down when the flaps are extended
Which ELAC normally controls the ailerons ?
ELAC 1
What happens if ELAC 1 fails on the ailerons ?
ELAC 2 takes over automatically
What happens if both ELAC fail on the ailerons ?
The ailerons revert to damping mode
Which spoilers does the SEC 3 control for roll ?
Spoiler n°2
Which spoilers does the SEC 2 control for roll ?
Spoiler n°5
Which spoilers does the SEC 1 control for roll ?
Spoilers n°3 and 4
What happens if a SEC fails regarding the roll spoilers ?
The spoiler it controls automatically retract
How many control modes the servojacks on the ailerons have ?
They have 2 modes :
- Active (jack is electrically controlled)
- Damping (the jack follows the surface movement)
What happens if both servojack fail on the ailerons ? (regarding the control mode)
The system selects “damping mode”
What happens to the symmetrical spoiler of the failed one ?
It is inhibited to prevent asymmetrical control
Which hydraulic systems power the spoilers ?
All 3, the GREEN, YELLOW and BLUE
Which spoilers are speedbrakes ?
2 - 3 and 4
When does the speedbrake extension is inhibited ?
When :
AoA protection active
Flaps are FULL
Thrust lever above MCT
Alpha floor activated
…
(not exhaustive)
What happens if speedbrakes are extended and inhibition occurs ?
They retract automatically until the inhibition disappears
How much time to retract speedbrakes when speed is above 315kt or M.075 ?
25 seconds
What is the maximum deflection of the speedbrakes when autopilot is engaged ?
25° for spoilers 3 and 4
12,5° for spoiler 2
What is the maximum deflection of the speedbrakes in manual flight ?
40° for spoilers 3 and 4
20° for spoiler 2
Which spoilers are ground spoilers ?
All spoilers, 1-2-3-4-5
What is the aileron anti droop
Upon landing, both ailerons are deflected upward to act as spoilerons (to improve landing performance)
How does the spoiler extension work during the rejected takeoff ?
- If spoilers are armed and wheel speed exceeds 72kt, ground spoilers will automatically extend as soon as both thrust levers are reset to IDLE.
- If spoilers are NOT armed and wheel speed exceeds 72kt, ground spoilers will automatically extend as soon as reverse is selected on one engine.
How does the spoiler extension work during the landing ?
Speedbrakes lever not in the retracted position or ground spoilers armed :
- Both main landing gear on the ground
- Both thrust levers at or below IDLE, or reverse selected on at least one engine
Speedbrakes lever in the retracted position but ground spoilers NOT armed :
- Both main landing gear on the ground
- Reverse selected on at least one engine
When do the ground spoilers retract ?
After landing when the ground spoilers are disarmed
After a RTO, when the ground spoilers are disarmed
After a Touch & Go, when at least one thrust lever is above 20°
How many hydraulic actuators power the yaw damping system ?
2 actuators.
Active actuator is powered by the GREEN hydraulic system
SBY actuator is powered by the YELLOW hydraulic system
What happens if the yaw damping actuactor fails ?
The SBY actuator takes over.
What happens if both GREEN and YELLOW actuator fail on the yaw damping system ?
A return spring sets the two actuator to the neutral position
How many hydraulic actuators power the rudder system ?
3 mechanical actuated hydraulic servojacks.
All 3 actuators are controlled mechanically without electrical inputs
What is the maximum deflection of the rudder ?
25°
Which system controls the rudder ?
By the FAC.
FAC 1 normally controls the rudder, rudder trim, turn coordination and yaw damping.
FAC 2 remains on SBY
What is the Rudder Travel Limiter ?
It limits the deflection of the rudder based on speed
How many motors does the TLU have ?
2 electric motors (FAC 1 controls motor 1 and FAC 2 controls motor 2)
Can rudder trim be used in manual flight ?
Yes, by using the rudder trim rotary switch
Can rudder trim be used with the autopilot ?
Rudder trim is done automatically by the FMGS (rotary switch and trim reset button are not active)
What is the rate and maximum deflection by using the rudder trim rotary switch ?
It moves 1°/sec, up to 20°
What is the rate by using the rudder trim reset button ?
It resets to zero at a rate of 1.5°/sec
