Flight Controls Flashcards
How are the elevators and THS controlled? Which hydraulic systems?
Elevators are electrically controlled and hydraulically activated.
In normal operations, ELAC 2 controls the Elevators and THS. The Left and Right elevators are controlled by the G and Y hydraulic jacks respectively. The THS is driven by no.1 of 3 electric motors.
If ELAC 2 fails, ELAC 1 controls through B hydraulic jacks. THS through no.2 motor.
If both ELACs fail, SEC 1 or 2 take over, and THS is controlled through motor 2 or 3.
Do you need hyd to use mechanical THS? Which Hyds?
Yes, G or Y is required for mechanical control. Mechanical control of THS has priority over electrical control.
How many servojacks are there for elevators? What control modes are there?
2 electrically-controlled hydraulic servojacks drive each elevator.
3 modes:
Active- electrically controlled
Damping- follows surface movement
Centering- neutral position
One Jack is in active mode, while other is damping.
If one Jack fails, it goes to damping mode, while other takes over as active.
If both lose electrical control, they are centred.
If both lose hydraulic control, both switch to damping mode
How is stabilizer controlled?
2 hydraulic motors drive stabilizer
Controlled by:
- One of 3 electric motors
- Mechanical Trim wheel
What flight controls are used for roll control?
1 aileron and 4 roll spoilers (no. 2-5) per wing.
Aileron max deflection is 25 degs
(Aileron droop extends the 5 degs down when flaps extended.
Max deflection of spoilers for roll is 35 degs.
How are ailerons controlled?
ELAC 1 normally controls. If failed, transfers control to ELAC 2. If both fail, ailerons revert to damping mode.
This controls:
- 2 electrically controlled hydraulic servojacks (one operates at a time).
Two modes for servojacks:
- Active
- Damping
Spoiler control? What happens if they lose hydraulics? Lose electrical power?
Controlled by SEC 1, 2 or 3.
Hydraulic failure: retains deflection it had at time of fault.
Electrical failure: retracts spoilers to zero position.
If a spoiler fails on one wing, it is inhibited on the other.
Speedbrake - which spoilers? When are they inhibited?
2,3,4
Inhibited when:
- SEC 1 + 3 fault
- L or R elevator fault
- AOA protection active
- Flaps Conf Full
- Thr levers are above MCT
- Alpha Floor
Which computers control turn coordination and yaw damping orders?
ELACs compute orders and transmit them to FACs
How are rudders actuated?
3 Independent hydraulic servojacks operating in parallel actuate rudders.
In automatic operation (turn coordination/yaw damping), a green servo actuator drives all 3 servojacks. If this fails,, yellow servo actuation takes over.
Rudder travel limit?
As speed increase, travel is limited to avoid high structural loads.
If sys fails, it is limited by last value before failure. As slats extended again, full control is recovered.
Rudder Trim? Powered by what and which computers?
Two electric motors
Normally: motor 1, controlled by FAC 1
Otherwise: motor 2, controlled by FAC 2
With AP engaged, FMGC computes trim orders.
Which protections are avail in Rotation Mode (NEOs)?
Pitch Attitude
High Angle of Attack
Protections in Flare Mode?
High AOA
Flare mode?
Passing 50ft, THS frozen, memorises attitude.
Passing 30ft, begins to reduce pitch Att to -2 degs over 8 secs.
Direct stick to elevator relationship.
Transition happens over 1s from 50ft.
