Flight Controls Flashcards
How are th flight controls operated?
Electrically controlled Hyrdaulically activated.
Which parts of the aircraft can be mechanically controlled?
The stabalizer and rudder
What are the 7 flight control computers?
What do they control?
2 ELAC - Elevator Aileron Computer
For :
Normal elevator and stabilizer control.
Aileron control.
3 SEC - Spoiler Elevator Computer
For :
Spoilers control.
Standby elevator and stabilizer control.
2 FAC - Flight Augmentation Computer
For :
Electrical rudder control.
What is an FCDC?
Flight Control Data Concentrators (FCDC) acquire data from the ELACs and SECs and send it to the electronic instrument system (EIS) and the centralized fault display system (CFDS).
In normal operations which computer controls the elevators?
In normal operations, ELAC2 controls the elevators and the horizontal stabilizer, and the green and yellow hydraulic jacks drive the left and right elevator surfaces respectively.
The THS is driven by N° 1 of three electric motors.
If a failure occurs in ELAC2, or in the associated hydraulic systems, or with the hydraulic jacks, the system shifts pitch control to ELAC1. ELAC1 then controls the elevators via the blue hydraulic jacks and controls the THS via the N° 2 electric motor.
If neither ELAC1 nor ELAC2 is available, the system shifts pitch control either to SEC1 or to SEC2, (depending on the status of the associated circuits), and to THS motor N° 2 or N° 3.
How many jacks control each elevator?
What are the 3 modes of operation?
Two electrically-controlled hydraulic servojacks drive each elevator.
Each servojack has three control modes :
Active :
The jack position is electrically-controlled.
Damping :
The jack follows surface movement.
Centering :
The jack is hydraulically retained in the neutral position.
In normal operation :
One jack is in active mode.
The other jack is in damping mode.
Some maneuvers cause the second jack to become active.
What controls the stabalizer?
A screwjack driven by two hydraulic motors drives the stabilizer.
The two hydraulic motors are controlled by :
One of three electric motors, or
The mechanical trim wheel.
Which computer controls the ailerons?
What about when it fails?
The ELAC 1 normally controls the ailerons.
If ELAC1 fails, the system automatically transfers aileron control to ELAC2.
If both ELACs fail, the ailerons revert to the damping mode
How are the ailerons controlled in actuation?
Each aileron has two electrically controlled hydraulic servojacks.
One of these servojacks per aileron operates at a time.
Each servojack has two control modes :
Active : Jack position is controlled electrically Damping : Jack follows surface movement. The system automatically selects damping mode, if both ELACs fail or in the event of blue and green hydraulic low pressure.
When we use speedbrake which of the spoilers deploy?
2 3 and 4
During an RTO what speed has to of been reached for the ground spoilers to deploy?
72kts
What is aileron droop?
What is aileron anti droop?
Aileron droop is where the aileron extend 5 degrees down to act as a mini wing flap and improve lift for take off and landing.
Anti droop is where on touch down the ailerons will fully extend provided the ground spoilers have done the same, to help increase drag.
How do we get full spoiler extension on landing?
Partial?
Lever armed, weight on wheels, idle thrust or reverse on one.
Lever not armed, weight on wheels, reverse on one.
Partial the same but only one wheel on ground.
How is the rudder controlled?
The ELACs compute yaw orders for coordinating turns and damping yaw oscillations, and transmit them to the FACs.
Why do we have a rudder travel limiter?
To prevent the rudder from being overstressed at high speed.
