Flight Controls Flashcards
How is roll control achieved?
2 ailerons
2 flaperons
14 spoilers (also for speedbrakes)
Where do inputs from the pilot go?
4 ACE (actuator control electronics)
Then to the 3 PFC primary flight computers ( mixed with other data)
Then back to the ACEs and on to the control actuators. PCUs supply the force to move the flight controls.
Envelope protection consists of what?
Warnings for :
Stall
Over speed
Bank angle
What does the EEC thrust asymmetry function do?
Decrease power on the live engine to ensure yaw control is available. It is always available when flight controls are in normal mode.
How many flight control modes are there?
3
Normal
Secondary
Direct
What do you lose in secondary flight mode?
Autopilot
Stall, over speed, bank angle, gust suppression and thrust asymmetry
Manual control is fully available.
What is direct flight mode?
There is no input from the primary flight computers. Pilot controls go straight from the ACEs to the actuators. Little difference in practice to secondary mode.
How many high lift devices are there?
2 outboard flaps
2 inboard flaps
2 Krueger flaps
12 slats
Which hydraulics move the elevators?
The centre moves both. The left moves the left, and the right moves the right.
What moves the stabiliser?
2 electric actuators.
In secondary and direct mode, does a control input for pitch move the stabiliser?
No, only the elevators.
If armed, autothrottle will engage and provide a speed at the minimum manoeuvering speed. It will NOT engage when?
Pitch mode FLCH Pitch mode TOGA After take off below 400ftAGL On approach below 100ftRA During descent in VNAV SPD
What is the difference in control ‘feel’ logic between normal and secondary/direct modes?
Normal uses speed - high speed high force
Secondary and direct use flap position. Flaps up high, flaps out decreased force.
Does the alternate trim signal through a computer?
No, wires go directly from the switch to the stabiliser to control pitch.
When do you see the stab trim on EICAS?
When on the ground, and after take off 10 seconds after gear up, or 60 seconds after lift off.
Various non normals, with Stab, flight computers, modes etc
After landing and trim is used, or ground speed less than 40kts
Wheel to rudder cross tie function works in what flight mode?
Secondary and direct.
Where are the trim weight sensors?
Nosewheel
Are all the spoilers hydraulically activated?
No. Pairs 4 and 11, and 5 and 10 are electrical actuators.
When will speedbrakes automatically deploy?
Thrust levers closed after 85 Kts on take off
Landing with speedbrakes armed
Reverse thrust selected on landing even if not in armed
How many slats are there?
6
5 outboard 1 inboard of the engine.
What are the operating modes for the the flaps and slats?
Primary - flap lever, hydraulic
Secondary- flaps lever, hydraulic or electric
Alternate - alternate flap selector, electric
Do flaps move for ‘Flap 1’ selection?
No, only the leading edge slats go to mid range, aloe with the Krueger flaps.
When do the slats go beyond mid range?
25 and 30 selection
When does the autogap function work?
With a high angle of attack, and speed below 225 Kts.
Does the pilot have control over cruise flaps?
No, and no indications.
Does the secondary mode use the slat pre gap function?
Yes, below 225kts and flap lever out of up.
