Flight controls Flashcards
What flight controls do we have on each wing?
5 x slats
5 x spoilers
2 x flaps
1 x aileron (at the end of the wing)
How are the flight controls - controlled and then actuated?
Fly by wire
“All flight controls are ELECTRONICALLY CONTROLLED and HYDRAULICALLY activated”
How does the flight control system work
(Caution - check answer)
- Demand made by pilot
- Goes to F/CTR computer
- Signal sent to actuator
- Actuator moves surface
- Response feedback back to F/CTR computer
Note: in normal law the computers prevent excessive manoeuvres and keeps us inside the flight envelope in the pitch and roll axis
Flight control - side stick
Are the FO AND CAPT side sticks mechanically linked?
No - they are not mechanically linked
Side stick - what is the SOP for disconnecting autopilot in flight?
Side stick red push button.
Why? Because this prevents an ECAM warning (albeit you still get the cavalry noise)
Side stick - Dual Inputs
They are algebraically added. Therefore:
- Half side deflection from CAPT plus half side stick deflection from FO (in same direction) = full deflection
- Full bank left from CAPT and full bank right from FO = no deflection
When doing flight control check (during taxi) - remember to look at the ECAM display (not the PFD)
Side stick - Priority
What is shown if Capt takes priority from the PF?
- Red arrow appears in front of the person that lost control (FO) and points to the person that has control (Capt)
- A green “CAPT” light illuminates (I.e says who now has control)
Side Stick - how do you take control from copilot?
Press and hold red pb for 40 seconds (this then semi locks out the co-pilot)
Does not fully lock because the co-pilot could request control back again
Rudder Trim Switch. What is the impact of autopilot on?
Autopilot on - turning the trim knob on the pedestal has no impact
What are the Cockpit THS controls? What happens if you manually control them in cockpit
2 x THS Hand wheels
If grab, you override the automatic computer and are directly controlling the electric motors which in turn move THS
What flight control computers does the a320 have?
Caution - not sure if below is 100% correct yet
- 2 x ELAC [Elevator and Aileron Computer]
- 3 x SEC [Spoiler and Elevator Computer] (note: also controls the standby elevators and stab control)
- 2 x FAC [Flight Augmentation Computer]
Not a computer as such but there are also:
2 x FCDC [Flight Computer Data Concentrators]
Elevators. Basic components of the system?
Each elevator is:
- Driven by 2 x electrically controlled hydraulic servo jacks
- Only 1 servo jack active at a time (the other is in damping mode)
- Left Elevator (Green Hyd). Right Elevator (Yellow Hyd) [Instructor advised don’t need memorise colours]
Elevators - how do they work in normal conditions?
There are 2 servojacks per elevator
A) 1 x servojack does all of the work; and
B) 1 x servo-Jack “relaxes” and simply follows what the other is doing (“Damping mode”) [instructor likened it to floating around)
Elevators - how do they work in abnormal (neither hydraulic Jack being controlled electrically)?
Reverts to “Central Mode” (elevator locks at the central / neutral position)
Elevators. What modes do the servojacks have?
- Active (the servojack is electronically controlled)
- Damping (the jack follows the surface movement)
- Centering (elevator locks at center/neutral)
Elevators - Pitch control.
Re computers. How is the system controlled in normal and abnormal?
Normal = controlled by ELAC 2 (for both left and right elevators)
Abnormal (I.e. ELAC 2 fail) = ELAC 1 active
Abnormal (lose both ELAC 1 and 2) - control reverts to SEC 1 and then SEC 2
Stabilisers (pitch control)
How are they controlled?
- Operated by a screw jack
- Screw Jack driven by 2 x Hydraulic motors (Green and Yellow)
- Hydraulic motors controlled bya) one of three electric servo motors (depending on which is controlling); OR
b) the mechanical trim wheel (which will override point a)
Which parts of wing are used for roll control (per wing)?
Each wing has/uses:
- 4 spoilers (2-5) [i.e all of the outboard ones]
- 1 aileron
What are the three different spoiler configurations for a) roll b) speed brakes (in the air) c) speed brakes (ground)?
A) roll = 1 x aileron and 4 x spoilers (nos 2-5)
B) speed brakes (air) = 3 x spoilers (no. 2-4) [middle ones]
C) Speed brakes (ground) = all 5 spoilers
Key point: only the no. 1 spoiler (inboard) is ever used on the ground
Which computer controls ailerons?
ELACs
Ailerons. What is the backup if both ELACS inop?
None. There is no back up
What computer controls the spoilers?
SEC (Spoiler Elevator Computer)
(Note: Each spoiler (per wing) is controlled by an individual SEC)
Spoilers. What happens if a left wing individual spoiler is loses Hyd pressure and inop (e.g the no.2)?
It will “float” (damping mode). The no.2 spoiler on the right wing will also go to damping mode (to avoid asymmetric flight)
What is “Aileron droop”?
When the flaps are extended, the ailerons are extended down by 5 degrees in order to provide additional lift
Yaw control system / computers
- Controlled by the ELACs
- ELACS send signals to the 3 x hydraulic jacks on the rudder
- The hydraulic jacks then move the rudder
Yaw control. What controls the rudder trim?
2 x FACs (Flight Augmentation Computers)
What is the Rudder Travel Limiter?
When you go faster there is a decrease in the rudder authority (ie the maximum rudder movement you can command from rudder pedals decreases as you faster - even with your foot to the floor!)
What happens if the rudder travel limiter fails?
Caution - check below is correct
It freezes at last known position. Unlocks again during approach (when not clean config)
