Flight Controls Flashcards
What are the roles of the Elevator Aileron Computers (ELAC 1 and 2)
1) Provide Control of Elevators, Ailerons and Trimable Horizontal Stabilizer (THS)
2) Determines the requirement for and activates spoiler assist during rolls, and rudder input for yaw
Are both ELACs normally active? What happens if one fails
Both are normally active, should one fail, the remaining ELAC will assume all ELAC related functions
What is the role of the Flight Augmentation Computers (FAC 1 and 2)
Provides control of the Rudder to include:
1) Turn Coordination
2) Yaw Dampening
3) High/ Low Speed Rudder Limiting
4) Rudder Trim
Are both FACs active at the same time?
No, one is active with the other serving as a backup.
What are the roles of the Spoiler Elevator Computers (SEC 1, 2 and 3)
Responsible for a specific pair or pairs of spoiler panels
Specifically, what can SEC 1 and 2 additionally provide?
backup control of the Elevators and THS in the event of a dual ELAC failure
What is normal law? what protections does it provide?
1) Defines the Flight Control Computers logic of aircraft pitch, roll and yaw limits during normal ops
2) All protections are available and prevents the aircraft from exceeding the designed flight envelope.
What is alternate law? What protections does it provide?
1) Defines the Flight Control Computers logic on all axis when multiple failures involving a FC, HYD or ADIRS (Nav System)
2) Maintains a high level of capability, but some flight envelope protections are lost
What is direct law? What protections does it provide
1) Typically occurs as the result of the landing gear being lowered while in Alternate Law, but can also be the result of more significant system failures
2) All protections are lost - airplane feels and responds like a conventional aircraft.
What is mechanical backup law? What flight controls will you have available?
1) Occurs when all flight control computers have failed or total loss of electrical power
2) Side sticks are inop and the aircraft can only be controlled by manual pitch trim, rudder pedals and engine thrust.
What is abnormal Attitude Law? What is it a subset of?
1) Provides sufficient control to recover from unusual attitudes as the result of an extraordinary external event (windshear etc.)
2) Is a subset of Alternate Law
What is load factor demand?
The flight control computers interpret pitch change commands as G Load changes
- Climb Commands (stick aft) - result in pos G load change
- Descent Commands (stick fwd) - result in negative G load change
- Neutral stick results in zero G-load change
In which Law(s) is load factor demand available?
Normal and Alternate
How is Automatic Pitch Trim provided during a roll and in what Law(s)
provided by the ELACs in normal and alternate Law
Up to what bank angles is automatic pitch trim provided?
Up to and including 33 degrees.
What is Maneuver Protection?
Restricts flight control surface movement that would cause the aircraft to exceed designed structural G-load limits
1) Clean (flaps and slats retracted): -1g to +2.5gs
2) Slats Extended, Flaps Up: -1g to +2.5gs
3) Slats and Flaps extended: 0g to +2gs
In which Law(s) is Maneuver Protection available
Normal and Alternate Law
What is pitch protection and how is it provided?
Provided by the ELACs to prevent excessive nose up (no greater than 30 deg) and nose down (no greater than 15 deg). Even if the sidestick is fully aft or fwd.
What is High Speed Protection and how is it provided?
1) Attempts to prevent the aircraft from exceeding VMO/MMO.
2) Autopilot will automatically dis-engage
3) ELACs automatically pitch the aircraft up to limit further acceleration, even if sidestick is fully forward
In which Law(s) is High Speed protection available?
Normal only
What is Alpha Protection (Alpha Prot)
AOA where FCCs intervene to prevent a stall.
In what Law(s) is Alpha Prot available
Normal only
How is Alpha Prot indicated on the airspeed indicator
Top of the amber and black band (tiger tail)
Can Alpha Prot be over-ridden and allow the aircraft to slow further?
Yes, with Aft Sidestick movement
What is Alpha Max
The highest Angle of Attack (AOA) the FC computers will allow.
In which law(s) is Alpha Max available, can it be over-ridden by pilot sidestick and how is it represented on the airspeed indicator
1) Avail in Normal Law only
2) Cannot be over-ridden by sidestick
3) Top of the red band on the airspeed indicator
What max roll rate will Full Sidestick deflection yield in Normal Law
15 deg per second regardless of airspeed or configuration
What happens if you deflect a sidestick halfway in Normal Law
you get a roll rate half of the max allowable rate
What will a Neutral Sidestick do to roll rate in Normal Law
Zero change in roll rate