Flight Controls Flashcards
Describe the roles of the Elevator Aileron Computers (ELAC 1 and ELAC 2).
Provide controls for elevator, ailerons and Trimmable Horizontal Stabilizer (THS)
Determines requirements for spoiler and rudder inputs during turns
Both ELACs active, other ELAC will takeover if 1 fails
Describe the roles of the Flight Augmentation Computers (FAC 1 and FAC 2).
▪ Provides control of the Rudder to include:
• Turn coordination
• Yaw damping
• High/Low speed rudder limiting
• Rudder trim
• Only one FAC is active at a time with the other serving as a backup.
Describe the roles of the Spoiler Elevator Computers (SEC 1, SEC 2 and SEC 3).
▪ All SECs are active during operations with each responsible for a specific pair, or pairs, of spoiler panels.
▪ SEC 1 and SEC 2 can provide backup control of the Elevators and THS in the event of a dual ELAC failure.
Describe Normal Law
All protections available
Describe Alternate Law
reverts with multiple failures involving Flight control computer, hydraulic or nav systems
some flight envelope protections lost
Describe Direct Law
when landing gear is lowered during alternate law
flight controls are direct, all protections lost
Mechanical Backup
Flight control computers have failed or all electrical power lost
sidesticks inop, aircraft can be controlled by manual pitch trim, rudder pedals and engine thrust
Abnormal Law
provides sufficient control to recover from unusual attitude
Describe Load factor demand
available in normal and alternate law
stick aft signals positive g-load change
stick forward signals negative g-load change
stick neutral signals zero g-load change
Auto pitch trim
provided by ELACs in normal and alternate law
auto pitch trim for bank angles up to 33 degrees
Describe Maneuver Protection
- Available in Normal AND Alternate law
- Restricts flight control surface movement that would cause the aircraft to exceed its designed structural G-load limits:
Clean or slats extended and flaps retracted: -1 G to +2.5 G
Flaps extended: 0 G to +2.0 G
Describe Pitch protection
only available in normal law
ELACs allow no greater than 30 degrees nose up or 15 degrees nose down
Describe High speed protection
only available in normal law
prevents aircraft from exceeding vmo/mmo
autopilot automatically disconnects
ELACs automatically pitch aircraft up
Describe Alpha Protection (Alpha Prot)
Available only in Normal Law.
Flight control computers prevent the aircraft’s angle of attack (AOA) from exceeding a predetermined threshold at low airspeeds.
The autopilot automatically disengages and speed brakes, if deployed, automatically retract.
Flight control computers logic changes from Load Factor Demand to direct sidestick pitch control.
Pilot sidestick input can override the Flight Control computers and further degrade the AOA.
Describe the indication of Alpha Prot on the airspeed indicator.
amber and black band
Describe Alpha Max and how it is indicated on the airspeed indicator.
Red band
highest AOA that computer will allow
cannot be overridden
available only in normal law