Flight Controls. FCTRL Flashcards
What are the roles of the Elevator Aileron Computers(ELAC1 and ELAC2)?
- Control of elevators, ailerons, trimmable horizontal stabilizer(THS)
- Determines requirement for and activated spoiler assist during rolls, and rudder input for yaw
- Both are normally active. If one fails the remaining one assumes control automatically for the other one
What are the roles of the Flight Augmentation Computers(FAC 1 and FAC2)
1 Control of rudder including Turn coordination Yaw damping High/low speed rudder Limiting Rudder Trim 2. Only one FAC is active at a time with the other one a backup
What are the roles of the Spoiler Elevator Computers?(SEC1, SEC 2, SEC3)
- All SECs are active with each responsible for a specific pair, or pairs, of spoiler panels
- SEC1 and SEC2 can provide backup of the elevators and THS in the event of a dual ELAC failure
Describe normal law
- FCCs logic of the aircrafts pitch roll and yaw limits during normal ops
- ALL protections are available to keep aircraft in design envelope.
- Active when all or nearly all systems are functioning properly
Describe alternate law
- FCCs logic for pitch, roll, and yaw limits in response to system failures involving the FCC, hydraulic, or NAV systems(ADIRS)
- Some flight control characteristics change
- Some flight envelope protections are lost
Describe Direct Law
1 typically as a result of the landing gear being lowered while in Alternate Law but can be the result of more significant failures
- Flight control feel, and response is like a conventional aircraft
- All protections are lost
Describe Mechanical Backup Law
- Occurs when all FCCs have failed or total loss of electrical power
- Inoperative side sticks
- Only controlled by manual pitch trim, rudder pedals, engine thrust
Describe Abnormal Law
- Provides sufficient controls for unusual attitudes
2. A subset of Alternate Law
Describe Load Factor Demand
What’s Law/s is it available?
- Available in Normal and Alternate Law
- FCCs interpret pitch change command as G loading
A. Climb commands(stick aft) result in a
Positive G load change
B. Descent commands(stick forward)
Result in negative G load
C. Neutral Stick result in 0 G loading
Describe automatic Pitch Trim during a roll
Which law/s is it available
- Automatic pitch trim is provided by the ELACs in Normal AND Alternate mode
- Automatically provided for pitch trim up to 33 degrees
Describe Maneuver Protection
Available in which Law/s
- Available in Normal and Alternate modes
- Restricts flight control movement that exceed its designed structural G loading
A. Clean = -1.0g to 2.5g
B. Slats extended/flaps retract = -1g to 2.5g
C. Slats and flaps extended = 0g to 2.0g
Describe pitch Protection
Available in which Law/s?
- Available ONLY in Normal Law
- Prevents excessive nose up or nose down attitudes
- ELACs will allow attitudes no greater than 30* nose up and 15* nose down
Describe high speed protection
Available in which Law/s?
- Only in Normal Law
- Attempts to prevent aircraft from exceeding VMO/MMO
- Autopilot automatically disengaged
- ELACs auto pitch the aircraft up to limit acceleration regardless of stick position
Describe Alpha Protection (Alpha Prot.)
Available in which Law/s?
- Normal Law only
- FCCs prevent AOA from exceeding predetermined threshold at low speed
- Auto pilot disengages and speed brakes auto retract
- FCC Load Factor Demand to direct side stick pitch control.
- Pilot side stick input CAN override the FCC and further degrade AOA
Describe Roll Rate Demand
Available in which Law/s?
- Only in Normal Law
- Full sidestick give max roll rate if 15* per second regardless of airspeed or configuration
- Half stick deflection yield half max roll rate
- Neutral side stick commands a zero change in rate
Describe Bank Angle Hold and Positive Spiral Stability
Both roll characteristics are only available in Normal Law
Bank Angle Hold = at bank angles of less than or equal to 33* the bank is maintained with automatic pitch trim when side stick is released
Positive Spiral Stability- at bank angles greater than 33* if sidestick is released the aircraft will auto roll back to 33*
1. Continuous pressure on sidestick to hold bank angles exceeding 33* as well as pitch adjustments
Describe the roll of Automatic Pitch Trim during turns
Available in which Law/s?
- Available in Normal Law and Alternate Law
- At bank angles of 33* or less, the ELACs auto introduce necessary back pressure through auto pitch trim
- At bank angles over 33* the feature is inhibited and aft sidestick will be necessary to maintain a level turn
Describe bank angle protection
Available in which Law/s?
- Only inNormal Law
2. ELACs restrict bank angle to max 67* even if full left or right sidestick is maintained
What are the indications of Normal Law on the PFD?
Pic
Green equal signs at:
- 67* bank angle limit
- +30* and -15* pitch attitude limits
- High speed protection limit
Describe the Ground Mode, Flight Mode, and Landing Modes of Normal Law
Ground Mode:
- Active on ground
- Direct relationship between sidestick and flight control surfaces
- Allows flight control check and rotation
Flight Mode:
- Active shortly after takeoff
- All FCCs protections and flight characteristics take effect
Landing Mode:
- On descent through 50’ AGL at which point the ELACs memorize pitch attitude
- At 30’ AGL, ELACs add gentle down pitch commands
- Pilot instinctively counters nose down moment resulting in Normal flare
- Shortly after landing it returns to ground mode and the THS resets to 0.
How is roll control maintained while in Alternate Law
- Direct relationship between sidestick deflection and aileron/elevator deflection
- All roll control flight characteristics and protections are lost
Describe high and Low speed stabilities in Alternate Law
High Speed Stability:
1. Active below VMO/MMO
2. ELACs command elevators to increase pitch, attempting to prevent an increase in speed
3 High SpeedStability CAN be overridden by sidestick input
Low Speed Stability:
- Active at airspeeds slightly higher than stall
- FCCs command elevators to decrease aircrafts pitch, attempting to increase speed
- Low Speed Stability can be overridden by sidestick
What is the Stall Speed indication on the PFD when in Normal or Alternate Law?
By the top of the red and black “barber pole” of the airspeed indicator
What are the indications of Alternate Law?
Pic
- Normal Law indications are replaced with Amber Xs
- F/CTL ALTN LAW (PROT LOST) message in the E/WD memo section
- Contrary to the ECAM message, SOME GCC protections remain active.