Flight Controls

Question 1

Describe the roles of the Elevator Aileron Computers (ELAC 1 and ELAC 2).

Answer 1

▪ Provides control of the Elevators, Ailerons, and Trimmable Horizontal Stabilizer (THS).
▪ Determines requirement for and activates spoiler assist during rolls, and rudder input for yaw.
▪ Both ELACs are normally active. Should one fail, the remaining ELAC automatically assumes all ELAC-related functions.

Question 2

Describe the roles of the Flight Augmentation Computers (FAC 1 and FAC 2).

Answer 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.

Question 3

Describe the roles of the Spoiler Elevator Computers (SEC 1, SEC 2 and SEC 3).

Answer 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.

Question 4

Flight Control Laws.

❇️Normal Law:

Answer 4

▪ Defines the Flight Control Computers’ logic of the aircraft’s pitch, roll, and yaw limits during normal operations.
▪ All protections are available in order to prevent the aircraft from exceeding its designed flight envelope. Active when all, or nearly all, systems are functioning correctly.

Question 5

Flight Control Laws.

❇️ Alternate Law:

Answer 5

▪ Defines the Flight Control Computers’ logic of the aircraft’s pitch, roll, and yaw limits in response to multiple failures involving a Flight Control computer, Hydraulic, or Navigation system/s (ADIRS).
▪ Maintains a high level of capability, though some flight control characteristics change, and some flight envelope protections are lost.

Question 6

Flight Control Laws:

❇️Direct Law:

Answer 6

❇️Typically occurs as the result of the landing gear lowered while in Alternate Law but, can also be the result of more significant system failures.
▪ Flight control feel, and response is like a conventional aircraft but, all protections are lost.

Question 7

Flight Control Laws

❇️Mechanical Backup Law:

Answer 7

▪ Occurs when all flight control computers have failed or there has been a total loss of electrical power.
▪ Side sticks are inoperative, and the aircraft can only be controlled by manual pitch trim, rudder pedals and engine thrust.

Question 8

Flight Control Laws

❇️Abnormal Law:

Answer 8

▪ Provides sufficient control to recover from unusual attitudes as the result of extraordinary external event.
▪ Is a subset of Alternate Law.

Question 9

Describe Load Factor Demand.

Answer 9

▪ Available in Normal and Alternate Law.
▪ Flight control computers interpret pitch change commands as G-load changes:
• Climb commands (Stick aft) result in a positive G-Load change
• Descent commands (Stick forward) result in negative G-Load change
• Neutral stick results in zero G-Load change

Question 10

Describe Automatic Pitch Trim during a roll.

Answer 10

▪ Automatic pitch trim is provided by the ELACs in Normal and Alternate Law.
▪ Pitch trim is automatically provided for bank angles up to and including 33 degrees.

Question 11

Describe Maneuver Protection.

Answer 11

▪ 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 configuration (Flaps and Slats retracted): -1.0g to +2.5g
• Slats extended, and Flaps retracted: -1.0g to +2.5g
• Slats and Flaps extended: 0.0g to +2.0g

Question 12

Describe Pitch Protection.

Answer 12

▪ Available only in Normal Law.
▪ Prevents excessive nose-up and nose-down attitudes.
▪ ELACs will allow attitudes no greater than 30º nose-up, or 15º nose-down, even if the sidestick is held full aft/forward.

Question 13

Describe High Speed Protection.

Answer 13

▪ Available only in Normal Law.
▪ Attempts to prevent aircraft from exceed VMO/MMO.
▪ Autopilot automatically disengages.
▪ ELACs automatically pitch the aircraft up to limit further acceleration, even if the sidestick is held full

Question 14

Describe Alpha Protection (Alpha Prot).

Answer 14

▪ Available only in Normal Law.
▪ Flight control computers prevent the aircraft’s angle of attack (AOA) from exceeding a predetermined threshold at low airspeeds.
▪ 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.

Question 15

Describe the indication of Alpha Prot on the airspeed indicator.

Answer 15

▪ Alpha Prot is represented by the position of the top of the amber and black band.
▪ Is available only in Normal Law.
▪ It can be overridden with aft side stick movement.

Question 16

Describe Alpha Max and how it is indicated on the airspeed indicator.

Answer 16

▪ Alpha Max is the highest angle of attack (AOA) that the flight control computers will allow:
❇️Available only in Normal Law.
❇️It cannot be overridden by the pilot even with full aft sidestick pressure.
▪ It is represented by the top of the red band on the airspeed indicator.

Question 17

Describe roll rate in Normal Law.

Answer 17

▪ Full sidestick deflection yields the maximum allowable roll rate of 15º per second, regardless of airspeed or configuration.
▪ Deflecting a sidestick only halfway yields a roll rate half of the maximum allowable rate.
▪ Neutral sidestick commands a zero change in roll rate.

Question 18

Describe Bank Angle Hold

Answer 18

Only available in Normal Law. Bank Angle Hold - At commanded bank angles of ≤33º, the bank angle is maintained with automatic pitch trim when sidestick is released.

Question 19

Describe Positive Spiral Static Stability.

Answer 19

❇️Only available in normal law.
Positive Spiral Static Stability - At commanded bank angles of >33º, if the sidestick is released, bank angle returns to and maintains 33º. Continuous pressure must be applied to the sidestick to hold bank angles exceeding 33º as well as pitch.

Question 20

Describe the role of Automatic Pitch Trim during turns.

Answer 20

▪ Available in Normal and Alternate Law.
▪ At bank angles ≤33º, the ELACs automatically introduce the necessary back pressure through automatic pitch trim.
▪ At bank angles above 33º, this feature becomes inhibited, and aft sidestick will be necessary to maintain a level turn.

Question 21

Describe Bank Angle Protection.

Answer 21

▪ Available only in Normal Law.

▪ ELACs restrict bank angle to a maximum of 67º, even if full left or right sidestick is maintained

Question 22

Recall the indications of Normal Law on the PFD.

Answer 22

▪ Green equal signs displayed at:
• 67º bank angle limit.
• +30º and -15º pitch attitude limits.
• High speed protection limit.

Question 23

Describe the Ground mode of Normal Law.

Answer 23

❇️Ground Mode:
• Active when aircraft is on the ground.
• Direct relationship between the sidesticks and flight control surfaces
• Permits pilot to perform a flight control check and rotate the aircraft on takeoff.

Question 24

Describe the Flight mode of Normal Law.

Answer 24

❇️Flight Mode:
• Active shortly after takeoff.
• All flight control computer protections and flight characteristics take effect.

Question 25

Describe the Landing mode of Normal Law.

Answer 25

❇️Landing Mode:
• Becomes active as the aircraft descends through 50’ AGL, at which point the ELACs “memorize” the aircraft’s pitch attitude.
• Beginning at 30’ AGL, the ELACs add a gentle nose down pitch command.
• Instinctively, the pilot counters this nose-down action with aft sidestick input, resulting in a landing flare maneuver much like a conventional aircraft.
• Shortly after landing, the aircraft returns to ground mode, and the THS resets to 0.

Question 26

Explain how roll control is maintained while in Alternate Law.

Answer 26

▪ Direct relationship exists between sidestick deflection and elevator/aileron deflection.
▪ All roll control flight characteristics and protections are lost.

Question 27

Describe High Speed stabilities in Alternate Law.

Answer 27

❇️High Speed Stability:
▪ Becomes active slightly below VMO/MMO
▪ ELACS command the elevators to increase the aircraft’s pitch, attempting to prevent an increase in speed.

NOTE: High Speed Stability can be overridden by sidestick input.

Question 28

Describe Low Speed stabilities in Alternate Law.

Answer 28

❇️Low Speed Stability:
▪ Becomes active at airspeed slightly higher than stall speed.
▪ Flight control computers command the elevators to decease aircraft’s pitch, attempting to increase airspeed.

NOTE: Low Speed Stability can be overridden by sidestick input.

Question 29

Recall the indications of Alternate Law.

Answer 29

▪ All green equal signs on the PFD associated with Normal Law are replaced with amber Xs.
▪ F/CTL ALTN LAW (PROT LOST) message in the E/WD memo section.

NOTE: Contrary to the ECAM message, some flight control computer protections remain active.

Question 30

Recall the indications of Direct Law.

Answer 30

▪ The amber Xs present in Alternate Law remains in view.
▪ USE MAN PITCH TRIM appears above the artificial horizon on the PFD.
▪ F/CTL DIRECT LAW (PROT LOST) message in the E/WD memo section.

NOTE: In this case, the ECAM message is correct and all protections are lost.

Question 31

Describe Mechanical Backup Law.

Answer 31

▪ Provides mechanical control of the aircraft in the event all flight control computers have failed or there is total electrical failure.
▪ It is intended to be used only for as long as it takes to restore flight control computers or electrical power.

Question 32

Recall which flight control surfaces are operational when in Mechanical Backup Law.

Answer 32

▪ Rudder
▪ Trimmable Horizontal Stabilizer (THS)

❇️Mechanical (cable) connections to these flight controls permit continued use only if hydraulic power to the respective servos is available.

Question 33

Recall the PFD indications of Mechanical Backup Law.

Answer 33

▪ Amber Xs present in Alternate and Direct Law remain.
▪ MAN PITCH TRIM ONLY appears above the artificial horizon on the PFD.

NOTE: PFD displays are predicated on electrical power being available

Question 34

Describe Abnormal Law.

Answer 34

▪ Ensures flight characteristics and protections associated with Normal Law do not interfere with recovery from an abnormal flight attitude.
▪ Essentially it is Alternate Law with no automatic pitch trim or yaw damping. After the recovery has been made, the aircraft remains in Alternate Law for the remainder of the flight.

NOTE: Law will not degrade to Direct Law once the landing gear is extended.

Question 35

Describe the Rudder and Rudder Trim displays on the ECAM F/CTL page.

Answer 35

▪ The rudder is depicted in green and represents actual rudder position. ▪ Commanded rudder trim is represented by the cyan (Blue) tick mark.

Question 36

Recall the meaning of a pulsing A-LOCK (blue) on the E/WD.

Answer 36

▪ A-LOCK is displayed as an indication that leading-edge slat retraction has been inhibited due to excessively low airspeed or high angle of attack.
▪ Once airspeed and/or angle of attack corrections have been made, the slats will respond to flap lever commands and retract, and A-LOCK indication disappears.

Question 37

Describe the sidestick priority system.

Answer 37

The sidestick priority system allows either pilot’s sidestick to have sole control of the aircraft in the event of an opposing sidestick’s failure.
▪ Pressing and holding the Autopilot Disconnect/Priority pb:
• Disengages the autopilot/s, if engaged.
• Temporarily deactivates the opposite sidestick.
• Generates respective “Priority Left” or “Priority Right” voice message
• A red arrow illuminates only on the SIDE STICK PRIORITY indicator of the pilot whose sidestick has been deactivated.
• If the deactivated sidestick is sensed not to be in the neutral position, CAPT or F/O (both green) illuminates only on the SIDE STICK PRIORITY indicator of the pilot who has taken priority.

▪ After 40 seconds of pressing the sidestick Autopilot Disconnect/Priority pb, it may be released, and the opposing sidestick will remain temporarily deactivated.

NOTE: A deactivated sidestick may be reactivated at any time by simply be pressing its Autopilot Disconnect/Priority pb.

Question 38

Explain what occurs should both sidesticks be simultaneously moved.

Answer 38

▪ “Dual Input” is heard over the flightdeck loudspeakers.
❇️If moved in the same direction:
• ELACs will sum their inputs, up to a maximum of one sidestick’s full deflection. ❇️If moved in opposite directions:
• ELACs cancels both inputs

Question 39

Recall the two references on the ECAM F/CTL page which represent the neutral aileron positions.

Answer 39

▪ The two white tick marks represent the ailerons neutral position when the flaps are retracted.
▪ The white square represents the ailerons’ neutral position when the flaps are extended. This is referred to as “Aileron Droop” and provides additional aerodynamic lift when the flaps are extended.

Question 40

What are the speed brake deployment limits with Autopilot engagement?

Answer 40

▪ With an autopilot engaged, the range of speed brake deployment is limited to half the maximum possible deployment range. Placing the speed brake lever beyond the ½ position will yield no further deployment.
▪ Should autopilot failure occur with the speed brake lever beyond the ½ position, the speed brakes will immediately deploy further to meet the lever’s commanded position

Question 41

Recall the method/s of monitoring Speed Brake and Ground Spoiler deployment.

Answer 41

▪ Vertical pointing arrows (green) appear on both ECAM F/CTL and WHEEL pages.
▪ On landing, the ground spoilers are monitored on the WHEEL page, which is automatically displayed with landing gear extension.

Question 42

What are the conditions that will cause Speed Brakes to automatically retract if deployed in-flight?

Answer 42

▪ FLAPS FULL selected.
▪ Airspeed decreases to Alpha Prot.
▪ Thrust Levers placed in TOGA.

Question 43

What are the requirements for automatic Ground Spoilers deployment during landing or rejected takeoff.

Answer 43

▪ Both main gear struts must be compressed.
▪ Main gear wheel speed must be at 72 knots or greater
▪ If the spoilers are ARMED:
• Spoilers deploy when both thrust levers are placed to the IDLE stop.
▪ If the spoilers are NOT ARMED:
• Spoilers deploy when at least one thrust lever is in the REV range and the other is at the IDLE stop.