MQF Speed Brakes / Spoilers [Flight Controls]

Question 1

Discuss the ground spoiler logic on a rejected takeoff.

Answer 1

• If the ground spoilers are armed and the speed exceeds 72 knots, the ground spoilers will automatically extend as soon as both thrust levers are set to idle.
• If the ground spoilers are not armed and the speed exceeds 72 knots, the ground spoilers will automatically extend as soon as reverse is selected on one engine (the other thrust lever remains at idle).
• Therefore, selecting at least idle reverse will always provide ground spoiler deployment.

Question 2

Discuss the ground spoiler logic on landing.

Answer 2

• Full extension:
  The ground spoilers will automatically extend when the following conditions are met:
  
  • Speed brake lever not in the retracted position or ground spoilers armed and:
    
    • Both main landing gears on ground,
    • Both thrust levers at or below idle position, or Reverse selected
      on at least one engine (and the other thrust lever below MCT
      position).
  • Speed brake lever in the retracted position but ground spoilers not
    armed and:
    
    • Both main landing gears on ground,
    • Reverse selected on at least one engine (and the other thrust lever below MCT position)
  The ailerons are fully-extended, provided one aileron servocontrol is available on each side, when:
  * The ground spoilers are fully extended o Flaps are not in clean CONF
  * Pitch attitude is lower than 2.5 °
  * Flying manually
  * In normal law only
• Partial extension:
  In order to accelerate the full spoiler extension, the Phased Lift Dumping (PLD) function allows the ground spoilers to deploy with a reduced deflection when the following conditions are met:
  
  • Speed brake lever not in the retracted position or ground spoilers armed and:
    
    • One main landing gear on ground,
    • Both thrust levers at or below idle position.
  • Speed brake lever in the retracted position, but ground spoilers not
    armed and:
    
    • One main landing gear on ground,
    • Reverse selected on at least one engine (and the other thrust
      lever below MCT position).
      In order to reduce the bounce severity at landing in the case of an inappropriate thrust lever handling during flare, ground spoilers are also partially deployed when the following conditions are met:
  • Ground spoilers armed,
  • Both main landing gears on ground,
  • Both thrust levers at or below the Climb position.
• Retraction
  The ground spoilers retract:
  
  • After landing,
  • After a rejected takeoff, when the ground spoilers are disarmed.
  • During a touch and go, when at least one thrust lever is advanced above 20°.

Question 3

When will the ground spoilers automatically retract?

Answer 3

During a touch and go/balk landing and at least one thrust lever is advance above 20%

Question 4

What are some conditions that inhibit speed brake extension?

Answer 4

• Angle of Attack protection is active
• Thrust levers above the MCT position
• ALPHA FLOOR is active

Question 5

In flight, what happens if a spoiler fault is detected, or electrical power is lost?

Answer 5

The spoilers automatically retract

Question 6

Is there any landing configuration when speed brake extension is inhibited?

Answer 6

• A319/A320 – Flaps FULL
• A321 – Flaps 3 and FULL