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Airbus A320 > Landing Gear > Flashcards

Flashcards in Landing Gear Deck (18)
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1
Q

Explain the operation of the landing gear

A
  • flight crew normally operate landing gear via lever
  • LGCIUs (1 or 2) control the sequencing of gear and doors electrically
  • LGCIUs switch at the completion of each retraction cycle or failure
  • green hydraulic system actuates all gears and doors
  • LGCIUs electronically monitor 16 proximity switches to determine sequence of landing gear and doors.
2
Q

Does the landing gear have any protections?

A
  • If aircraft is flying faster than 260 kt, a safety valve automatically cuts off hydraulic supply to the landing gear system
  • interlock mechanism prevents anyone from accidentally retracting the gear while the aircraft is on the ground
3
Q

What happens when you turn the landing gear hand crank?

A

‐ Isolates the landing gear hydraulics from the green hydraulic system
‐ Unlocks the landing gear doors and the main and nose main gear
‐ Allows gravity to drop the gear into the extended position

4
Q

What information do the LGCIUs receive from the proximity detectors?

A

‐ The landing gears are locked down or up
‐ The shock absorbers are compressed or extended
‐ The landing gear doors are open, or closed
‐ The bogie are aligned or not

5
Q

Which LGCIU is connected to the Landing Gear Indicator Panel?

A

LGCIU 1

6
Q

How many turns of the crank to manually extend the landing gear?

A

3 turns

7
Q

On WHEEL SD page how to confirm if the gear is down and locked?

A
  • 2 triangles for each gear

- Only one green triangle on each landing gear strut is sufficient to confirm that the landing gear is downlocked

8
Q

Which hydraulic system operates nose wheel steering?

A

Yellow hydraulic system

9
Q

What is required for the steering system to receive hydraulic pressure?

A

‐ A/SKID & N/W STRG switch is ON
‐ Towing control lever is in normal position
‐ At least one engine is running
‐ Aircraft is on ground

10
Q

Steering angle limits

A

+/- 6 degrees via rudder
+/- 75 degrees via steering hand wheel
+/- 95 degrees with steering system off for towing

11
Q

How many braking systems?

A
  • normal system via green hydraulic pressure
  • alternate system via the yellow hydraulic system
  • anti-skid and autobrake system
12
Q

When does anti skid deactivate?

A

20 knts

13
Q

How is wheel reference speed determined?

A
  • reference speed is determined by the Brake Steering Control Unit (BSCU) from the horizontal acceleration of ADIRU 1, or ADIRU 2, or ADIRU 3
  • in case of all ADIRU failure reference speed equals maximum of either main landing gear wheel speeds
14
Q

Auto break arming conditions

A

‐ Green pressure available
‐ Anti-skid electrically powered
‐ No failure in the braking system
‐ At least one ADIRU is available

  • MAX cannot be armed in flight
15
Q

Conditions to activate Autobrake

A

In LO or MED: ground spoilers extension
In MAX: ground spoilers extension and above 40knts
ground spoiler extend above 72knt wheel speed
- 2 SECs operative

16
Q

Breaking modes

A

‐ Normal braking
‐ Alternate braking with antiskid
‐ Alternate braking without antiskid
‐ Parking brake

17
Q

What can the accumulator supply?

A
  • 7 full brake applications, or

- parking pressure for at least 12 h

18
Q

When is the landing gear safety valve activated

A

Above 260 knts hydraulic supply is cut off from the landing gear system