Landing Gear

Question 1

What controls the extension and retraction of the gear and provides information to ECAM?

Answer 1

2 x Landing Gear Control and Interface Units

Question 2

Which hydraulic system is used for the landing gear brakes? Which system is used as back up?

Answer 2

Normal (green)

Yellow (back up)

Question 3

What do the main gear wheel fusible plugs do?

Answer 3

Protect against tire burst in the event of overheat or high brake temperature

Question 4

Which hydraulic system is used for parking brakes and nosewheel steering?

Answer 4

Yellow

Question 5

Generally, how are brakes controlled?

Answer 5

Electronically controlled and hydraulically actuated

Question 6

Re brake pressure on the ACCU/PRESS indicator on centre instrument panel - what does this show?

Answer 6

Indicates pressure in the yellow hydraulic pressure being delivered to the left and right brake systems

Question 7

How do you recharge brake accumulator pressure on the ground?

Answer 7

Turn on yellow hydraulic pump

Question 8

Landing Gear and Interface Unit key facts

Answer 8

1. 2 x installed
2. They control the sequencing of the gear and gear doors
3. Each controls one complete cycle, then switches to the other

Question 9

How do the LGCIUs know the position of the gear?

Answer 9

Via proximity detectors (1 set per LGCIU) and other proximity detectors on shock absorbers

Question 10

Describe system for raising/lowering the gear

Answer 10

1. Green hydraulic system Used to supply pressure
   2A. Gear lever down - hydraulic safety valve opens and electrical signal sent to LGCIU
2. LGCIU sends commands to the doors selector valves and gear selector valves

Note: at or above 260kts - the hydraulic safety valves close.

Question 11

What does “red down arrow” mean on landing gear lever

Answer 11

It means the gear is not locked down when aircraft is in the landing configuration

Question 12

How many doors per main landing gear?

Answer 12

3 doors:

1. Main door
2. Fixed fairing door
3. Hinged fairing door

Question 13

How many doors for nose landing gear?

Answer 13

1. 2 x main door
2. 2 x smaller aft doors
3. 1 x small fairing door

Question 14

Emergency extension. How does it work?

Answer 14

1. Gravity
2. Use GRAVITY GEAR EXT crank handle (turn 3 times)
3. Shuts off green hydraulic pressure to landing gear system

Question 15

Lights in the gear indicator panel

Answer 15

1. No lights - up and locked
2. Red “UNLK” - in transit or not locked
3. Green arrows - down and locked

If there is one UNLK indication - you can confirm landing gear position by the ECAM WHEEL page (where one green triangle in each gear is sufficient to confirm gear is down and locked).

Question 16

What do Amber “XX” mean in ECAM WHEEL page?

Answer 16

LGCIU failure (i.e computer for sending signals to the display)

Question 17

What is the BSCU and what does it do?

Answer 17

Brake and Steering Control Unit controls:

1. Normal braking and anti-skid
2. Checks residual pressure in brakes
3. Monitors brake temperature
4. Wheel speed info
5. BSCU channels change at each down landing gear selection

Question 18

What are the two modes of brake operation?

Answer 18

1. Manual:
   a. Pilot brake pedals
   b. BSCU controls pressure to brakes depending on pressure applied by pilot
2. Automatic
   a. Pre programmed
   b. Pressure supplied by green hydraulic system
   c. Uses max for RTO
   d. Low or Med usually used for landing