Landing Gear Flashcards
What controls the extension and retraction of the gear and provides information to ECAM?
2 x Landing Gear Control and Interface Units
Which hydraulic system is used for the landing gear brakes? Which system is used as back up?
Normal (green)
Yellow (back up)
What do the main gear wheel fusible plugs do?
Protect against tire burst in the event of overheat or high brake temperature
Which hydraulic system is used for parking brakes and nosewheel steering?
Yellow
Generally, how are brakes controlled?
Electronically controlled and hydraulically actuated
Re brake pressure on the ACCU/PRESS indicator on centre instrument panel - what does this show?
Indicates pressure in the yellow hydraulic pressure being delivered to the left and right brake systems
How do you recharge brake accumulator pressure on the ground?
Turn on yellow hydraulic pump
Landing Gear and Interface Unit key facts
- 2 x installed
- They control the sequencing of the gear and gear doors
- Each controls one complete cycle, then switches to the other
How do the LGCIUs know the position of the gear?
Via proximity detectors (1 set per LGCIU) and other proximity detectors on shock absorbers
Describe system for raising/lowering the gear
- Green hydraulic system Used to supply pressure
2A. Gear lever down - hydraulic safety valve opens and electrical signal sent to LGCIU - LGCIU sends commands to the doors selector valves and gear selector valves
Note: at or above 260kts - the hydraulic safety valves close.
What does “red down arrow” mean on landing gear lever
It means the gear is not locked down when aircraft is in the landing configuration
How many doors per main landing gear?
3 doors:
- Main door
- Fixed fairing door
- Hinged fairing door
How many doors for nose landing gear?
- 2 x main door
- 2 x smaller aft doors
- 1 x small fairing door
Emergency extension. How does it work?
- Gravity
- Use GRAVITY GEAR EXT crank handle (turn 3 times)
- Shuts off green hydraulic pressure to landing gear system
Lights in the gear indicator panel
- No lights - up and locked
- Red “UNLK” - in transit or not locked
- 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).
What do Amber “XX” mean in ECAM WHEEL page?
LGCIU failure (i.e computer for sending signals to the display)
What is the BSCU and what does it do?
Brake and Steering Control Unit controls:
- Normal braking and anti-skid
- Checks residual pressure in brakes
- Monitors brake temperature
- Wheel speed info
- BSCU channels change at each down landing gear selection
What are the two modes of brake operation?
- Manual:
a. Pilot brake pedals
b. BSCU controls pressure to brakes depending on pressure applied by pilot - Automatic
a. Pre programmed
b. Pressure supplied by green hydraulic system
c. Uses max for RTO
d. Low or Med usually used for landing
