Landing Gear & Brakes Flashcards
What powers the landing gear system?
Green hyd system
Can be extended by gravity
What manages the extension and retraction of the landing gear?
The MFC
When will the fusible plugs release tyre pressure?
When they exceed 177 degrees
What angle does the nose wheel steering system provide?
60 degrees either side
What provides gear position information?
Two independent Position Detection & Indicating Systems
They also control extension and retraction
What is the primary system controlled by?
MFC 1A
Provides position indication on the flight instruments panel
Powered by DC stby bus
What controls the secondary system?
MFC module 2A
Gera position indication on the overhead panel
Powered by DC Bus 2
When can the landing gear be considered down and locked?
As long as one set of landing gear position indicators are green
What manages the Weight on Wheels system?
WOW 1 - MFC Module 1B
WOW 2 - MFC Module 2B
What are the nose gear door position when the nose gear is extended?
Two forward doors will be closed and two aft doors will be open
How is the gear held in the up position?
By an up lock mechanism and hydraulic pressure is removed from the retract side of the gear actuator
What assists during an emergency gear extension?
Main - gas actuators and springs
Nose - mechanical extension device
What happens to the nose wheel steering system in the absence of hydraulic pressure?
Can be deflected up to 91 degrees either side of centre during towing operations
What removes hydraulic pressure from the steering system when the nose gear is not locked down?
A swivel valve
A solenoid valve when main gear and nose gear shock absorbers are not compressed - nose gear will be mechanically centred
When will nosewheel steering be available?
After all gear shock absorbers are compressed
If one gear leg comes off the ground after they are compressed, nose wheel steering will be maintained as long as one gear stays on the ground
What happens when the nose wheel steering switch is ON?
Steering solenoid valve is armed for operation
Valve opens when steering is commanded
How can you steer the aircraft if nosewheel steering is lost?
Differential braking
Differential thrust
What is available for braking if park brake handle is in the centre notch?
500 psi
Additional pressure by moving the handle one half an inch aft below 60 kt (above 60kt will supply the whole 3000 psi)
When should the tires be visually inspected?
If the emergency and park system were used with a GS above 20 kt
What does the anti-skid system provide?
Protection against tire skidding
Locked wheel and touchdown protection
Controls each brake pressure to achieve maximum stopping performance
When does the anti-skid system become available?
As soon as the landing gear is down and locked and as long as aircraft GS is above 10 kt
What will the anti-skid system do if it senses that a wheel is skidding?
It will release hydraulic pressure to the associated brake to alleviate the skidding
What is locked wheel protection?
Compares the wheel speeds of the inner pair of main gear wheels and the outer pair
Locked wheel signal generated if there is a speed difference of more than 50%
Brake pressure will be released to prevent wheels from locking
When is locked wheel protection available?
When the ground speed is above 23 kt
What is touchdown protection?
Brakes are prevented from operating for the first 5 seconds after touchdown or as long as wheel speed is below 35 kt
Prevents the use of brakes prior to wheel spin up on low friction pavements or if there is a light load in the wheels
When will the red light on the landing gear handle illuminate?
As long as the gear is not sensed to be in the down and locked position
When will the UNLK caption illuminate red?
When associated gear is not locked in the position selected by the landing gear lever
If the aircraft is on the ground and the associated unlock box is not in the open position
What happens when the emergency gear extension handle is used?
Uplocks are released and a valve is opened to allow fluid in the lines to return back to the reservoir
Gears falls by gravity assisted by a compressed gas strut
When is the emergency brake usable?
Speed sup to V1
When will you get a BRK TEMP HOT light?
When at least one brake temperature exceeds 160 degrees
Pressing the BRK TEMP TEST pb will illuminate the lgiht
What does an amber F on the anti-skid panel mean?
A failure of the associated anti-skid channel
In this case the anti-skid function is lost completely
When can you do the anti-skid test pb?
If the aircraft is on the ground or in flight
Should not be done if the park brake is not set when the aircraft is on the ground with engines running
What is the anti-skid test?
Test is performed by applying brakes through the brake pedals
Will last 6 secs and brakes will be compressed and released
Fault lights will illuminate during the test
Failure is indicated if the fault light remains on after the test
When is the anti-skid test mode inhibited?
When the aircraft is on the ground and GS exceeds 17 kt
