Landing Gear components
What is an over-centre link?
An over-centre link in the landing gear downlock is used to apply pressure to the centre pivot joint ina drag or side strut. This prevents the struts from pivoting at this joint except when retracting orextending the gear. By straightening beyond 180°, the link prevents collapse of the gear duringground operation. The over-centre link is hydraulically retracted to allow gear retraction. Groundlocking pins are usually installed in the over-centre link
what are 4 means of lowering the landing gear in an emergency situation?
Mechanical, electrical, alt hydraulic, compressed air, gravity
What does the green lights on the landing gear system mean
Gear is down and locked
What are aircraft wheels used for?
Absorb high loads during landing and taxiing
What are the 5 different sections of the tyre?
tread, carcass plies, bead, under tread, sidewall
What is used to maintain the landing gear in a retracted position?
Landing gear uplock
The access door to the manual extension control mechanism handles has a position switch on it to send a signal to the .......?
bypass valve in the landing gear selector valve to move to bypass. It connects all the hydraulic components in the landing gear extension and retraction system to the hydraulic system return.
what does the landing gear system use to determine the position of the gear
Micro switches and proximity sensors
what is the most common type of wheel rim?
Split
why does a tyre have Ply rating and load rating
to identify the maximum static load the tyre can be subject to.`
what is used to lock the landing gear in the extended position
Landing gear down lock
What do Electric landing gear extension and retraction systems use for emergency operation.
a hand crank or a ratchet handle to drive the same mechanism
What blocks movement of the cockpit landing gear selector lever while the aircraft is on the ground.
A safety switch operates as an electrical energised solenoid.
Name components fitted to a wheel assembly?
pressure relief valve, rotor alignment guide, heat shield, rotor drive key, inflation valve, thermal plugs, bearings
The Three-Part Nomenclature Type is designated as follows
M x N - D
where:
M is? N is? and D is?
M = Nominal overall diameter
N = Nominal section width
D = Rim diameter
What are 2 methods of maintaining the wheel well doors in the closed position?
Landing Gear Door Uplock or mechanical connection with the landing gear strut
In an Emergency Landing Gear Manual Extension System, how are the gear and doors unlocked
Pulling on the manual extension handle pulls on the control cable for the manual extension system.The cable goes to the manual extension linkage.
Each manual extension linkage moves the uplock mechanism for that landing gear to the unlocked position. The landing gear extends by air loads and its own weight
What systems do some aircraft have to determine landing gear position when warning lights are inoperable?
Mirrors and witness marks, pins on upper wing surface or mechanical indications in the cockpit.
what type of bearings are fitted to most aircraft wheels?
Tapered roller bearings
The chine tyre is a nose wheel tyre designed?
to deflect water and slush to the side and away from engine intakes
What are the four basic steps of landing gear extension in an electronically controlled landing gear operation
Gear down selection, doors open, gear down, doors closed
Hydraulic landing gear systems will use a _____ valve to automatically switch from the normal system to an alternate system in case of normal system hydraulic failure.
Shuttle
When does the landing gear warning system operate?
When certain conditions exist during approach to land and the landing gear is still retracted
Why are tapered roller bearings used for wheel installations?
they have good axial and radial load carrying capabilities
What occurs as a result of tyre spin-up during landing on cross-groove-cut runways?
Chevron Cutting