Landing Gear, Wheels, And Brakes Flashcards
Type of strut
Conventional oleo-pneumatic
Method of gear retraction and extension
Hydraulic power
How is hydraulic pressure supplied, and when does this system operate
Electric pump controlled by a pressure switch, only operates when system pressure falls below a set value
What other than hydraulics assists the extension and locking of the gear
Springs
What do 3 greens
And red
Mean in relation to the landing gear
3 greens: gear down and locked
Red: gear in transit/ neither locked down nor up
Type of brakes, which wheel are they attached to, and how are they operated
Hydraulic disk brakes, attached to main wheels, operated via toe brakes
Amount of strut that should be visible on the nose and main gear
15cm and 4cm respectively
Tyre pressure of nose and main wheels
6 bar and 4.5 bar respectively
Max nose wheel deflection with and without differential braking
With: 52 deg
Without: 30 deg
Turning circle with and without differential braking
6m and 9.5m
What happens to nosewheel steering upon retraction
Steering linkage disengaged to reduce rudder pedal loads
Braking system is….
Hydraulic
n.b. Separate system from gear hydraulics
Where is hydraulic fluid for braking stored
2 reservoirs attached to co-pilots brake pedal actuators
How does parking brake work
Once engaged and hydraulic pressure applied (by pumping brakes) stops hydraulic pressure from dissipating away from brake disks
How is hydraulic pressure applied to the gear
Each gear assembly has an actuator
How is constant system pressure maintained during actuator operation
A pressurised gas container (accumulator) maintains constant system pressure
How long does normal gear extension take
6-10 seconds
What assists hydraulic pressure in extension and locking down of the gear
Springs, by holding down lock hooks in place once engaged
How does retraction take place
Hydraulic pressure flows to both sides of actuator. Since retraction side has larger surface area, fluid flows from the extension side and the gear retracts
What prevents ground retraction
Left squat switch
What holds the gear in the retracted position
Hydraulic pressure, primarily from the accumulator
How does emergency gear extension work
Releases hydraulic pressure to allow gear to fall due to gravity
When will the landing gear warning sound
When airborne if either power lever is reduced below 25% when gear is not locked down
Or
Flaps are set LDG but gear is up
