S Landing Gear Flashcards
What is a bogey truck?
Allows the fitment of more wheels
Which landing gear should touch down first?
Main wheels, touching down on the nose could cause collapse
What is the oleo strut?
Landing gear leg - Hydro-pneumatic shock absorber
What is the state of the oleo strut when the aircraft is stationary?
Gas pressure = weight force of the aircraft
Additional load causes oleo to compress
What can cause low ride height/oleo compression?
Low gas pressure or fluid leak
What hydraulic fluid does the oleo usually have?
Mineral hydraulic oil - DTD585, red in colour
What is the oleo leg?
Absorbs loads and dampens rebound
What is the purpose of wheel axles?
Allow wheels to rotate freely
What is a drag a strut?
Brace the assembly against shock loads
What is a side stray ?
Braces assembly against side loads during taxiing and landing
What are torque/scissor links?
Prevent rotation of the inner oleo cylinder, allows the to be telescopic whist preventing the 2 sections rotating independently
What is a down lock?
Over centre lock ensuring the gear cannot be accidentally retracted
What is released in an emergency to drop the gear?
The up lock
What is a ground lock?
Mechanical device which physically prevents the gear from retracting - fitted with remove before flight flag
What is Vlo?
Velocity landing gear operation
What is Vle?
Velocity landing gear extended
What are emergency methods to release gear?
- Manual hand crank
- Compressed nitrogen to blow the gear down
- Gravity free fall system
- Manual handle
How does the manual handle work?
- Release up locks
- Opens safety valve
- Gear descends under gravity
- Over centre locks ensure the gear is down and locked
What are 3 ways nose whee steering can be achieved?
- Differential breaking
- Rudder pedal steering
- Tiller operation
What is the maximum steering direction that nose wheel steering can achieve?
75 degrees in either direction
What is nose wheel shimmy?
Lateral oscillation along the longitudinal axis
What are 3 ways to stop nose wheel shimmy?
- Shimmy damper - Hydraulic cylinder acts as damper
- Dual nose wheel - 2 points of contact
- Maarstrand tyre - Special tyre that has 2 points of contact
What faults can nose wheel shimmy indicate?
- Worn or broken torque links
- Wear in the wheel bearings
- Low or uneven tyre pressures
