AMT Hydraulics, Pneumatics & Landing Gear Flashcards

What is the purpose of a shimmy damper on an aircraft nose gear?

Answer: To absorb and dampen rapid oscillations of the nose wheel

A shimmy damper uses hydraulic resistance to control and suppress the rapid side-to-side oscillation (shimmy) of the nose wheel during ground operations.

Which component absorbs landing shock energy in most aircraft landing gear struts?

Answer: Oleo (air-oil) pneumatic strut

Oleo struts use a combination of compressed air/nitrogen and hydraulic oil to absorb and dissipate the energy of landing impact.

What safety device prevents accidental retraction of landing gear while the aircraft is on the ground?

Answer: Weight-on-wheels (squat) switch

The weight-on-wheels (squat) switch is a safety switch that senses aircraft weight on the gear and electrically prevents retraction while the aircraft is on the ground.

What is the typical inflation medium used in aircraft oleo struts?

Answer: Nitrogen gas and hydraulic oil

Aircraft oleo struts are typically serviced with dry nitrogen gas (to prevent moisture and oxidation) and hydraulic oil to provide proper shock absorption.

What system provides an emergency means of extending the landing gear if the normal hydraulic system fails?

Answer: Emergency free-fall or alternate extension system

Aircraft are equipped with an emergency gear extension system that allows the gear to free-fall by gravity and/or uses an alternate hydraulic or pneumatic source if the normal system fails.

How is tire inflation pressure most accurately verified on aircraft tires?

Answer: Using a calibrated tire pressure gauge

A calibrated tire pressure gauge is the only accurate method to verify aircraft tire inflation pressure, which must match the aircraft manufacturer's specifications.