FAA Aviation Mechanic Airframe (AMA)Landing Gear SystemsMedium
A technician notices a nose landing gear oscillating rapidly side-to-side during high-speed taxi. Which component is most likely malfunctioning?
- ADownlock spring
- BSquat switch
- CShimmy damper
- DTorque link bushing
Show answer & explanationAnswer & explanation
Correct answer: C. Shimmy damper
The shimmy damper controls oscillation (shimmy) of the nose wheel during taxi, takeoff, and landing roll by hydraulically or mechanically dampening lateral movement. A failed or low-fluid damper allows the wheel to oscillate rapidly.
Why the other options are wrong
- A. Downlock springs hold gear in the extended position and don't affect taxi oscillation.
- B. Squat switches sense weight-on-wheels, unrelated to shimmy.
- D. Worn torque link bushings can contribute to play but the shimmy damper is the primary anti-oscillation component.
Shimmy Damper
A hydraulic or mechanical device on the nose landing gear that dampens lateral oscillation (shimmy) during ground operations.
- Prevents rapid side-to-side wheel oscillation
- Can be piston-type (hydraulic) or vane-type
- Low fluid or worn seals cause shimmy to reappear
Memory trick: Shimmy damper stops the wobble like training wheels