FAA Aviation Mechanic Airframe (AMA)Landing Gear SystemsHard
During a functional check, the hydraulic system that normally extends the landing gear has failed completely. The pilot uses an alternate method that releases the uplocks and allows the gear to fall by gravity and airflow. This system is called
- Afree-fall (gravity) emergency extension
- Bauxiliary power unit extension
- Csequence valve bypass extension
- Danti-skid override extension
Show answer & explanationAnswer & explanation
Correct answer: A. free-fall (gravity) emergency extension
Free-fall (gravity) emergency extension systems mechanically release the gear uplocks, allowing gravity and aerodynamic airflow (sometimes assisted by a nitrogen bottle) to extend and lock the gear when normal hydraulic power is lost.
Why the other options are wrong
- B. There is no standard 'APU extension' system for landing gear.
- C. Sequence valves control retraction timing, not emergency backup extension.
- D. Anti-skid relates to braking, not gear extension.
Emergency Gear Extension (Free-Fall)
A backup method of lowering landing gear by mechanically releasing uplocks so gravity and airflow extend and lock the gear when hydraulic power fails.
- Bypasses normal hydraulic actuators
- May be assisted by a separate nitrogen or spring-loaded bottle
- Requires manual downlock verification after use
Memory trick: Free-fall gear drops like an anchor when the hydraulics quit