FAA Aviation Mechanic General (AMG)Regulations, Records and Human FactorsMedium
A mechanic is calculating when the next 100-hour inspection is due. According to 14 CFR 1.1, 'time in service' for this purpose is defined as the time:
- ARecorded by the flight data recorder during cruise flight only
- BFrom engine start to engine shutdown
- CFrom the moment the aircraft leaves the surface until it touches down at the next landing
- DLogged by the pilot in the aircraft logbook regardless of flight
Show answer & explanationAnswer & explanation
Correct answer: C. From the moment the aircraft leaves the surface until it touches down at the next landing
14 CFR 1.1 defines 'time in service' as the time from the moment an aircraft leaves the surface (takeoff) until it touches down at the next point of landing. This 'wheels off to wheels on' time is used to calculate inspection and component life intervals, not total engine run time.
Why the other options are wrong
- A. Flight data recorder cruise time is unrelated to the regulatory definition.
- B. Engine start-to-shutdown includes taxi time, which is not 'time in service' under 1.1.
- D. Logbook entries reflect time in service but the definition itself is takeoff-to-landing time.
Time in Service (14 CFR 1.1)
The time from the moment an aircraft leaves the surface of the earth until it touches down at the next point of landing; used to compute inspection and overhaul intervals.
- Also called 'flight time' in this context.
- Excludes taxi time before takeoff and after landing.
- Basis for 100-hour, annual, and component life calculations.
Memory trick: 'Wheels up to wheels down' counts, not taxi time.