Plain English Meaning

A required check-up that certain aircraft must have after every 100 hours of flying. It applies to planes used for paid flights or for flight training where the owner provides the airplane. A qualified mechanic does the inspection and signs the logbook before the aircraft can keep flying for those purposes.

Full Definition

A federally required inspection of an aircraft and its engine that must be completed every 100 hours of flight time when the aircraft is used for hire or for flight instruction provided by the aircraft owner. The inspection covers the same scope as an annual inspection but is tied to flight hours rather than the calendar. It must be performed and signed off by an appropriately certificated mechanic, and the aircraft cannot legally be operated for hire beyond the 100-hour limit until the inspection is completed.