What does airframe hours indicate and how is it used in maintenance scheduling?

• A. The number of hours the engine has run.
• B. The cumulative time the airframe has been in service; used to schedule inspections and overhauls.
• C. The time since the last landing.
• D. The time the avionics have been powered.

Answer: (B)

Airframe hours indicate the cumulative time the aircraft’s airframe has been in service. This measurement is used to plan maintenance by tying inspection and overhaul intervals to the total airframe time, so tasks occur at predetermined points regardless of how many engine hours or flights have occurred. Tracking airframe hours helps manage fatigue, aging, and wear on the structure and related systems. It’s not the engine’s run time, not the time since the last landing, and not the time the avionics have been powered, so those other metrics don’t drive airframe-related maintenance in the same way.