Aircraft Maintenance and Airworthiness
This domain tests whether you can keep aircraft legally airworthy and prove it. CAM items focus on inspection programs, airworthiness directives, deferrals, records, and return-to-service authority under Parts 91 and 135.
Core rules
- Airworthiness directives are mandatory. Service bulletins are manufacturer recommendations and become mandatory only when incorporated by an AD, an STC, or the operator's approved program.
- Part 91 requires an annual inspection and, for many operations, a 100-hour inspection; a progressive inspection or an approved aircraft inspection program can replace the 100-hour requirement when authorized. Part 135 operators follow an approved inspection program under 135.411 and 135.425.
- The MEL allows deferral only of items listed for that aircraft, with the specified maintenance and operational procedures. It is not a general permission to fly with a known defect.
- Return to service requires the correct authority: an A&P for maintenance, an IA for annual inspections, and, under Part 135, a person authorized by the certificate holder's manual.
- Records must show AD compliance, life-limited part status, inspections, and return to service; a tracking system is only as good as the data entered.
Worked example
A recurring AD is due every 100 hours. Last compliance was at 2,450 aircraft hours. The aircraft now shows 2,510 hours. Next due is 2,550 hours, leaving 40 hours. If the aircraft flies 30 hours per week, the AD falls due in about nine days, so maintenance control must schedule it before the next trip block rather than at the next phase check.
Traps
Calling a service bulletin mandatory; using the MEL for an item not listed; assuming an annual inspection satisfies a 100-hour requirement; letting a pilot sign a maintenance release not authorized by the manual; recording AD compliance without a reliable due list.