Maintenance recording requirements

This regulation requires Part 135 operators to maintain detailed maintenance records using the system described in their maintenance manual.

Operators must track total time in service for major components (airframe, engines, propellers, rotors), the status of life-limited parts, time since last overhaul for items requiring periodic overhaul, current inspection status, airworthiness directive compliance, and major alterations or repairs.

Most maintenance records must be kept for one year or until the work is repeated or superseded. However, records of complete overhauls must be retained until equivalent work is performed. The records tracking component times, life-limited parts, and inspection status must stay with the aircraft when it's sold—they transfer to the new owner.

All records must be available for FAA or NTSB inspection. This ensures continuous tracking of an aircraft's maintenance history, which is essential for safety and airworthiness compliance throughout the aircraft's operational life.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*