Maintenance recording requirements

This regulation requires Part 121 air carriers to maintain detailed maintenance records using the system described in their maintenance manual. Airlines must track critical information including total airframe time, engine and propeller time (with limited exceptions for certain older aircraft), life-limited parts status, overhaul times, inspection status, airworthiness directive compliance, and major alterations.

Most maintenance records must be kept until the work is repeated or superseded, or for one year. However, records of complete overhauls must be retained until equivalent work is performed, and the operational status records (like total time and AD compliance) must stay with the aircraft when it's sold.

This ensures continuous tracking of an aircraft's maintenance history throughout its service life, which is essential for safety and regulatory compliance. Airlines must make these records available to FAA and NTSB inspectors upon request. The regulation provides the foundation for maintaining airworthiness in commercial operations.

*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.*