Authority to perform and approve maintenance, preventive maintenance, and alterations

This regulation governs who can perform and approve maintenance work on Part 121 air carrier aircraft.

What it permits:

Certificate holders (airlines) may perform their own maintenance, preventive maintenance, and alterations, or contract with other organizations to do this work—as long as it follows their FAA-approved maintenance program and manual. Airlines can also perform maintenance for other certificate holders under the same conditions.

Return to service authority:

The certificate holder may approve aircraft and components for return to service after maintenance work. For routine maintenance, this approval can be given according to their maintenance program. However, major repairs or major alterations require an additional step: the work must be done using technical data that the FAA has specifically approved.

This regulation essentially establishes the framework for how airlines manage their maintenance operations while ensuring FAA oversight of significant work through the technical data approval requirement.

*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.*