MEL
Minimum Equipment List
A document authorizing an aircraft to be dispatched with specific equipment inoperative under defined conditions.
A Minimum Equipment List is an FAA-approved document that lets a specific aircraft fly with certain equipment inoperative — provided the deferral is documented, placarded, and accompanied by any required operational procedures.
The MEL is built from the FAA's Master Minimum Equipment List (MMEL) for the aircraft type, then customized to the specific aircraft. Items deferred under MEL still have a maximum time to repair (Category A, B, C, or D) and may require operational limitations (no IFR, no night, etc.) until corrected.
For aircraft operated without an MEL, FAR 91.213(d) provides the alternative: a defined process for deferring inoperative equipment that isn't required by certification, regulation, or AD.
When it matters
Common in Part 91 corporate, Part 135 charter, and any operator running an FAA-approved MEL. Part 91 GA operators more often rely on FAR 91.213(d) for deferrals.
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