Definition 1 of 2
Plain English Meaning
Something that isn't the way it's supposed to be. A pilot or mechanic spots that a part, system, or instrument isn't behaving correctly, writes it down, and it stays on the record until someone fixes it or formally clears it.
Full Definition
A noted difference between the actual condition or performance of an aircraft, system, or component and the condition or performance required by approved specifications, manuals, or standards. In maintenance practice, a discrepancy is recorded so it can be investigated, deferred, or corrected before the aircraft is returned to service.
Context Anchor
Pilots most often see this word in preflight inspections, , maintenance write-ups, and .