Definition 1 of 2
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.
Plain English
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.
Context Anchor
Pilots most often see this word in preflight inspections, aircraft logbooks, maintenance write-ups, and checklist procedures.
Derivation
From Latin discrepare, meaning 'to sound differently' or 'to disagree.' The original sense was of two things not matching — like two voices out of tune. In aviation, that idea carries directly: the actual condition disagrees with the required condition.
Why Pilots Care
Unresolved discrepancies in fuel, instruments, or airworthiness records can affect safety and regulatory compliance.
Intuition Check
Do not read discrepancy as just a small paperwork difference. In aviation, a discrepancy can be anything from a minor record issue to a real aircraft problem that must be fixed or approved before flight.
Example Sentence 1
After landing, the pilot wrote up a discrepancy noting that the landing light failed to illuminate during the approach.
Example Sentence 2
Maintenance noted a discrepancy in the engine tachometer logs from the previous two flights.