Definition
A formal report submitted to the FAA by mechanics, owners, operators, or repair stations describing a failure, malfunction, or defect found on an aircraft, engine, propeller, or appliance. The reports are filed on FAA Form 8010-4 (often called M or D Reports) and are used by the FAA and manufacturers to identify trends, issue Airworthiness Directives, and improve safety across the fleet.
Plain English
A written report sent to the FAA whenever something on an aircraft fails or is found defective, so problems can be tracked and fixed across all aircraft of the same type.
Context Anchor
Seen in maintenance documentation, repair station work, inspection findings, and FAA reporting discussions.
Derivation
Malfunction comes from the Latin 'mal-' meaning bad and 'functio' meaning performance — literally bad performance. Defect comes from Latin 'defectus,' meaning a falling away or failure. Together they describe parts that are not working as they should or that have flaws.
Why Pilots Care
Filing these reports ensures the FAA can track recurring issues across the fleet and issue alerts or fixes that protect all pilots.
Intuition Check
Do not read this as just a casual complaint or a mechanic’s note. In this context, it means a formal report of a failure or faulty condition that matters to aviation safety tracking.
Example Sentence 1
After finding repeated cracks in the same engine mount bracket, the shop submitted a Malfunction and Defect Report to the FAA.
Example Sentence 2
Review of past Malfunction and Defect Reports revealed a pattern of fuel pump issues on this model.