Definition
A formal report submitted to the FAA describing a mechanical malfunction, failure, or defect found on an aircraft, engine, propeller, or appliance. It is used to alert the FAA and the wider aviation community to problems that could affect airworthiness, allowing trends to be tracked and corrective action — such as Airworthiness Directives — to be issued when needed.
Plain English
A standard form a mechanic or operator fills out to tell the FAA when something on an aircraft has broken, failed, or shown a defect that could matter for safety.
Context Anchor
Seen in aircraft maintenance records, inspection follow-up, and maintenance reporting discussions.
Derivation
The name simply describes what is being reported: a malfunction (something not working correctly) and a defect (a flaw or fault in a part or system). The pairing reflects that the report covers both outright failures and conditions that could lead to failure.
Why Pilots Care
Ensures safety issues are recorded and tracked so recurring problems can be addressed before they affect flight operations.
Intuition Check
Do not think of an M&D report as just a casual note that something seems wrong. In maintenance use, it is a formal record of a specific problem that may require corrective action and follow-up.
Example Sentence 1
After finding a cracked cylinder flange during a routine inspection, the technician filed an M&D report so the FAA could track whether the same problem was showing up on other engines of that model.
Example Sentence 2
Review of recent M&D reports revealed a pattern of starter motor failures on the fleet.