Definition
A category of in-flight abnormalities in which an airplane system or piece of equipment fails to operate as designed, requiring the pilot to recognize the problem, apply the correct procedure, and continue the flight safely. Examples include partial or total power loss, landing gear or flap failures, electrical or hydraulic system problems, instrument failures, smoke or fire, pitot-static blockages, and door or window opening in flight. In flight instructor training, this is a specific area of instruction in which the CFI must be able to teach a student how to recognize each malfunction and respond using the manufacturer's checklist and sound aeronautical decision-making.
Plain English
Things going wrong with the airplane itself in flight -- the engine, the instruments, the gear, the electrics, and so on -- and how a pilot recognizes and handles each one.
Context Anchor
Seen in flight training, emergency procedures, checklists, and discussions of how instructors teach students to respond when something on the airplane does not work as expected.
Derivation
“Malfunction” combines “mal-,” meaning bad or wrong, with “function,” meaning to work or perform. In aviation, it points to something that is not doing its normal job, even if it has not completely failed.
Why Pilots Care
Recognizing and responding correctly prevents loss of control or unsafe flight conditions and is a required skill for certification.
Intuition Check
Do not assume a malfunction means something has completely stopped working. In aviation, it can also mean something is working partly, working off and on, or giving information the pilot cannot trust.
Example Sentence 1
During the flight instructor checkride, the applicant was asked to teach a lesson on systems and equipment malfunctions, including landing gear and electrical failures.
Example Sentence 2
The pilot followed the emergency checklist after experiencing systems and equipment malfunctions in the electrical system.