Definition
Procedures published by the aircraft manufacturer for handling system malfunctions or unusual situations that are not immediately life-threatening but require pilot action to prevent the situation from becoming an emergency. Found in the Pilot's Operating Handbook (POH) or Airplane Flight Manual (AFM), they sit between normal procedures and emergency procedures in urgency.
Plain English
Steps the pilot follows when something is wrong with the aircraft, but it's not yet a full emergency. The aim is to fix or manage the problem before it gets worse.
Context Anchor
Seen in aircraft handbooks, checklists, and emergency training when discussing how to respond to unusual conditions such as warning lights, system failures, rough engine operation, or equipment problems.
Derivation
From Latin abnormis, meaning 'departing from the rule.' In aviation use, it points to a situation that is off-normal but not yet at the level of an emergency.
Why Pilots Care
Following the correct abnormal procedures prevents a minor issue from developing into an emergency and maintains safe flight.
Intuition Check
Do not read “abnormal” as automatically meaning “disaster.” In aviation, an abnormal procedure may be for a serious problem, but it can also be for a manageable condition that simply is not normal.
Example Sentence 1
When the alternator warning light came on in cruise, the pilot opened the POH to the abnormal procedures section and worked through the checklist.
Example Sentence 2
Abnormal procedures for a partial flap failure differ from the emergency procedures used for total hydraulic loss.