Definition
A pilot's loss of the physical or mental ability to safely operate the aircraft, whether sudden (such as a heart attack, stroke, or loss of consciousness) or subtle (such as impaired judgment from hypoxia, fatigue, medication, or illness).
Plain English
Becoming unable to fly the aircraft safely, either all at once or gradually, because something has gone wrong with your body or mind.
Context Anchor
Seen in aeromedical and instrument flying discussions when describing conditions that can make a pilot unable to control the aircraft, make decisions, or communicate safely.
Derivation
From the Latin 'in-' (not) and 'capax' (able). Literally 'made unable.' In aviation it specifically means made unable to fly the aircraft safely.
Why Pilots Care
Unrecognized incapacitation can result in loss of aircraft control, requiring immediate use of autopilot, crew intervention, or ATC assistance to prevent an accident.
Grounding Statement
A pilot who becomes confused, severely ill, or unable to move normally may be incapacitated even before becoming fully unconscious.
Intuition Check
Incapacitation does not always mean a pilot is unconscious. In aviation, it can mean any physical or mental condition that keeps the pilot from safely doing the job.
Example Sentence 1
The captain recognized the early signs of his own incapacitation from hypoxia and immediately descended to a lower altitude.
Example Sentence 2
The captain suffered sudden incapacitation, so the first officer took over and declared an emergency.