FAA Instrument Rating Airplane (IRA)Aeromedical and ADMMedium
While holding in actual IMC, a pilot stares at a single, isolated light on the instrument panel in an otherwise dark cockpit. After several seconds, the light appears to drift, even though it has not moved. This phenomenon is known as:
- ACoriolis illusion
- BFalse horizon
- CAutokinesis
- DElevator illusion
Show answer & explanationAnswer & explanation
Correct answer: C. Autokinesis
Autokinesis is a visual illusion in which a stationary point of light, when stared at for several seconds in a dark environment, appears to move on its own. This can lead a pilot to make unnecessary and potentially dangerous control corrections.
Why the other options are wrong
- A. Coriolis illusion involves head movement during a sustained turn, not a stationary light.
- B. False horizon involves misidentifying a visual reference as the horizon, not a moving-light perception.
- D. Not a recognized FAA illusion term.
Autokinesis
A visual illusion where a stationary light stared at in darkness for several seconds appears to move, potentially causing false control corrections.
- Occurs in dark conditions with a single fixed light source
- Caused by small involuntary eye movements
- Avoid by moving the eyes and not fixating on one light
Memory trick: Stare at one star long enough, it starts to wander.