FAA Airline Transport Pilot (ATM)Human Factors and CRMMedium
While flying in IMC during a prolonged, steady turn, a pilot briefly tilts her head down to check a chart on her kneeboard. Immediately afterward, she experiences a sudden, intense sensation of tumbling or rotating about a completely different axis than the actual turn. This illusion is known as:
- AThe Coriolis illusion
- BThe somatogravic illusion
- CSpatial disorientation from vestibular habituation
- DThe leans
Show answer & explanationAnswer & explanation
Correct answer: A. The Coriolis illusion
The Coriolis illusion occurs when a pilot moves their head out of the plane of an ongoing turn, stimulating multiple semicircular canals simultaneously and creating a false, often violent sensation of rotation or tumbling about a different axis. It is considered one of the most disorienting and dangerous vestibular illusions.
Why the other options are wrong
- B. The somatogravic illusion involves a false sense of pitch from linear acceleration, not head movement during a turn.
- C. Vestibular habituation is not a recognized standard illusion name in this context and doesn't match the mechanism.
- D. The leans is a false sensation of banking after abrupt correction to level flight, without the head-movement trigger described.
Coriolis Illusion
A vestibular illusion caused by moving the head out of the plane of a sustained turn, stimulating multiple semicircular canals and producing a false sensation of rotation on a different axis.
- Triggered specifically by head movement during a prolonged turn
- Considered one of the most severe and disorienting illusions
- Avoided by minimizing head movements during turns in IMC
Memory trick: Tilt your head mid-turn and your inner ear spins a whole new story — that's Coriolis.