Aeromedical factorsQuestion 727 of 934

A pilot returns suddenly to level flight after a gradual turn that went unnoticed. Which illusion can result?

  1. The elevator illusion
  2. The autokinesis illusion
  3. The leans
  4. The inversion illusion
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Correct answer: The leans

The leans follow a sudden return to level flight after a gradual, prolonged turn that went unnoticed.

Source: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Chapter 17: Aeromedical Factors — Vestibular Illusions, page 429

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Questions last reviewed: 18 October 2026