Which illusion is most associated with misperception of bank angle during a coordinated turn?

• A. The Leans
• B. Somatogravic illusion
• C. Graveyard Spiral
• D. Visual illusion

Answer: (A)

The Leans describes a misperception of bank angle that often happens after you roll out of a turn. The semicircular canals adapt to the initial bank, and when you return the wings toward level, your vestibular system may no longer sense the roll correctly. Your brain then may think you’re still banked or even feel like you’re rolling in the opposite direction, leading to the illusion that the aircraft isn’t level or that you’re in a bank when you’re actually straight.

This is especially likely in conditions with limited visual references, where you rely more on your vestibular sense. Other illusions involve acceleration affecting pitch perception (somatogravic) or visual cues (visual illusion) or a spiraling descent due to misperception in a prolonged turn (graveyard spiral), but the misperception of bank angle during a coordinated turn is classically the Leans.