Leans: what is it?

• A. A physical sensation caused by abrupt correction of a banked attitude entered too slowly to stimulate the motion sensing system
• B. A type of weather phenomenon
• C. A navigation error due to misreading a VOR
• D. A structural failure due to overloading

Answer: (A)

Leans is a type of spatial disorientation that comes from how the inner ear’s vestibular system responds to a banked attitude. When the aircraft banks gradually, the semicircular canals may not register a strong, noticeable sensation. If you then correct to level abruptly, your vestibular system interprets the sudden change as a turn in the opposite direction, giving you a false feeling of banking even though you’re actually wings-level. That’s why this description fits: the bank was entered slowly so the motion-sensing system wasn’t stimulated, and the abrupt correction produces the deceptive sensation. It’s not related to weather, navigation errors, or structural failures. In practice, pilots counter spatial disorientation by relying on flight instruments and cross-checking them, especially in instrument meteorological conditions.