FAA Instrument Rating Airplane (IRA)Aeromedical and ADMEasy
A pilot flying in smooth IMC encounters a sudden updraft. The upward acceleration creates a sensation that the airplane is pitching nose-up, prompting the pilot to push forward on the controls. Which illusion is being described?
- ACoriolis illusion
- BAutokinesis
- CElevator illusion
- DThe leans
Show answer & explanationAnswer & explanation
Correct answer: C. Elevator illusion
The elevator illusion is caused by an abrupt vertical acceleration, such as an updraft, which stimulates the otolith organs and creates a false sensation of pitching, prompting an inappropriate control input. Pilots must rely on the attitude indicator to avoid overcorrecting.
Why the other options are wrong
- A. The Coriolis illusion is caused by head movement during a turn, not vertical acceleration.
- B. Autokinesis is a visual illusion involving a stationary light, unrelated to vertical acceleration.
- D. The leans results from an undetected bank returning to level, not from vertical acceleration.
Elevator Illusion
A vestibular illusion caused by abrupt vertical acceleration (e.g., an updraft or downdraft) that creates a false sensation of pitch change.
- Updrafts create a false sense of pitching up
- Downdrafts create a false sense of pitching down
- Pilots should trust instruments over bodily sensations in turbulence
Memory trick: Elevator goes up, nose feels like it goes up too