FAA Instrument Rating Airplane (IRA)Aeromedical and ADMMedium
A pilot on a rapid takeoff roll experiences a strong sensation that the nose is pitching up excessively, even though the airplane is actually in a normal climb attitude. Trusting this sensation, the pilot pushes the yoke forward, risking controlled flight into terrain. Which illusion caused this sensation?
- AInversion illusion
- BAutokinesis
- CCoriolis illusion
- DSomatogravic illusion
Show answer & explanationAnswer & explanation
Correct answer: D. Somatogravic illusion
The somatogravic illusion results from rapid linear acceleration, such as during a fast takeoff, which stimulates the otolith organs in a way that mimics the sensation of pitching up. This often leads pilots to erroneously push the nose down, which can be dangerous especially at low altitude.
Why the other options are wrong
- A. Inversion illusion is caused by an abrupt change from climb to level flight, producing a tumbling backward sensation, not simple acceleration.
- B. Autokinesis involves a stationary light appearing to move, unrelated to acceleration.
- C. Coriolis illusion is caused by head movement during a sustained turn, not linear acceleration.
Somatogravic Illusion
An illusion caused by rapid acceleration or deceleration that creates a false sensation of pitch change, often leading to inappropriate control inputs.
- Rapid acceleration (e.g., takeoff, go-around) feels like nose-up pitch
- Rapid deceleration can feel like nose-down pitch
- Trust attitude indicator, not seat-of-the-pants sensations
Memory trick: Speed up, feel like you're climbing — check the gauge, not your gut.