FAA Commercial Pilot Airplane (CAX)Human Factors and ADMHard
A pilot is on a moonless night visual approach and notices the airplane seems to be pitching up steeply despite maintaining a constant attitude on the attitude indicator. The pilot recently accelerated to a higher airspeed. This sensation is most likely caused by:
- AThe Coriolis illusion
- BThe somatogravic illusion
- CStructural illusion from runway width
- DThe elevator illusion
Show answer & explanationAnswer & explanation
Correct answer: B. The somatogravic illusion
The somatogravic illusion occurs when linear acceleration (such as during a rapid airspeed increase) is misinterpreted by the vestibular system as a pitch-up sensation, potentially causing a pilot to push the nose down inappropriately if not cross-checking instruments.
Why the other options are wrong
- A. The Coriolis illusion results from head movement during a prolonged turn, not linear acceleration.
- C. Runway width illusions affect perceived height/distance during landing, not pitch sensation from acceleration.
- D. There is no standard illusion called the 'elevator illusion' in aviation human factors.
Somatogravic Illusion
A vestibular illusion in which linear acceleration is misinterpreted as pitching up, and deceleration as pitching down.
- Caused by the inner ear misreading acceleration forces
- Common during rapid takeoff acceleration or go-around power application
- Can lead to inappropriate nose-down control input if not cross-checking instruments
Memory trick: Speed up, feel like you're pitching up — somatogravic