FAA Sport Pilot Airplane (SPA)Human Factors and ADMHard
During a turn in flight, a pilot's inner ear continues to sense a bank after the aircraft has actually returned to level flight, causing the pilot to feel an unwarranted urge to bank further. This vestibular illusion is known as:
- ASomatogravic illusion
- BThe leans
- CCoriolis illusion
- DGraveyard spiral
Show answer & explanationAnswer & explanation
Correct answer: B. The leans
The leans occur when a pilot fails to perceive a bank or its correction due to a slow, gradual entry, causing a false sensation that the aircraft is still turning when it is actually level, prompting an incorrect corrective bank.
Why the other options are wrong
- A. Somatogravic illusion is caused by rapid acceleration or deceleration, not banking.
- C. Coriolis illusion results from rapid head movement during a turn, causing a sensation of rotation about a different axis.
- D. Graveyard spiral involves a prolonged turn perceived as level flight, often leading to a descending spiral.
The Leans
A spatial disorientation illusion where a pilot senses being in a bank when the aircraft is actually level, or vice versa, due to a slow return to level flight.
- Most common vestibular illusion in flight
- Caused by insufficient stimulation of inner ear during a gradual bank correction
- Corrected by trusting flight instruments over bodily sensations
Memory trick: Leans, Coriolis, Graveyard, Somatogravic — trust your gauges, not your gut.