FAA Airline Transport Pilot (ATM)Human Factors and CRMMedium
While flying in IMC, a pilot completes a gradual, prolonged turn that the vestibular system fails to detect due to fluid settling in the inner ear. After returning the wings to level flight per the instruments, the pilot feels a strong, false sensation of banking in the opposite direction and is tempted to re-enter the original turn to counter it. Which illusion is the pilot experiencing?
- AThe leans
- BCoriolis illusion
- CGraveyard spiral
- DSomatogravic illusion
Show answer & explanationAnswer & explanation
Correct answer: A. The leans
The leans occur when a slow, prolonged turn goes undetected by the semicircular canals; upon returning to level flight, the pilot perceives a false banking sensation and feels compelled to lean or re-bank to compensate. Trusting the instruments over this false sensation is critical.
Why the other options are wrong
- B. Coriolis illusion involves head movement during a turn, not the return to level flight.
- C. Graveyard spiral is a spatial disorientation scenario involving a descending spiral, not this symptom pattern.
- D. Somatogravic illusion relates to acceleration/deceleration causing false pitch sensations.
The Leans
A vestibular illusion in which a pilot fails to perceive a slow, prolonged turn and, upon leveling the wings, feels falsely banked, creating an urge to re-enter the turn.
- Caused by fluid settling in semicircular canals during gradual turns
- Most common vestibular illusion in instrument flying
- Pilot may physically lean to 'correct' the false sensation
- Trust instruments, not bodily sensations, to overcome it
Memory trick: Slow turn goes unnoticed, then you 'lean' the wrong way