Aero Academic
Aero Academic
A state in which a pilot's perception of aircraft attitude, position, or motion does not match reality, common in low-visibility flight.
Spatial disorientation occurs when a pilot's perception of the aircraft's position, attitude, or motion fails to match reality. It arises because the vestibular system in the inner ear, which senses motion and balance, was not evolved for the accelerations and lack of outside visual reference found in flight — it can be readily fooled, especially at night or in instrument meteorological conditions.
Common illusions include the graveyard spiral (a pilot in a prolonged, gentle turn perceives level flight, and on rolling out perceives a turn in the opposite direction, prompting a dangerous corrective re-entry into the original turn), the leans (a false sensation of banking after an abrupt correction back to level flight), and somatogravic illusion (a rapid acceleration on takeoff perceived as a nose-up pitch, tempting the pilot to push the nose down into terrain).
The FAA's standard guidance is to trust the flight instruments over bodily sensation whenever visual reference to the horizon is not reliable, and this principle is a recurring theme across FAA human-factors and instrument-related knowledge-test questions.