Which type of illusion occurs due to a roll rate exceeding the threshold after an initial correction?

The correct answer is the leans illusion, which is caused by a roll rate that exceeds the threshold after an initial correction. This phenomenon occurs when a pilot experiences a faulty perception of the aircraft’s bank angle due to the way the vestibular system interprets changes in motion and orientation.

When a pilot is subjected to a prolonged period of constant roll, they may become accustomed to that bank angle (the initial correction). If the roll rate changes or a return to level flight occurs sharply, the pilot may misinterpret the actual aircraft orientation due to the changing motion cues, leading them to believe they are in a level position or have not banked as much as they actually have. This sensory mismatch can lead pilots to incorrectly correct for a non-existent roll, potentially resulting in an unintentional turn.

Understanding this physiological response is crucial for pilots, as the leans illusion can lead to dangerous situations if they do not rely on visual references or aircraft instruments when responding to aircraft orientation changes.