Which conditions could lead to Elevator Illusion?

• A. Overspeed with nose-down input or stall with nose-up input.
• B. Underspeed with nose-up input only.
• C. Constant speed with coordinated turn.
• D. Increased bank angle with level flight.

Answer: (C)

Elevator Illusion comes from what your vestibular system feels when the aircraft’s acceleration or load factor changes. When you experience a change in vertical acceleration or a change in the g-force acting on you, you can momentarily misinterpret your pitch attitude, so you feel that the nose is higher or lower than it actually is.

In a constant-speed coordinated turn, you don’t change the airspeed or the pitch attitude, but you do experience an increased load factor due to the bank. The higher g-force felt in the seat can be interpreted by your senses as a pitch change, leading to the illusion that the nose is rising even though the aircraft is actually in level flight. This combination of constant speed and a turn can trigger Elevator Illusion.

The other cases involve scenarios where the aircraft’s actual attitude is changing or where the primary cues are different (e.g., vertical acceleration with pitch changes, or situations not primarily driven by a change in load factor), so they don’t align with the typical elevator-illusion mechanism as cleanly.