How will an increase in airspeed affect a tailplane stall?

• A. Can make it worse.
• B. Will always recover automatically.
• C. Has no effect on tailplane stall.
• D. Eliminates tailplane stall at all speeds.

Answer: (A)

Tailplane stall happens when the horizontal stabilizer’s angle of attack becomes too high and the airflow over it separates, causing a loss of downward force and allowing the airplane to pitch up further.

When you increase airspeed, the wing produces more lift and the downwash behind the wing increases. That increased downwash effectively changes the flow that reaches the tail, so for the same pitch attitude you can end up with a higher tailplane angle of attack. If you’re holding a nose-up attitude or using elevator input that keeps the stabilizer at a high AoA, the tailplane can reach its critical point sooner, making the stall more likely. The stall is not automatically recovered by speed, and speed does not universally prevent it at all attitudes or configurations, so higher speed can indeed worsen tailplane stall in some situations.