Dynamic stability leads to what behavior after disturbance?

• A. Immediate pitch up
• B. Return to straight-and-level flight
• C. Divergence from flight path
• D. No reaction

Answer: (B)

Dynamic stability describes how an airplane’s motion changes over time after a disturbance. If the aircraft has positive dynamic stability, the forces and moments acting on it damp out the initial deviation, so the airplane tends to return to its original trimmed state rather than continue moving away. After a disturbance, the motion may overshoot a little, but it will settle back toward straight-and-level flight as the restoring effects diminish the deviation. This is in contrast to divergence, where the disturbance grows, or no reaction where nothing changes.