What does positive static stability describe?

• A. The initial tendency to return to a state of equilibrium when disturbed from that state.
• B. The tendency to depart from equilibrium when disturbed.
• C. The ability to hover in a fixed position without control input.
• D. The aerodynamic stability at maximum cruise speed.

Answer: (B)

Positive static stability means that when the aircraft is displaced from its equilibrium attitude, the aerodynamic forces create a restoring moment that tends to return it to that equilibrium. In other words, a small disturbance prompts a push back toward the original attitude rather than away from it. If the aircraft tends to move further away after a disturbance, that’s negative static stability; if it stays where it is after the disturbance, that’s neutral static stability.