What are the two main categories used to describe how stability is classified in aircraft?

• A. Static stability
• B. Dynamic stability
• C. Static stability; Dynamic stability
• D. Positive stability

Answer: (C)

The basic way we classify aircraft stability is into two categories: static stability and dynamic stability. Static stability looks at the immediate tendency of the aircraft to return to its original attitude after a disturbance—whether the initial reaction tends to restore equilibrium (positive static stability), hold new attitudes (neutral), or diverge away from the original attitude (negative). Dynamic stability goes beyond that first moment and examines how the aircraft’s motion evolves over time after the disturbance—do any oscillations damp out, persist, or grow. The correct option lists both categories, making it the best answer. Describing only one category or naming a specific static condition like positive stability doesn’t capture the full framework used to describe how stability behaves over time.