Which stability is described when the airplane attitude tends to return to its original position after the elevator control is pressed forward and released?

Which stability is described when the airplane attitude tends to return to its original position after the elevator control is pressed forward and released?

• A. Neutral longitudinal static stability
• B. Positive static stability
• C. Negative static stability
• D. Lateral stability

Answer: (B)

This question is about longitudinal static stability. Positive static stability means that when the airplane is perturbed from its trimmed attitude, the aerodynamic forces produce a restoring moment that brings it back toward the original attitude after the disturbance is removed. Here, pressing the elevator forward causes a nose-down tendency. If the aircraft has positive static stability, the restoring pitching moment will act to raise the nose back to the original pitch once you release the control, so the airplane returns to its initial attitude. If the stability were neutral, it would stay in the new attitude; if negative, it would continue to diverge. Lateral stability concerns roll, not pitch, so it doesn’t describe this scenario.

This question is about longitudinal static stability. Positive static stability means that when the airplane is perturbed from its trimmed attitude, the aerodynamic forces produce a restoring moment that brings it back toward the original attitude after the disturbance is removed.

Here, pressing the elevator forward causes a nose-down tendency. If the aircraft has positive static stability, the restoring pitching moment will act to raise the nose back to the original pitch once you release the control, so the airplane returns to its initial attitude. If the stability were neutral, it would stay in the new attitude; if negative, it would continue to diverge. Lateral stability concerns roll, not pitch, so it doesn’t describe this scenario.