If an airplane tends to return to its original position after a disturbance, what does this indicate?

The correct choice indicates that the airplane exhibits positive static stability. Positive static stability refers to an aircraft's tendency to return to its original equilibrium position after a disturbance. This means if the aircraft is momentarily displaced from its straight-and-level flight path—whether by turbulence or a slight control input—it will naturally seek to return to that original state without needing further input from the pilot.

When an airplane is designed with positive static stability, it provides a more forgiving flight experience for the pilot, allowing for ease of control and maintenance of altitude or heading with minimal effort. This characteristic is important for ensuring that aircraft can effectively handle small disturbances without being overly difficult to manage.

Understanding this concept helps pilots and engineers appreciate the design features that contribute to an aircraft’s handling qualities and overall flight safety. Other forms of stability, like neutral or negative stability, would not provide the same return-to-center behavior after disturbances.