The primary purpose of using a gust lock on an aircraft is to ______.

The primary purpose of using a gust lock on an aircraft is to prevent control surfaces from moving on the ground. This is crucial because, during ground handling or in windy conditions, control surfaces like ailerons, rudders, and elevators can be affected by gusts of wind, which may cause unwanted movement. By locking these surfaces in place, the gust lock helps maintain the aircraft's stability and prevents potential damage to the control systems and structures.

While enhancing performance in flight, reducing wear on flight controls, and increasing aerodynamic efficiency are all relevant aspects of aircraft operation, they do not directly pertain to the function of a gust lock. The gust lock is specifically designed to secure control surfaces when the aircraft is stationary on the ground, to mitigate the impact of external forces.