What is the primary function of the gust lock in an aircraft?

The primary function of the gust lock in an aircraft is to prevent movement of the control surfaces when the aircraft is parked, particularly in windy conditions. This ensures that external forces from gusts of wind do not adversely affect the aircraft's control surfaces, which could potentially lead to damage or misalignment.

When a gust lock is engaged, it physically immobilizes the control surfaces, thereby safeguarding the aircraft while it is not in use. The option that mentions keeping the door open and being released by pressing a button describes a mechanism that is typically associated with door operation rather than any aspect of managing the aircraft’s aerodynamic components against wind forces.

Understanding the specific role of the gust lock is crucial for maintaining the integrity of the aircraft on the ground and ensuring safety measures are effectively in place.