A slip is an out-of-balance flight condition used to increase sink rate and lose excess altitude while maintaining what two conditions?

A slip is a maneuver that involves flying the aircraft in an out-of-balance state, which allows for increased sink rate when needing to lose altitude without gaining airspeed. The primary purpose of executing a slip is to maintain control of the aircraft while modifying altitude effectively.

The correct answer emphasizes maintaining a constant airspeed while achieving a specific track over the ground. This is critical because maintaining a constant airspeed allows the pilot to manage the aircraft’s control and response characteristics effectively, ensuring it remains stable during the maneuver. The concept of maintaining a specific track over the ground reinforces the pilot's ability to manage the flight path while losing altitude, which is essential for aligning with a landing approach or avoiding terrain.

In this context, other considerations like drag and vertical speed are important in their own right, but they do not encapsulate the dual aspects of maintaining flight condition that the correct response does. The focus of a slip is primarily on controlling airspeed and ensuring the aircraft's path remains directed toward a desired landing spot, which is why this answer is appropriate.