When executing an emergency approach to land in a single-engine airplane, it is important to maintain a constant glide speed because variations in glide speed will

Explanation

During a power-off emergency approach, the Airplane Flying Handbook (Ch. 18) stresses holding the best glide speed. Any variation in airspeed changes the glide path and distance, which nullifies the pilot's efforts to judge gliding distance and pick the landing spot. Shock cooling is an engine-management concern, not the reason for a constant glide speed, and a constant speed alone does not 'assure' a descent angle down to the flare.