What does the term "sink rate" refer to in gliding?

The term "sink rate" specifically refers to the rate at which a glider loses altitude. It is typically described in feet per minute (fpm) and is a critical factor for pilots to understand as it directly impacts how a glider performs in the air, especially when looking for lift and managing flight patterns.

Pilots need to monitor sink rate to efficiently navigate through the atmosphere, making it essential for maximizing distance and duration in the air. A lower sink rate indicates better performance, as it suggests that the glider is efficiently maintaining altitude or finding rising air currents. In contrast, a higher sink rate can indicate poor performance or a lack of lift, which requires corrective action by the pilot, such as seeking areas of lift or managing the glide path.

Understanding sink rate helps glider pilots make informed decisions during flight, affecting their overall strategy for managing altitude and flight time.