Glider performance and the Glide Ratio

A little bit more about the Glide. If the air is still (not going up or down) then any glider is always on a decending path, normally about 100-200 feet per minute. Glider performance is measured in the distance forward it can fly for the height loss it is incurring.

So for example you are at 2000 feet and gliding forward in still air. Let's say you flew forward 30,000 feet (about 10 km) and are now at 1000 feet, i.e. you lost 1000 feet of height and moved forward 30,000 feet, so your performance is 1/30. This is called the Glide Ratio.

Training gliders have a glide ration of about 1/28. My glider is about 1/36, high performance gliders can have a ratio of 1/60. For comparison, small single engine planes have a glide ration of about 1/8.

What you're doing in the Glide part of the flight is try and choose good air i.e. air which is going up, in order to improve that ratio. So typically in my flight i manange to achieve glide ration of 1/45 or better despite my glider still air ration being 1/36.