Flight computer

A flight computer is a form of slide rule used in aviation, is and one of very few analog computers in widespread use in the 21st century. Sometimes it is called by the make or model name like E6B, CR, CRP-1, or by colloquial terms such as the Whizz wheel, or in German, as the Dreieckrechner.

They are mostly used in flight training, but many professional pilots still carry and use flight computers. They are used during flight planning (on the ground before takeoff) to aid in calculating fuel burn, wind correction, time en-route, and other items. In the air, the flight computer can be used to calculate ground speed, estimated fuel burn and updated estimated time of arrival. The back is designed for wind correction calculations, i.e., determining how much the wind is affecting one's speed and course.