The E6B flight computer is a circular slide rule used in aviation and one of the few analog calculating devices still in widespread use today. It is commonly used during flight planning to calculate fuel burn, wind correction, time en route, and other essential flight calculations. In flight, it can be used to determine ground speed, estimated fuel consumption, and updated time of arrival. The back side is designed for wind vector calculations, helping pilots assess the impact of wind on speed and course. Often referred to as a "whiz wheel," this tool remains popular due to its lightweight, compact size, durability, ease of one-handed use, and lack of reliance on electrical power. While digital versions are easier to learn at first, many flight schools require students to train with mechanical E6Bs, and pilots are encouraged to use them during FAA written exams and checkrides for required calculations.Product Category: E6B Flight Computer Product Number: E6B Application: Pilot training, internships, drills Color: As shown Material: Plastic Size: 9.05 x 4.72 x 0.19 inches Package Contents: 1 x E6B Aviation Flight Training Ruler Note: Light reflection and different display settings may cause slight variations in color between the image and the actual item. Measurement may vary by +/- 1-3 cm.