

Genuine WWII USAAF pocket sized Type D-3 computer, for the pilot's use in determining speed, time and distance problems. It is a convenient pocket size and consists of a circular slide rule 3 ½ inches in diameter with a suitable scale on each side. The reverse side are scales for applying calibrated air speed in order to obtain the true air speed.
Manufactured by Cruver Mg. Co., Chicago, Illinois and marked Property of U.S. Army Air Corps.
Delivered with a protactor.
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Genuine WWII USAAF pocket sized Type D-3 computer, for the pilot's use in determining speed, time and distance problems. It is a convenient pocket size and consists of a circular slide rule 3 ½ inches in diameter with a suitable scale on each side. The reverse side are scales for applying calibrated air speed in order to obtain the true air speed.
Manufactured by Cruver Mg. Co., Chicago, Illinois and marked Property of U.S. Army Air Corps.
Delivered with a protactor.