USAAF 'used' simplified flight calculator
By the Simplified Flight Calculator Co., San Antonio, Texas. Approximately 24.5 x 9cm. 1942 copyright. Small plastic tool designed to solve dead reckoning problems calculating drift angle and correction, course, heading, magnetic or compass reading, wind speed and direction, duration, air speed correction for altitude, and temperature for variation and deviation. Excellent condition with instruction sheets and card case. Stock code M22293.