Compass, Aperiodic, US Army Air Force Type D-12 Victor made by Kollsman

made by Kollsman

See diagram from the UH-1 Flight Manual

The knurled center knob was then tightened to secure it in place

or film spools

according to their flight manuals from the 1950's

Compass, Aperiodic, US Army Air Force Type D-12 Victor made by KollsmanThe US Army Air Force Type D 12 Direct Reading Aperiodic Compass was used at the navigators station across many US WWII aircraft, including heavy bombers B 17, B 24, B 29, medium bombers B 25 and B 26, and transports C 46, C 47, and C 54. Made by Bendix, part number 1832 1 A, it has a serial number prefix of AF 45, indicative of a manufacturing year 1945. The navigators' direct reading compass is known as an aperiodic (without a period) compass, since