Turn and Bank Indicator Type A-11 Air Force US Army, WWII, B-17, P-51, P-38 Czech as used in aircraft of

as used in aircraft of the British Royal Air Force

Vice versa for a short pilot

and our educated guess is that this is the altitude of the threat and its air speed relative to the interceptor

or whether the gunner is strafing a stationary target

Turn and Bank Indicator Type A-11 Air Force US Army, WWII, B-17, P-51, P-38 Czech as used in aircraft ofThis Turn & Bank Indicator Army Type A 11, made by Bendix Part No. 1721 2U A2, was used across virtually all aircraft of the US Army Air Force during WWII, including bombers B 17, B 24, B 25, B 26, fighters, P 38, P 39, P 40, P 47, P 51, and transports C 46 and C 47. Imprinted on the face, but barely discernible in the photos, is "AF US Army", and its serial number prefix is AC 42, indicates the manufacturing year 1942. This unit has the filter for