Turn and Bank Indicator Type A-11, AN5820-1 Air Force US Army, WWII, B-17, P-51, P-38
This Turn & Bank Indicator Army Type A-11, AN5820-1, 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 cleaning vacuum air as it is pulled across the gyro to power it.