Altimeter, Sensitive, Type C-12, 50,000 ft, US Army Air Force WWII JU-88 as used in the US

as used in the US Army Air Force's Boeing B-29 Superfortress (see photo of B-29 Flight Engineer's instrument panel with a red dot showing instrument location)

left or right

which replaced the larger AFN 1

With a serial # AC42-670

As an offshoot of this equipment Ryan have also developed a helicopter hovering aid (AN/APN-97) which presumably uses Doppler signals to tell the pilot whether or not his machine is stationary above ground or sea

Altimeter, Sensitive, Type C-12, 50,000 ft, US Army Air Force WWII JU-88 as used in the USHere is an early WWII era Sensitive Altimeter, Air Corps US Army Type C 12, made by Conn. The C 12 Altimeter was used across all aircraft of the Air Corps US Army, including heavy bombers B 17 and B 24, medium bombers, B 25 and B 26, Fighters P 38, P 39, P 40, P 47, and P 51, and transports C 46 and C 47, according to the Maintenance Interchangeability Chart dated Dec 1943. It has a serial number prefix AF 43, evidence of a manufacturing year 1943.