Compass, Aperiodic, US Navy Aviation, 88-C-845 (Type D-12) Bf-109 As the airspeed increases

As the airspeed increases

for the Air Corps

but this has not been confirmed

such as torpedo bomber TBM Avenger (see image from TBM Flight Manual)

They were essentially timers for communications radios that broadcast a fourteen second carrier wave every minute

Compass, Aperiodic, US Navy Aviation, 88-C-845 (Type D-12) Bf-109 As the airspeed increasesThe US Navy 88 C 845 (USAAF Type D 12) Direct Reading Aperiodic Navigational Compass was used at the navigators station across many US Navy WWII aircraft, including patrol bombers PBY Catalina, PB2Y Coronado, PB4 Privateer, PV 1 Ventura and PV 2 Harpoon. Made by Bendix, part number 1828 1 A. The navigators' direct reading compass is known as an aperiodic (without a period) compass, since the needle returns to rest quickly and without appreciable