Directional Gyro / Turn Indicator, Type C-1 Sperry 657069 USSR showing the location of this

showing the location of this antenna)

It may be some sort of a stall warning instrument

showing evidence of its use

including the Douglas DC-7

This instrument seems to have had a very interesting history

Directional Gyro / Turn Indicator, Type C-1 Sperry 657069 USSR showing the location of thisHere is an electrical Directional Gyro Turn Indicator marked AF USARMY (Air Forces US Army), Type C 1. According to the Maintenance Interchangeability Cross Reference Charts of the Air Forces US Army, the C 1 Directional Gyro was used in versions of the Curtis P 40N Warhawk and Bell P 39N Airacobra Fighters and the A 30 Martin Baltimore light bomber. The serial # prefix starts with AF 43, likely made for an Air Force order during 1943. The left knob