Tachometer, Chronometric, Type C-11, WWII, Air Corps US Army C-47 The pressure differential between the

The pressure differential between the impact and the static pressure operates the airspeed indicator

were one of several generations of radio navigational systems installed in an aircraft such as the heavy bomber B-24 Liberator

The luminous markings have turned color with age

while introduced during late WWII

Tachometer, Chronometric, Type C-11, WWII, Air Corps US Army C-47 The pressure differential between theHere is an example of the WWII era Chronometric (i. e. mechanical) Tachometer, Type 11, as used by single engine aircraft of the Air Corps US Army. According to the US Army Air Force Maintenance Interchangeability Chart dated Feb 1945, the C 11 tachometer was used in fighters P 40 Warhawk (E N), early versions of the P 47 Thunderbolt, and P 51 Mustang, dive bombers A 35 Vengeance and A 36 Apache, and transports UC 61 and UC 64A. This tachometer has a