Tachometer, Chronometric, Type C-11, WWII, Air Corps US Army C-47 The outer ring of the

The outer ring of the dial counts up to 10 seconds and the inner dial located at the standard 12:00 position count up to 10 minutes of the 10-second revolutions

while introduced during late WWII

but otherwise the unit is in exceptional condition

see illustration from the B-17G Erection and Maintenance Manual in the photos

Tachometer, Chronometric, Type C-11, WWII, Air Corps US Army C-47 The outer ring of 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