Grimes WW2 USAAF Signal Light Lamp Model C-3A K3 B17 B24 Aldis

Grimes WW2 USAAF Signal Light Lamp

Model C-3A K3

As used on B17 B24 etc...
Each B-17 carried a signal light (also called an Aldis Lamp) at the Tail-Gun position. It was used by the tail gunner, who flashed the letter "C" [- . - .) using a white lens, from take-off until assembly was completed. It was also used anytime that there was reduced visibility conditions, or darkness existed. The Aldis lamp was used so that you could see the aircraft in front of you and the aircraft behind you could see your B-17. It also assisted in locating the Lead aircraft and formation with whom you would assemble. The Aldis lamp was also used on D-day to flash the code of the day so the navy wouldn't shoot down Allied aircraft.