Stopwatch, Type A-8, Navigation Watch for Ground Speed 1944 "Jitterburg"
Here is an authentic WWII-era aircraft navigator's Watch, Navigation (Ground Speed) Stopwatch, Type A-8, made by Waltham to Air Corps US Army spec #94-27749,'#AM.#3'. With a serial # AF-44-17967, indicating manufacturing year of 1944. Type A-8 stopwatches were used in any WWII aircraft with a navigator, such as heavy (B-17, B-24, B-29) and medium bombers (B-25, B-26) and large transports (C-46, C-47, C-54).
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. The A-8 was known as the ‘jitterbug’ because of the loud and fast ticking of the balance at 144,000 beats per hour. Yep, just try to hear that over the cacophony of multiple radial engines...
According to C.G. Sweeting’s book "Combat Flying Equipment":
The Type A-8 was a navigation stopwatch designed for timing ground speed meters for determining the velocity of aircraft relative to the ground. One revolution of the Type A-8 hand was equivalent to ten seconds. The dial was white on early Wittnauer Type A-8 watches and black on Waltham watches produced from 1940 onwards. Elgin produced a Type A-8, 15 jewel, black dial stopwatch under military specification no. 27749. Waltham, the Federal Television Corp. and Aristo Import Co. manufactured Type A-8 stopwatches under military specification MIL-W-6510 (specification published in August 1951 and superseded No. 94-27749A published in July 1945). Under MIL-W-6510, continuous running movements were required to have not less than 15 jewels and the non-continuous movements were required to have not less than 9 jewels.
After winding, one press of the crown starts the second hand in motion. As the hand passes 10 seconds, the small hand on the inner dial advances one mark on the scale and counts minutes. One revolution of the inner hand is 5 minutes, another revolution is 10 minutes. Another press of the crown stops the hands. Press again to reset to 0..
Our Waltham A-8 appears to be either NOS or lightly used. The engraving on the back is perfectly legible. The back screws off, but reveals another sealed metal plate. The face supposedly screws off, but seems tight and has not been attempted. The second hand has a small bit of corrosion on its opposing end, but otherwise all details appear fine cosmetically. The box, while of the same manufacturer, spec, and year of manufacture, has a different serial number so is not the original for this watch. Comes with its cotton storage sleeve. In working condition.