JAEGER LECOULTRE CHRONOFLITE
In 1930 LeCoultre designed the first CHRONOFLITE, a clock for airplanes with double chronograph, the “Air Corps”, predecessor of USAF, bought to Jaeger of New York this clock, it was the first clock with “elapsed time”.
It was the movement more widely used before WW II, Smith from England mounted a CHRONOFLITE movement just with elapsed time, and the Russian Wostok copied the movement without license and equipped from the Policarpov I-16 Rata, up till the MIG 15. It was also used in racing cars of the 30 and 40 decades.
The first models of Chronoflite was built with a 12 hour DIAL and without “civil date”. All of them have 13 jewels and only one mainspring barrel for eight days.
Both on top are from U.S. NAVY, 24 hours with date and 12 hours without date, written on the dial JAEGER.
On the right one fron U.S.A.F. written LeCoultre on the dial.
The next is the Rusian Wostok Flyer its movement is an exact copy without licence of the Chronoflite.
The last three are from Smith MK IIIA 12 hours and MK IIIB 24 hours dial.
The main disadvantage of this clock is the winding up, which is done counterclockwise. Frequently people would wind it up it in the wrong direction (which was the natural direction), and it would break.
Another inconvenient is that the minute hand move counter clockwise. Both of these problems were solved with Elgin Hamilton 37500 design.
THE MOVEMENT
Top US NAVY 24 HR Chronoflite with elapsed time, chrono, minutes counter 
Here follows the back part of 4 movements the third is from the Rusian Wostok Flyer.
