Flyback chronograph

[3] Given the emergence of high-speed flight, e.g. Maurice Prévost reached 200 km/h in 1913, recording multiple time intervals with a conventional chronograph generated a significant margin of error.

In fact, the early years of the 20th century not only made flying a reliable technology, but also developed aeronautical navigation systems.

A major problem rapidly experienced by pilots: the high speed of the aircraft combined with the lengthy computations' methods meant longer periods of time flying in the wrong direction.

Thanks to the flyback function, anything involving time measured in sequences or at close intervals, such as dead reckoning or coordinated maneuvers, had been pushed to a higher level of accuracy.

Richard Byrd, who flew first over the South Pole in 1929, led several expeditions wearing a Longines wrist chronograph (cal.

1928 Longines Wrist-Chronograph with the 1925 modified Cal. 13.33Z Flyback function. The oldest Flyback Chronograph in existence, to be seen in the Museum of Longines. [ 1 ]
Patent attesting to the invention of the Flyback mechanism by Longines. The application was filed on June 12, 1935. The patent was registered on March 31, 1936.