Longines Monopusher Chronograph 13.33Z

Breitling and AOPA The US Aircraft Owners and Pilots Association (AOPA) approached Breitling in 1952, and asked them to create a new chronograph for its members. The watch would enable pilots to perform all necessary flight calculations, including average speed, distance traveled, fuel consumption, rate of climb or descent, and conversion of miles to kilometers or nautical miles. Willy Breitling adapted the original logarithmic slide of the 1940s Breilting Chronomat for aviation purposes and integrated it into a rotating bezel, with a beaded bezel to make it easier to use. The case was fixed at 41mm to make it large enough to ensure that all the information would be easy to read. The numerals were filled with radium that contrasted with the black dial and the oversized Arabic numerals to increase legibility. When the Navitimer was finally introduced to the AOPA, it was an instant success among the association members.