Breitling Navitimer
The pilot's chronograph with a slide rule on the bezel for calculating speed, fuel and distance.
The Navitimer came out in 1952 and became the official watch of the American pilots' association, the AOPA. The slide rule let the pilot calculate on the wrist. The model has been made without interruption.
Materials: Steel or gold; chronograph movement
Manufacture: Made in Switzerland; the bezel is turned to set the scales against one another.
The logarithmic scale around the dial.
The many scales and the three small subdials.
The bezel and the outer scale of the dial form a circular slide rule. With it the pilot can calculate speed, distance and fuel consumption and convert units.
A busy dial with the slide rule’s two scales, three subdials and a ribbed bezel turned with the fingers.
The Cosmonaute from 1962 has a 24-hour dial. The astronaut Scott Carpenter wore one in space the same year.