The Breitling Navitimer Replica Watches, which debuted in 1952, was designed to help pilots coordinate time and navigation: it was equipped with calculating functions. Advertisements described this multifunctional device, which contained the hand-wound Caliber Venus 178, as a “personal onboard instrument.” The built-in slide rule enabled aviators to multiply and divide, convert nautical miles to land miles, and calculate averages, fuel consumption, average gain of altitude, and distances during ascent and landing. Fumbling with paper and pencil while in flight could be at least partially eliminated. Since it was introduced, the Navitimer Replica Watches has undergone various changes, mainly to its case and the calibers it housed, i.e., hand-wound, hand-wound with date, or self-winding, but no one has ever tampered with its most distinctive feature: its circular slide rule.
Once activated, the transmitter would repeatedly emit a 0.75-second impulse every 2.25 seconds. If transmitted from flat terrain, the signal could be received within 160 kilometers (99.4 miles) of the disaster site by search planes flying at an altitude of 6,000 meters (19,685 feet). Two lithium batteries in the Breitling Navitimer Replica Watches provided enough power to keep the transmitter operating for 48 hours. The electronic time-measuring module, which could measure elapsed intervals to the nearest 1/100 of a second, also had a countdown function, an alarm, and a time display in a second zone. This information was shown in digital form. Pilots in aerobatic squadrons from many nations chose to wear these Breitling Navitimer Replica Watches.