With the increase in the number of transatlantic flights in the 1960s, airlines began to realize the importance of dual-time wristwatches as an important “tool” for flight crews to keep track of both local and home time. Many brands began to manufacture these watches and Heuer introduced its first Autavia GMT in 1968.
Early examples used screw-back cases, however shortly thereafter, the brand began utilizing snap-back compressor cases made by E. Piquerez SA (EPSA), which tighten as a watch submerges underwater. The reference 2446 GMT is a manual wind, three-register chronograph and was part of these newly-designed timepieces for pilots and jet set glitterati. The 24 hour bi-directional bezel offered clear readability to the wearer with the blue and red sector divided per hour.

Ref. 2446, 2446M, 2446C, 2446-3,