IWC Mark XI from the British R.A.F. from 1948

In 1948, IWC designed new pilot’s watches for the Royal Air Force (RAF). These pilot’s watches were used by the Royal Australian Air Force (RAAF), the South African Air Force (SAAF), the Royal Australian Air Force (RAAF), the Royal New Zealand Air Force (RNZAF), as well as by the British Overseas Airline Company (BOAC, the predecessor of British Airways) and in civilian versions.
Between 1949 and 1953, the Royal Air Force purchased approximately 7,400 Mark 11 watches. Equipped with the now legendary hand-wound “Caliber 89” movement, they promised maximum reliability under the harshest conditions and protection against magnetic interference in the aircraft cockpit without compromising accuracy. The testing conditions were also unprecedented; the “Mark 11” had to pass the most extreme tests over 648 hours before it was delivered. The reliable IWC “Mark 11” timepiece was also used as an expedition watch; for example, it accompanied Sir Edmund Hillary and Mr. J.H. Miller, chief navigator of the “Ross Sea Expedition,” on their grueling Antarctic expedition.