The de Havilland Vampire, also known as the DH.100, is the second military jet built by the United Kingdom, with the de Havilland company. It entered service just after the Second World War, and has the particularity of being equipped with a double-braced rear fuselage. It was the first jet to cross the Atlantic Ocean, and the first jet capable of operating from an aircraft carrier. More than 4,500 examples were built, some under license, and used by about 25 different countries. Switzerland tested it as early as 1946, followed by an order for 75 aircraft in 1949 and the manufacture under license of 100 aircraft. Originally acquired as a fighter, it was used until 1970 as a fighter and ground attack aircraft. It was then used as a training aircraft and target aircraft for the DCA. The last military flights took place at the end of 1990, many of them were then sold at auction and some still fly in various countries. The Vampire DH-100 underwent two important modernizations: the first one in 1960 with the installation of an ejection seat and modernized instrumentation (artificial horizon and gyrocompass). The second one in 1980 by the addition of a UHF radio equipment and a transponder (IFF), which required the lengthening of the nose which became pointed similar to that of the DH-112 Venom of that time. The 1960's were also the beginning of blind flight (IFR) for the Swiss Air Force. The existing direction-finding stations were supplemented by approach radar installations (GCA) and a very original omnidirectional talking radio system (NAFU). We tried to reproduce the operation of this system and thus to provide our Vampire with means of flight and landing without visibility.