The true origin of the Mirage 2000 is the less-known Mirage 4000 , a twin engine delta air interceptor that was a private venture from Dassault, and was very capable. The Royal Saudi Air Force was very interested, but eventually it dropped from the project in favor of the American F-15 . As a result of this lost sale, Dassault built a scaled down, less expensive, but still very capable version of the 4000: the Mirage 2000. Its first role is to be an interceptor, yet it retains a ground-attack capability. Using only the basic concept of the delta interceptor previously seen on the classic Mirage III , Dassault built a totally new design. Using fly-by-wire controls and relaxed stability , Dassault was capable of bringing the classic delta to a new level, with loads up to 12g's (for short periods of time, the default is 9g's), a more powerful engine (but not so powerful as the latest American engines, an old problem the French aircraft industries were still not able to overcome). Development began on the aircraft in the 1970s and the first flight took place in 1978 . By 1983 it began seeing service in the French Air Force. The Mirage 2000 has many variants. The first operational Mirage 2000 was the 2000C, using first the stopgap RDM radar, and later the definitive RDI digital radar. The evolution of the 2000 came with the Mirage 2000-5, with much improved RDY radar, glass cockpit, MICA fire-and-forget BVR missiles and numerous other improvements. The Mirage 2000 has a maximum speed of Mach 2.2. More than 500 have been produced.