The MiG-21 originated with an official request from the Soviet authorities in 1954 for a light, high-performance (Mach 2 at 20 000 m) frontline fighter to protect military and production installations from potential raids by American bombers. Built for almost half a century in twenty or so different versions, in four successive generations, the "Fishbed" (its NATO codename) was not only the jet which was built in the largest numbers in the whole of aviation history, but also the aircraft which was built in greatest numbers since the end of the Second World War, all types and all countries...