The MiG-25 “Foxbat” is a supersonic interceptor and reconnaissance aircraft. The prototype flew in 1964 and entered service in 1970 with an operational speed of Mach 2.83 but if needed Mach 3.2 possibly damaging the engines. The MiG-25 caused concern for the U.S. who demanded increases in the performance of the F-15 Eagle under development. The MiG-25s large wings gave the impression of a high weight of stainless steel used to manufacture the MiG-25. On September 6, 1976 Soviet pilot Viktor Belenko; flew his MiG-25 to Japan and defected. This gave the Americans their first-hand look at the new aircraft that had become the nightmare of the USAF. After testing and disassembling it the U.S. returned the aircraft to the Soviets in 40 crates. With this technology now known to the Americans; the Soviet Union set about making improvements to the MiG-25. The MiG-25PD entered service in 1979 with new engines and radar along with weapons systems upgrades so NATO labeled this variant the Foxbat-E.