The Mikoyan-Gurevich MiG-19 is a Soviet second generation, single-seat, twinjet fighter aircraft. It was the first Soviet production aircraft capable of supersonic speeds in level flight. A comparable U.S. "Century Series" fighter was the North American F-100 Super Sabre, although the MiG-19 primarily fought against the more modern McDonnell Douglas F-4 Phantom II and Republic F-105 Thunderchief over North Vietnam. This aircraft was originally used by the Soviet Union but it was later used by the People's Liberation Army Air Force of China.