The Republic F-105 Thunderchief, commonly known as the "Thud" by its crews, was a single-seat supersonic fighter-bomber used by the United States Air Force. The Mach 2 capable F-105 bore the brunt of strike bombing over North Vietnam early during the Vietnam War. It was later used in the specialized SEAD role suppressing missile sites.
As a follow-on to Mach 1 class F-100 Super Sabre, the F-105 was also armed with missiles and a cannon. But its design was tailored to high-speed low-altitude penetration carrying a single nuclear bomb internally. First flown in 1955, the Thunderchief entered service in 1958. As the largest single-engined fighter ever employed by the USAF, the single-seat F-105 would be adapted to deliver a greater iron bomb load than the four-engined ten-man strategic bombers of World War II. The F-105 would be best remembered as the primary strike bomber over North Vietnam in the early stages of the Vietnam War. After flying over 20,000 missions, 382 F-105s were lost, of which 62 were operational casualties. Although not designed for air combat, F-105s were also credited with 27.5 enemy aircraft by the USAF.
During the war, the two-seat F-105F and F-105G Wild Weasel variants became the first dedicated Suppression of Enemy Air Defenses (SEAD) platforms fighting against the Soviet-built S-75 Dvina (SA-2 Guideline) surface-to-air missiles. Two Wild Weasel pilots earned the Medal of Honor attacking missile sites, with one shooting down two MiG-17s the same day. The dangerous missions often required them to be the "first in, last out" in order to suppress the threat of air defenses prior to strike aircraft arriving and keeping them suppressed until the strike aircraft left the area.
Although the F-105 weighed 50,000 pounds (22,680 kg), the aircraft could exceed the speed of sound at sea level and Mach 2 at high altitude. It could carry up to 14,000 pounds (6,700 kg) of bombs and missiles. The Thunderchief was later replaced as a strike aircraft over North Vietnam by both the F-4 Phantom II and the swing-wing F-111. However, the "Wild Weasel" variants remained in service until 1984, when they were replaced by a specialized F-4G "Wild Weasel V".