High Quality Content by WIKIPEDIA articles! The Republic F-105 Thunderchief, was a supersonic fighter-bomber used by the United States Air Force. The Mach 2 capable F-105 conducted the majority of strike bombing missions during the early years of the Vietnam War; it has the dubious distinction of being the only US aircraft to have been removed from combat due to high loss rates. Originally designed as a single-seat, nuclear-attack aircraft, a two-seat Wild Weasel version for the Suppression of Enemy Air Defenses (SEAD) role against surface-to-air missile sites. It was commonly known as the "Thud" by its crews.