The Republic F-105 Thunderchief was the first supersonic tactical fighter-bomber developed from scratch. Apart from being the biggest single-seat, single-engine combat aircraft in history, the F-105 was notable for its large internal bomb bay and unique swept-forward engine inlets in the wing roots. The wing was highly swept and incorporated low-speed ailerons and high-speed spoilers for lateral control, and a droop-snoot leading edge.
Known as "the Thud", this greatest of all single-engine combat jets bore a huge burden throughout the Vietnam War, and was a deadly and effective tactical fighter-bomber. A supersonic jet, the Thud is characterized by two unique systems: it is the only jet fighter to refuel from a side-fuselage boom, and was the first jet fighter to employ a Vulcan 20mm "Gatling Gun" cannon. The D-model made more air strikes against North Vietnam than any other US aircraft, and also suffered more losses. During the war, the versatile Thud was also credited with 25 MiG kills.
The F-105 evolved from a project begun in 1951 by Republic Aviation at Farmingdale NY to develop a supersonic tactical fighter-bomber to replace the F-84F. The massive F-105 was intended primarily for nuclear strike missions. The prototype first flew on October 22, 1955, but the first production aircraft, an F-105B, was not delivered to the USAF until 1958. With the designation F-105B came an engine change to a Pratt & Whitney J75-P-3. Other changes were made in this model too, including the use of a unique type of swept-forward air intake to control the shock-wave and introduction of “area rule” on the fuselage. A total of 75 F-105Bs were built.
The F-105D all-weather strike fighter and the two-place F-105F dual-purpose trainer-fighter were also built before F-105 production (833 aircraft) ended in 1964. No "C" or "E" series were produced and "Gs" were modified "Fs" outfitted with extensive electronic countermeasure equipment. F-105G aircraft were nicknamed "Wild Weasels" and specialized in jamming enemy radar and destroying surface-to-air missile sites.