Designed in 1954 as an all-weather supersonic attack aircraft, capable of carrying nuclear or conventional armaments, the F-105 was the culmination of the series of warplanes built by Republic since the early days of World War II. The prototype had its first flight on October 22, 1955, and production began with 71 F-105B, which started to be delivered in May 1958. On June 9, 1959 the prototype appeared of the second, more powerful version, the F-105D, with a more powerful engine and improved electronic equipment. This went into service in 1961, with 610 machines built. The last variant was the two-seater, advanced trainer F-105F, delivered from 1963 (143 planes). During its busy operational career, 350 F-105Ds were continuously strengthened and modernized, particularly in the electronic field.
The F-105 Thunderchief, familiarly called 'Thud' by its pilots, received its baptism of fire in Vietnam and is indissolubly associated with that war, even though it was never used for the tactical atomic bombing for which it had been designed. In action in Vietnam from 1964 to 1970 was the single-seat F-105D, modified so as to carry bombs of the traditional type both in the hold and in under-wing pylons, and also the two-seat F-105G, Wild Weasel, widely used for locating the radar emissions of SAM batteries, which they would either neutralize with their own electronic equipment, making enemy tracking impossible, or by means of direct bombing. All USAF squadrons furnished with the F-105 served in rotation in Southeast Asia, carrying out more than 20,000 offensive missions, and losing 330 planes, over a third of the total Thunderchief production. Employed without respite in strikes, mainly against North Vietnamese territory, the Thunderchiefs paid a heavy toll at the hands of anti-aircraft batteries, SAM missiles and enemy fighters, for they were easy prey unescorted and with a full bomb-load. It was rare for an F-105 pilot to complete his rota of 100 missions without being shot down at least once. On October 5, 1965, for example, in the attack on the Lang Met bridge, out of 24 F-105Ds of the 562nd Squadron of the 23rd TFW, only eight found their way back to their departure base in Thailand. Yet with their bombs they destroyed the objective. Free of their bombs, on the other hand, the F-105s were no sitting ducks for enemy fighters; from 1966 to 1967 they shot down 26 MiG-17s and one MiG-21 in air duels, a tally second only to that of the Phantom F-4s. The first F-105Ds arrived at Korat, in Thailand, in August 1964 with the 36th Squadron of the 7441st TFW, followed by those of the 18th, 355th and 388th TFW. To assess the importance of the Thunderchiefs as a strike force during the early part of the war, it is enough to point out that during 1965 three-quarters of all attack missions against North Vietnam were carried out by this fighter-bomber, sometimes guided to its target by the Douglas EB-66 and subsequently escorted by Phantoms when the latter were thrown into action.
Aircraft: Republic F-105D Year:1959