Probably more than any other aircraft the Republic F-105 Thunderchief epitomises the air war against North Vietnam.  From 1965 to the bombing halt in 1968 the F-105 bore the brunt of the air war in the north flying more missions than any other aircraft type with the result that more F-105s were lost than any other aircraft type with the exception of the ubiquitous F-4 Phantom.

The Thunderchief was designed in the early 1950s as a single-seat, single-engined fighter bomber with the primary role of nuclear attack.  The entire design was optimised for this role which, when the aircraft came to be used for tactical strike using conventional weapons, had both advantages and disadvantages.  On the plus side the aircraft had been designed to be very fast and stable at low level to perform its nuclear attack mission.  Like most Republic-built aircraft it was heavy but sturdy and could carry a total of 16x750lb bombs on racks under the fuselage and wings, although the normal load in Southeast Asia’s hot and humid climate was usually only six or eight 750lb bombs.  However, it had not been designed with a high degree of survivability in mind and had very little systems redundancy for the flight controls, fuel or hydraulic systems.  Although there were no fuel tanks in the wings, fuel tanks were built into the internal bomb bay prior to use in Vietnam.  While the structure of the Thunderchief was very sturdy and aircraft came back with large sections of wing or tail missing, the aircraft appears to have been susceptible to catching fire when hit in the fuselage, even from small arms fire.  Twin-engined fighters like the F-4 Phantom and RF-101 Voodoo also had the edge over the single-engined F-105 as far as battle damage was concerned.  With one engine out an F-4 or RF-101 could still make it home!

When the conflict in Vietnam escalated in late 1964 the USAF had a total of 24 Thunderchief squadrons operational in the USA, Europe and Japan having largely replaced the F-100 Super Sabre as the Air Force’s primary front-line fighter-bomber.  The first F-105s to arrive in Thailand were eight aircraft of the 36th TFS that departed Yokota AB, Japan on 9 August for a spell of temporary duty. The Thai bases of Takhli and Korat were to become the eventual homes of the F-105 wings that were later deployed to Southeast Asia.  Although destined to become the USAF’s primary tactical bomber in the war against North Vietnam, in 1964 it was restricted to supporting the CIA’s secret war in Laos.  The US refused to acknowledge that F-105s were based in Thailand for some considerable time.  By the end of the war in Southeast Asia 397 Thunderchiefs (53%) of the total production of 753 F-105D and F models had been lost in the conflict.