The F-105 served for 27 years and changed the way the Air Force thought about supersonic bombers.
On February 25th 1984, the Air Force Reserve’s 466th Tactical Fighter Squadron, a part of the 508th Tactical Fighter Wing, made the last operational fight of the Republic F-105D Thunderchief or Thud. The flight occurred 19 years nearly to the day after the F-105 saw its combat debut in Vietnam and a little bit less than 27 years after the F-105 was first accepted for service by the United States Air Force. Air Force Thuds sure packed a lot of service into those 27 years.
Weighing in at a whopping 50,000 pounds (23,000 kilograms) when it entered service the Thunderchief was the largest single-seat single-engine combat aircraft in history. The F-105 could move at supersonic speeds at sea level and at Mach 2 speeds at altitude. The “Thud” was capable of regularly carrying 14,000 pounds of ordnance and was armed with a 20 millimeter Vulcan Gatling gun.
Without realizing just how effective a weapon the Air Force had in the F-105 yet, derisive nicknames such as “Lead Sled”, “Squat Bomber”, “Hyper Hog”, and “Ultra Hog” were hung on the F-105. It was even said that the Thud was a triple threat in that it could bomb you, it could strafe you, or it could fall on you. Sarcasm aside, the F-105’s strengths, such as its electronics suite and its capabilities, highly responsive controls, and its hair-raising performance, eventually made believers out of pilots who flew the big jet.
Initial F-105 prototypes did not perform as expected in part because of aerodynamic inefficiencies like trans-sonic drag in the fuselage design. This led to a redesign of the fuselage with an area ruled “coke bottle” profile similar to that found on the Convair F-102 Delta Dagger and the later F-106 Delta Dart, both of which experienced similar performance improvements after initial models were found to have similar trans-sonic drag issues. The performance of the F-105B was also vastly improved due to the distinctive forward-swept variable-geometry air intakes which regulated airflow to the engine at supersonic speeds and, when eventually installed, the Pratt & Whitney J75 afterburning engine.
Entering service with Tactical Air Command’s 335th Tactical Fighter Squadron in August of 1958 and becoming fully operational in 1959, an F-105B set a world record of 1,216.48 miles per hour (1,958 kilometers per hour). While proven to be quick in the air, maintenance requirements slowed the F-105 to a crawl on the ground, requiring up to 150 hours of maintenance for each flying hour.
For the 1964 show season, the United States Air Force Flight Demonstration Team, otherwise known as the Thunderbirds, modified F-105Bs with fuselage and wing reinforcements, added a smoke generation system. Tragically they flew only six performances with the F-105B before a fatal accident led the team to revert to the F-100 Super Sabre as their show aircraft.
The F-105D began replacing the B in frontline service in the early sixties. The first D-model Thunderchief took to the skies on June 9th 1959. The D-model Thud featured improved and more advanced radar and fire control systems, all-weather flight capability, and the ability to carry the Mark 43 atomic bomb. In order to accommodate the improved radar and its larger antenna the forward fuselage was lengthened by 16 inches (41 centimeters). By 1964, only Air National Guard (ANG) squadrons were equipped with the F-105B.
In June of 1961, an F-105D delivered 15,430 pounds (7,000 kilograms) of bombs during a test, which was a record for a single-engine aircraft at the time. That works out to a payload roughly three times that carried by World War II four-engine heavy bombers like the Boeing B-17 Flying Fortress and the Consolidated B-24 Liberator.
In spite of a troubled early service life, the F-105 became the dominant attack aircraft early in the Vietnam War. The F-105 could carry more than twice the ordnance, faster and farther, than the F-100 Super Sabre that it replaced. F-105s carried out attacks on difficult-to-hit targets all over North Vietnam and neighboring belligerent countries.
F-105s attacking Vietnamese targets were often escorted by F-4s to protect them from enemy fighters and to prevent the F-105s from having to jettison their external loads to maneuver with the nimble Vietnamese MiGs. When forced to fight for themselves, Thuds were officially credited with 27.5 air-to-air victories against North Vietnamese MiG-17s while 17 F-105s were lost to enemy fighters. While one victory was shared with an F-4 Phantom II, 24.5 of the MiG-17s were shot down using the internal Gatling gun and three victories were achieved using AIM-9 Sidewinder missiles.
There was even one F-105F (unofficially) credited with “shooting down” three MiG-17s on one sortie- one victory was achieved by missile, another using the internal gun, and the third by extraordinarily expedient jettisoning of the Thud’s centerline bomb rack, which dropped right into the path of one very unfortunate MiG.
The last 143 Thunderchiefs built were two-seat F-105F trainers. Continuing upgrades improved the reliability and weapons capacity of the existing F-105Ds. In response to the surface-to-air missile (SAM) threat, dozens of F-105Fs were converted into anti-radar Wild Weasel aircraft, developing eventually into the F-105G.
The F-105F Wild Weasel III added the ability to fire the AGM-45 Shrike anti-radar missiles and to deliver conventional iron bombs to its sensors and jamming equipment. This gave the F-105F offensive capabilities that the F-100F did not possess. The first of these aircraft flew on January 15th 1966. They began arriving in Southeast Asia in May and flew their first sorties on June 6th 1966. Five of the new Wild Weasels were assigned to the 13th Tactical Fighter Squadron, based at Korat Royal Thai Air Force Base. Six more went to the 354th Tactical Fighter Squadron, based at Takhli Royal Thai Air Force Base. The name of their game was Suppression of Enemy Air Defenses- SEAD.
One program, code-named Combat Martin, fitted some F-105Fs with communication jamming systems installed in the rear seat area. These systems were intended to disable the ground controlled intercepts upon which the North Vietnamese pilots so heavily relied. Capable of delaying and garbling radio communications, the system was used one time before the National Security Agency (NSA) had the Air Force pull the systems from the Wild Weasels because they (the NSA) used them to listen to enemy radio communications (it was said with great effectiveness) themselves.
The F-105G incorporated a considerable amount of new SEAD-specific avionics, including an upgraded Radar Homing and Warning (RHAW) system which required a redesign of the Thud’s wingtips to incorporate RHAW receiver antennae. So the outer wing hard points could be used for carrying additional weapons, including the AGM-78 Standard anti-radiation missile, the electronics associated with the Westinghouse AN/ALQ-105 electronic countermeasures system were moved to two long fairings or “bumps” mounted on the underside of the fuselage.
Because production of F-105s had ended in 1964, Thunderchiefs were replaced by other aircraft, primarily the McDonnell Douglas F-4 Phantom II. In October 1970, the 355th Tactical Fighter Wing, based at Takhli Royal Thai Air Force Base and the last operational F-105D unit in the Vietnam War, began their rotation back to the United States. F-105F and F-105G Wild Weasels continued their SEAD duties until the end of the war.
The F-105 was the primary attack aircraft during the first several years of the Vietnam War. Thuds flew more than 20,000 sorties in the skies over Vietnam and neighboring countries. 395 F-105s were lost (to all causes) out of the 833 Thunderchiefs produced (all models), including 62 operational (non-combat) losses.
The Thunderchief was rapidly withdrawn from USAF service after the end of the Vietnam War. Following the war the U.S. Air Force began transferring the remaining D, F, and G model aircraft to Air Force Reserve (AFRES) and Air National Guard (ANG) units. By the late 1970s, these well-worn antique Thunderchiefs were becoming even more difficult for the AFRES and ANG units to maintain. The F-4 Phantom II eventually replaced the F-105 in every mission, including in the Wild Weasel role with the dedicated F-4G Wild Weasel V variant. The 128th Tactical Fighter Squadron of the Georgia Air National Guard retired the last operational F-105G Wild Weasels on May 25th 1983.