F-105 Thunderchief
Encyclopedia
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.
As a follow-on to the Mach 1 capable F-100, the F-105 was also armed with missiles and a cannon; however, its design was tailored to high-speed low-altitude penetration carrying a single nuclear weapon
internally. First flown in 1955, the Thunderchief entered service in 1958. Following adaption, the F-105 could deliver a greater bomb load than the large strategic bombers of World War II
like the B-17 Flying Fortress and B-24 Liberator. The F-105 was one of the primary strike bombers of the Vietnam War
; over 20,000 Thunderchief sorties were flown, with 382 aircraft lost (nearly half of the 833 produced) including 62 operational losses. Although less agile than smaller MiG fighters, USAF F-105s were credited with 27.5 kills.
During the war, the single-seat F-105D was the primary aircraft delivering the heavy bomb loads against the various military targets. Meanwhile, the two-seat F-105F and F-105G Wild Weasel variants became the first dedicated Suppression of Enemy Air Defenses (SEAD) platforms, fighting against the Soviet
-built S-75 Dvina
(NATO reporting name
: SA-2 Guideline) surface-to-air missile
s. Two Wild Weasel pilots were awarded the Medal of Honor
for attacking North Vietnamese surface-to-air missile sites, with one shooting down two MiG-17s the same day. The dangerous missions often required them to be the "first in, last out", suppressing enemy air defenses while strike aircraft accomplished their missions and then left the area.
Although the F-105 weighed 50000 pounds (22,679.6 kg), the aircraft could exceed the speed of sound
at sea level and Mach 2
at high altitude. It could carry up to 14000 lb (6,350.3 kg) of bombs and missiles. The Thunderchief was later replaced as a strike aircraft over North Vietnam by both the McDonnell Douglas F-4 Phantom II and the swing-wing General Dynamics F-111 Aardvark. However, the "Wild Weasel" variants of the F-105 remained in service until 1984, when they were replaced by a specialized F-4G "Wild Weasel V".
examined some 108 configurations before settling on a large, single-engine AP-63FBX (Advanced Project 63 Fighter Bomber, Experimental) - AP-63-31 actual. The new aircraft was intended primarily for supersonic, low altitude penetration into the Soviet Union
on a hi-lo-hi mission and delivery of a single, internally carried nuclear bomb. The emphasis was placed on low-altitude speed and flight characteristics, range and payload. The aircraft would be fitted with a large engine, and a relatively small wing with a high wing loading
which would give a stable ride at low altitudes, and less drag at supersonic speeds. Traditional fighter attributes such as maneuverability were a secondary consideration.
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Enthusiastic at first, the United States Air Force
awarded Republic with a contract for 199 aircraft in September 1952. However, by March 1953, the USAF had reduced the order to 37 fighter-bombers and nine tactical reconnaissance aircraft, citing the approaching end of the Korean War
. By the time the F-105 mock-up had been completed in October 1953, the aircraft had grown so large that the Allison J71
turbojet intended for it, was abandoned in favor of an even more powerful Pratt & Whitney J75. Anticipating a protracted development of the engine, it was expected that the first aircraft would use the smaller Pratt & Whitney J57. Near the end of 1953, the entire program was cancelled by the USAF due to a number of delays and uncertainties regarding the aircraft, however on 28 June 1954, the USAF officially ordered 15 F-105s (two YF-105As, four YF-105Bs, six F-105Bs and three RF-105Bs) under the Weapon System designation WS-306A.
The YF-105A prototype first flew on 22 October 1955, with the second YF-105A following on 28 January 1956. In spite of being powered by a less potent J57-P-25 engine with 15000 pound-forces (66.7 kN) of afterburning
thrust (the J75 was expected to generate 24500 lbf (109 kN) with afterburner), the first prototype attained the speed of Mach 1.2 on its maiden flight. Both prototypes featured conventional wing root air intakes and slab-sided fuselages typical of the early jets; Republic viewed the YB-105As as not being representative of the true capability of the aircraft due to numerous changes prior to production. Insufficient power and aerodynamic problems with transonic
drag
, as well as Convair
's experience with their F-102, had led to a redesign of the fuselage in order to conform to the Area rule
, giving it a characteristic "wasp waist". In combination with the distinctive forward-swept variable-geometry air intakes which regulated airflow to the engine at supersonic speeds and the J75 engine, this enabled the F-105B to attain Mach 2.15.
In March 1956, the USAF placed a further order for 65 F-105Bs and 17 RF-105Bs. In order to conduct the nuclear mission, an MA-8 fire control system, AN/APG-31 ranging radar
, and K-19 gunsight to allow for toss bombing
was intergrated. The first pre-production YF-105B flew on 26 May 1956. Five of the F-105C trainer variant were added to the procurement plan in June 1956, before being canceled in 1957. The RF-105 reconnaissance variant was canceled in July 1956. The first production F-105B was accepted by the Air Force on 27 May 1957. In June 1957 Republic Aviation requested that the F-105 be named Thunderchief, continuing the sequence of the company's Thunder-named aircraft, e.g. P-47 Thunderbolt, F-84 Thunderjet, and F-84F Thunderstreak; the USAF made the name official a month later.
To fill the Air Force requirement for all-weather attack, Republic proposed the F-105D variant in 1957. It added more advanced navigation system, and improved cockpit displays for adverse weather operation. The ability to carry the TX-43 nuclear weapon was also added. The RF-105 reconnaissance development was also restarted; now based on the F-105D. The first D-model took its maiden flight on 9 June 1959. Plans to build over 1,500 F-105Ds were cut short when the Secretary of Defense Robert McNamara
decided to equip no more than seven combat wings with the type. In November 1961, production was cut in favor of the Air Force adopting the Navy's F-4 Phantom II, and in the longer term, the General Dynamics F-111 Aardvark of the TFX program.
The final 143 Thunderchiefs built were of the two-seat F-105F trainer variant. Based on the F-105D, this model was 31 inches (79 cm) longer to provide room for the rear cockpit, otherwise the aircraft had similar flight performance to the preceeding F-105D. A total of 833 F-105s were completed before production ended in 1964. Subsequent upgrades improved the reliability and weapons capacity of the existing F-105Ds. In response to the surface to air missile (SAM) threat experienced in the skies above Vietnam, dozens of F-105Fs were converted into anti-radar "Wild Weasel
" aircraft, culminating with the F-105G.
The F-105 was a mid-wing monoplane with a 45° swept wing
and tail surfaces. The single engine was fed by two intakes in the wing roots, leaving the nose free for a radome
housing the multi-mode radar
. Its fuselage provided room for 1184 gal of fuel and an internal bomb bay. The bomb bay measured 15 in 10 in (4.83 m) by 32 in (0.8128 m) by 32 in (0.8128 m); it was originally to carry a single nuclear weapon
but typically held an additional 350 gal fuel tank. It featured four under-wing and one centerline pylon; the two inner wing and centerline pylons were capable of accepting fuel from 450 gal drop tank
s. Two outer dry stations were wired for missiles or bombs. One M61 Vulcan
(initially designated T-171E3) 20 mm
6-barrel Gatling-style cannon
was installed in the left side of the nose. A short-range AIM-9 Sidewinder air-to-air missile could be carried on each of the outer wing pylons.
The F-105 was designed primarily for low-level interdiction and its low-altitude speed was its greatest asset when dealing with enemy fighters such as the MiG-17
/J-5
s and MiG-21
. The F-105 managed 27.5 air-to-air victories. Based on combat experience, the F-105D was updated with a better ejection seat, additional armor, improved gun sights, and Electronic Counter Measures (ECM) pods on the wings.
Former F-86 Sabre pilot Jerry Noel Hoblit recalled being in awe of the F-105's size after seeing it for the first time; he could not manage to reach the air intake lip even with a running jump. The F-105 had a spacious cockpit with good visibility and layout (particularly after introduction of "tape" instruments); the advanced electronics were easy to learn and operate. Takeoffs and landings were often performed in the 230 mph (370.1 km/h) range. The spoilers
provided good roll control at all speeds and the distinctive four-petal airbrakes
(which also opened slightly when the afterburner was engaged to allow for the larger flow of exhaust gases) were highly effective even at supersonic speeds. Loss of control due to a spin
or complications of adverse yaw
required deliberate effort from the pilot and spontaneous spin recovery was rapid.
The initial reaction of the fighter pilot community to their new aircraft was lukewarm. Between its massive dimensions and troubled early service life, the F-105 had garnered a number of uncomplimentary nicknames. In addition to the aforementioned "Thud", nicknames included the "Squat Bomber", "Lead Sled", and the "Hyper Hog" and/or "Ultra Hog". The aircraft's offensive capabilities were sarcastically referred to as a "Triple Threat" — it could bomb you, strafe you, or fall on you. Positive aspects, such as the F-105's responsive controls, strong performance at high speed and low altitude, and its outfit of electronics won over some pilots. For some, "Thud" was a term of endearment; retroactively the RF-84F Thunderflash became known as "Thud's Mother". F-105 pilot Colonel Jack Broughton said of the nickname: "The Thud has justified herself, and the name that was originally spoken with a sneer has become one of utmost respect through the air fraternity".
The rear cockpits of several two-seat F-105Fs were modified under project Commando Nail with an R-14A radar and a radar scope that offered high resolution. These aircraft were used for all-weather and night low-level strikes against especially dangerous targets by a unit from the 13th Tactical Fighter Squadron
(1966–1975) dubbed "Ryan's Raiders" starting in April 1967. Some of these aircraft were later converted to the Wild Weasel III standard.
In an effort to thwart MiG attacks, several F-105Fs were also fitted with Hallicrafters
QRC-128 VHF jammers under project Combat Martin. The North Vietnamese interceptor force followed Soviet air-defense doctrine, with pilots under rigid direction of ground controllers over radio links. The QRC-128, nicknamed "Colonel Computer", filled up the rear cockpit of the F-105F and bounced voice communications over the radio channel back out after a delay, resulting in an obnoxious garble. However, the first time the Combat Martin was used, the US National Security Agency
(NSA), in charge of US strategic signals intelligence, ordered the Air Force to cease and desist immediately, since the NSA believed that the intelligence obtained by monitoring the channels outweighed the benefits of jamming them. Some of these aircraft were eventually brought to the Wild Weasel III standard.
receiver, an inertial navigation system, and solid-state electronics for the R-14A radar. Persistent problems with the AN/ARN-85 LORAN receiver resulted in substitution of the AN/ARN-92. This was housed in a long, raised dorsal spine. Known as Thunderstick II aircraft, these F-105s could achieve a bombing circular error of probability
(CEP) of 50 feet (15.2 m) from an altitude of 15000 ft (4,572 m). Although the first Thunderstick II aircraft flew in 1969, they were never used in Vietnam. A total of 30 F-105Ds received this modification.
, these aircraft achieved a number of victories against North Vietnamese surface-to-air missile
radars. The second crew member was a Navigator trained as an Electronic Warfare Officer (EWO) to decipher sensor information and guide the pilot towards the targets. However, the F-100F was an interim solution, its limited payload often required multiple aircraft to conduct a successful strike; it also lacked the speed and endurance to effectively protect the F-105.
The resulting EF-105F Wild Weasel III (the EF designation was popularly used but unofficial) supplemented its sensors and electronic jamming equipment with AGM-45 Shrike
anti-radiation missiles and conventional bombs, giving it an offensive capability lacking in the F-100F. The first of these aircraft flew on 15 January 1966 and they began arriving in Southeast Asia in May, flying their first mission on 6 June 1966, with five assigned to the 13th TFS at Korat RTAFB and six more to the 354th TFS at Takhli RTAFB.
In a typical early mission, a single EF-105F would accompany one or two flights of F-105Ds to provide protection from enemy ground fire. While this strategy was effective in reducing F-105D losses, the Weasel aircraft suffered heavy casualties with five of the first 11 lost in July and August 1966. Attacks into high-risk environments saw the Weasels operating in "Iron Hand" Hunter-Killer flights of mixed single-seat and two-seat Thunderchiefs, suppressing sites during attacks by the strike force and attacking others en route. In the fall of 1967, EF-105Fs began to be upgraded to the definitive Wild Weasel Thunderchief, the F-105G.
The F-105G incorporated a considerable amount of new SEAD-specific avionics, including an upgraded RHAW system which required a redesign of the wingtips. To free outboard hardpoints for additional weapons, the Westinghouse AN/ALQ-105 electronic countermeasures
were permanently installed in two long blisters on the underside of the fuselage. Thirty aircraft were fitted with pylons to carry the AGM-78 Standard anti-radiation missile. On a typical mission, the F-105G carried two Shrikes on outboard pylons, a single Standard on an inboard pylon balanced by a 450 gal fuel tank on the other side, and a 650 gal centerline fuel tank.
Notes: The costs above are in approximately 1960 United States dollar
s and have not been adjusted for inflation.
's 335th Tactical Fighter Squadron
of the 4th Tactical Fighter Wing
in August 1958, although the squadron did not become fully operational until 1959. On 11 December 1959, an F-105B piloted by Brig Gen Joseph Moore (commander of the 4th Tactical Fighter Wing) set a world record of 1216.48 miles per hour (1,957.7 km/h) over a 62 miles (99.8 km) circuit. Difficulties with its avionics
and the MA-8 fire-control system
were experienced early on, typically the F-105 required 150 hours of maintenance for each flying hour. Most of these problems were addressed under Project Optimize. The lack of spares resulted in the entire F-105B fleet being briefly grounded in 1960. In 1964, modified F-105Bs with ballast replacing the cannon, fuselage and wing reinforcement for aerobatics, and the addition of a smoke generator, briefly flew with the United States Air Force Thunderbirds demonstration team. After only six shows, a fatal accident from overstressing the airframe led to the reintroduction of the F-100 Super Sabre
.
By 1964, the F-105B was relegated to ANG squadrons. It was replaced in frontline service by the definitive F-105D whose advanced NASARR R-14A radar and AN/ASG-19 Thunderstick fire-control system gave it all-weather performance. The R-14A radar also added a terrain-following radar
capability, while a completely new instrument panel was fitted, replacing dial-type instrument with vertical tape instruments which were easier to read in combat. In order to accommodate the new radar, with a much larger radar dish, the forward fuselage was redesigned, increasing overall length by 16 inches (40.6 cm).
The F-105D entered service with the 335th TFS in September 1960, although it was not fully operational on the F-105D until early 1961. The first overseas F-105 units formed in West Germany in 1961, with the 36th Tactical Fighter Wing at Bitburg Air Base
in May and the 49th Tactical Fighter Wing at Spangdahlem Air Base
in October. Both wings had a primary tactical nuclear strike role for NATO. The F-105D was also deployed to the Pacific, with the 18th Tactical Fighter Wing at Kadena
in Okinawa converting in 1962 and the 8th Tactical Fighter Wing converting from 1963.
Like the F-105B, the F-105D's early career was plagued with maintenance problems and in-flight failures. The origins of the nickname "Thud" were obscure, some claim that it stood for the sound of an F-105 crashing into the ground. The entire F-105D fleet was grounded in December 1961 and then again in June 1962. Many of the issues were worked out during the production run and by 1964, early F-105Ds were upgraded with these fixes under Project Look Alike, although engine failures and fuel system problems persisted until 1967.
Meanwhile, the USAF was gradually changing the anticipated F-105 mission from nuclear interdiction to conventional bombing. The Look Alike upgrades increased the aircraft's capacity from four to 16 conventional 750 lb (340.2 kg) bombs on underwing and fuselage centerline hardpoints and added the equipment to launch AGM-12 Bullpup
air-to-ground missiles. In June 1961, an F-105D delivered 15430 lb (6,998.9 kg) of conventional bombs during a USAF test—at the time a record for a single-engine aircraft and a payload three times heavier than World War II
's four-engine heavy bombers such as the Boeing B-17 Flying Fortress and the Consolidated B-24 Liberator, though aerial refueling would be required for long missions. One of the F-105Ds was named Memphis Belle II after the famed World War II B-17.
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 bomb load farther and faster than the F-100, which was used mostly in South Vietnam. In a foreshadowing of its Wild Weasel
role, the first F-105D combat mission of the war involved an attack on 14 August 1964 against an anti-aircraft artillery site on Plaine des Jarres
. This mission was carried out by aircraft of the 36th TFS, 6441st Tactical Fighter Wing deployed from Yokota Air Base
, Japan to Korat Royal Thai Air Force Base
, Thailand. The first Thunderchief lost in the war also occurred during this mission, although the pilot managed to return the aircraft to Korat. The first strike mission took place on 13 January 1965 with the destruction of the Ben Ken bridge in Laos
. In early 1965 additional F-105 squadrons were deployed to Korat and Takhli
air bases in Thailand. At the start of Operation Rolling Thunder
in March 1965, large numbers of F-105Ds were shipped to these bases to participate in intense bombing missions.
On 3 April 1965, a total of 79 aircraft, including 45 F-105 Thunderchiefs, were sent against the Thanh Hoa Bridge
, nicknamed "Dragon's Jaw". The next day, enemy MiGs were encountered during a second run upon the bridge; a total of eight MiG-17s faced 46 F-105s escorted by a MiGCAP flight of 21 F-100 Super Sabres. The MiG-17s evaded the escorts using altitude and cloud-cover, instead focusing upon the bomb-laden Thunderchiefs. Two Thuds were lost to the MiG-17s; a third, thought to be lost to groundfire, was later claimed by the North as downed by a MiG-17. An F-100 claimed the only probable MiG-17 kill, although a Vietnamese pilot believes three of his comrades were shot down by F-105s. One F-105 piloted by John Boyd
narrowly escaped. USAF Chief of Staff General John P. McConnell was "hopping mad" to hear that two F-105s had been shot down by Korean War-era subsonic North Vietnamese MiGs. The Thanh Hoa Bridge proved resistant to aerial bombing, multiple missions were flown to damage the bridge both by F-105s and U.S. Navy aircraft.
On a typical combat mission into North Vietnam, the F-105D carried two 450 gal wing-mounted fuel tanks, a 390 gal fuel tank in the bomb bay, and five 1000 lb (453.6 kg) or six 750 lb (340.2 kg) bombs, and required inflight refueling
going to and sometimes returning from Hanoi
700 mi (1,126.5 km) distant. F-105s flying in the vicinity of Hanoi would routinely travel around mountainous terrain nicknamed Thud Ridge
(21°16′47"N 105°49′37"E) to evade the air defenses surrounding the city. Colonel Jack Broughton, an F-105 pilot in Vietnam, noted the demands of flying close to Hanoi gave "simply no room for error".
On 11 August 1967, F-105Ds from 335th Tactical Fighter Squadron with support from F-105 Wild Weasels from 338th Tactical Fighter Squadron made the first of many successful attacks on the Paul Doumer bridge
over the Red River. Flying low-altitude missions and conducting dive bombings forced the F-105s to range of North Vietnamese anti-aircraft, sometimes coming under heavy fire. Designed originally as a nuclear bomber rather than a conventional precision bombing, the F-105 had only a basic bombing sight, it lacked a bomb guidance system that would allow attacks at a higher altitude, dive bombing was its only mission profile, putting it in reach of ground fire. A total of 382 F-105s were lost in Southeast Asia, 320 of those in combat—most to enemy ground fire, leading to the USAF experiencing a shortage of combat-ready aircraft. Of the 610 single-seat F-105Ds built, 283 were shot down and 52 lost operationally. Of the 143 F-105F/G two-seaters, 37 were shot down and 10 lost operationally.
USAF F-105s were escorted by F-4s to protect them from against enemy fighters. However, the Thunderchief was officially credited with 27.5 air-to-air victories against North Vietnam
ese aircraft at the cost of 17 aircraft lost to enemy fighters (North Vietnamese pilots claimed to have shot down an additional 23 F-105s but none have been confirmed by USAF). All victories were against MiG-17s. Of these 24.5 were shot down with cannon fire (one victory was shared with an F-4), and three with AIM-9 Sidewinder
missiles. One F-105F is unofficially credited with downing three MiGs—one by air-to-air missile, the second by cannon fire and the third by jettisoning the centerline rack full of bombs directly into the path of a surprised MiG.
As production of F-105s had ended, the type was replaced in the Vietnam War by other aircraft, primarily the McDonnell Douglas F-4 Phantom II and the LTV A-7 Corsair II. In October 1970, the 355th Tactical Fighter Wing
, the last F-105D unit in Vietnam, began to return to the U.S. The F-105G Wild Weasel versions soldiered on until the end of the war. They were gradually replaced by F-4G Wild Weasel IVs.
:
The Thunderchief was rapidly withdrawn from USAF service after the end of the Vietnam War. Of the 833 F-105s built, nearly 50% were lost in Vietnam. By US military standards the F-105 was no longer considered combat-effective. Some aircraft remained in service in the 1970s and 1980s with Air Force Reserve
and Air National Guard units, but their extended wartime service meant that many F-105s had already reached or exceeded their service lives by the mid-1970s. The F-105 Thunderchief was officially retired on 25 February 1984. The F-105 had a lengthy service life considering many of the "Century series" fighter aircraft were retired in the mid-1970s, a decade before the F-105 was retired.
YF-105B
F-105B
JF-105B
RF-105B
F-105C
F-105D
RF-105D
F-105E
F-105F
EF-105F
F-105G
Supersonic
Supersonic speed is a rate of travel of an object that exceeds the speed of sound . For objects traveling in dry air of a temperature of 20 °C this speed is approximately 343 m/s, 1,125 ft/s, 768 mph or 1,235 km/h. Speeds greater than five times the speed of sound are often...
fighter-bomber
Fighter-bomber
A fighter-bomber is a fixed-wing aircraft with an intended primary role of light tactical bombing and also incorporating certain performance characteristics of a fighter aircraft. This term, although still used, has less significance since the introduction of rockets and guided missiles into aerial...
used by the United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
. The Mach 2 capable F-105 conducted the majority of strike bombing missions during the early years of the Vietnam War
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...
; 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
Wild Weasel
A Wild Weasel is an aircraft specially equipped with radar seeking missiles, and tasked with destroying the radars and SAM installations of enemy air defence systems....
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.
As a follow-on to the Mach 1 capable F-100, the F-105 was also armed with missiles and a cannon; however, its design was tailored to high-speed low-altitude penetration carrying a single nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...
internally. First flown in 1955, the Thunderchief entered service in 1958. Following adaption, the F-105 could deliver a greater bomb load than the large strategic bombers of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
like the B-17 Flying Fortress and B-24 Liberator. The F-105 was one of the primary strike bombers of the Vietnam War
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...
; over 20,000 Thunderchief sorties were flown, with 382 aircraft lost (nearly half of the 833 produced) including 62 operational losses. Although less agile than smaller MiG fighters, USAF F-105s were credited with 27.5 kills.
During the war, the single-seat F-105D was the primary aircraft delivering the heavy bomb loads against the various military targets. Meanwhile, the two-seat F-105F and F-105G Wild Weasel variants became the first dedicated Suppression of Enemy Air Defenses (SEAD) platforms, fighting against the Soviet
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
-built S-75 Dvina
S-75 Dvina
The S-75 Dvina is a Soviet-designed, high-altitude, command guided, surface-to-air missile system...
(NATO reporting name
NATO reporting name
NATO reporting names are classified code names for military equipment of the Eastern Bloc...
: SA-2 Guideline) surface-to-air missile
Surface-to-air missile
A surface-to-air missile or ground-to-air missile is a missile designed to be launched from the ground to destroy aircraft or other missiles...
s. Two Wild Weasel pilots were awarded the Medal of Honor
Medal of Honor
The Medal of Honor is the highest military decoration awarded by the United States government. It is bestowed by the President, in the name of Congress, upon members of the United States Armed Forces who distinguish themselves through "conspicuous gallantry and intrepidity at the risk of his or her...
for attacking North Vietnamese surface-to-air missile sites, with one shooting down two MiG-17s the same day. The dangerous missions often required them to be the "first in, last out", suppressing enemy air defenses while strike aircraft accomplished their missions and then left the area.
Although the F-105 weighed 50000 pounds (22,679.6 kg), the aircraft could exceed the speed of sound
Speed of sound
The speed of sound is the distance travelled during a unit of time by a sound wave propagating through an elastic medium. In dry air at , the speed of sound is . This is , or about one kilometer in three seconds or approximately one mile in five seconds....
at sea level and Mach 2
Mach number
Mach number is the speed of an object moving through air, or any other fluid substance, divided by the speed of sound as it is in that substance for its particular physical conditions, including those of temperature and pressure...
at high altitude. It could carry up to 14000 lb (6,350.3 kg) of bombs and missiles. The Thunderchief was later replaced as a strike aircraft over North Vietnam by both the McDonnell Douglas F-4 Phantom II and the swing-wing General Dynamics F-111 Aardvark. However, the "Wild Weasel" variants of the F-105 remained in service until 1984, when they were replaced by a specialized F-4G "Wild Weasel V".
Design phase
Republic Aviation started the Thunderchief as an internal project to replace the RF-84F Thunderflash, which first used the characteristic wing-root air intakes to place cameras in a pointed nose. The design team led by Alexander KartveliAlexander Kartveli
Alexander Kartveli 1896–1974, born Kartvelishvili) was a famous and influential aircraft engineer and a pioneer of American aviation history. Kartveli achieved important breakthroughs in military aviation in the time of turbojet fighters...
examined some 108 configurations before settling on a large, single-engine AP-63FBX (Advanced Project 63 Fighter Bomber, Experimental) - AP-63-31 actual. The new aircraft was intended primarily for supersonic, low altitude penetration into the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
on a hi-lo-hi mission and delivery of a single, internally carried nuclear bomb. The emphasis was placed on low-altitude speed and flight characteristics, range and payload. The aircraft would be fitted with a large engine, and a relatively small wing with a high wing loading
Wing loading
In aerodynamics, wing loading is the loaded weight of the aircraft divided by the area of the wing. The faster an aircraft flies, the more lift is produced by each unit area of wing, so a smaller wing can carry the same weight in level flight, operating at a higher wing loading. Correspondingly,...
which would give a stable ride at low altitudes, and less drag at supersonic speeds. Traditional fighter attributes such as maneuverability were a secondary consideration.
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
awarded Republic with a contract for 199 aircraft in September 1952. However, by March 1953, the USAF had reduced the order to 37 fighter-bombers and nine tactical reconnaissance aircraft, citing the approaching end of the Korean War
Korean War
The Korean War was a conventional war between South Korea, supported by the United Nations, and North Korea, supported by the People's Republic of China , with military material aid from the Soviet Union...
. By the time the F-105 mock-up had been completed in October 1953, the aircraft had grown so large that the Allison J71
Allison J71
|-External links:*...
turbojet intended for it, was abandoned in favor of an even more powerful Pratt & Whitney J75. Anticipating a protracted development of the engine, it was expected that the first aircraft would use the smaller Pratt & Whitney J57. Near the end of 1953, the entire program was cancelled by the USAF due to a number of delays and uncertainties regarding the aircraft, however on 28 June 1954, the USAF officially ordered 15 F-105s (two YF-105As, four YF-105Bs, six F-105Bs and three RF-105Bs) under the Weapon System designation WS-306A.
The YF-105A prototype first flew on 22 October 1955, with the second YF-105A following on 28 January 1956. In spite of being powered by a less potent J57-P-25 engine with 15000 pound-forces (66.7 kN) of afterburning
AfterBurner
The AfterBurner is a lighting solution for the Game Boy Advance system that was created by Triton-Labs.Originally, portablemonopoly.net was a website created to petition Nintendo to put some kind of light in their Game Boy Advance system...
thrust (the J75 was expected to generate 24500 lbf (109 kN) with afterburner), the first prototype attained the speed of Mach 1.2 on its maiden flight. Both prototypes featured conventional wing root air intakes and slab-sided fuselages typical of the early jets; Republic viewed the YB-105As as not being representative of the true capability of the aircraft due to numerous changes prior to production. Insufficient power and aerodynamic problems with transonic
Transonic
Transonic speed is an aeronautics term referring to the condition of flight in which a range of velocities of airflow exist surrounding and flowing past an air vehicle or an airfoil that are concurrently below, at, and above the speed of sound in the range of Mach 0.8 to 1.2, i.e. 600–900 mph...
drag
Drag (physics)
In fluid dynamics, drag refers to forces which act on a solid object in the direction of the relative fluid flow velocity...
, as well as Convair
Convair
Convair was an American aircraft manufacturing company which later expanded into rockets and spacecraft. The company was formed in 1943 by the merger of Vultee Aircraft and Consolidated Aircraft, and went on to produce a number of pioneering aircraft, such as the Convair B-36 bomber, and the F-102...
's experience with their F-102, had led to a redesign of the fuselage in order to conform to the Area rule
Area rule
The Whitcomb area rule, also called the transonic area rule, is a design technique used to reduce an aircraft's drag at transonic and supersonic speeds, particularly between Mach 0.75 and 1.2....
, giving it a characteristic "wasp waist". In combination with the distinctive forward-swept variable-geometry air intakes which regulated airflow to the engine at supersonic speeds and the J75 engine, this enabled the F-105B to attain Mach 2.15.
Into production
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
, and K-19 gunsight to allow for toss bombing
Toss bombing
Toss bombing is a method of bombing where the attacking aircraft pulls upwards when releasing its bomb load, giving the bomb additional time of flight by starting its ballistic path with an upward vector.The purpose of toss bombing is to compensate for the gravity drop of the...
was intergrated. The first pre-production YF-105B flew on 26 May 1956. Five of the F-105C trainer variant were added to the procurement plan in June 1956, before being canceled in 1957. The RF-105 reconnaissance variant was canceled in July 1956. The first production F-105B was accepted by the Air Force on 27 May 1957. In June 1957 Republic Aviation requested that the F-105 be named Thunderchief, continuing the sequence of the company's Thunder-named aircraft, e.g. P-47 Thunderbolt, F-84 Thunderjet, and F-84F Thunderstreak; the USAF made the name official a month later.
To fill the Air Force requirement for all-weather attack, Republic proposed the F-105D variant in 1957. It added more advanced navigation system, and improved cockpit displays for adverse weather operation. The ability to carry the TX-43 nuclear weapon was also added. The RF-105 reconnaissance development was also restarted; now based on the F-105D. The first D-model took its maiden flight on 9 June 1959. Plans to build over 1,500 F-105Ds were cut short when the Secretary of Defense Robert McNamara
Robert McNamara
Robert Strange McNamara was an American business executive and the eighth Secretary of Defense, serving under Presidents John F. Kennedy and Lyndon B. Johnson from 1961 to 1968, during which time he played a large role in escalating the United States involvement in the Vietnam War...
decided to equip no more than seven combat wings with the type. In November 1961, production was cut in favor of the Air Force adopting the Navy's F-4 Phantom II, and in the longer term, the General Dynamics F-111 Aardvark of the TFX program.
The final 143 Thunderchiefs built were of the two-seat F-105F trainer variant. Based on the F-105D, this model was 31 inches (79 cm) longer to provide room for the rear cockpit, otherwise the aircraft had similar flight performance to the preceeding F-105D. A total of 833 F-105s were completed before production ended in 1964. Subsequent upgrades improved the reliability and weapons capacity of the existing F-105Ds. In response to the surface to air missile (SAM) threat experienced in the skies above Vietnam, dozens of F-105Fs were converted into anti-radar "Wild Weasel
Wild Weasel
A Wild Weasel is an aircraft specially equipped with radar seeking missiles, and tasked with destroying the radars and SAM installations of enemy air defence systems....
" aircraft, culminating with the F-105G.
Overview
Swept wing
A swept wing is a wing planform favored for high subsonic jet speeds first investigated by Germany during the Second World War. Since the introduction of the MiG-15 and North American F-86 which demonstrated a decisive superiority over the slower first generation of straight-wing jet fighters...
and tail surfaces. The single engine was fed by two intakes in the wing roots, leaving the nose free for a radome
Radome
A radome is a structural, weatherproof enclosure that protects a microwave or radar antenna. The radome is constructed of material that minimally attenuates the electromagnetic signal transmitted or received by the antenna. In other words, the radome is transparent to radar or radio waves...
housing the multi-mode radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
. Its fuselage provided room for 1184 gal of fuel and an internal bomb bay. The bomb bay measured 15 in 10 in (4.83 m) by 32 in (0.8128 m) by 32 in (0.8128 m); it was originally to carry a single nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...
but typically held an additional 350 gal fuel tank. It featured four under-wing and one centerline pylon; the two inner wing and centerline pylons were capable of accepting fuel from 450 gal drop tank
Drop tank
In aeronautics, a drop tank is used to describe auxiliary fuel tanks externally carried by aircraft. A drop tank is expendable and often jettisonable...
s. Two outer dry stations were wired for missiles or bombs. One M61 Vulcan
M61 Vulcan
The M61 Vulcan is a hydraulically or pneumatically driven, six-barreled, air-cooled, electrically fired Gatling-style rotary cannon which fires 20 mm rounds at an extremely high rate. The M61 and its derivatives have been the principal cannon armament of United States military fixed-wing aircraft...
(initially designated T-171E3) 20 mm
20 mm caliber
The 20 mm caliber is a specific size of cannon or autocannon ammunition, commonly the smallest caliber which is unambiguously a cannon and not a heavy machine gun....
6-barrel Gatling-style cannon
Rotary cannon
A rotary cannon, or Gatling-type cannon, is a rapid-firing weapon that utilizes multiple barrels in a rotating cluster to provide a sustained rate of fire greater than single-barrelled machine guns or automatic cannons of equivalent caliber...
was installed in the left side of the nose. A short-range AIM-9 Sidewinder air-to-air missile could be carried on each of the outer wing pylons.
The F-105 was designed primarily for low-level interdiction and its low-altitude speed was its greatest asset when dealing with enemy fighters such as the MiG-17
Mikoyan-Gurevich MiG-17
The Mikoyan-Gurevich MiG-17 is a high-subsonic fighter aircraft produced in the USSR from 1952 and operated by numerous air forces in many variants. Most MiG-17 variants cannot carry air-to-air missiles, but shot down many aircraft with its cannons...
/J-5
Shenyang J-5
The Shenyang J-5 , originally designated Dongfeng-101 - , and also Type 56 before being designated J-5 in 1964, is a Chinese-built single-seat jet interceptor and fighter aircraft derived from the Soviet Mikoyan-Gurevich MiG-17. The J-5 was exported as the F-5...
s and MiG-21
Mikoyan-Gurevich MiG-21
The Mikoyan-Gurevich MiG-21 is a supersonic jet fighter aircraft, designed by the Mikoyan-Gurevich Design Bureau in the Soviet Union. It was popularly nicknamed "balalaika", from the aircraft's planform-view resemblance to the Russian stringed musical instrument or ołówek by Polish pilots due to...
. The F-105 managed 27.5 air-to-air victories. Based on combat experience, the F-105D was updated with a better ejection seat, additional armor, improved gun sights, and Electronic Counter Measures (ECM) pods on the wings.
Flight characteristics
Spoiler (aeronautics)
In aeronautics, a spoiler is a device intended to reduce lift in an aircraft. Spoilers are plates on the top surface of a wing which can be extended upward into the airflow and spoil it. By doing so, the spoiler creates a carefully controlled stall over the portion of the wing behind it, greatly...
provided good roll control at all speeds and the distinctive four-petal airbrakes
Air brake (aircraft)
In aeronautics, air brakes or speedbrakes are a type of flight control surface used on an aircraft to increase drag or increase the angle of approach during landing....
(which also opened slightly when the afterburner was engaged to allow for the larger flow of exhaust gases) were highly effective even at supersonic speeds. Loss of control due to a spin
Spin (flight)
In aviation, a spin is an aggravated stall resulting in autorotation about the spin axis wherein the aircraft follows a corkscrew downward path. Spins can be entered intentionally or unintentionally, from any flight attitude and from practically any airspeed—all that is required is sufficient yaw...
or complications of adverse yaw
Adverse yaw
Adverse yaw is a yaw moment on an aircraft which results from an aileron deflection and a roll rate, such as when entering or exiting a turn. It is called "adverse" because it acts opposite to the yaw moment needed to execute the desired turn. Adverse yaw has three mechanisms, listed below in...
required deliberate effort from the pilot and spontaneous spin recovery was rapid.
The initial reaction of the fighter pilot community to their new aircraft was lukewarm. Between its massive dimensions and troubled early service life, the F-105 had garnered a number of uncomplimentary nicknames. In addition to the aforementioned "Thud", nicknames included the "Squat Bomber", "Lead Sled", and the "Hyper Hog" and/or "Ultra Hog". The aircraft's offensive capabilities were sarcastically referred to as a "Triple Threat" — it could bomb you, strafe you, or fall on you. Positive aspects, such as the F-105's responsive controls, strong performance at high speed and low altitude, and its outfit of electronics won over some pilots. For some, "Thud" was a term of endearment; retroactively the RF-84F Thunderflash became known as "Thud's Mother". F-105 pilot Colonel Jack Broughton said of the nickname: "The Thud has justified herself, and the name that was originally spoken with a sneer has become one of utmost respect through the air fraternity".
Commando Nail
13th Fighter Squadron
The 13th Fighter Squadron is part of the 35th Fighter Wing at Misawa Air Base, Japan.-History:The 13th flew antisubmarine patrols in the Gulf of Mexico from, June–August 1942 and served as an operational and replacement training unit from, April 1942–October 1943...
(1966–1975) dubbed "Ryan's Raiders" starting in April 1967. Some of these aircraft were later converted to the Wild Weasel III standard.
In an effort to thwart MiG attacks, several F-105Fs were also fitted with Hallicrafters
Hallicrafters
The Hallicrafters Company manufactured, marketed, and sold radio equipment beginning in 1932. The company was based in Chicago, Illinois, USA.-History:William J. Halligan founded his own radio manufacturing company in Chicago in late 1932...
QRC-128 VHF jammers under project Combat Martin. The North Vietnamese interceptor force followed Soviet air-defense doctrine, with pilots under rigid direction of ground controllers over radio links. The QRC-128, nicknamed "Colonel Computer", filled up the rear cockpit of the F-105F and bounced voice communications over the radio channel back out after a delay, resulting in an obnoxious garble. However, the first time the Combat Martin was used, the US National Security Agency
National Security Agency
The National Security Agency/Central Security Service is a cryptologic intelligence agency of the United States Department of Defense responsible for the collection and analysis of foreign communications and foreign signals intelligence, as well as protecting U.S...
(NSA), in charge of US strategic signals intelligence, ordered the Air Force to cease and desist immediately, since the NSA believed that the intelligence obtained by monitoring the channels outweighed the benefits of jamming them. Some of these aircraft were eventually brought to the Wild Weasel III standard.
Thunderstick II
Experience in Vietnam demonstrated the need for a better visual and blind bombing capability. In March 1968, the Air Force ordered development of a new bombing/navigation system incorporating a LORANLORAN
LORAN is a terrestrial radio navigation system using low frequency radio transmitters in multiple deployment to determine the location and speed of the receiver....
receiver, an inertial navigation system, and solid-state electronics for the R-14A radar. Persistent problems with the AN/ARN-85 LORAN receiver resulted in substitution of the AN/ARN-92. This was housed in a long, raised dorsal spine. Known as Thunderstick II aircraft, these F-105s could achieve a bombing circular error of probability
Circular error probable
In the military science of ballistics, circular error probable is an intuitive measure of a weapon system's precision...
(CEP) of 50 feet (15.2 m) from an altitude of 15000 ft (4,572 m). Although the first Thunderstick II aircraft flew in 1969, they were never used in Vietnam. A total of 30 F-105Ds received this modification.
Wild Weasel
In 1965, the USAF began operating two-seat F-100F Super Sabres specially equipped for Suppression of Enemy Air Defenses mission in Vietnam. Nicknamed the Wild WeaselWild Weasel
A Wild Weasel is an aircraft specially equipped with radar seeking missiles, and tasked with destroying the radars and SAM installations of enemy air defence systems....
, these aircraft achieved a number of victories against North Vietnamese surface-to-air missile
Surface-to-air missile
A surface-to-air missile or ground-to-air missile is a missile designed to be launched from the ground to destroy aircraft or other missiles...
radars. The second crew member was a Navigator trained as an Electronic Warfare Officer (EWO) to decipher sensor information and guide the pilot towards the targets. However, the F-100F was an interim solution, its limited payload often required multiple aircraft to conduct a successful strike; it also lacked the speed and endurance to effectively protect the F-105.
The resulting EF-105F Wild Weasel III (the EF designation was popularly used but unofficial) supplemented its sensors and electronic jamming equipment with AGM-45 Shrike
AGM-45 Shrike
AGM-45 Shrike is an American anti-radiation missile designed to home in on hostile antiaircraft radars. The Shrike was developed by the Naval Weapons Center at China Lake in 1963 by mating a seeker head to the rocket body of an AIM-7 Sparrow. It was phased out by U.S...
anti-radiation missiles and conventional bombs, giving it an offensive capability lacking in the F-100F. The first of these aircraft flew on 15 January 1966 and they began arriving in Southeast Asia in May, flying their first mission on 6 June 1966, with five assigned to the 13th TFS at Korat RTAFB and six more to the 354th TFS at Takhli RTAFB.
In a typical early mission, a single EF-105F would accompany one or two flights of F-105Ds to provide protection from enemy ground fire. While this strategy was effective in reducing F-105D losses, the Weasel aircraft suffered heavy casualties with five of the first 11 lost in July and August 1966. Attacks into high-risk environments saw the Weasels operating in "Iron Hand" Hunter-Killer flights of mixed single-seat and two-seat Thunderchiefs, suppressing sites during attacks by the strike force and attacking others en route. In the fall of 1967, EF-105Fs began to be upgraded to the definitive Wild Weasel Thunderchief, the F-105G.
The F-105G incorporated a considerable amount of new SEAD-specific avionics, including an upgraded RHAW system which required a redesign of the wingtips. To free outboard hardpoints for additional weapons, the Westinghouse AN/ALQ-105 electronic countermeasures
Electronic countermeasures
An electronic countermeasure is an electrical or electronic device designed to trick or deceive radar, sonar or other detection systems, like infrared or lasers. It may be used both offensively and defensively to deny targeting information to an enemy...
were permanently installed in two long blisters on the underside of the fuselage. Thirty aircraft were fitted with pylons to carry the AGM-78 Standard anti-radiation missile. On a typical mission, the F-105G carried two Shrikes on outboard pylons, a single Standard on an inboard pylon balanced by a 450 gal fuel tank on the other side, and a 650 gal centerline fuel tank.
Costs
| F-105B | F-105D | F-105F/G | |
|---|---|---|---|
| Unit R&D Research and development The phrase research and development , according to the Organization for Economic Co-operation and Development, refers to "creative work undertaken on a systematic basis in order to increase the stock of knowledge, including knowledge of man, culture and society, and the use of this stock of... cost |
2,716 prorated per aircraft | ||
| Airframe | 4,914,016 | 1,472,145 | 1,524,000 |
| Engine | 328,797 | 244,412 | 290,000 |
| Electronics | 141,796 | 19,346 | 251,000 |
| Armament | 232,913 | 167,621 | 154,000 |
| Ordnance | 32,021 | 19,346 | 21,000 |
| Flyaway cost | 5,649,543 | 2.14 million | 2.2 million |
| Modification costs by 1973 | 261,793 | 282,687 | 701,645 plus 1,803 for F-105G conversion |
| Cost per flying hour | 1,020 | 1,020 | |
| Maintenance cost per flying hour | 718 | 809 | 808 |
Notes: The costs above are in approximately 1960 United States dollar
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....
s and have not been adjusted for inflation.
Introduction
The F-105B entered USAF service with the Tactical Air CommandTactical Air Command
Tactical Air Command is an inactive United States Air Force organization. It was a Major Command of the United States Air Force, established on 21 March 1946 being headquartered at Langley Air Force Base, Virginia...
's 335th Tactical Fighter Squadron
335th Fighter Squadron
The 335th Fighter Squadron ' is a United States Air Force unit. It is assigned to the 4th Operations Group and stationed at Seymour Johnson Air Force Base, North Carolina....
of the 4th Tactical Fighter Wing
4th Fighter Wing
The 4th Fighter Wing is a United States Air Force unit assigned to the Air Combat Command Ninth Air Force. It is stationed at Seymour Johnson Air Force Base, North Carolina, where it is also the host unit....
in August 1958, although the squadron did not become fully operational until 1959. On 11 December 1959, an F-105B piloted by Brig Gen Joseph Moore (commander of the 4th Tactical Fighter Wing) set a world record of 1216.48 miles per hour (1,957.7 km/h) over a 62 miles (99.8 km) circuit. Difficulties with its avionics
Avionics
Avionics are electronic systems used on aircraft, artificial satellites and spacecraft.Avionic systems include communications, navigation, the display and management of multiple systems and the hundreds of systems that are fitted to aircraft to meet individual roles...
and the MA-8 fire-control system
Fire-control system
A fire-control system is a number of components working together, usually a gun data computer, a director, and radar, which is designed to assist a weapon system in hitting its target. It performs the same task as a human gunner firing a weapon, but attempts to do so faster and more...
were experienced early on, typically the F-105 required 150 hours of maintenance for each flying hour. Most of these problems were addressed under Project Optimize. The lack of spares resulted in the entire F-105B fleet being briefly grounded in 1960. In 1964, modified F-105Bs with ballast replacing the cannon, fuselage and wing reinforcement for aerobatics, and the addition of a smoke generator, briefly flew with the United States Air Force Thunderbirds demonstration team. After only six shows, a fatal accident from overstressing the airframe led to the reintroduction of the F-100 Super Sabre
F-100 Super Sabre
The North American F-100 Super Sabre was a supersonic jet fighter aircraft that served with the United States Air Force from 1954 to 1971 and with the Air National Guard until 1979. The first of the Century Series collection of USAF jet fighters, it was the first USAF fighter capable of...
.
By 1964, the F-105B was relegated to ANG squadrons. It was replaced in frontline service by the definitive F-105D whose advanced NASARR R-14A radar and AN/ASG-19 Thunderstick fire-control system gave it all-weather performance. The R-14A radar also added a terrain-following radar
Terrain-following radar
Terrain-following radar is an aerospace technology that allows a very-low-flying aircraft to automatically maintain a relatively constant altitude above ground level. It is sometimes referred-to as ground hugging or terrain hugging flight...
capability, while a completely new instrument panel was fitted, replacing dial-type instrument with vertical tape instruments which were easier to read in combat. In order to accommodate the new radar, with a much larger radar dish, the forward fuselage was redesigned, increasing overall length by 16 inches (40.6 cm).
The F-105D entered service with the 335th TFS in September 1960, although it was not fully operational on the F-105D until early 1961. The first overseas F-105 units formed in West Germany in 1961, with the 36th Tactical Fighter Wing at Bitburg Air Base
Bitburg Air Base
Bitburg Airport is a commercial airport serving Bitburg, a city in the Rhineland-Palatinate state of Germany. It is located 2 miles southeast of Bitburg, 20 miles north of Trier, and 135 miles west of Wiesbaden....
in May and the 49th Tactical Fighter Wing at Spangdahlem Air Base
Spangdahlem Air Base
Spangdahlem Air Base is a United States Air Force base located near the small German town of Spangdahlem, approximately 30 km NNE of the city of Trier, Rhineland-Palatinate.-Units:...
in October. Both wings had a primary tactical nuclear strike role for NATO. The F-105D was also deployed to the Pacific, with the 18th Tactical Fighter Wing at Kadena
Kadena Air Base
, is a United States Air Force base in the towns of Kadena and Chatan and the city of Okinawa, in Okinawa Prefecture, Japan. Kadena Air Base is the hub of U.S. airpower in the Pacific, and home to the USAF's 18th Wing and a variety of associate units.-Units:The 18th Wing is the host unit at Kadena...
in Okinawa converting in 1962 and the 8th Tactical Fighter Wing converting from 1963.
Like the F-105B, the F-105D's early career was plagued with maintenance problems and in-flight failures. The origins of the nickname "Thud" were obscure, some claim that it stood for the sound of an F-105 crashing into the ground. The entire F-105D fleet was grounded in December 1961 and then again in June 1962. Many of the issues were worked out during the production run and by 1964, early F-105Ds were upgraded with these fixes under Project Look Alike, although engine failures and fuel system problems persisted until 1967.
Meanwhile, the USAF was gradually changing the anticipated F-105 mission from nuclear interdiction to conventional bombing. The Look Alike upgrades increased the aircraft's capacity from four to 16 conventional 750 lb (340.2 kg) bombs on underwing and fuselage centerline hardpoints and added the equipment to launch AGM-12 Bullpup
AGM-12 Bullpup
The AGM-12 Bullpup is an air-to-ground missile which was used on the A-4 Skyhawk, A-6 Intruder, F-105 Thunderchief and F-4 Phantom among others...
air-to-ground missiles. In June 1961, an F-105D delivered 15430 lb (6,998.9 kg) of conventional bombs during a USAF test—at the time a record for a single-engine aircraft and a payload three times heavier than World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
's four-engine heavy bombers such as the Boeing B-17 Flying Fortress and the Consolidated B-24 Liberator, though aerial refueling would be required for long missions. One of the F-105Ds was named Memphis Belle II after the famed World War II B-17.
Vietnam War
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...
. The F-105 could carry more than twice the bomb load farther and faster than the F-100, which was used mostly in South Vietnam. In a foreshadowing of its Wild Weasel
Wild Weasel
A Wild Weasel is an aircraft specially equipped with radar seeking missiles, and tasked with destroying the radars and SAM installations of enemy air defence systems....
role, the first F-105D combat mission of the war involved an attack on 14 August 1964 against an anti-aircraft artillery site on Plaine des Jarres
Plain of Jars
The Plain of Jars is a megalithic archaeological landscape in Laos. Scattered in the landscape of the Xieng Khouang plateau Xieng Khouang, Lao PDR, are thousands of megalithic jars...
. This mission was carried out by aircraft of the 36th TFS, 6441st Tactical Fighter Wing deployed from Yokota Air Base
Yokota Air Base
, is a United States Air Force base in the city of Fussa, one of 26 cities in the Tama Area, or Western Tokyo.The base houses 14,000 personnel. The base occupies a total area of and has a runway...
, Japan to Korat Royal Thai Air Force Base
Korat Royal Thai Air Force Base
Korat Royal Thai Air Force Base is a base of the Royal Thai Air Force. It is located in northeast Thailand, located approximately 157 miles northeast of Bangkok and about 5 miles south of Nakhon Ratchasima , the second largest city in Thailand.During the Vietnam War, Korat RTAFB was the...
, Thailand. The first Thunderchief lost in the war also occurred during this mission, although the pilot managed to return the aircraft to Korat. The first strike mission took place on 13 January 1965 with the destruction of the Ben Ken bridge in Laos
Laos
Laos Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ Sathalanalat Paxathipatai Paxaxon Lao, officially the Lao People's Democratic Republic, is a landlocked country in Southeast Asia, bordered by Burma and China to the northwest, Vietnam to the east, Cambodia to the south and Thailand to the west...
. In early 1965 additional F-105 squadrons were deployed to Korat and Takhli
Takhli Royal Thai Air Force Base
Takhli Royal Thai Air Force Base is a Royal Thai Air Force facility. It is located in Central Thailand, approximately 144 miles northwest of Bangkok in Takhli district, Nakhon Sawan Province, near the city of Nakhon Sawan.- Units :...
air bases in Thailand. At the start of Operation Rolling Thunder
Operation Rolling Thunder
Operation Rolling Thunder was the title of a gradual and sustained US 2nd Air Division , US Navy, and Republic of Vietnam Air Force aerial bombardment campaign conducted against the Democratic Republic of Vietnam from 2 March 1965 until 1 November 1968, during the Vietnam War.The four objectives...
in March 1965, large numbers of F-105Ds were shipped to these bases to participate in intense bombing missions.
On 3 April 1965, a total of 79 aircraft, including 45 F-105 Thunderchiefs, were sent against the Thanh Hoa Bridge
Thanh Hoa Bridge
The Thanh Hoa Bridge, spanning the Song Ma river, is situated northeast of Thanh Hóa , the capital of Thanh Hoa province in Vietnam. The Vietnamese gave it the nickname Ham Rong . In 1965 during the Vietnam war, it was the objective of many attacks by US Air Force and US Navy aircraft which would...
, nicknamed "Dragon's Jaw". The next day, enemy MiGs were encountered during a second run upon the bridge; a total of eight MiG-17s faced 46 F-105s escorted by a MiGCAP flight of 21 F-100 Super Sabres. The MiG-17s evaded the escorts using altitude and cloud-cover, instead focusing upon the bomb-laden Thunderchiefs. Two Thuds were lost to the MiG-17s; a third, thought to be lost to groundfire, was later claimed by the North as downed by a MiG-17. An F-100 claimed the only probable MiG-17 kill, although a Vietnamese pilot believes three of his comrades were shot down by F-105s. One F-105 piloted by John Boyd
John Boyd (military strategist)
Colonel John Boyd was a United States Air Force fighter pilot and Pentagon consultant of the late 20th century, whose theories have been highly influential in the military, sports, and business.-Biography:...
narrowly escaped. USAF Chief of Staff General John P. McConnell was "hopping mad" to hear that two F-105s had been shot down by Korean War-era subsonic North Vietnamese MiGs. The Thanh Hoa Bridge proved resistant to aerial bombing, multiple missions were flown to damage the bridge both by F-105s and U.S. Navy aircraft.
On a typical combat mission into North Vietnam, the F-105D carried two 450 gal wing-mounted fuel tanks, a 390 gal fuel tank in the bomb bay, and five 1000 lb (453.6 kg) or six 750 lb (340.2 kg) bombs, and required inflight refueling
Aerial refueling
Aerial refueling, also called air refueling, in-flight refueling , air-to-air refueling or tanking, is the process of transferring fuel from one aircraft to another during flight....
going to and sometimes returning from Hanoi
Hanoi
Hanoi , is the capital of Vietnam and the country's second largest city. Its population in 2009 was estimated at 2.6 million for urban districts, 6.5 million for the metropolitan jurisdiction. From 1010 until 1802, it was the most important political centre of Vietnam...
700 mi (1,126.5 km) distant. F-105s flying in the vicinity of Hanoi would routinely travel around mountainous terrain nicknamed Thud Ridge
Thud Ridge
Thud Ridge is a 1969 memoir by Jack Broughton about flying the F-105 "Thud" for the United States Air Force in the Vietnam War during Operation Rolling Thunder...
(21°16′47"N 105°49′37"E) to evade the air defenses surrounding the city. Colonel Jack Broughton, an F-105 pilot in Vietnam, noted the demands of flying close to Hanoi gave "simply no room for error".
On 11 August 1967, F-105Ds from 335th Tactical Fighter Squadron with support from F-105 Wild Weasels from 338th Tactical Fighter Squadron made the first of many successful attacks on the Paul Doumer bridge
Long Bien Bridge
Long Bien Bridge is a historic cantilever bridge across the Red River that connects two parts of the city of Hanoi, Vietnam. It was originally called Paul Doumer Bridge.- History :...
over the Red River. Flying low-altitude missions and conducting dive bombings forced the F-105s to range of North Vietnamese anti-aircraft, sometimes coming under heavy fire. Designed originally as a nuclear bomber rather than a conventional precision bombing, the F-105 had only a basic bombing sight, it lacked a bomb guidance system that would allow attacks at a higher altitude, dive bombing was its only mission profile, putting it in reach of ground fire. A total of 382 F-105s were lost in Southeast Asia, 320 of those in combat—most to enemy ground fire, leading to the USAF experiencing a shortage of combat-ready aircraft. Of the 610 single-seat F-105Ds built, 283 were shot down and 52 lost operationally. Of the 143 F-105F/G two-seaters, 37 were shot down and 10 lost operationally.
North Vietnam
The Democratic Republic of Vietnam , was a communist state that ruled the northern half of Vietnam from 1954 until 1976 following the Geneva Conference and laid claim to all of Vietnam from 1945 to 1954 during the First Indochina War, during which they controlled pockets of territory throughout...
ese aircraft at the cost of 17 aircraft lost to enemy fighters (North Vietnamese pilots claimed to have shot down an additional 23 F-105s but none have been confirmed by USAF). All victories were against MiG-17s. Of these 24.5 were shot down with cannon fire (one victory was shared with an F-4), and three with AIM-9 Sidewinder
AIM-9 Sidewinder
The AIM-9 Sidewinder is a heat-seeking, short-range, air-to-air missile carried mostly by fighter aircraft and recently, certain gunship helicopters. The missile entered service with United States Air Force in the early 1950s, and variants and upgrades remain in active service with many air forces...
missiles. One F-105F is unofficially credited with downing three MiGs—one by air-to-air missile, the second by cannon fire and the third by jettisoning the centerline rack full of bombs directly into the path of a surprised MiG.
As production of F-105s had ended, the type was replaced in the Vietnam War by other aircraft, primarily the McDonnell Douglas F-4 Phantom II and the LTV A-7 Corsair II. In October 1970, the 355th Tactical Fighter Wing
355th Fighter Wing
The 355th Wing is a United States Air Force unit assigned to the Air Combat Command's Twelfth Air Force. It is stationed at Davis-Monthan Air Force Base in Tucson, Arizona, where in operates the A-10 Thunderbolt II...
, the last F-105D unit in Vietnam, began to return to the U.S. The F-105G Wild Weasel versions soldiered on until the end of the war. They were gradually replaced by F-4G Wild Weasel IVs.
Medal of Honor recipients
Two Wild Weasel pilots received the Medal of HonorMedal of Honor
The Medal of Honor is the highest military decoration awarded by the United States government. It is bestowed by the President, in the name of Congress, upon members of the United States Armed Forces who distinguish themselves through "conspicuous gallantry and intrepidity at the risk of his or her...
:
- USAF Captain Merlyn H. Dethlefsen was awarded the Medal of HonorMedal of HonorThe Medal of Honor is the highest military decoration awarded by the United States government. It is bestowed by the President, in the name of Congress, upon members of the United States Armed Forces who distinguish themselves through "conspicuous gallantry and intrepidity at the risk of his or her...
and Capt Kevin "Mike" Gilroy the Air Force CrossAir Force Cross (United States)The Air Force Cross is the second highest military decoration that can be awarded to a member of the United States Air Force. The Air Force Cross is the Air Force decoration equivalent to the Distinguished Service Cross and the Navy Cross .The Air Force Cross is awarded for extraordinary heroism...
for an F-105F Wild Weasel mission on 10 March 1967, flying F-105F, AF Ser. No. 63-8352. After their aircraft was damaged by ground fire, Dethlefsen and Gilroy elected to stay in the skies above the steel works at Thai Nguyen until the SAM site was found and destroyed. - USAF Captain Leo K. ThorsnessLeo K. ThorsnessLeo Keith Thorsness is a retired colonel in the United States Air Force who received the Medal of Honor for his actions in the Vietnam War. He was awarded the medal for an air engagement on April 19, 1967. He was shot down two weeks later and spent six years in captivity in North Vietnam as a...
was awarded the Medal of Honor and Capt Harold Johnson the Air Force Cross for an F-105F Wild Weasel mission on 19 April 1967, flying F-105F, AF Ser. No. 63-8301. Thorsness and Johnson protected an attempted rescue of another Wild Weasel crew that had been shot down, in the process destroying two MiG-17s. After running out of ammunition, Thorsness and Johnson continued to act as decoys to draw the MiGs away from the rescue aircraft.
Retirement
Air Force Reserve Command
The Air Force Reserve Command is a major command of the U.S. Air Force with its headquarters at Robins AFB, Georgia.It stood up as a major command of the Air Force on 17 February 1997....
and Air National Guard units, but their extended wartime service meant that many F-105s had already reached or exceeded their service lives by the mid-1970s. The F-105 Thunderchief was officially retired on 25 February 1984. The F-105 had a lengthy service life considering many of the "Century series" fighter aircraft were retired in the mid-1970s, a decade before the F-105 was retired.
Variants
YF-105A- Two pre-production prototypes with P&W J57 engine model.
YF-105B
- Four pre-production aircraft with P&W J75 engine.
F-105B
- Initial production model with AN/APN-105 navigational radar, 71 built.
JF-105B
- Test aircraft built from re-allocated RF-105B airframes; three built.
RF-105B
- Proposed reconnaissance version of the F-105B; none built. Three were ordered but completed as JF-105Bs.
F-105C
- Proposed dual-control trainer; canceled in 1957, none built.
F-105D
- The definitive production model, all-weather capability because of advanced avionics, including AN/APN-131 navigational radar; 610 built.
RF-105D
- Proposed reconnaissance version of the F-105D; none built.
F-105E
- Proposed trainer version of F-105D; cancelled in 1959, none completed.
F-105F
- Two-seat trainer version of F-105D with lengthened forward fuselage. It was fully combat-capable and had dual controls, taller fin, and increased takeoff weight; its first flight took place on 11 June 1963. 143 were built. AN/APN-148 navigational radar replaced the AN/APN-131 radar used in earlier models.
EF-105F
- Initial designation for a Wild WeaselWild WeaselA Wild Weasel is an aircraft specially equipped with radar seeking missiles, and tasked with destroying the radars and SAM installations of enemy air defence systems....
/SEAD version, 54 conversion from F-105Fs.
F-105G
- Two-seat Wild Weasel/SEAD improved version of EF-105F conversions. AN/APN-196 navigational radar replaced AN/APN-148 used in earlier models
Operators
- United States Air ForceUnited States Air ForceThe United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
- Air Force ReserveAir Force Reserve CommandThe Air Force Reserve Command is a major command of the U.S. Air Force with its headquarters at Robins AFB, Georgia.It stood up as a major command of the Air Force on 17 February 1997....
- Air National GuardAir National GuardThe Air National Guard , often referred to as the Air Guard, is the air force militia organized by each of the fifty U.S. states, the commonwealth of Puerto Rico, the territories of Guam and the U.S. Virgin Islands, and the District of Columbia of the United States. Established under Title 10 and...
Specifications (F-105D)
See also
External links
- USAF Museum F-105D Factsheet
- USAF Museum F-105f/G Factsheet
- The Republic F-105 Thunderchief from Greg Goebel's AIR VECTORS
- The F-105 Thud, a legend flown by legends
- Craig Baker's F-105 Site
- Thud Ridge Web: Republic F-105 Thunderchief In Combat
- F-105 Thunderchief on break-left.org
- F-105 Thunderchief Walk Around
- Aerospaceweb.org profile of the F-105
- Twenty-five hour day; film primarily covering an F-105 attack over North Vietnam; plenty of Thud footage, and coverage of the support required for such an operation: maintenance crews, planning, refuelling, search and rescue, etc. (thumbnails)
- AeroWeb list of F-105 Thunderchiefs on display in the US.