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86-433: Since the original civil engine was designed for subsonic speeds, parts had to be thickened and made from improved materials for the higher pressures and temperatures which occur in a Mach 2 military engine. These are higher than in a Mach 2 civil airliner because supersonic combat aircraft go faster at sea level. Here the ambient temperature and pressure are higher than at altitudes where civil airliners are accelerating through

172-543: A forward looking infrared (FLIR) sensor, optical camera and laser rangefinder / designator . The Pave Tack pod allowed the F-111 to designate targets and drop laser-guided bombs on them. Australian RF-111Cs carried a pallet of sensors and cameras for aerial reconnaissance use. The FB-111 could carry two AGM-69 SRAM air-to-surface nuclear missiles in its weapons bay. General Dynamics trialed an arrangement with two AIM-9 Sidewinder air-to-air missiles carried on rails in

258-668: A tandem -seat aircraft for low-level penetration ground-attack, while the Navy wanted a shorter, high altitude interceptor with side-by-side seating to allow the pilot and radar operator to share the radar display. Also, the USAF wanted the aircraft designed for 7.33 g with Mach 2.5 speed at altitude and Mach 1.2 speed at low level with an approximate length of 70 ft (21.3 m). The Navy had less strenuous requirements of 6 g with Mach 2 speed at altitude and high subsonic speed (approx. Mach 0.9) at low level with

344-551: A FAD fighter, the Navy started with the subsonic , straight-winged aircraft, the Douglas F6D Missileer in the late 1950s. The Missileer was designed to carry six long-range missiles and loiter for five hours, but would be defenseless after firing its missiles. The program was formally canceled in 1961. The Navy had tried variable geometry wings with the XF10F Jaguar , but abandoned it in the early 1950s. It

430-515: A ceiling price of $ 529 million along with provisions for deficiency correction amongst other operational clauses and performance criteria. General Dynamics' design team was led by Robert H. Widmer . Recognizing its lack of experience with carrier-based fighters, General Dynamics teamed with Grumman in November 1963 for the assembly and testing of the F-111B. In addition, Grumman would also build

516-593: A detachment of six aircraft from the 474th Tactical Fighter Wing (474th TFW Roadrunners) were sent in March 1968 to Southeast Asia for Combat Lancer testing in real combat conditions in the Vietnam War . During the deployment, 55 night missions were flown against targets in North Vietnam, but two aircraft had been lost. 66–0022 was lost on 28 March, and 66-0017 on 30 March. Replacement aircraft left Nellis, but

602-594: A heart for transplant. The aircraft landed at Bradley International Airport to deliver the organ to a waiting ambulance. On 14 April 1986, 18 F-111s and approximately 25 Navy aircraft conducted air strikes against Libya under Operation El Dorado Canyon . The 18 F-111s of the 48th Tactical Fighter Wing and 4 EF-111As from the 20th Tactical Fighter Wing flew what turned out to be the longest fighter combat mission in history. The round-trip flight between RAF Lakenheath / RAF Upper Heyford , United Kingdom and Libya of 6,400 miles (10,300 km) spanned 13 hours. One F-111

688-671: A length of 56 ft (17.1 m). The Navy also wanted the aircraft with a nose large enough for a 48 in (1.2 m) diameter radar dish. McNamara developed a basic set of requirements for TFX based largely on the USAF's requirements and, on 1 September 1961, ordered the USAF to develop it. Nevertheless, a request for proposals (RFP) for the TFX was provided to industry in October 1961. In December, proposals were received from Boeing , General Dynamics , Lockheed , McDonnell , North American and Republic . The evaluation group found all

774-622: A major cause of the aircraft's protracted development and weight increases. The F-111A and F-111B shared the same airframe structural components and Pratt & Whitney TF30-P-1 turbofan engines. They featured side-by-side crew seating in an escape capsule as required by the Navy. The F-111B 's nose was 8.5 feet (2.59 m) shorter as the aircraft could fit on existing carrier elevator decks, and had 3.5-foot-longer (1.07 m) wingtips to improve on-station endurance time; it also carried an AN/AWG-9 Pulse-Doppler radar to guide its AIM-54 Phoenix missiles. The USAF's F-111A would be equipped with

860-510: A speed advantage at low altitudes. The USAF's Tactical Air Command (TAC) was largely concerned with the fighter-bomber and deep strike/ interdiction roles. TAC was in the process of receiving its latest design, the Republic F-105 Thunderchief , which was designed to deliver nuclear weapons fast and far, but required long runways. A simpler variable geometry wing configuration with the pivot points farther out from

946-514: A trapeze arrangement from the bay, but this was not adopted. Early F-111 models had radars equipped to guide the AIM-7 Sparrow medium-range air-to-air missile, but it was never fitted. Each wing was equipped with four underwing pylons. The inner two pylons on each wing rotated to align with the fuselage, while the outer two were fixed. Each pylon had a capacity of 5,000 pounds (2,300 kilograms). Various bombs and missiles could be carried on

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1032-590: A troubled development and Navy requirements changed to a maneuverable aircraft for dogfighting. The swing-wing configuration, TF-30 engines, AIM-54 Phoenix air-to-air missiles and AWG-9 radar developed for the F-111B were used on its replacement, the Grumman F-14 Tomcat. The Tomcat was large enough to carry the AWG-9 and Phoenix missiles while exceeding both the F-111's and the F-4's maneuverability. The F-111C

1118-526: Is a military low-bypass turbofan engine originally designed by Pratt & Whitney for the subsonic F6D Missileer fleet defense fighter, but this project was cancelled. It was later adapted with an afterburner for supersonic designs, and in this form it was the world's first production afterburning turbofan, going on to power the F-111 and the F-14A Tomcat , as well as being used in early versions of

1204-422: Is a retired supersonic, medium-range, multirole combat aircraft. Production models of the F-111 had roles that included attack (e.g. interdiction ), strategic bombing (including nuclear weapons capabilities), reconnaissance and electronic warfare . Aardvark comes from a South African animal that has a long nose and hugs the terrain. It is an Afrikaans word that translates literally as "earth pig"—hence

1290-591: Is the export version for Australia, combining the F-111A with longer F-111B wings and strengthened FB-111A landing gear. Australia ordered 24 F-111s and, following delays, the Royal Australian Air Force accepted the aircraft in 1973. Four were converted to the RF-111C reconnaissance variant in 1979–80. Australia also purchased four ex-USAF F-111As and converted them into F-111Cs. In the 1990s,

1376-713: The A-7 Corsair II without an afterburner. First flight of the TF30 was in 1964 and production continued until 1986. In 1958, the Douglas Aircraft Company proposed a short-range, four-engined jet airliner to fill the gap below its new DC-8 intercontinental, known internally as the Model 2067 . Intended to be marketed as DC-9, it was not directly related to the later twin-engined Douglas DC-9 . Pratt & Whitney (P&W) had offered its JT8A turbojet for

1462-836: The Allison Engine Company offered to the Air Force its TF41 turbofan, a license-built version of the RB.168-25R Spey . The USAF selected the more powerful TF41 for the A-7D, as did the USN, for its similar A-7E. The Grumman F-14 Tomcat with the TF30-P-414A was underpowered, because it was the Navy's intent to procure a jet fighter with a thrust-to-weight ratio (in clean configuration) of 1 or better (the US Air Force had

1548-823: The Boeing F/A-18E/F Super Hornet as an interim measure until the Lockheed Martin F-35 Lightning II became available. The May 1960 U-2 incident , in which an American CIA U-2 reconnaissance plane was shot down over the USSR, stunned the United States government. Besides greatly damaging US–Soviet relations, the incident showed that the Soviet Union had developed a surface-to-air missile that could reach aircraft above 60,000 feet (18,000 meters). Consequently,

1634-563: The Case–Church Amendment . The 347th TFW was stationed at Korat Royal Thai Air Force Base from 12 July 1974 until 30 June 1975. In May 1975, 347th TFW F-111s provided air support during the Mayaguez incident . One of the most unusual missions occurred on 14 February 1986, when two FB-111s of the 509th Bombardment Wing were dispatched from then Pease Air Force Base , New Hampshire to Tinker Air Force Base , Oklahoma to pick up

1720-1000: The General Electric AN/APQ-113 attack radar mated to a separate Texas Instruments AN/APQ-110 terrain-following radar lower in the nose and a Litton AJQ-20 inertial navigation and nav/attack system. The terrain-following radar (TFR) was integrated into the automatic flight control system, allowing for "hands-off" flight at high speeds and low levels (down to 200 ft or 61 m). A total of 159 F-111As were produced, including 30 pre-production aircraft that were rebuilt to production standards. 42 F-111As were converted to EF-111A Ravens for an electronic warfare tactical electronic jamming role. In 1982, four surviving F-111As were provided to Australia as attrition replacements and modified to F-111C standard, including its longer-span wings and reinforced landing gear. Three pre-production F-111A were used by NASA for various tests. The 13th F-111A received new wing designs for

1806-796: The Operation Linebacker II aerial offensive against the North Vietnamese, who called the aircraft "Whispering Death". They also supported regional aerial operations against other communist forces such as Operation Phou Phiang III during the Laotian Civil War in Laos . Crews described their flying in Vietnam as "speed is life", "one pass, haul ass", and "you do more than one pass in a target area you die". The F-111's ability with terrain-following radar ("the best in

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1892-489: The Saab 35 Draken with a Rolls-Royce Avon turbojet engine and Swedish-developed afterburner had a thrust boost at take-off of 38%. For short landings the engine exhaust was deflected partially forwards by an airframe-mounted reverser. The exhaust passed through three slots (which otherwise supply ambient air to the airframe-mounted exhaust ejector) to give a braking force about 60% of the maximum dry take-off thrust. In comparison

1978-618: The United States Air Force Strategic Air Command (SAC) and the RAF Bomber Command 's plans to send subsonic, high-altitude Boeing B-47 Stratojet and V bomber formations into the USSR were realized to be much less viable. By 1960, SAC had begun moving to low-level penetration , which greatly reduced radar detection distances. At the time, SAMs were ineffective against low-flying aircraft while interceptor aircraft had less of

2064-698: The United States Navy selected the JT10A, designated TF30-P-1, to power the proposed Douglas F6D Missileer , but the project was canceled in April 1961. Meanwhile, the TF30 had been chosen by General Dynamics for its entrant in the TFX competition for the United States Air Force and USN, which was selected for production as the F-111 . The version of the TF30 for the F-111 included an afterburner. The F-111A, EF-111A and F-111E used

2150-538: The 1990s; the last F-111Fs were withdrawn in 1996 while the remaining EF-111s also departed in 1998. The F-111 was replaced in USAF service by the F-15E Strike Eagle for medium-range precision strike missions, while the supersonic bomber role has been assumed by the B-1B Lancer . The RAAF continued to operate the type up until December 2010, when the last F-111C was retired; its role was transitioned to

2236-598: The AN/APQ-113 attack radar and the AN/APQ-110 terrain-following radar and air-to-ground armament. During September 1963, the F-111A mockup was inspected. On 15 October 1964, the first test F-111A was rolled out of Plant 4 of General Dynamics' facility in Fort Worth, Texas; it was powered by YTF30-P-1 turbofans and used a set of ejector seats as the escape capsule was not yet available. On 21 December 1964,

2322-614: The Australians have a bomber that can put a bomb through that window on to the table here in front of us?" Australian F-111s were ready to attack Indonesian forces during the establishment of East Timor 's independence and the deployment of the Australian-led International Force for East Timor . In 2006, an RAAF F-111 scuttled the North Korean ship Pong Su on 23 March 2006. Because of

2408-793: The EF-111 electronic warfare variant in 1998. The Australian government ordered 24 F-111C aircraft to replace the RAAF's English Electric Canberras in the bombing and tactical strike role. While the first aircraft was officially handed over in September 1968, structural issues delayed the entry into service. The first F-111C was accepted at Nellis Air Force Base on 15 March 1973. The RAAF's first six F-111Cs arrived at RAAF Base Amberley on 1 July 1973, and three subsequent flights of six F-111s arrived on 27 July, 28 September and 4 December. F-111Cs were allocated to No. 1 Squadron and No. 6 Squadron , under

2494-413: The EF-111 electronic warfare versions were later developed for the USAF. Production of the F-111 ended in 1976, following the completion of 563 aircraft. The F-111 was an all-weather attack aircraft, capable of low-level penetration of enemy defenses to deliver ordnance on the target. The F-111 featured variable-geometry wings, an internal weapons bay and a cockpit with side-by-side seating. The cockpit

2580-534: The F-111 and began operating the F-111C in 1973. As early as March 1968, the USAF were deploying F-111s into active combat situations; the type saw heavy use during the latter half of the Vietnam War to conduct low-level ground-attack missions, flying in excess of 4,000 combat missions while incurring only six combat losses in the theatre. The F-111s also participated in the Gulf War (Operation Desert Storm) in 1991;

2666-680: The F-111 is a larger and less-maneuverable aircraft. Though the F-14A entered service with the Navy powered by the Pratt & Whitney TF30, by the end of the decade, following numerous problems with the original engine, the Department of Defense began procuring General Electric F110-GE-400 engines and installed them in the F-14A Plus (later redesignated to F-14B in 1991), which entered service with

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2752-462: The F-111 were troubled by compressor surges and stalls across certain portions of the flight regime. General Dynamics had elected to use an uncommon spike-shaped variable intake for the engine for the performance. Studies performed by NASA, the USAF, and General Dynamics led to the engine inlet being redesigned; modifications were implemented between 1965 and 1966, culminating with the "Triple Plow I" and "Triple Plow II" designs. During February 1965,

2838-599: The F-111. Early A-models used the TF30-P-1 engine. Most A-models used the TF30-P-3 engine with 12,000 lbf (53 kN) dry and 18,500 lbf (82 kN) afterburning thrust and "Triple Plow I" variable intakes, providing a maximum speed of Mach 2.3 (1,450 mph, 2,300 km/h) at altitude. The variant had a maximum takeoff weight of 92,500 lb (42,000 kg) and an empty weight of 45,200 lb (20,500 kg). The F-111A's Mark I avionics suite included

2924-414: The F-111A achieved a speed of Mach 1.3 while flying with an interim intake design. On 18 May 1965, the F-111B made its first flight; it was also equipped with ejector seats initially. Separately, cracks in the F-111's wing attach points were first discovered in 1968 during ground fatigue testing; during the following year, the crash of an F-111 was attributed to a cracked wingbox. On 22 December 1969,

3010-429: The F-111A made its first flight from Carswell Air Force Base , Texas. Lasting for 22 minutes, less than planned due to a flap malfunction, this initial flight was considered to be satisfactory overall; category I testing commenced immediately thereafter. Early flights of the F-111, which included supersonic flights, demonstrated favorably simplistic maintenance requirements, amongst other qualities. Various changes to

3096-789: The F-111C underwent a comprehensive digital avionics upgrade program (AUP) which introduced new nav/attack systems (PAVE TACK Laser/infrared targeting system) and digital flight control computers. Later, the C model was upgraded with a unique version of the TF-30 engine known as the P-108. This local version mated the P-109 engine to a P-107 afterburner, delivering 20,840 lb of thrust and significantly increased reliability. The RAAF retired its last F-111Cs in December 2010 after 37 years of service. The F-111D

3182-530: The F-111F had the TF30-P-100. RAAF F-111Cs were upgraded with the unique P-108 version, using a P-109 engine mated to a P-107 afterburner. The F-111 Engine Business Unit (later taken over by TAE) at RAAF Base Amberley became the world experts on the TF-30 in the years after the USAF retired their fleet and achieved extraordinary increases reliability of the TF-30. The TF30 proved itself to be well-suited to

3268-583: The F-111Fs completed 3.2 successful strike missions for every unsuccessful one, better than any other U.S. strike aircraft used in the operation. RAAF F-111s never saw offensive action, but were deployed periodically as a deterrent, such as for the Australian-led International Force East Timor . Being relatively expensive to maintain amid post- Cold War budget cuts, the USAF elected to retire its F-111 fleet during

3354-428: The Navy found both submissions unacceptable for its operations. Two more rounds of updates to the proposals were conducted, with Boeing being picked by the selection board. In November 1962, McNamara selected General Dynamics' proposal due to its greater commonality between USAF and Navy versions. The Boeing aircraft shared less than half of the major structural components. On 21 December 1962, General Dynamics signed

3440-647: The TF30-P-3 turbofan. The F-111 had problems with inlet compatibility, and many faulted the placement of the intakes behind the disturbed air of the wing. Newer F-111 variants incorporated improved intake designs and most variants featured more powerful versions of the TF30 engine. The F-111E was updated to use TF30-P-103 engines, the F-111D included the TF30-P-9/109, the FB-111A used the TF-30-P-7/107, and

3526-423: The TFX contract. A congressional investigation into the procurement processed was conducted, but did not change the selection. On 1 May 1964, the definitized contract was issued for the program, including flight testing, spares, ground equipment, training devices, static and fatigue test data, and the production of an initial 23 F-111 aircraft; it was structured as a fixed price incentive fee (FPIF) contract with

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3612-772: The Tomcat into an upright or inverted spin, from which recovery was very difficult. The F-14's problems did not afflict TF30 engines in the USAF and RAAF F-111s to nearly the same extent. The F-111, while technically designated as a "fighter," was actually used as a ground attack aircraft and tactical bomber. A typical ground strike mission is characterized by less abrupt changes in throttle, angle of attack and altitude than an air-to-air combat mission. While it can still involve hard and violent maneuvers to avoid enemy missiles and aircraft, these maneuvers are generally still not nearly as hard and violent as those required in air-to-air combat, and

3698-624: The Transonic Aircraft Technology and Advanced Fighter Technology Integration programs in the 1970s and 1980s. It retired to the United States Air Force Museum at Wright-Patterson Air Force Base in 1989. Unconverted F-111As were mothballed at Aerospace Maintenance and Regeneration Center at Davis-Monthan Air Force Base in June 1991. The F-111B was to be a fleet air defense (FAD) fighter for

3784-701: The U.S. Rockwell B-1 Lancer bomber (1974); and the European Panavia Tornado (1974). The Sukhoi Su-24 was very similar to the F-111. The U.S. Navy's role intended for the F-111B was instead filled by another variable-geometry design, the Grumman F-14 Tomcat . The first of six initial production F-111s was delivered on 17 July 1967 to fighter squadrons at Nellis Air Force Base . These aircraft were used for crew training. 428th Tactical Fighter Squadron achieved initial operational capability on 28 April 1968. After early testing,

3870-432: The U.S. Navy, fulfilling a requirement for a carrier-based fighter aircraft armed with heavy, long-range missiles to defend aircraft carriers and their battle groups from Soviet bombers and fighter-bombers equipped with anti-ship missiles. General Dynamics, lacking experience with carrier-based aircraft, partnered with Grumman for this version. Seven F-111Bs were completed for testing but it never entered fleet service. It had

3956-548: The US Navy was to carry two AIM-54 Phoenix long-range air-to-air missiles in the bay. The cannon had a large 2,084-round ammunition tank, and its muzzle was covered by a fairing; however, it was rarely fitted on F-111s. The F-111C and F-111F were equipped to carry the AN/AVQ-26 Pave Tack targeting system on a rotating carriage that kept the pod protected within the weapons bay when not in use. Pave Tack featured

4042-505: The USAF opted to ground the fleet due to this issue, save for those involved in flight testing. The resolution involved the redesigning of the attach structure and necessitated testing to ensure adequate design and workmanship. On 31 July 1970, the grounding was lifted. Category I flight testing of the F-111A, which had started in 1964, continued through to 31 March 1972. Category II tests started in January 1966, while Category III testing

4128-400: The aft fuselage and the landing gear of the F-111A. The General Dynamics and Grumman team faced ambitious requirements for range, weapons load, and aircraft weight. Thus, the F-111 was designed to incorporate numerous features that were new to production military aircraft, such as variable-geometry wings and afterburning turbofan engines. This use of unfamiliar features has been attributed as

4214-496: The aircraft's "Pig" nickname during its Australian service. Developed in the 1960s by General Dynamics under Robert McNamara 's TFX Program , the F-111 pioneered variable-sweep wings , afterburning turbofan engines, and automated terrain-following radar for low-level , high-speed flight. Its design influenced later variable-sweep wing aircraft, and some of its advanced features have become commonplace. The F-111 suffered problems during initial development, largely related to

4300-408: The aircraft's centerline was reported by NASA in 1958, which made swing-wings viable. This led USAF leaders to encourage its use. In June 1960, the USAF issued specification SOR 183 for a long-range interdiction/strike aircraft able to penetrate Soviet air defenses at very low altitudes and high speeds. Specifically, it was to be capable of at least 800 miles of low-level flight, 400 of which

4386-477: The airliner, but Douglas preferred to go with a turbofan engine, which would have a greater fuel efficiency than a turbojet. P&W then proposed the JT10A, a half-scale version of its newly developed JT8D turbofan. Development of the new design began in April 1959, using the core of the JT8. Douglas shelved the model 2067 design in 1960, as the targeted US airlines preferred the newly offered Boeing 727 . In 1960,

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4472-526: The best option was to base the design on the USAF requirement, and use a modified version for the Navy. In June 1961, Secretary McNamara ordered the go ahead of Tactical Fighter Experimental (TFX), despite USAF and Navy efforts to keep their programs separate. According to aviation author Peter E. Davis, military officials were disconcerted by McNamara's focus on compromised requirements for financial reasons. The two services could agree only on swing-wing, two-seat, twin-engine design features. The USAF wanted

4558-723: The braking force with the reverser design used on the JT8D engine installation on the McDonnell Douglas DC-9 airliner was 40/45% of take-off thrust. The flight envelope for the fighter-version demanded both more thrust and better stall margins at high altitudes. This led to redesigns for the fan, the low-pressure compressor and the combustion-chambers with four injectors in each for more complete fuel mixing. Data from Flight International . Related development Related lists Pratt %26 Whitney TF30 The Pratt & Whitney TF30 (company designation JTF10A )

4644-535: The control of No. 82 Wing . In Australia, the F-111 was affectionately known as the "Pig". The purchase proved to be highly successful for the RAAF. Although it never saw combat, the F-111C was the fastest, longest range combat aircraft in Southeast Asia, providing Australia with independent strike capability. Benny Murdani told Kim Beazley that when others became upset with Australia during Indonesian cabinet meetings , Murdani told them "Do you realise

4730-423: The engines. The F-111's maximum practical weapons load was limited, since the fixed pylons could not be used with the wings fully swept. Tactical F-111s were fitted with shoulder rails on the four inner swiveling pylons to mount AIM-9 Sidewinder air-to-air missiles for self-defense. Australian F-111Cs were equipped to launch the Harpoon anti-ship missile, and the Popeye stand-off missile. FB-111As could carry

4816-473: The engines. A fighter variant intended for the United States Navy , the F-111B , was canceled before production; it was intended for aircraft carrier-based roles, including long-range interception . Several specialized models, such as the FB-111A strategic bomber and the EF-111A electronic warfare aircraft, were also developed. The F-111 entered service in 1967 with the United States Air Force (USAF). The Royal Australian Air Force (RAAF) also ordered

4902-422: The fighter world", according to F-111 pilot Richard Crandall) to fly as low as 200 feet (61 m) above ground level at 480 knots (890 km/h) or faster in most weather conditions made it very effective; missions did not require tankers or ECM support, and they could operate in weather that grounded most other aircraft. One F-111 could carry the bomb load of four McDonnell Douglas F-4 Phantom IIs. The worth of

4988-527: The fleet in 1988. These engines solved the reliability problems and provided nearly 30% more thrust, achieving a 1:1 dry thrust to weight ratio with a low fuel load. The subsequent F-14D, a combination of both remanufactured/upgraded F-14As and new manufacture F-14Ds, also used F110-GE-400 engines. Source: Source: Data from The Engines of Pratt & Whitney: A Technical History. Comparable engines Related lists General Dynamics F-111 Aardvark The General Dynamics F-111 Aardvark

5074-403: The high maintenance time required for every flight hour, the F-111's retirement began with the F-111G models operated by No. 6 Squadron in late 2007. Twenty-four Boeing F/A-18E/F Super Hornets were procured as an interim replacement as the Lockheed Martin F-35 Lightning II program was delayed. The last F-111s were retired on 3 December 2010. The F-111A was the initial production version of

5160-405: The improved A-7B and A-7C. In 1965, the USAF selected the A-7D as a replacement for its fast-jet F-100 and F-105 supersonic fighter-bombers in the close air support role. Though the USAF had wanted the TF30, Pratt & Whitney was unable to meet the production timetable, because its facilities were already committed to producing other engines. Instead of producing the TF30 under license for P&W,

5246-418: The loss of a third F-111A (66-0024) on 22 April halted F-111A combat operations. The squadron returned to the United States in November. The cause of the first two losses is unknown as the wreckages were never recovered. It turned out that the third loss was traced to a failure of a hydraulic control-valve rod for the horizontal stabilizer which caused the aircraft to pitch up uncontrollably. Further inspection of

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5332-411: The maintenance budget" —the F-111 was in service with the USAF from 1967 through 1998. The FB-111s were operated by Strategic Air Command from 1969 before conversion to F-111G and transferred to Air Combat Command (ACC) until their retirement in 1993. At a ceremony marking the F-111's USAF retirement, on 27 July 1996, it was officially named Aardvark, its long-standing unofficial name. The USAF retired

5418-399: The new aircraft was beginning to show; F-111s flew more than 4,000 combat missions in Vietnam with only six combat losses. From 30 July 1973, F-111As of the 347th Tactical Fighter Wing (347th TFW) were stationed at Takhli Air Base. The 347th TFW conducted bombing missions in Cambodia in support of Khmer Republic forces until 15 August 1973 when US combat support ceased in accordance with

5504-404: The nose of the aardvark . The origin of the name has been attributed to F-111A Instructor Pilot Al Mateczun in 1969, as the aircraft had not received an official USAF name. During September 1972, the F-111 returned to Southeast Asia, stationed at Takhli Air Base , Thailand. F-111As from Nellis AFB participated in the final month of Operation Linebacker and later flew 154 low-level missions in

5590-405: The penetrating bunker-buster GBU-28 . Eighteen F-111Es were also deployed during the operation. The US Air Force credited F-111s with destroying more than 1,500 Iraqi tanks and armored vehicles. Their use in the anti-armor role was dubbed " tank plinking ". Expensive to operate—Crandall said that the aircraft "was nine percent of Tactical Air Command's fleet but ate up a whopping 25 percent of

5676-454: The program were enacted throughout 1965; this was chiefly in response to a steep climb in unit costs from $ 4.5 million to $ 6 million. The cause of the cost rises has been attributed, at least partially, to a directive issued to General Dynamics to incorporate improved avionics as well as to work on strategic bomber and aerial reconnaissance variants of the aircraft, the latter of which was eventually cancelled. During April 1965, General Dynamics

5762-476: The proposals lacking, but Boeing and General Dynamics were selected to submit enhanced designs. Boeing's proposal was recommended by the selection board in January 1962, with the exception of the engine, which was not considered acceptable. Switching to a crew escape capsule, instead of ejection seats and alterations to radar and missile storage were also needed. Both companies provided updated proposals in April 1962. USAF reviewers favored Boeing's offering, while

5848-400: The pylons. Auxiliary fuel drop tanks with 600 US gallons (2,300 litres) capacity each could be fitted. The design of the F-111's fuselage prevented the carriage of external weapons under the fuselage, but two stations were available on the underside for electronic countermeasures (ECM) pods and/or datalink pods; one station was on the weapons bay, and the other on the rear fuselage between

5934-423: The remaining fleet of F-111As revealed 42 aircraft with the same potential failures. It is speculated that this failure could also have contributed to the two earlier losses had the failure caused a pitch down while at low altitude. It was not until 1971 that 474 TFW was fully operational. The word "aardvark" is Afrikaans for "earthpig" and reflects the look of the long nose of the aircraft that might remind one of

6020-404: The requirements of a high-speed low-altitude strike aircraft with a relatively long operational range, and F-111s in all guises would continue to use TF30s until their retirement. In 1964, the subsonic LTV A-7A Corsair II won the US Navy's VAL competition for a light attack aircraft to replace the Douglas A-4 Skyhawk . The A-7A used a non-afterburning variant of the TF30, which would also power

6106-583: The same conventional ordnance as the tactical variants, but their wing pylons were more commonly used for either fuel tanks or strategic nuclear gravity bombs. They could carry up to four AGM-69 SRAM nuclear missiles on the pylons. The F-111 was the first production variable-geometry wing aircraft. Several other types have followed with similar swing-wing configuration, including the Soviet Sukhoi Su-17 "Fitter" (1965), Mikoyan-Gurevich MiG-23 "Flogger" (1967), Tupolev Tu-22M "Backfire" (1969), Sukhoi Su-24 "Fencer" (1970) and Tupolev Tu-160 "Blackjack" (1981);

6192-513: The same goals for the F-15 Eagle and F-16 Fighting Falcon ). However, due to reliability issues with the intended Pratt & Whitney F401 engines and the intent to incorporate as many of the systems of the failed Navy version of the F-111, the F-111B , into the project, it was deemed that the initial production run of F-14s utilize the F-111B's powerplant. The F-14A's thrust-to-weight ratio

6278-452: The speed of sound. The Viggen was designed with a maximum speed at sea level of Mach 1.2. As an example of a required material change the diffuser case, where the compressed air is slowed for entry to the flame tubes, was changed from steel to nickel alloy to withstand the higher temperatures leaving the compressor. Air cooling for the HP turbine blades was introduced as the turbine entry temperature

6364-455: Was 110 degC higher than on the civil engine. Hamilton Standard had supplied the fuel control for the JT8D but Bendix was chosen for the engine and afterburner fuel control systems due to their experience developing the fuel controls for another augmented turbofan engine, the Pratt & Whitney TF30 . RM8 thrust boosting of 76% at take-off was much higher than possible with a turbojet. In comparison

6450-419: Was NASA's simplification which made the variable geometry wings practical. By 1960, increases in aircraft weights required improved high-lift devices , such as variable geometry wings. Variable geometry offered high speeds, and maneuverability with heavier payloads , long range, and the ability to take off and land in shorter distances. The USAF and Navy were both seeking new aircraft when Robert McNamara

6536-515: Was also included in the specification. In the 1950s, the United States Navy sought a long-range, high-endurance interceptor aircraft to protect its carrier battle groups against long-range anti-ship missiles launched from Soviet jet bombers and submarines. The Navy needed a fleet air defense (FAD) fighter with a more powerful radar, and longer range missiles than the F-4 Phantom II to intercept both enemy bombers and missiles. Seeking

6622-403: Was an all-moving stabilator . The F-111 used a three-point landing gear arrangement, with a two-wheel nose gear and two single-wheel main landing gear units. The landing gear door for the main gear, which was positioned in the center of the fuselage, also served as a speed brake in flight. Most F-111 variants included a terrain-following radar system connected to the autopilot. The aircraft

6708-404: Was an upgraded F-111A equipped with newer Mark II avionics, more powerful engines, improved intake geometry, and an early glass cockpit . It was first ordered in 1967 and delivered from 1970–73 after delays due to avionics issues. The F-111D reached initial operational capability in 1972; the sole operator was the 27th TFW stationed at Cannon AFB , New Mexico. 96 were built. The F-111D used

6794-433: Was appointed secretary of defense in January 1961. The aircraft sought by the two armed services shared the need to carry heavy armament and fuel loads, feature high supersonic speed, twin engines and two seats, and probably use variable geometry wings. On 14 February 1961, McNamara formally directed the services to study the development of a single aircraft that would satisfy both requirements. Early studies indicated that

6880-582: Was authorized to produce 431 F-111s, less than half the number of aircraft which had originally been forecast. On 10 May 1967, a new multi-year FPIP contract replaced the prior procurement process, increasing the total aircraft on order to 493 F-111s of multiple models, including 23 F-111Bs intended for the US Navy, 24 F-111Cs for the Royal Australian Air Force , and 50 F-111Ks intended for the Royal Air Force . Early flights of

6966-473: Was lost over Libya and crashed into the Mediterranean Sea, probably shot down. F-111s participated in the Gulf War (Operation Desert Storm) in 1991. During Desert Storm, F-111Fs completed 3.2 successful strike missions for every unsuccessful one, better than any other U.S. strike aircraft used in the operation. The group of 66 F-111Fs dropped almost 80% of the war's laser-guided bombs, including

7052-474: Was part of an escape crew capsule . The wing sweep varied between 16 degrees and 72.5 degrees (full forward to full sweep). The wing included leading edge slats and double slotted flaps over its full length. The airframe was made up mostly of aluminum alloys with steel, titanium and other materials used in places. The fuselage was made of a semi- monocoque structure with stiffened panels and honeycomb structure panels for skin. The horizontal stabilizer

7138-498: Was powered by two Pratt & Whitney TF30 afterburning turbofan engines. The F-111's variable-geometry wings, escape capsule, terrain following radar and afterburning turbofans were new technologies for production aircraft. The F-111 featured an internal weapons bay that could carry bombs, a removable 20 mm M61 cannon or auxiliary fuel tanks. For bombs, the bay could hold two 750 lb (340 kg) M117 conventional bombs, one nuclear bomb or practice bombs. The F-111B for

7224-403: Was repeatedly postponed before being cancelled, having been deemed to be unnecessary. During 1968, the F-111B was canceled by the Navy on account of weight and performance issues together with revised tactical requirements. Australia would procure its own model, the F-111C. Subsequently, the improved F-111E, F-111D, and F-111F models were developed for the USAF. The strategic bomber FB-111A and

7310-500: Was similar to the F-4 Phantom II ; however, the new fuselage and wing design provided greater lift and a better climb profile than the F-4. The TF30 was found to be ill-adapted to the demands of air combat and was prone to compressor stalls at high angle of attack (AOA), if the pilot moved the throttles aggressively. Because of the Tomcat's widely spaced engine nacelles, compressor stalls at high AOA were especially dangerous because they tended to produce asymmetric thrust that could send

7396-400: Was to be at a speed of no less than Mach 1.2. Furthermore, the specification also called for the aircraft to possess short takeoff and landing (STOL) capabilities to permit operations from short, unprepared airstrips that had a length of no more than 3,000 feet. An internal payload of 1,000lb was to be carried in the primary mission role. A variant suitable for aerial reconnaissance flights

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