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F-111 "Aardvark"
An F-111C of the Royal Australian Air Force with its wings unswept in 2006
Role Fighter-bomber
National origin United States
Manufacturer General Dynamics
First flight 21 December 1964
Introduced 18 July 1967
Retired USAF: 1998
Status Active with RAAF
Primary users United States Air Force
Royal Australian Air Force
Number built 563[1]
Unit cost US$9.8 million (FB-111A)[2]
Variants General Dynamics/Grumman F-111B
EF-111A Raven

The General Dynamics F-111 "Aardvark" is a medium-range interdictor and tactical strike aircraft that also fills the roles of strategic bomber, reconnaissance, and electronic warfare in its various versions. Developed in the 1960s and first entering service in 1967, the United States Air Force (USAF) variants were officially retired by 1998. The Royal Australian Air Force (RAAF) is the sole remaining operator of the F-111.[3]

The F-111 pioneered several technologies for production military aircraft including variable-sweep wings, afterburning turbofan engines, and automated terrain following radar for low-level, high-speed flight. Its design was influential, being reflected in later Soviet aircraft such as the Sukhoi Su-24,[4] and some of its advanced features have since become commonplace. During its inception, however, the F-111 suffered a variety of development problems, and several of its intended roles, such as naval interception through the F-111B, failed to materialize.

In USAF service the F-111 has been effectively replaced 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. In 2007, the RAAF decided to replace its 21 F-111s in 2010 with 24 F/A-18F Super Hornets.[5][6]

Contents

Development

The beginnings of the F-111 were in the TFX program, an ambitious early 1960s project to combine the United States Air Force requirement for an improved fighter-bomber with the United States Navy's need for a long-range carrier-based Fleet Air Defense fighter. The fighter design philosophy of the day concentrated on very high speed, raw power, and air-to-air missiles.

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TAC's fighter-bomber

Through the history of air combat until the 1950s, the solution to avoiding air defenses of any sort was always the same; fly higher and faster. Increasing speed reduced the time the defender had to deal with the aircraft while it was still within the range of their defensive weapons, and flying higher meant it took longer to guide an interceptor into range, while dramatically increasing the size and expense of anti-aircraft guns. These underlying assumptions produced series of ever-faster and higher-flying strategic bombers, and with the introduction of small tactical nuclear weapons, interdictors and fighter-bombers as well. In the late 1950s, this evolution was well represented in all the latest US types being worked on; the B-70 Valkyrie long-range strategic bomber, its B-58 Hustler shorter-range counterpart, and the F-105 Thunderchief fighter-bomber.

By the late 1950s US intelligence was aware that the Soviets were focusing their anti-aircraft efforts on missiles of ever-increasing capability. In August 1956, Richard Bissell suggested that the U-2 would have only six months before the Soviets would be able to shoot it down,[7]although it was not until the 1960 U-2 incident that the point was demonstrated. Instead of high-and-fast, the ability to penetrate enemy defences now centred on avoiding detection, which was most easily arranged by flying lower, below the horizon of the radar systems.[8] Flying at low altitudes requires considerably more fuel - an aircraft tuned for high-and-fast missions generally produced one that was bad at low-and-far. The B-58, already in the process of being deployed, could only reach subsonic speeds when flown at low altitudes, and had seriously degraded range performance. The B-70's range was so greatly reduced that its mission capability became questionable, while the older B-52's huge fuel capacity allowed it to operate at low altitudes for extended periods. The B-70 was cancelled in favour of a new low-level design which emerged decades later as the B-1 Lancer, with the B-52 soldiering on as the basis for Strategic Air Command (SAC) throughout.

The Air Force's Tactical Air Command (TAC) was largely concerned with the fighter-bomber and deep strike/interdiction roles. Like SAC, TAC was in the process of receiving its latest high-and-fast design, the Thunderchief, which also had limited performance in the lo-lo-lo mission needed to penetrate Soviet defences. In June 1960 the USAF issued a specification for a long-range interdiction/strike aircraft able to penetrate Soviet air defenses at very low altitudes and high speeds to deliver tactical nuclear weapons against crucial targets.[9]

Navy's Missileer

Throughout the 1950s the US Navy was struggling with a problem of its own, how to protect its capital ships from air attack. Through the 1950s the Navy increasingly focused on the concept of the Fleet Air Defense (FAD) fighter, a long-range interceptor using missiles as its only weapon. In contrast to earlier fighter designs where performance, maneuverability and an unobstructed view were the most important design criterion, in the missile-dominated world these capabilities were needed by the missile, not the fighter. It made no difference if the aircraft flew at Mach 1 or Mach 2 - as long as the missile flew at Mach 3. In this sort of "push button warfare" scenario, the aircraft that shot first that would win the engagements, and that aircraft would be the one that had the best radar.

The F-4 Phantom II embodied some of these capabilities, but had too little endurance. In order to keep the requisite number of missiles in the air to defend against a strike package, enormous fleets of F-4s would be needed so some would be flying while others refuelled. Ideally the FAD would be an aircraft with considerably greater loiter times at distances further from the ships, but this would require a larger aircraft designed for loitering at low speed with more efficient engines. In 1957 the Navy started to design the F6D Missileer for this role. However, the Missileer concept soon ran into difficulties; although it was a dangerous opponent when armed, after firing its missiles it was completely defenceless, and subject to easy interception by fighters. This was not considered important as long as the system as a whole, with layered defences, was working, but this depended on every other aircraft in the fleet also being operational and working as expected. If, for instance, the early warning aircraft did not pan out, the Missileer would be at a serious disadvantage. The program was cancelled in December 1960.[10]

The Navy still felt it needed a design tuned primarily for long-range missile fire, but started looking for an aircraft with the performance to carry out this mission safely on its own. Studies for a higher performance design had already started by this point. A key problem was to provide the low landing speed needed to operate from carriers, while also having high speeds. This was easy enough to provide with modified delta wings on smaller aircraft, but by 1960 increases in aircraft weights required improved high-lift devices such as variable geometry wings.[11][12] The Navy experimented with on the XF10F Jaguar but abandoned that in the early 1950s, but a simpler geometry with the pivot points out from the aircraft fuselage was documented by NASA in 1958.[13]

Tactical Fighter Experimental (TFX)

Both the Air Force and Navy approached the government requesting new aircraft at about the same time. At first glance it would seem that the two designs could not be more different; the Navy was looking for a high performance fighter/interceptor with a large radar that would be shooting missiles from medium to high altitudes, while the Air Force was looking for a long-range aircraft delivering bombs at very low altitudes. But in other ways the two designs were similar; both were large long-range designs that needed to carry a large warload at high speeds. In the case of the Navy, low landing speeds were also required, and while this would not be a strict requirement for the Air Force, such a capability would also allow the design to operate from a wider variety of bases, giving them operational flexibility. A swing-wing platform might be able to fill both requirements.

On 14 February 1961 the new U.S. Secretary of Defense, Robert McNamara, formally directed that the services study the development of a single aircraft that would satisfy both requirements. Early studies indicated the best option was to base the design on the Air Force requirement, and use a modified version for the Navy.[14] In June 1961, Secretary McNamara ordered the go ahead on TFX despite Air Force and the Navy efforts to keep their programs separate.[15] The USAF and the Navy could only agree on swing-wing, two seat, twin engine design features. The USAF wanted a tandem seat aircraft for low level penetration, while the Navy wanted a shorter, high altitude interceptor with side by side seating to allow the pilot and RIO to share the radar display between them.[14] 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 a length of approx. 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 a length of 56 ft (17.1 m).[14][16] So McNamara developed a basic set of requirements for TFX based largely on the Air Force's requirements. On 1 September 1961 he ordered the Air Force to develop it.[14][16]

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 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. However, the Boeing's engine was not considered acceptable. Switching to a crew escape capsule, instead of ejection seats and alterations to radar and missile storage were also needed. The companies provided updated proposals in April 1962. Air Force reviewers favored Boeing's offering, but 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.

However, in November 1962 McNamara selected General Dynamics' proposal in due to its greater commonality between Air Force and Navy versions. The Boeing aircraft shared less than half of the major structural components. General Dynamics signed the TFX contract in December 1962. A Congressional investigation followed, but could not change the selection.[17]

Design phase

The F-111A and B variants used the same airframe structural components and TF30-P-1 turbofan engines. They featured side by side crew seating in escape capsule as required by the Navy. The F-111B's nose was 8.5 feet (2.59 m) shorter due to its need to fit on existing carrier elevator decks, and had 3.5 feet (1.07 m) longer wingtips to improve on-station endurance time. The Navy version would carry a AN/AWG-9 Pulse-Doppler radar and six AIM-54 Phoenix missiles. The Air Force version would carry the AN/APQ-113 attack radar and the AN/APQ-110 terrain-following radar and air-to-ground armament. Titanium was planned for most of the airframe. However, this proved to be too expensive and more conventional metals were used instead.[18]

Lacking experience with carrier-based fighters, General Dynamics teamed with Grumman for assembly and test of the F-111B aircraft. In addition, Grumman would also build the F-111A's aft fuselage and the landing gear. The F-111A mock-up was inspected in September 1963. The first test F-111A was rolled out of the General Dynamics' Fort Worth, Texas plant on 15 October 1964. It was powered by YTF30-P-1 turbofans and used a set of ejector seats as the escape capsule was not yet available.[18] The F-111A first flew on 21 December 1964 from Carswell AFB, Texas.[19] The first F-111B was also equipped with ejector seats and first flew on 18 May 1965.[20]

F-111 development continued. To address stall issues in certain parts of the flight regime, the engine inlet design was modified in 1965-66, ending with the "Triple Plow I" and "Triple Plow II" designs.[21] The F-111A achieved a speed of Mach 1.3 in February 1965 with an interim intake design.[18][21] Flight testing of the F-111A ran through 1973.[22] The F-111B was canceled by the Navy in 1968 due to weight and performance issues.[23] The F-111C model was developed for Australia. Subsequently, the improved F-111E, F-111D, F-111F models were developed for the US Air Force. The strategic bomber FB-111A and the EF-111 electronic warfare versions were later developed for the USAF.[24] Production ended in 1976[25] with a total of 563 F-111 variants built.[1]

Design

Four-photo series showing the F-111A wing sweep sequence.

The F-111 is an all-weather attack aircraft capable of low-level penetration of enemy defenses to deliver ordnance on the target.[26] The F-111 features variable geometry wings, an internal weapons bay and a cockpit with side by side seating. The cockpit is part of an escape crew capsule.[27] The wing sweep varies between 16 degrees and 72.5 degrees (full forward to full sweep).[28] The airframe is made up mostly of aluminum alloys with steel, titanium and other materials used in places.[29] The fuselage is a semi-monocoque structure with stiffened panels and honeycomb sandwich panels for skin.[28][29] Most F-111 variants included a terrain-following radar system connected to the autopilot. The aircraft is 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.[30]

Armament

F-111 cockpit prior to a night flight.

Although conceived as a multi-role fighter, the F-111 became a long-range attack aircraft primarily armed with air-to-surface ordnance.

Weapons bay

The F-111 has an internal weapons bay under the fuselage for various weapons.

  • Cannon: All tactical combat versions (that is, not the EF-111A or FB-111A/F-111G) could carry a single M61 Vulcan 20 mm cannon with a very large (2,084 round) ammunition tank, covered by an eyelid shutter when not in use. Although carried by some USAF aircraft, the cannon was never actually used in combat, and was removed by the early 1980s; provision for the cannon has also been deleted from Australian F-111Cs.
  • Bombs: The bay can alternately hold two conventional bombs, usually the Mk 117 type of nominal 750 lb/340 kg weight, although weapons up to the Mk 118 (3,000 lb/1,400 kg) were cleared.
  • Nuclear weapons: All F-111 models except the EF-111A and the Australian F-111C were equipped to carry various free-fall nuclear weapons: tactical models generally carried the B43, B57, or B61. The FB-111A was a dedicated nuclear bomber for most of its life, and carried all of those weapons just mentioned, as well as the B83 and the AGM-69 Short Range Attack Missile. The FB-111A could carry one or two AGM-69 SRAM nuclear missiles in its weapons bay and up to four SRAMs on external wing pylons.
  • Sensor pod: 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 is a FLIR and laser rangefinder/designator that allows the F-111 to designate and drop laser-guided bombs.
  • Reconnaissance pallet: Australian RF-111Cs carry a package of reconnaissance sensors and cameras for tactical recce missions. It contains two video cameras, a Honeywell AN/AAD-5 infrared linescan (recorded on video or film), a Fairchild KA-56E low-altitude and KA-93A4 high-altitude panoramic cameras, and a pair of CAI KS-87C split vertical cameras. It can also record photographs of the attack radar's display.
  • Missiles: The F-111B was intended to be capable of carrying two AIM-54 Phoenix air-to-air missiles in the bay. General Dynamics trialed an arrangement with two AIM-9 Sidewinders carried on rails in a trapeze arrangement from the bay. This was not adopted, with the four inner wing pylons equipped for the missile instead. The AIM-7 Sparrow medium range missile was never fitted, though later F-111 models had radars equipped to guide the Sparrow.[31]
  • Other equipment: Auxiliary fuel tanks and baggage pods were sometimes carried.
F-111F aircraft releasing its load of Mark 82 high-drag bombs over the Bardenas Reales range.
External ordnance

The design of the F-111's fuselage prevents the carriage of external weapons under the fuselage (although there are two small stations, one on the weapon bay, the other on the rear fuselage between the engines, for ECM pods and/or datalink pods for guided weapons). All aircraft, except the FB-111A have provision for eight underwing pylons, four under each wing, with a capacity of 6,000 lb (2,700 kg) each. The inner pylons (3, 4, 5 and 6) pivot with the wing, but only one on each side can be loaded at maximum sweep. The outer pylons (1, 2, 7 and 8) are fixed, and can be loaded only if the wings are spread at less than 26°, causing drag at takeoff angle. The outermost pylons (1 and 8) have never been used operationally, and the second pair of fixed pylons (2 and 7) are fitted only rarely, for the carriage of fuel tanks. FB-111/F-111G models have provision to jettison their empty pylons in flight, reducing drag.

The limited number of fully swiveling pylons restricts the F-111's maximum practical weapons load, since the aircraft cannot use all pylons with the wings fully swept. By contrast, aircraft such as the F-14 and Tornado can carry their maximum bomb loads with fully swept wings.

An F-111 carrying BLU-107 Durandals.

The primary external armament of USAF tactical F-111s included:

Although all F-111s can carry laser-guided munitions, only those with Pave Tack (i.e., F-111F and Australian F-111C) are capable of self-designation. Others can drop laser-guided weapons only with the aid of another ground or air designator.

From the early 1980s onward, tactical F-111s were fitted with shoulder rails on the sides of the outboard swiveling pylon (designated stations 3A and 6A) for two AIM-9 Sidewinder air-to-air missiles for self-defense. The standard Sidewinder fit was the AIM-9P, rather than the more modern AIM-9L or AIM-9M, whose larger fins were not compatible with the shoulder rail. The RAAF has considered replacing the Sidewinder with ASRAAM.

FB-111As could carry the same conventional ordnance as their tactical brothers, but their wing pylons were more commonly used for either fuel tanks or strategic nuclear gravity bombs. Until the weapon was withdrawn in 1990, they could carry up to four AGM-69 SRAM nuclear missiles on the wing pylons, although two was the more normal fit.

Australian F-111Cs have been equipped to launch the AGM-84 Harpoon anti-ship missile, AGM-88 HARM anti-radiation missile, and the AGM-142 Popeye stand-off missile.

Similar swing wing aircraft

The F-111 was the first production variable-geometry aircraft. The earlier subsonic Navy XF10F Jaguar had been canceled in 1953. It inspired a number of aircraft throughout the 1960s, and even fictional aircraft on the Thunderbirds, but swing wings are extinct in newer designs due to higher cost, and the extra weight imposed by the swing wing mechanism. Nevertheless, several other types have followed, including the Soviet Sukhoi Su-17 "Fitter" (1966), Mikoyan-Gurevich MiG-23 "Flogger" (1967), Tupolev Tu-22M "Backfire" (1969) and Tupolev Tu-160 "Blackjack" (1981), the U.S. F-14 Tomcat naval fighter (1970) and B-1 Lancer bomber (1974), and the European Panavia Tornado (1974). The Sukhoi Su-24 "Fencer" (1970), which resembles the F-111, also has side-by-side seating.

Operational history

United States

Combat Lancer F-111As over South-East Asia in 1968

The first production F-111s were delivered on 18 July 1967 to the 428th, 429th and 430th Tactical Fighter Squadrons of the 474th Tactical Fighter Wing based at first out of Cannon AFB, New Mexico, which relocated in 1968 to Nellis AFB.

After early testing a detachment of six aircraft were sent in March 1968 to Southeast Asia for Combat Lancer testing in real combat conditions in Vietnam. In little over a month, three aircraft were lost and the combat tests were halted. It turned out that all three had been lost through malfunction in the horizontal stabilizer, not by enemy action.[32] This caused a storm of political recrimination, with U.S. senators denouncing Secretary of Defense McNamara's judgment in procuring the aircraft. It was not until July 1971 that the 474 TFW was fully operational.

September 1972 saw the F-111 back in Southeast Asia, participating in the final month of Operation Linebacker and later the Operation Linebacker II aerial offensive against the North. F-111 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 F-4 Phantom IIs. The worth of the new aircraft was beginning to show, and over 4,000 combat F-111A missions were flown over Vietnam with only six combat losses.[33]

In 1977, under Operation Creek Swing/Ready Switch the remaining F-111As were transferred from Nellis AFB, Nevada to the 366 TFW based at Mountain Home AFB, equipping the 389th, 390th, and 391st TFS. As the Ready Switch component of that operation, F-111Fs and their crews flew their aircraft to RAF Lakenheath, England to replace the F-4s and their crews of the 492d, 493d, and 494th Tactical Fighter Squadrons. As part of that operation, the F-4s from Lakenheath may have moved to Nellis AFB, Nevada.

On 14 April 1986, 18 F-111s and approximately 25 Navy aircraft executed Operation El Dorado Canyon by conducting air strikes against Libya. The 18 F-111s belonging to the 48th Tactical Fighter Wing flew what turned out to be the longest fighter combat mission in history.[34] The round-trip flight between RAF Lakenheath, United Kingdom and Libya of 6,400 miles (10,300 km) spanned 13 hours. One F-111 was shot down over Libya.[34]

In Desert Storm, F-111Fs completed 3.2 successful strike missions for every unsuccessful one, making it 47% more capable than the next leading strike aircraft.[35] The small 66-plane F-111F force was credited with 1,500 kills of Iraqi tanks and other mechanized vehicles. The F-111F was the only Desert Storm aircraft to deliver the GBU-15 and the 5,000-pound laser-guided, penetrating GBU-28.

The F-111 was in service with the USAF from 1967 through 1998. The Strategic Air Command had FB-111s in service from 1969 through 1990. At a ceremony marking the F-111's USAF retirement, on 27 July 1996, it was officially named Aardvark, its long-standing unofficial nickname. Aardvark literally means "earth pig" in Dutch/Afrikaans, consequently, in Australia, the F-111 is often known by the affectionate nickname "Pig". The USAF retired the EF-111 variant in 1998 at Cannon Air Force Base in eastern New Mexico.

Australia

Four Australian F-111s in 2006

The Australian government ordered 24 F-111C aircraft in 1963 to replace the Royal Australian Air Force's English Electric Canberras in the bombing and tactical strike role. While the first aircraft was officially handed over in 1968, structural integrity problems found in the U.S. Air Force F-111s delayed the entry into service of the F-111C until 1973. USAF F-4 Phantom IIs were leased as an interim measure. Four F-111Cs were modified to the RF-111C reconnaissance configuration, but retained their air strike capability.

Since their introduction Australia's F-111s have been operated by the No. 1 Squadron RAAF in the strike role, with the No. 6 Squadron RAAF operating the aircraft as an operational conversion unit. A temporary flight designated the Washington Flying Unit ferried to Australia the first 12 F-111Cs from the United States in 1973, and F-111s had been lent to the RAAF's Aircraft Research and Development Unit.

RAAF F-111 performing a dump-and-burn fuel dump, a procedure where the fuel is intentionally ignited using the aircraft's afterburner.

The Royal Australian Air Force's F-111 fleet has at times been controversial. Controversies surrounding the F-111 include:

  • The long delay to the delivery of the aircraft was a significant political issue in the late 1960s and early 1970s. This occurred around the same time that massive delays and cost blowouts to the Sydney Opera House were making headlines, prompting some commentators to dub the F-111 the "Flying Opera House".[36]
  • Their use by the Hawke federal government to take surveillance photos of the Franklin Dam project in Tasmania. The use of an RAAF aircraft to "spy" on its own territory led to the minister responsible, Senator Gareth Evans earning the nickname "Biggles" (after the famous pilot-hero of a number of books by Captain W.E. Johns).[37][38]
  • Poor work conditions for F-111 ground crew involved in sealing/de-sealing F-111 fuel tanks resulted in serious health problems, including cancer, to a number of ground crew before conditions were improved.[39][40]

A number of ex-USAF aircraft have been delivered to Australia, as attrition replacements and to enlarge the fleet. Four aircraft modified to the F-111C standard were delivered in 1982, while 18 F-111Gs were purchased in 1992 and delivered in 1994. Additional stored former USAF F-111s are reserved as a spare parts sources.

In Australian military and aviation circles, the F-111 Aardvark is affectionately known as the "Pig", due to its Terrain Following ability,[citation needed] unique at the time of its introduction, that gives it the ability to "hunt amongst the weeds". Another, less generous explanation of the source of the nickname refers to the colloquialism "Pigs Might Fly".[citation needed] A third origin can be posited from the word aardvark, which translates into English as "Earth Pig".

While the F-111 has not seen combat in Australian service, it is known that F-111 aircraft were placed on high alert during the initial phase of the Australian-lead intervention (INTERFET) into East Timor in 1999. During the first Gulf War in 1991, the United States Government asked Australia to deploy RF-111 aircraft to the Persian Gulf. This request was denied as the Australian government judged that these aircraft were too important to Australia's security to risk in a distant war. In mid 2006, an RAAF F-111 was chosen to scuttle the North Korean ship the Pong Su which had been involved in one of Australia's largest drug hauls in recorded history. The ship had been sitting in "Snails Bay", off Birchgrove, while the government decided its fate, and it was decided in March 2006 it would be scuttled by air attack. She was sunk on 23 March 2006 by two GBU-10 Paveway II laser guided bombs.[41]

In 2007, Australia decided to retire all of its RAAF F-111s by 2010, and the government signed a contract to acquire 24 F/A-18F Super Hornets as an "interim" replacement,[5] pending the acquisition of the under development F-35 Lightning II. In March 2008, after a review, the new Labor government confirmed its purchase of the Super Hornets.[6] The drawdown of the RAAF's F-111 fleet has begun with the retirement of the F-111G models operated by the No. 6 Squadron RAAF in late 2007. The No. 1 and No. 6 Squadrons are to be reequipped with the F/A-18Fs beginning in 2010. One of the reasons given for the retirement is the average of 180 hours of maintenance required for every flight hour.[42]

Variants

F-111A

An F-111A dropping 24 Mark 82 low-drag bombs in-flight over a bombing range.

The F-111A was the initial production version of 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[18] and "Triple Plow I" variable intakes, providing a maximum speed of Mach 2.3 (1,450 mph, 2,300 km/h) at altitude.[43] 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).[44]

The A-model's Mark I avionics suite included 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).[45]

Total production of the F-111As was 158, including 17 pre-production aircraft that were later brought up to production standards.[46] A total of 42 F-111As were converted to EF-111A Ravens for an electronic warfare tactical electronic jamming role.[47] In 1982, four surviving F-111As were provided to Australia as attrition replacements and modified to F-111C standard.[48] These were fitted with the longer-span wings and reinforced landing gear of the C-model.

Three pre-production F-111A were provided to NASA for various testing duties. The 13th F-111A was fitted with new wing designs for the Transonic Aircraft Technology and Advanced Fighter Technology Integration programs in the 1970s and 1980s.[49] It was retired to the United States Air Force Museum at Wright-Patterson Air Force Base in 1989. The remaining unconverted F-111As were mothballed at Aerospace Maintenance and Regeneration Center at Davis-Monthan Air Force Base in June 1991.[50]

F-111B

The F-111B was to be a fleet air defense (FAD) fighter for the U.S. Navy, fulfilling a naval requirement for a fighter capable of carrying heavy, long-range missiles to defend 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. The F-111B had severe developmental problems, most related to carrier suitability. The swing-wing configuration, TF-30 engines, Phoenix missiles and radar developed for this aircraft were used on its replacement, the F-14 Tomcat, also designed by Grumman. The Tomcat would be large enough to carry the AWG-9 and Phoenix weapons system while exceeding the F-4's maneuverability.[51]

F-111C

The F-111C is the export version for Australia, combining the F-111A with longer F-111B wings and strengthened FB-111A landing gear. Australia decided to order 24 in 1963, and received their first F-111C in 1968. However development delays and structural problems delayed acceptance of aircraft by the Royal Australian Air Force until 1973.[52]

Four aircraft were modified to "RF-111C" reconnaissance configuration in 1979-80, retaining their strike capability. The RF-111C carries a reconnaissance pack with four cameras and an infrared linescanner unit.[53] Four ex-USAF F-111As were refitted to F-111C standard and delivered to Australia as attrition replacements in 1982.[48]

F-111C aircraft were equipped to carry Pave Tack FLIR/laser pods in the mid-1980s. They underwent an extensive Avionics Upgrade Program through 1998.[48] Under this program, the F-111C was upgraded to digital avionics. This included twin mission computers, modern digital databus, digital weapon management system, new AN/APQ-171 terrain-following radar, new AN/APQ-169 attack radar, twin ring-laser gyro INS, and GPS receiver. From 1994 F-111Cs and RF-111Cs were upgraded with TF30-P-109 engines, each rated at 20,840 lbf (93 kN) thrust.[54]

In late 2001, wing fatigue problems were discovered in one of the F-111C fleet. As a result a decision was made in May 2002 to replace the wings with spares taken from ex-USAF F-111Fs stored at the Aerospace Maintenance and Regeneration Center (AMARC). The short span wings underwent a refurbishment in Australia which included extending the span in effect making the wings the same as the F-111C and F-111G models.[55] Since the Avionics Upgrade Program, Australian F-111s have received weapons system and various other upgrades.[56]

F-111D

The F-111D was an upgraded F-111A equipped with newer Mark II avionics, more powerful engines, improved intake geometry, and an early glass cockpit. The variant was first ordered in 1967 and delivered from 1970-73. The F-111D reached initial operational capability in 1972. Deliveries were delayed due to avionics issues. A total of 96 F-111Ds were built.[57]

The F-111D used the new Triple Plow II intakes, which were located four inches (100 mm) further away from the airframe to prevent engine ingestion of the sluggish boundary layer air that was known to cause stalls in the TF30 turbofans. It had more powerful TF30-P-9 engines with 12,000 lbf (53 kN) dry and 18,500 lbf (82 kN) afterburning thrust.[58]

The Mark II avionics were digitally integrated microprocessor systems, some of the first used by the USAF, offering tremendous capability, but substantial problems. The Rockwell Autonetics digital bombing-navigation system included inertial navigation system, AN/APQ-130 attack radar system and Doppler radar. It also included digital computer set and multi-function displays (MFDs). The terrain-following radar was the Sperry AN/APQ-128.[59] The attack radar featured a Doppler beam-sharpening, moving target indicator (MTI), and continuous beam for guiding semi-active radar homing missiles.[60][61]

It took years to improve the reliability of the avionics, but issues were never fully addressed.[57][60] The F-111D was withdrawn from service in 1991 and 1992.[62]

F-111E

The F-111E was a simplified, interim variant ordered after the F-111D was delayed. The F-111E used the Triple Plow II intakes, but retained the F-111A's TF30-P-3 engines and Mark I avionics.[63] The weapon stores management system was improved and other small changes made.[64]

The E-model was first ordered in 1968 and delivered from 1969-71. It achieved initial operational capability in 1969.[65] The variant's first flight occurred on 20 August 1969. A total of 94 F-111Es were built.[64] Some F-111Es were based in the UK until 1991. The avionics was upgraded on some E-models as part of a Avionics Modernization Program. The variant saw service in Gulf War of 1990-91. Some F-111Es received improved TF30-P-109 engines in the early 1990s. All F-111Es were retired to AMARC by 1995.[66]

F-111F

Ground crew prepares a 48th Tactical Fighter Wing F-111F aircraft for a retaliatory air strike on Libya.

The F-111F was the final F-111 variant produced for Tactical Air Command, with a modern, but less expensive Mark IIB avionics system.[67] The USAF approved development of the variant in 1969. It also included the more powerful TF30-P-100 engine and strengthened wing carry through box. A total of 106 were produced between 1970 and 1976.[68]

The F-111F's Mark IIB avionics suite used a simplified version of the FB-111A's radar, the AN/APQ-144, lacking some of the strategic bomber's operating modes but adding a new 2.5 mi (4.0 km) display ring. Although it was tested with digital moving-target indicator (MTI) capacity, it was not used in production sets.[67] The Mark IIB avionics combined some Mark II components with FB-111A components, such as the AN/APQ-146 terrain-following radar. The F-111E's weapon management system was also included.[69]

The F-model used the Triple Plow II intakes, along with the substantially more powerful TF30-P-100 turbofan with 25,100 lbf (112 kN) afterburning thrust. An adjustable engine nozzle was added to decrease drag.[68] The P-100 engine greatly improved the F-111F's performance.[70] The engines were upgraded to the TF30-P-109 version,[71] later in the 1985-86 timeframe.

In the early 1980s, the F-111F began to be equipped with the AVQ-26 Pave Tack forward looking infrared (FLIR) and laser designator system. Pave Tack system provided for the delivery of precision laser-guided munitions and mounted in the internal weapons bay.[72] The Pacer Strike avionics update program replaced analog equipment with new digital equipment and multi-function displays.[73]

The F-111F made its combat debut in Operation El Dorado Canyon against Libya in 1986, and was used in Operation Desert Storm against Iraq in an anti-armor ("tank-plinking") role.[74]

The last USAF F-111s were withdrawn from service in 1996,[75] replaced by the F-15E Strike Eagle.

F-111K

The British government canceled the BAC TSR-2 in 1965, citing the lower costs of the TFX and ordered 50 F-111K aircraft in February 1967.[76] The F-111K was based on the F-111A with longer F-111B wings,[76] FB-111 landing gear, Mark II navigation/fire control system, and British supplied mission systems. Other changes include weapons bay modifications, addition of a centerline pylon, a retractable refueling probe, provisions for a reconnaissance pallet, and a higher gross weight with the use of FB-111A landing gear.[77]

In January 1968, the UK terminated its F-111K order.[78] Higher cost together with devaluation of the pound meant that the cost would be around £3 million each and this was the reason cited for cancellation.[79] The first two F-111Ks (one strike/recon F-111K and one trainer/strike TF-111K) were in the final stages of assembly when the order was canceled.[78] The two aircraft were later completed and accepted by the USAF as test aircraft with the YF-111A designation.[76] As a substitute, the RAF purchased Blackburn Buccaneers and F-4 Phantom IIs instead. These would eventually be replaced by the Panavia Tornado, another variable-geometry wing design.

FB-111A/F-111G

An air-to-air front overhead view of two FB-111s in formation

The FB-111A was a strategic bomber version of the F-111 developed as an interim aircraft for the Strategic Air Command to replace the elegant but troublesome supersonic B-58 Hustler and early models of the B-52 Stratofortress. The planned replacement program, the Advanced Manned Strategic Aircraft, was proceeding slowly, and the Air Force was concerned that fatigue failures in the B-52 fleet would leave the strategic bomber fleet dangerously under strength. The Air Force selected the FB-111A in 1965 and a contract signed the following year. Initially in 1968 263 aircraft were planned, but the total was cut to 76 in 1969. The first production aircraft flew in 1968. Deliveries ended in June 1971.[80]

When the United Kingdom canceled its order for the F-111K in 1968, components for the 48 F-111Ks in manufacturing were diverted to FB-111A production.[81][82] The FB-111A featured longer F-111B wings for greater range and load-carrying ability. The bomber variant was lengthened 2 ft 1 in (63 cm) over the F-111A.[83] Its fuel capacity was increased by 585 gallons (2,214 L) and had stronger landing gear to compensate for the higher maximum takeoff weight of 119,250 lb (54,105 kg). All but the first aircraft had the Triple Plow II intakes and the TF30-P-7 with 12,500 lbf (56 kN) dry and 20,350 lbf (90 kN) afterburning thrust.[84]

The FB-111A had new electronics, known as the SAC Mark IIB avionics suite. For the FB-111A the system used an attack radar improved from the F-111A's system, along with components that would be used on the F-111D, including the inertial navigation system, digital computers, and multi-function displays.[85] Armament for the strategic bombing role was the Boeing AGM-69 SRAM (short-range attack missile). Two could be carried in the internal weapons bay and four more on the inner underwing pylons. Nuclear gravity bombs were also typical FB armament. Fuel tanks were often carried on the third non-swivelling pylon of each wing. The FB-111A had a total weapon load of 35,500 lb (16,100 kg).[84]

Artist concept of a lengthened FB-111

Multiple advanced FB-111 strategic bomber designs were proposed by General Dynamics in the 1970s. The first design, referred to as "FB-111G" within the company,[86] was a larger aircraft with more powerful engines with more payload and range. The next was a lengthened "FB-111H". It featured more powerful General Electric F101 turbofan engines, a 12 ft 8.5 in longer fuselage and redesigned, fixed intakes. The rear landing gear were moved outward so armament could be carried on the fuselage there. The FB-111H was offered as an alternative to the B-1A in 1975.[86][87] The similar FB-111B/C was offered in 1979 without success.[88]

The FB-111A became surplus to SAC's needs after the introduction of the B-1B Lancer. The remaining FB-111s were subsequently reconfigured for tactical use and redesignated F-111G. The conversions began in 1989 and ended after 34 F-111G conversions were completed. With the disestablishment of SAC, the FB-111As and F-111Gs were transferred to the newly established Air Combat Command (ACC). They were used primarily for training.[89][90]

The F-111G did undergo an avionics upgrade program that added a digital computer, dual AN/ASN-41 ring-laser gyro INS, AN/APN-218 Doppler navigation, and an updated terrain-following radar. The astrocompass system was deleted.[citation needed] The remaining FB-111As were retired in 1991 and the F-111Gs were retired in 1993. Australia later bought 15 F-111Gs to supplement its F-111Cs.[91]

EF-111A Raven

To replace the aging Douglas EB-66, the USAF contracted with Grumman in 1972 to convert 42 existing F-111As into electronic warfare aircraft. The EF-111A can be distinguished from the F-111A by the equipment bulge atop their tails. In May 1998, the USAF withdrew the final EF-111As from service, placing them in storage at Aerospace Maintenance and Regeneration Center (AMARC).[84] The EA-6B Prowler has been fulfilling this function for both the U.S. Navy, Marines, and Air Force since.

Operators

 Australia
 United States
  • United States Air Force operated F-111A/D/E/F/G, FB-111A and EF-111A. Officially retired its F-111s in 1996 and the EF-111A in 1998.

Aircraft on display

The F-111's cockpit simulator on display.
F-111A
F-111B
EF-111A
F-111D
F-111E
FB-111A
F-111F

(F-111C aircraft that are still in service with the Royal Australian Air Force are not listed above.)

Specifications (F-111F)

An orthographically projected diagram of the F-111

Data from Miller,[93] Quest for Performance[94]

General characteristics

Performance

Armament

  • Guns:M61 Vulcan 20 mm (0.787 in) gatling cannon (seldom fitted)
  • Hardpoints: 9 in total (8× under-wing, 1× under-fuselage between engines)
  • Armament capacity: 31,500 lb (14,300 kg) ordnance mounted externally on hardpoints and internally in fuselage weapons bay

Popular culture

American artist James Rosenquist immortalized the aircraft in his acclaimed 1965 room-sized pop art painting entitled F-111 that features an early natural-finish example of the aircraft in USAF markings. The painting hangs in the Museum of Modern Art in New York City.

The Australian band Cold Chisel recorded a song called "F-111".[95] British pop-cyberpunk band Sigue Sigue Sputnik had a world hit in 1986 with the song "Love Missile F1-11". F-111 Records was an electronic music imprint within Warner Bros. Records that ran from 1995–2001. The F-111 is also the featured aircraft in the novel Chains of Command by former F-111 and B-52 crew member Dale Brown.

See also

Related development

Comparable aircraft

Related lists

References

Notes
  1. ^ a b Logan 1998, p. 9.
  2. ^ Knaack, Marcelle Size. Encyclopedia of US Air Force Aircraft and Missile Systems: Volume 1 Post-World War II Fighters 1945-1973. Washington, DC: Office of Air Force History, 1978. ISBN 0-912799-59-5.
  3. ^ "Boeing Press Release, 5 October 2009." boeing.mediaroom.com. Retrieved: 5 October 2009.
  4. ^ Goebel, Greg. "The Sukhoi Su-24 'Fencer'." Air Vectors, 1 April 2009. Retrieved: 30 September 2009.
  5. ^ a b Super Hornet Acquisition Contract Signed
  6. ^ a b ALP to stick with Super Hornet buy - National - theage.com.au
  7. ^ Pedlow, Gregory W. and Donald E. Welzenbach. The Central Intelligence Agency and Overhead Reconnaissance: The U-2 and OXCART Programs, 1954 - 1974, Chapter 6, "The U-2's Intended Successor:Project Oxcart, 1956-1968". Washington, DC: Central Intelligence Agency, 1992. Retrieved: 2 April 2009.
  8. ^ Spick, Mike. Modern Fighting Aircraft, B-1B. New York: Prentice Hall, 1986. ISBN 0-13-055237-2.
  9. ^ Gunston 1978, pp. 12–13.
  10. ^ Angelucci, Enzo. "The American Fighter". Haynes Publishing Group, 1987. ISBN 0-85429-635-2
  11. ^ Gunston 1978, pp. 11–12.
  12. ^ Miller 1982, p. 11.
  13. ^ Thomason 1998, pp. 5-6.
  14. ^ a b c d Gunston 1978, pp. 8–17.
  15. ^ Eden 2004, pp. 196-197.
  16. ^ a b Miller 1982, pp. 11–15.
  17. ^ Gunston 1978, pp. 18–20.
  18. ^ a b c d Baugher, Joe. "General Dynamics F-111A." USAAC/USAAF/USAF Fighters, 23 December 1999. Retrieved: 5 October 2009.
  19. ^ Eden 2004, p. 197.
  20. ^ Baugher, Joe. "General Dynamics/Grumman F-111B." USAAC/USAAF/USAF Fighters, 7 November 2004. Retrieved: 5 October 2009.
  21. ^ a b Gunston 1978, pp. 25–27.
  22. ^ Logan 1998, p. 32.
  23. ^ Donald, David, ed. "General Dynamics F-111". The Complete Encyclopedia of World Aircraft. New York: Barnes & Noble Books, 1997. ISBN 0-7607-0592-5.
  24. ^ Frawley, Gerald. "General Dynamics F-111 Aardvark". The International Directory of Military Aircraft, 2002/2003. London: Aerospace Publications, 2002. ISBN 1-875671-55-2.
  25. ^ Miller 1982, p. 65.
  26. ^ General Dynamics F-111D to F Aardvark, US Air Force National Museum.
  27. ^ Eden 2004, pp. 196-201.
  28. ^ a b Miller 1982, p. 80.
  29. ^ a b Logan 1998, pp. 17–18.
  30. ^ Logan 1998, p. 14.
  31. ^ Gunston, Bill. F-111, Modern Fighting Aircraft, Vol. 3, pp. 23-31. New York: Salamander Books, 1983. ISBN 0-668-05904-4.
  32. ^ Gunston 1983, pp. 33-34.
  33. ^ Logan 1998, pp. 283-284.
  34. ^ a b Boyne, Walter J. "El Dorado Canyon", Air Force Magazine, March 1999.
  35. ^ Archive
  36. ^ F-111
  37. ^ Stateline Tasmania, ABC 27 June 2003
  38. ^ "Papers on Parliament 1989, p. 27." "In preparing the Commonwealth's case for the inevitable High Court challenge by Tasmania, Evans earned the popular title of "Biggles" for arranging to have Royal Australian Air Force planes fly 'spy flights' over the dam site to collect court evidence."
  39. ^ Lane, Sabra (25 June 2009). "F-111 compensation scheme extended". The World Today (Australian Broadcasting Corporation). http://www.abc.net.au/news/stories/2009/06/25/2608585.htm. Retrieved 27 February 2010. 
  40. ^ Joint Standing Committee on Foreign Affairs, Defence and Trade. "Inquiry into RAAF F-111 Deseal-Reseal workers and their families". Parliament of Australia. http://www.aph.gov.au/house/committee/jfadt/deseal_reseal/index.htm. Retrieved 27 February 2010. 
  41. ^ Drug Freighter
  42. ^ McPhedran, Ian. "F-111 - the RAAF's white elephant in the sky." Daily Telegraph, August 2009. Retrieved: 3 August 2009.
  43. ^ Miller 1982, pp. 26, 66.
  44. ^ Logan 1998, p. 302.
  45. ^ Gunston 1978, pp. 46–47.
  46. ^ Miller 1982, p. 26.
  47. ^ Logan 1998, p. 92.
  48. ^ a b c Logan 1998, p. 263.
  49. ^ Logan 1998, pp. 289–293.
  50. ^ Logan 1998, p. 48.
  51. ^ Thomason 1998, p. 54.
  52. ^ Logan 1998, p. 261.
  53. ^ Logan 1998, pp. 261-262.
  54. ^ Baugher, Joe. "General Dynamics F-111C." USAAC/USAAF/USAF Fighters, 8 May 2000. Retrieved: 5 October 2009.
  55. ^ Pittaway, Nigel. "21st century Pigs: F-111 in RAAF Service". International Air Power Review, Vol. 6, 2002, pp. 18–31.
  56. ^ F/RF-111C Modifications and Support. Boeing Australia. Retrieved: 3 July 2009.
  57. ^ a b Logan 1998, pp. 26, 106-107.
  58. ^ Baugher, Joe. "General Dynamics F-111D." USAAC/USAAF/USAF Fighters, 5 January 2005. Retrieved: 5 October 2009.
  59. ^ Logan 1998, pp. 26-27.
  60. ^ a b Miller 1982, p. 31.
  61. ^ Gunston 1978, pp. 94–95.
  62. ^ Logan 1998, p. 108.
  63. ^ Gunston 1978, pp. 74–76.
  64. ^ a b Miller 1982, p. 32.
  65. ^ Logan 1998, pp. 137-138.
  66. ^ Logan 1998, p. 138.
  67. ^ a b Gunston 1978, pp. 95–97.
  68. ^ a b Logan 1998, pp. 169-171.
  69. ^ Logan 1998, pp. 27, 169.
  70. ^ Gunston 1978, p. 96.
  71. ^ Logan 1998, p. 301.
  72. ^ "Pave Tack operational on European F-111s". Flight International, 9 January 1982.
  73. ^ Logan 1998, pp. 28-29.
  74. ^ Bodner, Maj. Michael J. and Maj. William W. Bruner III. "Tank Plinking". Air Force magazine, October 1993.
  75. ^ Baugher, Joe. "General Dynamics F-111F." USAAC/USAAF/USAF Fighters, 22 December 1999. Retrieved: 5 October 2009.
  76. ^ a b c Gunston 1978, pp. 84-87.
  77. ^ Logan 1998, pp. 278-280.
  78. ^ a b Logan 1998, p. 278.
  79. ^ Buttler, Tony. British Secret Projects: Jet Bombers Since 1949. London: Midland Publishing, 2003. ISBN 1-85780-130-X.
  80. ^ Miller 1982, pp. 38–41.
  81. ^ Gunston 1978, p. 87.
  82. ^ Logan 1998, pp. 278-279.
  83. ^ Miller 1982, pp. 38–43.
  84. ^ a b c Baugher, Joe. "General Dynamics FB-111A." USAAC/USAAF/USAF Fighters, 22 December 1999. Retrieved: 5 October 2009.
  85. ^ Logan 1998, pp. 215–218.
  86. ^ a b Logan 1998, pp. 247–248.
  87. ^ Miller 1982, pp. 59–62, 73-77.
  88. ^ Logan 1998, pp. 249–251.
  89. ^ Logan 1998, p. 206.
  90. ^ Baugher, Joe. "General Dynamics F-111G." USAAC/USAAF/USAF Fighters, 22 December 1999. Retrieved: 5 October 2009.
  91. ^ Logan 1998, pp. 206, 218.
  92. ^ Wings Over the Rockies Air & Space Museum - FB-111A Denver, CO
  93. ^ Miller 1982, pp. 32–38, 66.
  94. ^ Loftin, LK, Jr. Quest for performance: The evolution of modern aircraft. NASA SP-468, NASA, 6 August 2004. Retrieved: 22 April 2006.
  95. ^ Song lyrics
Bibliography
  • Eden, Paul, ed. "General Dynamics F-111 Aardvark/EF-111 Raven". Encyclopedia of Modern Military Aircraft. London: Amber Books, 2004. ISBN 1-90468-784-9.
  • Gunston, Bill. F-111. New York: Charles Scribner's Sons, 1978. ISBN 0-684-15753-5.
  • Gunston, Bill. F-111, Modern Fighting Aircraft, Vol. 3. New York: Salamander Books, 1983. ISBN 0-668-05904-4.
  • Logan, Don. General Dynamics F-111 Aardvark. Atglen, PA: Schiffer Military History, 1998. ISBN 0-7643-0587-5.
  • Miller, Jay. General Dynamics F-111 "Arardvark". Fallbrook, California: Aero Publishers, 1982. ISBN 0-8168-0606-3.
  • Neubeck, Ken. F-111 Aardvark Walk Around. Carrollton, Texas: Squadron/Signal Publications, 2009. ISBN 978-0-89747-581-5.
  • Thomason, Tommy. Grumman Navy F-111B Swing Wing (Navy Fighters No. 41). Simi Valley, CA: Steve Ginter, 1998. ISBN 0-942612-41-8.
  • Thornborough, Anthony M. F-111 Aardvark. London: Arms and Armour, 1989. ISBN 0-85368-935-0.
  • Winchester, Jim, ed. "General Dynamics FB-111A". "Grumman/General Dynamics EF-111A Raven". Military Aircraft of the Cold War (The Aviation Factfile). London: Grange Books plc, 2006. ISBN 1-84013-929-3.

External links


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