US heavy fighter-bomber built by General Dynamics in the 1960s.

Background

In 1958 the US Air Force issued a specification for an aircraft that was supposed to replace the F-100 Super Sabre, F-101 Voodoo and F-105 Thunderchief in the Century Series tactical aircraft. At the same time the US Navy needed a replacement aircraft for its F-8 Crusader and F-4 Phantom II fleet air defense fighters. Defense secretary Robert S. McNamara directed the Navy and the Air Force to work together to issue a common specification so that the needs of both services could be fulfilled by a single aircraft. For good measure he told the US Marines and the Army to pitch in so that the plane could be used in the close-air support role. The program became known as Tactical Fighter Experimental - TFX. A tall order which General Dynamics later partly managed to fulfill, but not before the TFX program had overcome a great number of political and technical hurdles as well as serious cost overruns.

DoD envisioned a single flying machine able to replace all the aforementioned aircraft in all their different operational roles: air-to-air, air-to-ground, close air support, tactical reconnaissance and strategic bombing. It was also supposed to be able to zip along at Mach 2.5 at high altitudes and Mach 1.2 at a few hundred feet. As far as fuel was concerned, it was required to be able to cross the Atlantic Ocean without refueling.

Another requirement was Vertical Takeoff and Landing capability, probably influenced by research by contemporary British aircraft designers, but this requirement was dropped in February 1960. The British experimental P.1127 VTOL program had done tethered hovering for the first time in October 1960, but it would take almost ten more years before this evolved into a usable VTOL airplane: the Harrier Jump Jet. The TFX was also supposed to be sold to numerous NATO member countries as a replacement for the F-84 Thunderjet and F-86 Sabre fighters delivered on a lend/lease basis as military assistance during the fifties and sixties.

An aircraft type's frontline service in the US was typically much less than ten years in the fifties. That might be why the DoD started the TFX program almost as soon as the Century Series aircraft started to populate US squadrons.

In 1961, the US Army and Marines convinced defense secretary Robert S. McNamara that their operational needs could not be fulfilled by the TFX and was subsequently dropped from the program. McNamara still stuck to the idea that the US Navy and Air Force should work together on a joint request for proposals, something they reluctantly did. It soon became evident that the needs of the two services was very different, and about the only thing they could agree on was a design with variable sweep wings. McNamara ordered the Air Force to take the lead in developing common specifications. This of course, led to a number of compromising design decisions, none of which were particularly suited to Navy carrier operations. Hardcore industrialist McNamara again took it upon himself to decide what the Navy wanted, and this was in reality the end of the Navy's part in the TFX program.

In all fairness, it should be noted that a couple of design details were a bow to the US Navy: the cockpit side by side seating for the two pilots and the famous escape capsule. The escape capsule was meant to replace conventional ejector seats. Instead of ejecting the pilots from the aircraft in case of emergency, the entire nose section was to break free, parachuting to the ground or water with the pilots safely inside.

The Air Force variant was to be designated F-111A, the Navy variant F-111B, and in December 1961 nine responses from aircraft makers in the US had been received. Only Northrop turned down the invitation to submit a design. Boeing and General Dynamics designs were chosen among the nine, leading to several rounds of quarreling over Navy versus Air Force needs. In September 1962, all military organisations involved in the TFX program announced that their preferred aircraft was the Boeing design, and that would probably had been the end of it, but McNamara made himself heard once again.

Troubled times

On November 24, 1962, the United States Department of Defense announced that the design submitted by General Dynamics had been selected on grounds of promising a greater degree of commonality and a better approach to cost. All hell broke loose in the media, in congressional committees and congress itself.

You see, building a plane like this generates quite a bit of business, not only for the corporation involved in putting it together, but also for the thousands of subcontractors. One of the most vocal opponents of McNamara's decision in congress was Washington senator Henry M. Jackson, simply because Boeing was located in his home state and would miss out on a lot of business should the decision stand. For months the TFX was the subject of congressional investigations while headlining newspapers all over the USA. Eventually the whole affair fizzled and McNamara's decision stood.

Pressing on

The F-111A mock-up was inspected in September 1963. It was originally planned to use titanium for almost the entire airframe, but this proved too costly and more conventional materials had to be used, i.e. aircraft grade aluminium. Since General Dynamics lacked experience with carrier based aircraft, they teamed with Grumman for the Navy variant of the plane.

Ironically, General Dynamics' subcontractors ended up having more than 6700 suppliers in 44 states, thoroughly defanging senator Jacksons arguments.

22 months after the program's beginning, on October 15, 1964 the first F-111A rolled out of the factory in Forth Worth, Texas. The escape capsule was not available yet, so the first F-111 had regular ejector seats in the cockpit. The 11th built F-111 was the first to have the escape capsule fitted. Another novelty was the variable sweep wing design, allowing the pilot to adapt the plane's flight characteristics for low, high, fast and slow operation. The A variant had a dual radar setup consisting of a General Electric AN/APQ-113 attack radar and a Texas Instruments AN/APQ-110 terrain following radar.

The TF-30 turbofan jet engines were to be supplied by Pratt & Whitney, and Hughes Aircraft Company was brought in to develop the F-111's Phoenix missile.

So, what about bombs?

One of the questions that surfaced because of the variable sweep wing was "where do we hang the bombs?" The internal bomb bay wasn't big enough to hold the kind of offensive load the F-111 was required to have, and a wing that varies its sweep isn't useful for hanging bombs from. General Dynamics solved this in a pretty simple way. Out of the six pylons fitted to the wing undersides, four of them were made to swivel as the wing changed sweep. The remaining two outer pylons didn't swivel and automatically jettisoned their load when the wing swept beyond 26 degrees.

Going up and going down

Its maiden flight took place on December 21, 1964 from Carswell AFB outside Forth Worth. Behind the controls were General Dynamics test pilots Dick Johnson and Val Prahl. Thus began its test flight phase which lasted well into 1967. On its second flight in January 1965, the wings were swept from its minimum 16 degrees to the 72.5 degrees maximum.

In early 1965 DoD cut the F-111 program because of an increase in cost per plane from $4.5 million to just over $6.0 million. The order was now at 431 planes, a more than 50% reduction compared to what was originally planned when the program started.

The engines on a high-performance jet aircraft are in need of just two things: fuel and air. Cutting of the airflow to the jet engine, thus stalling the compressor is like running out of fuel. The engine simply stops because the jet fuel won't ignite. The F-111 initially had just this kind of problem because of the shape of the air inlets on each side of the cockpit. At high angles of attack and at high speeds, the compressors inside the jet engines sometimes stalled because the inlets stopped providing enough air. It took several years and a lot of bright minds to work out how the inlets should look. The revised inlets on the F-111 were dubbed Triple Plow I while a later enhancement was called Triple Plow II.

The F-111B

So what about the Navy version of the F-111? What happened to that? It flew for the first time on May 18, 1965, piloted by Grumman test pilots Ralph Donnell and Ernie von der Heyden. They took off from the Calverton, Long Island airport for a trouble free flight. The reason the Navy F-111 flew with Grumman pilots was that General Dynamics had teamed up with Grumman because of their experience in building carrier based aircraft.

The B variant had a much shorter nose and a slightly longer wingspan than its Air Force cousin. The former because it had to fit inside the carrier elevators, the latter because of endurance requirements. Because of the difference in mission profile and armament, the B variant was fitted with a Hughes AN/AWG-9 pulse-doppler radar. The B's armament was supposed to be up to six AIM-54 Phoenix missiles for fleet protection. Other than those and the fact that the B was able to land on a carrier, the two variants were identical.

So, General Dynamics and Grumman built a cool looking plane, fitted it with the latest in electronics and proved that it could fly. Still, the Navy was uncertain about the whole undertaking. The Navy started the formal evaluation of the B in October 1965 at NAS Patuxent River, and the F-111 was soon in trouble. The Navy had originally required the F-111 to weigh no more than 55,000 pounds/25,000 kgs, but with topped up fuel tanks, six missiles and ready to go do its job it weighed 78,000 pounds/35500 kgs. Requirements that are 40% off upon delivery pretty much means you will have to do something about it, and so the US Navy did. A weight reduction project called SWIP (Super Weight Improvement Program) was started, but when the delayed escape capsule was finally fitted to the plane, the F-111B weighed the same as it did before the SWIP. The Navy side of the project was terminated in July 1968, after $377 million had been spent on a lost cause and seven completed F-111Bs. By that time, a cancelled fighter project was the least of Robert McNamara's worries.

The AIM-54 Phoenix entered service in 1974 as the primary weapon on the F-14 Tomcat.

All remaining B variants were permanently grounded in 1971.

The last anyone ever saw of a F-111B was in a Washington scrapyard in 1999, wingless and gutted of whatever electronics it once had, covered in graffiti.

F-111s for Australia

In October 1963, the Australian government agreed to buy 24 F-111As to replace their aging RAAF English Electric Canberras. The original plan was to buy the legendary (and ill-fated) TSR.2 from the UK, but the Aussie delegation was sent home from London with orders to buy something else. Whatever reason the UK had for ouright denying Australia their plane, it's no secret that the TFX programme had a hand in the cancellation of the British Aircraft Corporation TSR.2 programme. It was nevertheless a bold move by the Australians, since they effectively bought an aircraft off the drawing board!

The Australians were supposed to be handed over a plane almost identical to the F-111A, but you know, shopping is shopping. By 1966 the specifications had changed so much that the official designation F-111C was issued for it. On September 6, 1968 the first of the 24 F-111Cs was delivered to Australia, but because of technical problems and a string of fleetwide groundings, the last of the 24 planes wasn't delivered until early in December 1973. Ten years after signing the contract and at $200 million over the negotiated price, the Royal Australian Air Force had their new plane. In 1993 RAAF bought fifteen more F-111Gs - actually just FB-111As with a new designation - secondhand from the USAF. These Australian F-111Cs can carry the AGM-84 Harpoon missile, something no other F-111s can.

After the initial problems however, the F-111C have soldiered on down under with great success. A recent report by the Australian ministry of defence stated that F-111 operations would continue until at least 2020 - 57 years after Australia signed the purchase contract.

Since 1998, the RAAF F-111s are the last operational ones anywhere.

Two RAAF F-111Gs were used in the Sydney 2000 Olympic Games closing ceremony, trailing a spectacular 200 metre long flame, symbolically taking the olympic flame with it. The flame trick is particular to the F-111, as the fuel dump valve is placed between the engine exhausts. Engaging the afterburner while dumping fuel will ignite it and produce what is known as a Dump and Burn.

The F-111 in combat

Combat Lancer

On March 18, 1968, an F-111A from the 428th Tactical Fighter Squadron flew the first combat mission for the type. It happened in the guise of Combat Lancer, an operation devised in order to both prove the F-111's worth as a combat aircraft and to try to lower the phenomenal loss rates experienced by attacking North Vietnamese targets with F-4s and F-105s. The F-111, flying out of Thakli in Thailand alone into North Vietnam managed both. At night, without fighter cover, ECM or refueling, at low level and in single ship formation, it proved untouchable for the enemy air defenses.

It was not, however, immune to technical shortcomings, and over the course of operation Combat Lancer, several F-111s crashed due to technical malfunctions. The first F-111 crash on March 28, 1968 was the 813th (!) aircraft lost over Vietnam, but the media and the politics behaved as if it was the first. After two more crashes and a similar accident stateside, media and congress denounced the plane as unsafe and defective, even calling it "the flying Edsel." A thorough examination of wreckages found a defective valve to be the cause of the crashes, leading to a sudden uncontrollable pitch-up and roll while flying low and fast.

It was too late. Combat Lancer was terminated and all remaining F-111s in Thailand had returned home by late November 1968.

Vietnam

In addition to Combat Lancer, the F-111 took part in the 1972 Operation Linebacker II bombing campaign. Despite a rash of technical problems, F-111s flew about 4000 combat missions for the loss of six planes, often in conditions that grounded other aircraft in the theatre. All missions were flown by 429th and 430th Tactical Fighter Squadron.

Libya

In the 1986 Operation El Dorado Canyon, 24 F-111Fs from 48th Tactical Fighter Wing stationed at RAF Lakenheath attacked Tripoli in Libya with laser guided and retarded bombs. One F-111 was lost to ground fire. Six EF-111A Raven aircraft provided ECM and jamming for the attack.

Iraq

During Operation Desert Storm in 1991, F-111Es from 20th Tactical Fighter Wing flew missions out of Incirlik, Turkey. From bases in Saudi Arabia, 67 F-111Fs from 48th TFW flew 2500 missions into Iraq and Kuwait. No aircraft were lost in these operations. The infamous GBU-28 "Deep Throat" deep penetrator bomb was dropped by a pair of 48th TFW F-111Fs on the last night of the war.

The only F-111 credited with downing an enemy plane was an EF-111A on January 17, 1991. It didn't spend any ammunition in doing so, since the Iraqi Mirage F1 chrashed into the ground chasing it. Even if the Raven is completely unarmed, the crew was credited with the "kill".

East Timor

During the International Force East Timor operations in 1999, Australian F-111 aircraft flew reconnaissance missions continually over East Timor. This marked the first operational missions flown by RAAF F-111s.

Since 1968, thirteen F-111s have been lost in combat operations, albeit only one of which being a confirmed shootdown. 115 pilots and co-pilots have lost their lives in the plane. The Aardvark Memorial in Clovis, New Mexico commemorates the lost flyers.

Nicknames

For one reason or another the F-111 served over 30 years in the US Air Force without getting an official name. So where does Aardvark come from then? Legend tells that the first to call it Aardvark was instructor pilot Al Mateczun at Nellis Air Force Base in the late sixities. Pictures of the F-111 and its characteristic nose is a dead giveaway with regards to that name. Aardvark is apparently Afrikaans for Earth Pig. The nose also led to 474th TFW at Nellis naming it Roadrunner when the type first appeared on the flightline.

Other nicknames:

  • Laotian troops called it Whispering Death
  • RAAF officially proposed Arkana, Galawindi and Taipan as nicknames, but nothing came out of it
  • The unofficial RAAF nickname was Pig during the early years in Australia
  • SAC used the name Switchblade for a while
  • The electronic warfare variant EF-111A was nicknamed Sparkvark because of the amount of electronics on board
  • Last but not least, there's the short version 'Vark

At the official retirement ceremony at Lockheed Martin's Tactical Aircraft Systems plant in Forth Worth, Texas in 1996, the name Aardvark was finally made official. The ceremony ended with a four-ship of Aardvarks taking off for AMARC. No Aardvarks in any variant are operational in the United States today, but they are plentiful as museum pieces and gate guards.

Variants and numbers

Out of the thousands of planned F-111s, General Dynamics only built a total of 562 in seven different variants. Granted, the list below lists more, but only seven actually took to the air at one point or another.

  • F-111A: US Air Force variant. 158 built
  • RF-111A: Abortive recce variant. One prototype converted from an F-111A
  • EF-111A: Unarmed electronic warfare conversion. 40 converted from the F-111A
  • F-111B: US Navy variant. Seven built.
  • F-111C: Australian variant of the F-111. 24 built.
  • RF-111C: Australian recce variant conversion. Four converted from F-111As
  • F-111D: Improved F-111 with glass cockpit and Triple Plow II intakes. 96 built
  • F-111E: Simpler interim version of F-111D. 94 built.
  • F-111F: The final and most advanced Aardvark variant. 106 built.
  • FB-111A: Strategic bomber variant. 76 built.
  • F-111G: Tactical conversion of the FB-111A. An unknown number converted.
  • F-111K: Aardvark variant ordered by RAF and cancelled in 1968. Two built.

Technical specifications

Specs are for F-111F, the final variant.

  • Crew: two
  • Engines: two Pratt & Whitney TF-30-P-100 turbofans. 25,100 lbs static thrust with afterburner per engine.
  • Top speed: Mach 2.33 at 53,450 feet
  • Maximum ferry range: 3,634 miles/5,847 km
  • Wingspan: 63 feet / 16 metres
  • Maximum takeoff weight: 98,950 lbs / 44,977 kgs
  • Maximum fuel capacity: 7,443 US gallons / 28,174 litres


Information on the Aardvark is abundant, both online and offline. A major online resource for anything regarding the F-111 is http://www.f-111.net. They've gathered more information than you'll ever absorb on the plane, so I'd like to give them credit. Another useful source on everything that flies and drop bombs or shoots missiles is Joe Baugher's writeups at http://home.att.net/~jbaugher/uscombataircraft.html.

A multipurpose tactical fighter/bomber capable of supersonic speeds, the F-111 was one of the most controversial military aircraft to ever fly, yet it achieved one of the safest operational records of any plane in United States Air Force history. The F-111 provided many firsts among weapons systems as well as being the first production aircraft with variable wings that could be swept back or brought forward to increase efficiency.

In early 1960, proposals that would lead to the development of the F-111 were issued to Boeing, Lockheed, Northrop, General Dynamics, Grumman, McDonnell, and Douglas Aircraft in dual response to the U.S. Navy’s need for a long-range carrier defense fighter to replace the F-4 Phantom and the F-8 Crusader, and the U.S. Air Force's requirement for a long range/high and low-altitude bomber.

The Air Force's Tactical Air Command expressed great desire for a fighter bomber with the ability to penetrate Soviet air defenses at extremely low altitude, but at the same time very high speeds to deliver nuclear weapons systems against crucial targets such as airfields, supply depots, and munitions dumps. Specifications for the request included a combat radius of nearly 900 miles, a low-altitude speed of Mach 1.2 and a high-altitude speed of Mach 2.5. The Air Force was not at first concerned with maneuverability, or cannon armament, but with good field performance and the ability to reach Europe without the need to refuel.

Meanwhile, the Navy had realized its own need for a high-endurance interceptor to defend aircraft carrier fleets against Soviet jet bombers that were being armed with nuclear anti-ship missiles capable of annihilating the large ships and their crews with an estimated zero survivability rate. The Navy required an aircraft with more load-carrying ability, a more powerful radar than the F-4 Phantom was designed for, and the capability to wield an array of long range weapons to intercept both bombers and missiles.

After a series of subsequent proposals the Department of Defense awarded the contract to General Dynamics in November of 1962, in part because the General Dynamics design promised to be more affordable and allow greater commonality with both requests.

General Dynamics presented an experimental aircraft in the 20-ton class with a maximum take-off weight of almost 50 tons. They had intended to use titanium for large portions of the fuselage to save weight, but this proved prohibitively expensive. The plane was powered by two afterburning Pratt & Whitney TF30-P-100 turbofans. Shoulder-mounted wings were attached to a pair of large pivots, allowing it to take off, land, loiter and cruise at high subsonic speeds with its wings forward, which offered the greatest surface area and amount of lift. When the wings were swept backwards the aircraft became streamlined for supersonic dashes at more than Mach 2. When landing, the wings would once again be spread, eliminating the need for a drag parachute or for reverse thrusting.

Largely at Navy insistence, the F-111 had a two pilot crew who were to be seated next to one another, and production versions did not have ejection seats but instead used a pressurized crew compartment that could be ejected as a self-contained escape capsule. When activated, explosive charges around the module would detonate and separate the cockpit from the aircraft and would then deploy a 70 ft parachute to bring the compartment safely to the ground. Airbags cushioned impact and helped to keep the module afloat in water. The module could be released at any speed or altitude, even under water. If the F-111 was put down into a body of water, the airbags raised the module to the surface after it had been severed from the plane.

The Aardvark could carry conventional as well as nuclear weapons, four mounted externally with two warheads and additional fuel in the internal weapons bay. External ordnance could also include combinations of bombs, missiles and fuel tanks. The weapon s nearest the fuselage on each side pivoted on anchors as the wings swept back, keeping ordnance parallel to the body of the craft. Weapons pylons near the tips of the wings did not pivot but could be jettisoned if supersonic speeds were needed with short notice.

A revolutionary automatic terrain-following radar system flew the craft at a constant altitude following the Earth's contours much like the cruise control system in a civilian vehicle manages speed. The system allowed the aircraft to fly in valleys and over mountains, day or night, and regardless of weather conditions. Should any of the system's circuits have failed, the aircraft automatically initiated a climb and the pilot would take manual control.

The first flight of the F-111A, as the Air Force version was designated, took place in December of 1964, and entered into service in July of 1967. The Navy never adopted an F-111 model, opting instead for the Grumman F-14 Tomcat which featured the same swept wing design, Pratt & Whitney TF30-P-100 turbofan engines, and weapons capabilities. The Tomcat entered service in 1968.

Able to fly in weather conditions that would ground most aircraft, the F-111 could also carry the equivalent ordnance load of four F-4 Phantoms and during the Viet Nam conflict although over 4000 missions were flown, only six combat losses occurred.

Commonly referred to as the "Aardvark" because of the elongated nose used to house its radar system, the F-111 was never officially given the name until its retirement ceremony to the United States Air Force Museum in 1992.

Specifications:
Length: 73 feet, 6 inches
Height: 17 feet, 1 1/2 inches
Wingspan: 63 feet full forward; 31 feet, 11 inches full aft
Speed: Mach 1.2 at sea level; Mach 2.5 at 60,000 feet
Ceiling: 60,000-plus feet
Range: 3,565 miles with external fuel tanks
Weight Empty: 47,481 pounds
Maximum Takeoff Weight: 100,000 pounds
Crew: Two, pilot and weapon systems officer


www.fas.org/man/dod-101/sys/ac/f-111.htm
home.att.net/~jbaugher1/f111.html
en.wikipedia.org/wiki/F-111_Aardvark

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