General Dynamics F-111

The General Dynamics F-111 Aardvark (the nickname was unofficial for most of its lifespan, but it was officially named "Aardvark" at its retirement ceremony for the United States Air Force) is a long-range strategic bomber, reconnaissance, and tactical strike aircraft. The F-111 project was long considered an expensive failure, but the end result was a capable, albeit costly, aircraft.

Development

The F-111's beginnings were in the TFX, an ambitious early 1960s project to combine the U.S. Air Force requirement for a fighter-bomber with the U.S. Navy's need for a long-range carrier defense fighter to replace the F-4 Phantom II and the F-8 Crusader. The fighter design philosophy of the day concentrated on very high speed, raw power, and air-to-air missiles.

Related Topics:
1960s - U.S. Air Force - Fighter-bomber - U.S. Navy - Carrier - F-4 Phantom II - F-8 Crusader - Air-to-air missile

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The USAF's Tactical Air Command (TAC) was largely concerned with the fighter-bomber and deep strike/interdiction role, which in the early 1960s still focused on the use of nuclear weapons. 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 very high speeds to deliver tactical nuclear weapons against crucial Soviet targets like airfields and supply depots. Included in the specification were a low-level speed of Mach 1.2, a high-altitude speed of Mach 2.5, a combat radius of 890 mi (1,475 km), good short-field performance, and a ferry range long enough to reach Europe unrefueled. Dogfighting maneuverability and cannon armament were considered of little importance. This would change within a few years as experience showed that close-in dogfighting remained important in air combat: guns and an emphasis on agility were reintroduced to fighter design, but only after the F-111 was developed.

Related Topics:
Tactical Air Command - Fighter-bomber - Nuclear weapon - 1960 - Soviet - Mach

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The U.S. Navy, meanwhile, had since 1957 been searching for a long-range, high-endurance interceptor to defend its carrier groups against the new generation of Soviet jet bombers, which by then were being armed with huge anti-ship missiles with nuclear warheads. The Navy needed a Fleet Air Defense (FAD) aircraft with better loitering performance and load-carrying ability than the F-4 Phantom II, equipped with a powerful radar and a battery of long-range missiles to intercept both bombers and their missiles.

Related Topics:
1957 - Soviet - Anti-ship missile

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Since the cancellation of the F6D Missileer in December 1960 the Navy had been reconsidering variable geometry for the FAD requirement. The trend toward ever bigger, more powerful fighters posed a problem for the Navy: the current generation of naval fighters were already barely capable of landing on an aircraft carrier deck, and a still larger and faster fighter would pose even greater problems. An airframe optimised for high speed — most obviously with a high-angle swept wing — is inefficient at cruising speeds, which reduces range, payload, and endurance, and leads to very high landing speeds. On the other hand, an airframe with a straight or modestly swept wing, while easier to handle and able to carry heavy loads over longer distances on a minimum of fuel, has lower ultimate performance. Variable geometry, which the Navy had tried and abandoned for the XF10F Jaguar in 1953, offered the possibility of combining both in a single airframe.

Related Topics:
F6D Missileer - 1960 - Variable geometry - Aircraft carrier - Swept wing - XF10F Jaguar - 1953

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Both of these requirements were about to be marred by politics, and then checkered by considerable controversy. Newly appointed Secretary of Defense Robert McNamara, who had just come from a successful stint as president of the Ford Motor Company, was a great believer in "commonality" — adapting a single common mechanical platform that could be customized for various applications. He felt that imposing this principle on military procurement would lead to substantial cost savings. As a result, on 16 February 1961, less than a month after taking office, McNamara ordered the services to consider a single basic aircraft that could be developed in different versions for each service. At one stage, it was even planned to use it for the U.S. Army and Marine Corps as a close air support platform. Although the services insisted that a single aircraft was not technically feasible, McNamara ordered the development of a common aircraft to proceed anyway.

Related Topics:
Secretary of Defense - Robert McNamara - Ford Motor Company - 16 February - 1961 - U.S. Army - Marine Corps - Close air support

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The program was dubbed TFX (Tactical Fighter Experimental). Requests for proposals were issued to Boeing, General Dynamics, Lockheed, Northrop, Grumman, McDonnell, Douglas Aircraft, North American Aviation, and Republic Aviation. Nine proposals were received in December 1961, and while the USAF and Navy felt that none were entirely suitable, on 19 January 1962 they indicated that the Boeing and General Dynamics proposals looked most promising.

Related Topics:
Boeing - General Dynamics - Lockheed - Northrop - Grumman - McDonnell - Douglas Aircraft - North American Aviation - Republic Aviation - 1961 - 19 January - 1962

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After a series of subsequent proposals, in September 1962 the USAF and Navy indicated they preferred the Boeing design, but McNamara again overrode their decision, and the Department of Defense awarded the contract to General Dynamics on 24 November 1962, in part because the General Dynamics design promised to be more affordable and allow greater commonality — a decision that was to seem particularly ironic consider what followed. Grumman, which had greater experience with carrier aircraft, was engaged as the primary subcontractor.

Related Topics:
1962 - 24 November - 1962

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The TFX design eventually emerged as an aircraft in the 20-ton (empty) class with a maximum take-off weight of almost 50 tons. It had been intended to use titanium for large portions of the airframe to save weight, but this proved prohibitively expensive. The TFX was powered by two afterburning Pratt & Whitney TF30-P-100 turbofans in the 80 kN class. The shoulder-mounted wings were attached to a pair of giant pivots, allowing it to take off, land, and loiter with a modest 16° sweep (for maximum lift and minimum landing speed), cruise at high subsonic speeds with a 35° sweep, or sweep back to a 72.5° maximum for fast supersonic dashes at more than Mach 2. Despite its high maximum speed, its modest thrust fraction (thrust-to-weight ratio) made early versions somewhat underpowered, exacerbated by compressor stalls and other engine problems that forced a hasty redesign of the engine inlets.

Related Topics:
Maximum take-off weight - Titanium - Afterburning - Pratt & Whitney - TF30-P-100 - Turbofan - Subsonic - Mach

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Largely at Navy insistence, the F-111 had a crew of two seated side-by-side, and production versions did not have ejection seats, instead using a pressurized crew compartment that could be ejected as a self-contained escape capsule. If deployed, it blew the nose off the aircraft and descended under a 70 ft (21 m) parachute. The escape module meant that two crew could work in "shirt sleeves" without pressure suits or oxygen masks.

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First flight of the F-111A, as the USAF version was designated, was 21 December 1964, and entry into service with the USAF began 18 July 1967.

Related Topics:
21 December - 1964 - 18 July - 1967

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The Navy version, the F-111B, was cancelled in December 1968 to be replaced by the F-14 Tomcat, but other F-111 variants went on to serve with the USAF through the mid-1990s, performing with distinction in the 1991 Gulf War. Although the United Kingdom had expressed interest in the program in 1965 in preference to the home grown BAC TSR-2, the British order for the F-111 was cancelled, and the F-111's only export customer was the Royal Australian Air Force.

Related Topics:
1968 - F-14 Tomcat - 1990s - 1991 Gulf War - United Kingdom - 1965 - BAC TSR-2 - Royal Australian Air Force

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The F-111 was the first regular production variable-geometry aircraft because the earlier Navy XF10F Jaguar had been cancelled in 1953, and the first supersonic swing-wing aircraft. Despite its clear advantages, variable geometry remains a relatively unusual feature in military aircraft, 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) and Tupolev Tu-160 'Blackjack' bomber (1981), the U.S. F-14 Tomcat naval fighter (1970) and B-1B Lancer bomber (1974), the European Panavia Tornado (1974). Of notable interest is the Sukhoi Su-24 'Fencer' (1970), which bears a more than superficial resemblance to the F-111, albeit possessing less capability.

Related Topics:
XF10F Jaguar - 1953 - Soviet - Sukhoi - Su-17 'Fitter' - 1966 - Mikoyan-Gurevich - MiG-23 'Flogger' - 1967 - Tupolev - Tu-160 'Blackjack' - 1981 - F-14 Tomcat - 1970 - B-1B Lancer - 1974 - Panavia - Tornado - Su-24 'Fencer'

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