Background '81|alt=Front view of two jet aircraft in two-tone green camouflage scheme in-flight, wings unswept. The trailing aircraft is slightly off-centered to the right In June 1960, the
United States Air Force (USAF) issued a requirement for an
F-105 Thunderchief replacement. The U.S. Navy began a program to develop a new air defense fighter for use on its large aircraft carriers. The Tactical Fighter Experimental (TFX) requirements were based largely on the Air Force's needs. A
request for proposals (RFP) for the TFX was provided to industry in October 1961. After four rounds of proposals,
General Dynamics (GD) was selected over
Boeing; GD signed the TFX contract in December 1962. The USAF F-111A and Navy F-111B variants used the same airframe structural components and TF30-P-1 turbofan engines. They featured side-by-side crew seating in an
escape capsule, as required by the Navy. Because of conflict between the Air Force and Navy over whose requirements had precedence, McNamara intervened in 1961, declaring that the Air Force desires would override suggestions by the Navy. It was followed by the F-111B, which first flew on 18 May 1965. As F-111 development continued, stall issues arose in certain parts of the flight regime; these were addressed by modifying the engine inlet in 1965–66, ending with the "Triple Plow I" and "Triple Plow II" designs. The F-111B was cancelled by the Navy in 1968 due to weight and performance deficiencies. The improved F-111E, F-111D, F-111F models were subsequently developed for the USAF. The FB-111A strategic bomber and the EF-111 electronic warfare versions were also later developed for the USAF. Production ended in 1976, with a total of 563 F-111s of all variants built, well below the prediction of 1,500. The non-supersonic Canberra lacked radar and
electronic countermeasures, all disadvantages based on
Korean War experience. The RAAF believed that it needed a new strategic bomber to fulfill the nation's obligations to the
Commonwealth Strategic Reserve in
Malaysia,
ANZUS, and
SEATO. Air Staff Requirement 36 that year mandated an all-weather attack aircraft by 1959 capable of delivering a variety of bombs and missiles. A study recommended one of the British
V bombers, but
Minister of Defence Frederick Shedden decided in 1956 that at
£1 million each they were too expensive. Air Marshal
Valston Hancock,
Chief of the Air Staff, stated in April 1960 that Australia needed a replacement for the Canberra. Although in mid-1962 the Menzies government again decided to not replace the Canberra,
Indonesia's increasingly aggressive statements regarding Malaysia soon caused Australia to reevaluate the decision.
The Sydney Morning Herald reported in October 1962 that the
Indonesian Air Force's Soviet
Tupolev Tu-16 bombers could reach
Sydney or any other Australian city with a light bomb load, while the Canberras could not
fly in all weather and had a range of , insufficient to reach
Jakarta. but
Minister for Air Frederick Osborne acknowledged that the Canberras were "the weakest link in our armory at the present moment". He stated, however, that the available foreign bombers were unsuitable for the RAAF. The American
Boeing B-52 Stratofortress and
Convair B-58 Hustler, for example, were too large for existing Australian runways. More suitable aircraft such as the British
BAC TSR-2 and the American TFX (later the F-111) would soon be available, Osborne said. From June to August, Hancock's team visited France, Britain and the United States to evaluate the competitors, and determined that the TFX would be the aircraft best suited for the role. The Mirage IV had insufficient range and the A£108 million price was too expensive. The F-4 and the A-5 were immediately available, but the less expensive F-4 would need air-to-air refueling to reach Indonesia from Australia. The TSR-2 was behind schedule and over budget, was the most expensive at A£122 million for 24 aircraft, and British government support for the program was uncertain. While the TFX was also controversial in the United States, its promised performance specifications and per-aircraft cost were superior to that of the TSR-2. As he did not expect TFX to be available before 1970, however, Hancock recommended buying 36 A-5 aircraft for A£88 million to counteract the perceived imminent threat from Indonesia. The Menzies government was reluctant to choose as interim replacement the A-5 or the F-4, which could not be deployed until 1966 and would cost
A$120–180 million. Waiting for the TSR-2 or TFX in 1969 or 1970 seemed to pose great risk, The British and American governments competed on behalf of their nations' unbuilt bombers, as both believed that export sales would increase domestic support for the aircraft. The Menzies government viewed the British promise to deploy a squadron of V bombers in Australia for interim defense until the TSR-2 was ready as unacceptable for both technical and political reasons. Beyond its cost, the
Royal Air Force had not ordered the TSR-2; the
Chief of the Defence Staff Lord Louis Mountbatten, who opposed it, advised the Australians against buying the aircraft and the RAAF feared being the only customer.
Decision The government determined that it did not need to go ahead with an immediate replacement for the Canberra and preferred Hancock's original choice of the TFX as a long-term solution, leading to the Menzies government's announcement on 24 October that it was ordering 24 F-111s for US$125 million, enough for two squadrons. The announcement came during the campaigning for the
1963 general election. Calwell's Labor party had on 22 October reiterated its pre-campaign promise that it would replace the Canberras as soon as it formed a government. The government's announcement, and the consequent improvement of its chances against Labor, likely also benefited the United States; the purchase helped rebut American critics of the TFX, The contract was signed the following year through the U.S. Department of Defense. The British government's cancellation of the TSR-2 in April 1965 showed that Australia's decision to not order it was correct.
Procurement, delays, and renaming The U.S. offered two squadrons of
Boeing B-47 Stratojets for free lease pending the delivery of the F-111; Australia declined the offer in June 1964—despite the aircraft having been demonstrated around the country just before the 1963 election as an interim Canberra replacement, likely another sign of the American preference for Menzies— because the B-47 did not offer significant improvements over the Canberra and, like the V bombers, would require longer runways.
Delivery The first F-111C was officially delivered in 1968, However, development delays and structural problems delayed acceptance of aircraft by the RAAF until 1973. These issues were mainly to do with the
wing attach points, and the redesign of the F-111 engine intakes. Completion of contractual requirements to the satisfaction of Australia also took time, The program costs, during 1963–1967, grew at an alarming rate; estimates by the USAF at the start of the program was placed at US$124.5 million, but by April 1967 had risen to $237.75 million. While the initial price of US$5.21 million per aircraft was capped at US$5.95 million, R&D, labor, and other costs were not. The rising price, three unexplained losses of USAF F-111As in
Vietnam during their first month of deployment, and the British and U.S. Navy's orders' cancellations caused further controversy in Australia during 1968. By 1973, however, when the F-111A had accumulated 250,000 flight hours, it had the best safety record among contemporary aircraft, which presaged the F-111C's own excellent record. Four aircraft were modified to RF-111C reconnaissance configuration during 1979–80, retaining their strike capability. The RF-111C carried a reconnaissance pack with four cameras and an infrared linescanner unit. Four ex-USAF F-111As were refitted to F-111C standard and delivered to Australia as attrition replacements in 1982. There F-111Cs were equipped to carry
Pave Tack FLIR/laser pods in the mid-1980s. They underwent an extensive Avionics Upgrade Program through 1998. 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. Following the Avionics Upgrade Program, Australian F-111s received weapons system and various other upgrades. ==Design==