F-111C, Avalon Airshow, 20-25 March 2007 “Breaking the Barriers!”
The General Dynamics F-111C (nicknamed "Pig") is a variant of the F-111 Aardvark medium-range interdictor and tactical strike aircraft, developed by General Dynamics to meet Australian requirements. The design was based on the F-111A model but included longer wings and strengthened undercarriage. The Australian government ordered 24 F-111Cs to equip the Royal Australian Air Force (RAAF) in 1963, but the aircraft were not delivered until 1973 because of long-running technical problems. During 1979 and 1980 four of these aircraft were converted to the RF-111C reconnaissance variant. Four ex-United States Air Force (USAF) F-111As were purchased by Australia and converted to F-111C standard in 1982 to replace F-111Cs destroyed during accidents. Australia also operated 15 F-111Gs between 1993 and 2007, mainly for conversion training. The RAAF retired its remaining F-111Cs in December 2010.
The F-111Cs gave the RAAF a powerful strike capability but were never used in combat. The aircraft went through modernisation programs in the 1980s and 1990s, and the RAAF acquired improved weapons to maintain their ability to penetrate hostile airspace. Despite this, by the 2000s the F-111Cs were becoming outdated and expensive to maintain, leading to a decision to retire them in 2010 rather than 2020 as originally planned. The F-111s were replaced by 24 Boeing F/A-18F Super Hornets pending delivery of F-35 Lightning IIs in development.
The immensely complex and ambitious F-111 design and construction process forced the Australian government to quickly adopt sophisticated American procurement and project management methods. Although Australia originally planned to buy the American F-111A design, RAAF liaison officers requested country-specific changes such as a long-distance radio, Aeronautical Research Laboratories in Melbourne participated in an intake redesign and provided metal fatigue expertise, and an Australian test pilot evaluated the Australian version's longer wings and performance in tropical conditions. The differences from the F-111A caused it to be designated the F-111C in 1966.
The first F-111C was officially delivered in 1968, finally giving Australia an aircraft that could fly to Jakarta, drop bombs, and return without refuelling. (The RAAF only acquired air-to-air refuelling for the F/A-18, possibly to avoid causing difficulties with other Asian countries by increasing the F-111C's already great range.) Training began in 1967, with RAAF personnel seeing terrain-following radar and other sophisticated equipment for the first time. 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, damaging the morale of the hundreds of trained RAAF personnel who had little to do. 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 line-scanner 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. 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, and twin ring-laser gyro INS.
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 Centre (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.
The F-111 was an all-weather attack aircraft capable of low-level penetration of enemy defences to deliver ordnance on the target. It featured variable geometry wings, an internal weapons bay and a cockpit with side-by-side seating. The cockpit formed part of an escape crew capsule. The F-111 had a three-point undercarriage arrangement with a two-wheel nose gear and two single-wheel main undercarriage. Most F-111 variants included a terrain-following radar system connected to the autopilot. The aircraft were powered by two Pratt & Whitney TF30 after-burning turbofan engines.
The F-111's internal weapons bay could also carry bombs, a removable 20 mm M61 cannon, or auxiliary fuel tanks. The F-111C was 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 allowed the F-111 to designate targets and drop laser-guided bombs on them. RF-111Cs carried a pallet of sensors and cameras for reconnaissance use. F-111Cs were also equipped to launch the AGM-84 Harpoon anti-ship missile and the AGM-142 Popeye stand-off missile.
