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.