The wing employed a centralised servicing regime, whereby all aircraft and maintenance personnel were held by No. 482 Squadron, which released the F-111s in line with Nos. 1 and 6 Squadrons' joint flying program. In February 1981, responsibility for operating-level servicing of the F-111s was transferred to the flying squadrons, which for the first time took direct control of their F-111s. No. 482 Squadron continued to provide intermediate-level servicing, while major upgrades and complex maintenance were carried out by No. 3 Aircraft Depot. These two organisations merged in 1992 to form No. 501 Wing, which handed over heavy maintenance of the F-111 to Boeing Australia in 2001. Between 1977 and 1993, the RAAF lost seven F-111Cs in crashes. Three of the accidents involved aircraft flown by No. 1 Squadron: in August 1979, January 1986 and September 1993, the last two killing both crew members. In July 1996, No. 1 Squadron took responsibility for aerial reconnaissance using specially modified RF-111Cs previously operated by No. 6 Squadron. This gave No. 1 Squadron five mission types: land strike, maritime strike, close air support, long-range air defence, and reconnaissance. In May 1999 the unit was again awarded the Gloucester Cup for proficiency. Along with its revolutionary variable-sweep wings, the F-111 was equipped with terrain-following radar and an escape module that jettisoned the entire cockpit in an emergency, rather than individual ejection seats. Its top speed was Mach 2.5 and its combat radius allowed it to reach targets in Indonesia from bases in northern Australia. Upon delivery in 1973 it was fitted with analogue avionics and could only drop unguided ("dumb") bombs. In its 37 years of service with the RAAF the type went through several upgrades, including the Pave Tack infra-red and laser-guided precision weapons targeting system, Harpoon anti-shipping missiles, and advanced digital avionics. Alan Stephens, in the official history of the post-war Air Force, described the F-111 as "the region's pre-eminent strike aircraft" and the RAAF's most important acquisition. The closest they came to being used in anger, though, was during Australian-led INTERFET operations in East Timor commencing in September 1999. Both F-111 squadrons were deployed to RAAF Base Tindal, Northern Territory, to support the international forces in case of action by the Indonesian military, and remained there until December; six of No. 1 Squadron's aircraft and approximately 100 personnel were involved.