Brisbane Centre is located adjacent to Brisbane Tower at Brisbane Airport. It also contains Brisbane Approach and Cairns Approach. Melbourne Centre The Melbourne FIR consists of all other Australian airspace outside the Brisbane FIR. This includes Victoria, Tasmania, southern New South Wales including Sydney, most of South Australia and the southern half of Western Australia. It also contains the Australian Indian and Southern Ocean airspace. Apart from international flights arriving from the Indian Ocean, most international flights will pass through Brisbane Centre first. However, as the FIR contains six of the eight capital cities, a very large portion of domestic flights are controlled from Melbourne Centre. Melbourne Centre is located adjacent to Melbourne Tower at Melbourne Airport. It also contains Melbourne Approach, Canberra Approach and Adelaide Approach. Military air traffic control Like civil air traffic control, the Australian Defence Force provide tower and approach services but do not provide en route services. Although historically each of the three services had its own air traffic controllers, the Royal Australian Air Force exclusively provides air traffic control services to the Australian Defence Force. 44 Wing (44WG) was formed to centrally manage ATC personnel and facilities at 11 defence bases. 44 Wing is an Air Command unit, belonging to the Surveillance and Response Group and is headquartered at RAAF Base Williamtown, Williamtown, NSW. 44WG is divided into two squadrons; No. 452 Squadron which consists of all ATC units at bases north of the Queensland border, and No. 453 Squadron which consists of ATC units at bases south of the Queensland border. The ATC unit established at each base in known as a flight and belongs to one of the two squadrons. Each flight manages air traffic control services at the base, although is ultimately commanded from HQ452SQN, RAAF Base Darwin or HQ453SQN RAAF Base Williamtown. The RAAF provides both tower and approach services, and in some cases a limited centre (or en route) service. However, centre services are normally amalgamated with approach control. Two bases, Richmond and Edinburgh, provide only a tower service, given their close proximity to Sydney and Adelaide respectively. Civilian ATC provides approach services to these bases. Tower and approach services are normally located within the control tower or an adjacent building. Unlike civilian ATC, no approach or en route services are provided remotely. Currently, most military ATC units use the Australian Defence Air Traffic System. The RAAF use Airservices