By April 1943, the disposition of the AAF was such that RAAF Command, headquartered in Brisbane, Queensland, controlled 27 squadrons: 24 Australian units plus one each from the Netherlands, the United Kingdom and the United States. Its main war-fighting effort was centred in North-Western Area Command, headquartered in Darwin, Northern Territory, while No. 9 Group conducted operations in New Guinea. RAAF Command units in the Western, Southern, Eastern, and North-Eastern Area Commands were engaged in maritime patrol, anti-submarine, and minelaying operations off the Australian coast. In June, the 380th Bombardment Group USAAF, operating B-24 Liberator heavy bombers, was also placed under the control of RAAF Command, which assigned the group to North-Western Area. By the end of 1943, No. 9 Group, originally the RAAF's mobile strike force, had become engaged in static garrison duties in New Guinea. No. 10 Operational Group was raised on 13 November 1943 at Nadzab to take over that mobile function. In February 1944, RAAF Command took over many of the units of No. 9 Group, as well as responsibility for the Port Moresby and Milne Bay sectors; South-Eastern New Guinea thus effectively became an extension of Australia for the purposes of RAAF Command's sphere of operations. No. 9 Group was subsequently renamed Northern Command, to better reflect its new function as a static area command covering New Guinea. No. 10 Group's initial combat missions were conducted from Cape Gloucester in March, before preparations began in April for the Hollandia–Aitape landings. These operations were supported by a bombing and mine-laying campaign directed by RAAF Command through North-Western Area. By October 1944, No. 10 Group's name had been changed to First Tactical Air Force (No. 1 TAF), and RAAF Command's complement had swelled to 41 Australian squadrons.