In the Battle of the Bismarck Sea, imported Bristol Beaufighters proved to be highly effective ground attack and maritime strike aircraft. Beaufighters were later made locally by the DAP from 1944. Although it was much bigger than Japanese fighters, the Beaufighter had the speed to outrun them. The RAAF operated a number of Consolidated PBY Catalina as long-range bombers and scouts. The RAAF's heavy bomber force was predominantly made up of 287 B-24 Liberators, equipping seven squadrons, which could bomb Japanese targets as far away as Borneo and the Philippines from airfields in Australia and New Guinea. By late 1945, the RAAF had received or ordered about 500 P-51 Mustangs, for fighter/ground attack purposes. The Commonwealth Aircraft Corporation initially assembled US-made Mustangs, but later manufactured most of those used.