The only aircraft that was completely designed built and operated exclusively in Australia during WWII. The Boomerang was not an exceptional fighter; it spent most of its career as a ground support aircraft and a feared one at that. Boomerangs were the only plane available to the RAAF at the beginning of the war, but were quickly replaced with Spitfires from Britain and the P-40 from the USA. 

After Japan's attack on Pearl Harbour, Australia found itself ill prepared. The only real fighters the RAAF had were a small number of the US built Brewster Buffalo, which were later found to be no match for the Japanese Zero fighter when flown by the RAF defending Singapore. To overcome this shortfall and the distinct possibility that Australia could not get fighters from overseas, design work was started on the CA-12 Boomerang. Using parts from the CA Wirraway, the Boomerang was designed and built in only three months. 105 airframes were built during 1942-3.