CAC Boomerang The CAC Boomerang was a World War II fighter aircraft designed and manufactured in Australia between 1942 and 1945 . The Commonwealth Aircraft Corporation produced Boomerangs under the production contract numbers CA - 12 , CA - 13 , CA - 14 and CA - 19 , with aircraft supplied under each subsequent contract incorporating modifications and improvements . The Boomerang is significant as the first combat aircraft designed and built in Australia . Development . Background . The Pacific War began on 7 December 1941 with surprise attacks by the Empire of Japan on Pearl Harbor , Thailand , Malaya , and the Philippines . Within a few months , Japanese forces had conquered vast areas of the Pacific and South East Asia . During these campaigns , the ill - prepared Allied air forces in the Pacific suffered devastating losses . Because of political and cultural ties between the United Kingdom and Australia , British manufacturers were the main source of RAAF aircraft . However , the British aircraft industry had long been hard - pressed to meet the needs of the RAF . Although United States companies had enormous aircraft manufacturing capacity , their output was destined for US air units . When new aircraft built overseas did become available , they would be shipped long distances in wartime conditions , with consequent delays and losses . While USAAF fighters damaged during service in Australia , such as the Curtiss Kittyhawk ( P - 40 ) and Bell Airacobra ( P - 39 / P - 400 ) , could be rebuilt by Australian workshops and loaned to RAAF units they were not available in sufficient numbers either . CAC examined the possibility of designing and building fighters . The main challenge was the fact that fighter aircraft had never been built in Australia . Only two military aircraft were in production at the time : the Bristol Beaufort twin - engined bomber and the CAC Wirraway , a single - engine armed trainer / ground attack aircraft , based on the North American Harvard . While the Beaufort was not a suitable basis for a single - engine fighter , its 1 , 200 horsepower ( 890 kW ) Pratt & Whitney Twin Wasp engines were made under license at the CAC plant in Lidcombe , Sydney and also powered the Grumman Wildcat fighters used by the U . S . Navy . Consequently , the Twin Wasp was a logical choice for a stop - gap fighter design . The Harvard had already become the basis of the North American NA - 50 ( P - 64 ) fighter ( which had already seen action with the Peruvian Air Force ) . The Wirraway likewise provided a starting point for the Boomerang ' s airframe . Like the latest fighters at the time , planning for the Boomerang included automatic cannons . As no such weapons were manufactured locally , a British - made Hispano - Suiza 20 mm which an Australian airman had collected as a souvenir in the Middle East was reverse engineered . Development . Lawrence Wackett , general manager and former chief designer of CAC , recruited designer Fred David , an Austrian Jew who had recently arrived in Australia as a refugee . As David was technically an enemy alien , he was interned by Australian immigration officials . He was well - suited to the CAC project , since he had previously worked for Heinkel in pre - Nazi Germany , as well as Mitsubishi and Aichi in Japan . As a result , David had an excellent understanding of advanced fighter designs , including the Mitsubishi A6M ( " Zero " ) ( used by the Imperial Japanese Naval Air Service ) and the Heinkel He 112 ( a contemporary of the Messerschmitt Bf 109 and used in small numbers by Axis air forces in Europe ) . Design work began on 21 December 1941 , at the CAC factory in Fishermans Bend , Melbourne . The Boomerang was a small fighter , designed with an emphasis on manoeuvrability . It had an overall length of just 7 . 7 metres ( 25 . 5 ft ) and an 11 m ( 36 ft ) wingspan . Although the original intention had been to use as many Wirraway components as possible , the final design was quite different , with shorter wings , a shorter , wood - sheathed , aluminium - framed fuselage , increased strength for combat stresses and a new centre section . On 2 February 1942 , before the debut flight of the Boomerang ' s prototype , the RAAF ordered 105 CA - 12 ( Mark I ) variants . The prototype commenced test flights on 29 May , with pilots Ken Frewin ( CAC ) and John Harper ( RAAF ) . On 15 July , No . 1 Aircraft Depot RAAF received " A46 - 1 " ( bu . no . " 824 " ) from CAC . Comparison flight tests were undertaken by 1 AD , against a Brewster Buffalo ( " A51 - 6 " ) that had been lightened and re - weighted to approximate the flight characteristics of a Zero , as well as a P - 40E ( " A29 - 129 " ) and a P - 400 ( " BW127 " ) . It was found that the Boomerang was faster in level flight than the " Zero " , although the Buffalo out - manoeuvred it . The Boomerang was superior in armament , with two 20 mm cannon and four . 303 calibre ( 7 . 7 mm ) machine guns , all mounted in the short , thick wings . Its pilots were better protected , with generous armour plating , than Japanese fighter pilots . While the CA - 12 was lively at low level , its performance fell away rapidly above altitudes of 15 , 000 ft ( 4 , 600 m ) , and its maximum speed of 265 knots ( 490 km / h ) was not sufficient to make it an effective counter to Japanese fighters like the Zero and the Imperial Japanese Army Air Force ' s Nakajima Ki 43 ( " Oscar " ) . Similarly , the best European fighters were reaching almost 350 knots ( 650 km / h ) , and even relatively sluggish fighters like the Wildcat and the Kittyhawk ( which would become the main fighter used by the RAAF during the war ) were much faster than the Boomerang . As test and trial flights commenced , CAC had already begun work on a new variant , the CA - 14 , to address the Boomerang ' s deficiencies in speed , climb and ceiling . The CA - 14 was designed around an order for 145 U . S . - built , 1 , 700 hp ( 1 , 268 kW ) Wright Cyclone R - 2600 engines . However , the Wright engines ordered were not delivered as scheduled , and in mid - 1942 Wackett authorised use of the 1 , 850 hp ( 1 , 380 kW ) Pratt & Whitney R - 2800 , which was available from the CAC factory in Lidcombe . However , the significantly greater weight of this powerplant led to an unacceptable risk of undercarriage failure . ( The R - 2800 engine would later be the basis of design work on the Boomerang ' s successor , the CAC CA - 15 , also known as the " Kangaroo " . ) CAC eventually returned to the Twin Wasp , to which it added a General Electric B - 2 turbo - supercharger mounted inside the rear part of the fuselage , new propellor gear , a geared cooling fan ( influenced by intelligence reports from Europe regarding captured German BMW 801 twin - row radial engines , which were used by the Focke - Wulf Fw 190 A ) and a larger , squared - off tailfin and rudder . By July 1943 , the significantly re - worked CA - 14 prototype , now known as the CA - 14A , had a top speed which was 25 – 30 % better than the CA - 12 , and an operational ceiling which was 4 , 000 ft ( 1 , 200 m ) higher . Testing of later Boomerang variants found that they compared favourably with the Spitfire Mk V and early Thunderbolt s and Mustang s . By this time , however , British - built Spitfires had filled the interceptor role and Mustangs had been ordered , to fill the bomber escort , air superiority and close air support roles . Consequently , production Boomerangs were never fitted with superchargers . Operational history . Boomerangs that reached RAAF training and frontline units were delivered under three different CAC production contract numbers : CA - 12 , CA - 13 and CA - 19 , incorporating various minor improvements and modifications . A total of 250 aircraft of these marques were built : 105 CA - 12s , 95 CA - 13s and 49 CA - 19s . The CA - 13 and CA - 19 are sometimes known collectively as the Boomerang Mark II . On 19 October 1942 , CA - 12 " A46 - 6 " ( bu . no . " 829 " ) became the first Boomerang to reach a training / conversion unit , when it was transferred to No . 2 OTU , from 1 AD . No . 83 Squadron ( 83 Sqn ) became the first fighter unit to receive Boomerangs , when several were delivered to it – replacing Airacobras – at Strathpine Airfield , in Strathpine , Queensland , on 10 April 1943 . A few weeks afterward , CA - 12s were also received by a frontline air defence unit , No . 84 Squadron which was stationed on Horn Island Airfield , in Torres Strait . The third Boomerang fighter unit , No . 85 Squadron – like 83 Sqn – was performing home defence duties , at RAAF Guildford ( known later as Perth Airport ) ; the Boomerangs replaced the squadron ' s Buffaloes . On the evening of 20 May 1943 , Flight Lieutenant Roy Goon became the first Boomerang pilot to scramble on the Australian mainland against Japanese bombers . Goon , part of an 85 Sqn detachment at RAAF Learmonth , near Exmouth , Western Australia , undertaking air defence of the Allied naval base at Exmouth Gulf ( codenamed " Potshot " ) , took off to intercept Japanese bombers . After Goon had sighted them , the bombers dropped their payloads wide of their target and left the area . 84 Sqn had been deployed to Horn Island – a US Army Air Forces bomber base – in an attempt to address Japanese air raids and the continuing shortage of fighters in this area . The squadron was only modestly successful however . The Boomerang ' s low top speed and poor high altitude performance meant that No . 84 could drive off enemy attacks but rarely get close enough to Japanese aircraft to bring their guns to bear . On the only occasion that a Boomerang did close on a Japanese aircraft , its guns jammed . There were not many air raids in this area , and after using Boomerangs for eight months No . 84 Sqn upgraded to the Kittyhawk . The Boomerang found its niche as a light ground attack aircraft , a vital role as the ground war in the jungles of the South West Pacific theatre was often characterised by widely dispersed , small unit actions , fought at close quarters , with uncertain front lines . The Boomerang was ideal in this role because it : had the range to go wherever it was needed when it was based close to ground operations ; had heavy armament ; was agile and easy to fly , meaning that pilots could get close to ground targets , avoid ground fire and rough terrain and ; featured extensive armour plating and a wood and aluminium airframe , that could withstand significant battle damage . Some of the aircraft were shot down , including two accidental " kills " by US forces , and many were damaged during accidents while landing , often because the Boomerang was prone to ground looping . No . 4 Squadron and No . 5 Squadron flew Boomerangs in New Guinea , the Solomon Islands Campaign and Borneo Campaign , also in the close support role , with marked success . Flying in pairs ( one to observe the ground , the other to observe the air around them ) , their tasks included bombing , strafing , close infantry support and artillery spotting . When attacking larger enemy formations Boomerangs often operated in conjunction with larger aircraft . In this role the Boomerang would get in close to confirm the identity of the target and mark it with a 20 lb ( 9 kg ) smoke bomb with the " cooperating " aircraft delivering the major ordnance from a safer distance . A partnership between 5 Sqn Boomerangs and Royal New Zealand Air Force Corsair fighter bombers during the Bougainville Campaign was said to be particularly effective . No . 8 Communications Unit used Boomerangs to assist with air sea rescue operations in New Guinea . The sole CA - 14A was used for research by No . 1 Aircraft Performance Unit RAAF , and was also seconded to the Bureau of Meteorology for a period after the war ended . Survivors . Three Boomerangs remain airworthy today , all in Australia : A full - scale , airworthy replica with many original parts is based in the United States . Several others are under restoration to fly in both Australia and the USA . This includes " A46 - 90 " which is currently being restored to airworthy status .