CAC Boomerang
Boomerang | |
---|---|
Boomerang from No. 5 Squadron RAAF | |
Role | Fighter aircraft |
National origin | Australia/United States |
Manufacturer | Commonwealth Aircraft Corporation |
Designer | Fred David |
First flight | 29 May 1942 |
Introduction | 1943 |
Status | Retired |
Primary user | Royal Australian Air Force |
Produced | 1942–1945 |
Number built | 250[1] |
The CAC Boomerang is a
Different variants of the Boomerang were manufactured under a series of corresponding production contract numbers CA-12, CA-13, CA-14 and CA-19, the aircraft supplied under each subsequent contract would incorporate various modifications, typically aimed at improving the aircraft's performance. The Boomerang was handicapped by the available engine variant, which gave low power at altitude and resulted in the aircraft proving to be slower than contemporary fighter aircraft. The Boomerang rarely engaged in aerial combat. During early wartime operations, the Boomerang was mainly dispatched to equip home-based squadrons, freeing up other fighters for use overseas. In later service, the Boomerang would commonly be used for
Development
Background
During the mid 1930s, some political leaders observed that both the Empire of Japan and Nazi Germany appeared to be preparing for war, which in turn led to several other countries commencing their own preparations.[3]
In Australia, the nation's small domestic aircraft industry required substantial expansion and reorganization to produce modern combat aircraft in sufficient numbers. While
CAC planned both engine and aircraft manufacturing and testing facilities at
On 7 December 1941, the
While most RAAF aircraft came from the UK, by 1942, the British aircraft industry was hard-pressed to even meet the needs of its own country.[3] Meanwhile, companies in the United States possessed enormous aircraft manufacturing capacity, but their output was at this point being monopolized by the United States Army Air Forces (USAAF) and United States Navy (USN), which were also at war with Japan. Even where capacity could be found for new aircraft to be built overseas, their delivery would require them to be shipped considerable distances in wartime conditions, with consequent delays and at the risk of considerable losses, in particular due to German U-boats and Japanese submarines.[3] While USAAF fighters such as the Curtiss P-40 Kittyhawk and Bell P-39 Airacobra that were being used in the region that were damaged during service could be rebuilt by Australian workshops and even loaned to RAAF units, they were not available in sufficient numbers.
Origins
In late 1941, Lawrence Wackett, Manager and Chief Designer of CAC, began examining the possibility of designing and building a new domestically-designed fighter aircraft.[3] The main challenge to this ambition was the fact that fighter aircraft had never been manufactured before in Australia; according to aviation author Rene J. Francillon, many experts considered that the licensed manufacture of a complete fighter aircraft would be beyond the capabilities of Australia's industry at that time.[3] Wackett quickly decided to use elements of aircraft which were already being produced in Australia. Only two military aircraft were in production at the time: the CAC Wirraway, based on the North American NA-16, and the Bristol Beaufort bomber.[4]
Overseas, the NA-16 had already become the basis of the North American NA-50 fighter (also known as the P-64), which had been used by the Peruvian Air Force in the 1941 Ecuadorian–Peruvian War. Crucially, CAC's licence to manufacture the Wirraway already contained a clause allowing the design to be modified.[4] Accordingly, Wackett decided to use the airframe of the Wirraway as a starting point for the design of the new domestic fighter; this choice had the advantage of requiring little additional tooling; it also had the effect of reducing the timescales that would be involved in the design phase and to establish the manufacturing of the new aircraft.[5]
Although British designers had reworked the twin-engined Beaufort into a successful attack aircraft, the Beaufighter, this was not a suitable basis for the sought-after single-engine interceptor aircraft. However, Australian-made Beauforts used 1,200 horsepower (890 kW) Pratt & Whitney R-1830 Twin Wasp engines, which were made under licence at the CAC plant in Lidcombe, Sydney.[5] Another factor in favour of the engine was that it was already in use to power the Grumman F4F Wildcat fighters of the United States Navy, which helped make the Twin Wasp a logical choice to power the domestic fighter design.[5]
Wackett promptly recruited designer
In December 1941, the management of CAC issued its authorisation to proceed with the detailed design of the new fighter aircraft.[5] The aircraft, which had received the internal designation of CA-12, used the wing, tail assembly, undercarriage, and center section of the Wirraway in combination with a new forward fuselage, which housed the larger Twin Wasp engine. It had a new single seat cockpit complete with a sliding hood, and carried an armament of two 20 mm Hispano-Suiza HS.404 cannons along with four .303 machine guns.[5] The proposal was presented to the Australian Government, which promptly gave its approval; the government viewed the CA-12 as an appropriate insurance against the delay or cancellation of its order for US-built P-40 fighters, as well as a desire to maintain work at CAC; the ready availability of usable Wirraway components for the CA-12, the latter of which would greatly speed up any manufacturing program, was also viewed favourably.[8]
Accordingly, on 18 February 1942, the Australian War Cabinet authorised an order for 105 CA-12 aircraft; shortly thereafter, the name Boomerang was selected for the aircraft.[5] The ordering of production aircraft had been made in advance of any prototype being produced or maiden flight performed, thus the Boomerang had been effectively ordered 'off the drawing board'.
Prototypes and early production
On 29 May 1942, the prototype Boomerang, A46-1, conducted its maiden flight from Fishermans Bend, flown by CAC pilot Ken Frewin.[9] This initial prototype had been completed within only three months of having received the order to proceed, which was a considerably rare accomplishment for the era. A46-1 was quickly put to use for a series of test flights, being flown either by Frewin or by RAAF pilot John Harper; these tests reportedly went smoothly, with the prototype proving to be easy to handle and quite manoeuvrable.[10] An issue with engine cooling was encountered, which led to a revision of the oil cooler intake and the addition of a spinner to the propeller upon A46-3 onwards.[9] On 15 July, No. 1 Aircraft Depot (1 AD) of the RAAF formally received A46-1 (bu. no. 824) from CAC.[10]
Comparison flight tests were undertaken by 1 AD, pitting the CA-12 against a
From March 1942, there was less pressure to place the CA-12 into production as multiple USAAF units, operating a mixture of P-40 and P-39 fighters, were being deployed in strength to northern Australia; the RAAF had also begun to receive new Kittyhawk fighters as well. In June 1943, manufacturing work upon the original order for 105 CA-12s was completed.[12] During production of this batch, several modifications and improvements were incorporated onto the CA-12, these included the strengthening of the spinner back plates and belly tank locating pins, the installation of underwing night flying identification lights, and a revised electrical starter system; many of these modifications would be retrofitted onto early production models at operational bases as well.[12]
In the face of difficulties experienced by CAC on the development of the CAC Woomera, a twin-engine bomber aircraft which was ultimately cancelled in September 1944, the Australian government elected to extend the production arrangement for the Boomerang, extending its orders from 105 to 250 aircraft.[13] These additional 145 aircraft were manufactured in four distinct versions, the CA-13, the CA-14, CA-14A and CA-19.[14] 95 CA-13s and 49 CA-19s, were completed, while only one prototype of the supercharged Boomerang CA-14 and its modified CA-14A form would be produced.[15] In February 1945, the final Boomerang to be manufactured, A46-249, a CA-19 model, was completed.[13]
Further development
During the flight testing phase of development work upon the initial CA-12 model, CAC commenced work upon a new variant which featured performance improvements in terms of speed, climb and ceiling.
Unfortunately, the addition of significantly greater weight of this powerplant imposed an unacceptable risk of undercarriage failure.[16] (The R-2800 engine would later be the basis of design work on the Boomerang's successor: the CAC CA-15 "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 propeller 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 190A) and a larger, squared-off tailfin and rudder.[16][17]
By July 1943, the significantly re-worked CA-14 prototype, now known as the CA-14A, had a top speed that was 25–30% better than the CA-12, and an operational ceiling 4,000 ft (1,200 m) higher.
Design
The Boomerang was a small single-engine monoplane fighter aircraft, designed with an emphasis on high manoeuvrability. It had a stubby appearance, which had resulted from the structure being derived from the smaller Wirraway being paired with a considerably larger engine in the form of a 1,200 horsepower (890 kW) Pratt & Whitney R-1830 Twin Wasp radial engine, which drove a three-bladed Hamilton Standard Hydromatic propeller, license-built by de Havilland.[9] The engine was closely cowled with two air scoops fixed to the upper and lower sides, the upper being for the carburetor and the lower for the oil cooler.[9] Fuel was divided between one fuselage-housed 70-imperial-gallon (320-litre) self-sealing fuel tank and a pair of 45 imp gal (200 L) tanks within the center section of the wing.[12]
Although the original intention during development had been to use as many Wirraway components as possible, the final design of the Boomerang had substantially differed from the source, having adopted shorter wings along with a shorter, wood-sheathed, aluminium-framed fuselage, which had increased strength to withstand combat stresses, and an original centre section.[12] The low-mounted cantilever wing consisted of five sections, these being a central section, a pair of outer sections, and two detachable wing tips; the outer sections had a swept-back leading edge along with a straight trailing edge.[9] The wing used a single spar and a stressed skin construction, along with fabric-covered ailerons, aluminium trim tabs and split trailing edge flaps. The main undercarriage hydraulically retracted into wheelwells forward of the main spar.[12]
The Boomerang had a new single seat cockpit located directly over the centre of the wing, which was furnished with a sliding canopy which had 1.5-inch (38 mm) bulletproof glass and armor protection.[12] Common to many of the latest fighters at the time, the Boomerang was equipped with automatic cannons; as no such weapons had previously been manufactured in Australia, a pair of British-made Hispano-Suiza 20 mm were used.[12] Allegedly, an example which an Australian airman had collected as a souvenir in the Middle East was reverse engineered.[citation needed] Other armament fitted included four Browning .303 machine guns along with provision for up to four 20 lb smoke bombs; all of these were mounted within the wings.[12]
Operational history
On 19 October 1942, CA-12 A46-6 (bu. no. 829) became the first Boomerang to reach a training/conversion unit, it was immediately put to use training pilots when it was transferred to
No. 83 Squadron became the first fighter unit to receive Boomerangs, when several were delivered to replace Airacobras at Strathpine Airfield in Strathpine, Queensland on 10 April 1943.[10] 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 No. 83 Squadron, was performing home defence duties, at RAAF Guildford (known later as Perth Airport); the Boomerangs replaced the squadron's Buffaloes.
On 16 May 1943, the first encounter between the Boomerang while on aerial patrol duties and Japanese aircraft occurred; a pair of Boomerangs, flown by Flying Officer Johnstone and Sergeant Stammer, spotted three
No. 84 Squadron had been deployed to a
While RAAF records show that the Boomerang was never recorded as having destroyed any enemy aircraft, the type proved to be more useful in its capacity as a light
The aircraft proved to be ideal in this ground attack role due to a number of qualities that it possessed. The Boomerang 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 along with 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.[10][18]
On 14 August 1945, the wartime role of the Boomerang came to an end when the suspension of all offensive operations against land targets, except for direct support of Allied ground forces in contact with the enemy, was issued.[1]
No. 8 Communications Unit operated a number of Boomerangs to assist with
The sole CA-14A was used for research by No. 1 Aircraft Performance Unit RAAF, and was also seconded to the
Variants
- CA-12 (Mark I)
- The first single-seat fighter version, 105 built.[23]
- CA-13 (Mark II)
- Improved version of the CA-12, 95 built.[23]
- CA-14
- One aircraft fitted with a turbo-supercharged engine, did not enter production. Serial number A46-1001.[23]
- CA-14A
- The CA-14 prototype was later modified to have a square tail and rudder.[23]
- CA-19
- Tactical reconnaissance variant with a single vertical camera in the fuselage, 49 built. Serial numbers: A46-201 to A46-249.[23]
Operators
- Royal Australian Air Force
- No. 2 Operational Training Unit (October 1942 – 1945)
- No. 4 Squadron (August 1943 – August 1945). Code letters: QE
- No. 5 Squadron (November 1943 – August 1946). Code letters: BF
- No. 83 Squadron (September 1943 – August 1945). Code letters: MH
- No. 84 Squadron (April 1943 – October 1943). Code letters: LB
- No. 85 Squadron (May 1943 – January 1945). Code letters: SH
- No. 8 Communications Unit(February 1944 – August 1944). Code letters: ZA
Surviving aircraft
- A46-30 – CA-12 on static display at the RAAF Museum in Point Cook, Victoria.[24][25]
- A46-63 – CA-12 airworthy with Boomerang Aviation Pty of Mile End South, South Australia.[26] It first flew again on 26 June 2009. The restoration includes the provision of a passenger seat.[citation needed]
- A46-77 – CA-12 under restoration to airworthy with Rotorworks Pty Ltd in Mareeba, Queensland.[27]
- A46-89 – CA-12 under restoration to airworthy with Ian Baker in Sydney.[28][29]
- A46-90 – CA-12 under restoration to airworthy with Ian Baker in Sydney, New South Wales.[30][29]
- A46-122 "Suzy Q" – CA-13 airworthy at the Temora Aviation Museum in Temora, New South Wales.[31][32][33] Ownership was transferred to the RAAF in July 2019[34] and it is operated by the Temora Historic Flight of the Air Force Heritage Squadron.[35]
- A46-140 – CA-13 under restoration to airworthy with Ian Baker in Sydney, New South Wales.[36][29]
- A46-147 "Zoot" – CA-13 under restoration to static with Nick Knight in Hoppers Crossing, Victoria.[37]
- A46-206 "Milingimbi Ghost" – CA-19 on static display at the Museum of Australian Army Flying in Toowoomba, Queensland.[38]
- Replica – Airworthy replica of an unknown variant, private owner based in the Netherlands. It was built using parts from the original A46-139. Previously registered in the United States as N32CS.[39][40][41]
Specifications (CA-12)
Data from The Great Book of Fighters and The Commonwealth Boomerang.[42][1]
General characteristics
- Crew: 1
- Length: 25 ft 6 in (7.77 m)
- Wingspan: 36 ft 0 in (10.97 m)
- Height: 9 ft 7 in (2.92 m)
- Wing area: 225 sq ft (20.9 m2)
- Empty weight: 5,373 lb (2,437 kg)
- Gross weight: 7,699 lb (3,492 kg)
- Powerplant: 1 × Pratt & Whitney R-1830 Twin Wasp 14-cylinder air-cooled radial piston engine, 1,200 hp (890 kW)
- Propellers: 3-bladed constant-speed propeller
Performance
- Maximum speed: 305 mph (491 km/h, 265 kn) at 15,500 ft (4,724 m)
- Range: 930 mi (1,500 km, 810 nmi)
- Service ceiling: 29,000 ft (8,800 m)
- Rate of climb: 2,940 ft/min (14.9 m/s)
- Wing loading: 34.2 lb/sq ft (167 kg/m2)
- Power/mass: 0.16 hp/lb (0.26 kW/kg)
Armament
- Guns:
- 2 × 20 mm (0.787 in) Hispano or CAC autocannons
- 4 × 0.303 in (7.7 mm) Browning machine guns
- 2 × 20 mm (0.787 in)
- Bombs: provision for a bomb, when the large ventral drop tank was not carried
See also
External videos | |
---|---|
Narrated video of a CAC Boomerang performing a flight display in New Zealand | |
Footage of the canopy restoration of a preserved Boomerang |
Related development
Aircraft of comparable role, configuration, and era
- Bloch MB.150
- Brewster F2A Buffalo
- Curtiss P-36 Hawk
- Curtiss-Wright CW-21
- FFVS J 22
- Mitsubishi A6M Zero
- Nakajima Ki-43
- North American P-64
- VL Myrsky
- Polikarpov I-16
- Vultee P-66 Vanguard
Related lists
- List of aircraft of the Royal Australian Air Force
- List of aircraft of World War II
- List of fighter aircraft
References
- ^ a b c Francillon 1967, p. 12.
- ^ Dennis et al. 2008, p. 98.
- ^ a b c d e f g h i j k Francillon 1967, p. 3.
- ^ a b Francillon 1967, pp. 3–4.
- ^ a b c d e f Francillon 1967, p. 4.
- ^ Ross 1995, p. 316.
- ^ Sunderland, Gary. "Elliptical Wings Part 2: The Fred David Story." Small Scale Squadron Down Under, v.6 no.3, September 2002.
- ^ Francillon 1967, pp. 4–5.
- ^ a b c d e Francillon 1967, p. 5.
- ^ a b c d e f g h i adf-serials.com RAAF Museum 2007, "A46 CAC Boomerang" (access: 10 April 2013).
- ^ Francillon 1967, p. 6.
- ^ a b c d e f g h Francillon 1967, p. 7.
- ^ a b Francillon 1967, p. 8.
- ^ Francillon 1967, pp. 8–9, 12.
- ^ a b Francillon 1967, pp. 8–9.
- ^ a b c d e f g Ross 1995, p. 321.
- ^ a b c d e Francillon 1967, p. 9.
- ^ a b c d e f g Francillon 1967, p. 10.
- ^ Government of Western Australia, 2013, "John C. Bailey." Archived 29 April 2013 at the Wayback Machine Retrieved 10 April 2013.
- ^ Francillon 1967, pp. 9–10.
- ^ Francillon 1967, pp. 10–12.
- ^ RAAF Historical Section 1995, p. 137.
- ^ a b c d e Kightly Aeroplane August 2016, p. 103.
- ^ "CAC Boomerang A46-30". RAAF Museum. Archived from the original on 17 August 2017. Retrieved 17 March 2023.
- ^ "Aircraft A46-30 Data". Airport-Data.com. Airport-Data.com. Retrieved 19 December 2016.
- ^ "Aircraft Register [VH-XBL]". Australian Government Civil Aviation Safety Authority. Retrieved 19 December 2016.
- ^ Goodall, Geoff (1 July 2021). "Commonwealth – CAC" (PDF). Geoff Goodall's Aviation History Site. Retrieved 18 July 2022.
- ^ "Boomerangs Downunder – Warbird Restoration Update". Vintage Aviation News. 28 March 2015. Retrieved 18 July 2022.
- ^ a b c Anderson, Sarah (6 April 2015). "Boomerang plane moved to the B-24 Liberator Restoration Fund hangar in Werribee". Leader Community News. News Corp. Retrieved 19 December 2016.
- ^ Rose, Scott. "CAC Boomerang/A46-090". Warbird Registry. Retrieved 18 July 2022.
- ^ "CA-13 Boomerang". Temora Aviation Museum. Temora Aviation Museum. Archived from the original on 27 December 2016. Retrieved 19 December 2016.
- ^ "Airframe Dossier – Commonwealth Aircraft Corporation (CAC) Boomerang II, s/n A46-122 RAAF, c/n 945, c/r VH-MHR". Aerial Visuals. AerialVisuals.ca. Retrieved 19 December 2016.
- ^ "Aircraft Register [VH-MHR]". Australian Government Civil Aviation Safety Authority. Retrieved 19 December 2016.
- ^ "May 2019 News". Temora Aviation Museum. 10 May 2019. Retrieved 10 February 2021.
- ^ Thorn, Adam (9 February 2021). "RAAF reforms legendary 100 Squadron to fly Warbirds". Australian Aviation. Retrieved 10 February 2021.
- ^ Parker, John (14 June 2015). "CAC Boomerang A46-140 – A Unique Warbird". Warbirds Online. Retrieved 18 July 2022.
- ^ Rose, Scott. "CAC Boomerang/A46-147". Warbird Registry. Retrieved 18 July 2022.
- ^ Rose, Scott. "CAC Boomerang/A46-206". Warbird Registry. Retrieved 18 July 2022.
- ^ "Aircraft N32CS Data". Airport-Data.com. Airport-Data.com. Retrieved 19 December 2016.
- ^ "FAA REGISTRY [N32CS]". Federal Aviation Administration. U.S. Department of Transportation. Archived from the original on 20 December 2016. Retrieved 19 December 2016.
- ^ "BOOMERANG FIRST FLIGHT". FAST. 18 October 2014. Retrieved 19 December 2016.
- ISBN 0-7603-1194-3.
Bibliography
- Caterson, Simon. "Magnificent men who built a vital flying machine". The Weekend Australian, 24 April 2010.
- Dennis, Peter et al. The Oxford Companion to Australian Military History. . South Melbourne, Australia: Oxford University Press, Second Edition 2008. ISBN 978-0-19-553227-2.
- Francillon, René J. The Commonwealth Boomerang, Aircraft in Profile number 178. Leatherhead, UK: Profile Publications, 1967.
- Green, William. War Planes of the Second World War, Fighters, Volume One. London: Macdonald, 1960 (10th impression 1972). ISBN 0-356-01445-2.
- Kightly, James. "Database: CAC Boomerang". ISSN 0143-7240
- Luranc, Zbigniew. Commonwealth Boomerang, Skrzydła W Miniaturze 24 (in Polish). Gdańsk: Wydawnicto Avia-Press, 2000. ISSN 1234-4109.
- Pentland, Geoffrey. Commonwealth Boomerang Described. Dandenong, Victoria, Australia: Kookaburra Technical Publications, 1964.
- Pentland, Geoffrey. RAAF Camouflage & Markings, 1939–1945, Vol. 1. Dandenong, Victoria, Australia: Kookaburra Technical Publications Pty Ltd., 1980. ISBN 0-85880-036-5.
- Pentland, Geoffrey. Wirraway and Boomerang Markings. Dandenong, Victoria, Australia: Kookaburra Technical Publications, 1970. ISBN 0-85880-007-1.
- RAAF Historical Section (1995). Units of the Royal Australian Air Force: A Concise History. Volume 4: Maritime and Transport Units. Canberra: Australian Government Publishing Service. ISBN 9780644427968.
- Ross, A.T. Armed and Ready: The Industrial Development and Defence of Australia 1900–1945. Wahroonga, New South Wales, Australia: Turton & Armstrong, 1995. ISBN 0-908031-63-7.
- Wilson, Stewart. Wirraway, Boomerang & CA-15 in Australian Service. Sydney, Australia: Aerospace Publications, 1991. ISBN 0-9587978-8-9.
- Zbiegniewski, Andre R. and Jacek Nowicki. CAC Boomerang & CAC Wirraway, Wydawnicto Militaria 43 (in Polish). Warszawa: Wydawnicto Militaria, 1997. ISBN 83-86209-57-7.