CAC Boomerang

Template:Infobox Aircraft The CAC Boomerang was a World War II fighter aircraft designed and manufactured in Australia between 1942 and 1945. The Commonwealth Aircraft Corporation gave Boomerangs the model numbers CA-12, CA-13, CA-14 and CA-19.

Background

Japan entered World War II in December 1941 and within just a few months conquered vast areas of the Pacific and South-east Asia. During this campaign the Allied air forces in the Pacific suffered devastating losses. As early as January 1942, Japanese forces were occupying bases just a few miles to the north of Australia with an invasion appearing imminent. For Australia the situation was desperate: her elite fighting forces were half a world away in Europe or the North African desert helping Britain to fight Germany and Italy and there was not a single modern fighter aircraft in the country.

Australia's traditional aircraft supplier, Britain, was already hard pressed to meet its own needs, and the Churchill government took the attitude that the defence of Australia was of secondary importance to the campaign in the Middle East. The United States was the only other possible source of aircraft. However, the enormous manufacturing resources of that country were only just starting to produce fighter aircraft in quantity, and there was no certainty that any could be spared for Australia.

Within days of the Japanese surprise attacks on Pearl Harbor, Siam, Malaya, and the Philippines—some reports say only three days—the small Australian aircraft industry began work on designing a fighter aircraft. This aircraft was to be designed using the limited components which were available in Australia. Only two aircraft were in production in Australia at that time; the Bristol Beaufort torpedo bomber, and the CAC Wirraway advanced trainer. The twin-engined Beaufort was unsuitable as the basis of a fighter, but it did have reasonably powerful 1,200 horsepower (890 kW) Pratt & Whitney Twin Wasp engines, which were being made under license in Sydney. While these engines were not particularly suited for use in fighter aircraft due to their high frontal area, they were the only high-performance engines available at the time.

Development

The Wirraway trainer provided a starting point for the Boomerang's airframe. From the roughed-out plans CAC general manager (and former chief designer) Lawrence Wackett and chief designer Fred David began detailed design work on 21 December 1941. The RAAF ordered 105 Boomerangs on 2 February 1942, and the prototype flew on 29 May 1942.

The Boomerang was a very small aircraft by fighter standards and designed for manoeuvrability rather than speed, with an overall length of just 7.7 m and an 11 m wingspan. Although the original intention had been to use as many Wirraway components as possible, the final design was quite different, with shorter wings and shorter, wood-sheathed, aluminium-framed fuselage, increased strength for combat stresses, and a new centre section.

The Boomerang handled well and, unlike most initial models of fighter aircraft, was well-armed from the start with two 20 mm cannon and four .303 machine guns (~7.7 mm), all mounted in the short, thick wings. The Boomerang was also generously equipped with armour plating to protect the pilot. Outright performance was mediocre, however. Although lively at low level, performance fell away rapidly over 15,000 feet (4,600 m) and at the maximum speed of 265 knots (490 km/h) was not sufficient to make it an effective counter to the Zero. In addition, by 1942 and 1943, the best European fighters were reaching almost 350 knots (650 km/h), and even relatively sluggish aircraft like the Wildcat and the Kittyhawk were much faster.

Later, more powerful radial engines, such as the Bristol Hercules could not be used in the Boomerang without a major re-design. The only CA-14 produced — an experimental prototype produced in 1943 — is said to have had a significantly better rate of climb and high altitude performance, thanks to a General Electric B-2 turbo-supercharger and squared-off tailfin. However, by this time the air defence/interceptor role had been filled and work had already begun on the Boomerang's successor, the CA-15 (also known as the CAC Kangaroo).

Operational history

Following the devastating first air raids on Darwin of February 19, 1942, the need for interceptors became more pressing. Despite the Boomerang's astonishingly short development phase — especially since the Australian aviation industry had never built fighters before, let alone designed them — by the time the Boomerang entered service, an adequate number of P-40 Kittyhawks had arrived from the United States. In January 1943, these were replaced in the air defence role over Darwin by No. 1 (Fighter) Wing RAAF, which had returned from Europe, equipped with the Spitfire Mk Vc.

Two of the first three operational Boomerang units, No. 83 Squadron and No. 85 Squadron, were used for home defence. No. 84 Squadron was deployed to New Guinea in an attempt to address 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 Squadron could drive off enemy attacks but rarely get close enough to Japanese aircraft to bring their guns to bear. After using Boomerangs for eight months in New Guinea, No. 84 Squadron upgraded to the Kittyhawk.

The Boomerang found its real use as a close support aircraft. In contrast to Europe or North Africa, the ground war in the jungles of the south-west Pacific was, in broad, an endless series of small unit actions fought at very close quarters by widely dispersed forces with no clear front lines. It was here that the Boomerang found its niche: as close to the troops on the ground as possible.

It had the range to go wherever it was needed, heavy armament by the standards of the day and, because it was easier to fly than most fighters, the pilot could get in close to the objective and have time to concentrate on the ground forces. Sprightly low-level handling helped avoid ground fire and rough terrain and the unusually extensive armour plating protected pilots. In addition, the aircraft's simple wood and aluminium airframe proved capable of resisting battle damage.

No. 4 Squadron and No. 5 Squadron flew Boomerangs in New Guinea, the Solomon Islands and Borneo in the close support role with marked success. Tasks included bombing, strafing, close infantry support, and artillery spotting. When attacking larger enemy formations Boomerangs often operated in conjunction with heavier 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 heavier aircraft delivering the major ordnance from a safer distance. The partnership between 4 and 5 Squadron Boomerangs and RNZAF Corsair fighter-bombers was said to be particularly effective.

See also the North American P-64 which is another single seat fighter that evolved from the basic NA-16 trainer design.

Survivors

Two Boomerangs remain airworthy today, both in Australia: CA-12 A46-122 "Suzy Q" (VH-MHR) with the Temora Aviation Museum and A46-206 with Lynette Zuccoli at Toowoomba. 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. Boomerang A46-090 is currently being restored to airworthy status.^[1]

Operators

Australia: Royal Australian Air Force

Units using the Boomerang

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

Variants

CA-12 Boomerang Mk I: The first single-seat fighter version, 105 built. Serial numbers A46-1 to A46-105.
CA-13 Boomerang Mk II: Improved version of the CA-12, 95 built. Serial numbers A46-106 to A46-200.
CA-14: One aircraft fitted with a turbo-supercharged engine, did not enter production. Serial number A46-1001.
CA-14A: The CA-14 prototype was later modified to have a square tail and rudder
CA-19 Boomarang Mk II: Tactical reconnaissance variant with a single vertical camera in the fuselage, 49 built. Serial numbers A46-201 to A46-249.

Specifications (CA-12 Boomerang)

Data from The Great Book of Fighters^[2]

General characteristics

Crew: 1

Performance Armament

Guns:
- 2× 20 mm (0.787 in) Hispano or CAC cannons
- 4× 0.303 in (7.7 mm) Browning machine guns
Bombs: Could be fitted when the large drop tank was not carried

References

^ www.warbirdregistry.org
^ Green, W. (2001). The great book of fighters. MBI Publishing. ISBN 0-7603-1194-3. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

Francillon, René J. The Commonwealth Boomerang, Profile Publication no.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.
Luranc, Zbigniew. Commonwealth Boomerang, Skrzydla W Miniaturze 24. Gdansk, Wydawnicto Avia-Press, 2000. ISSN 1234-4109. (Polish)
Pentland, Geoffrey. Commonwealth Boomerang Described. Dandenong VIC, Australia, Kookaburra Technical Publications, 1964.
__________. RAAF Camouflage & Markings, 1939-1945, Vol.1. Dandenong VIC, Australia, Kookaburra Technical Publications Pty Ltd., 1980. ISBN 0-85880-036-5.
__________. Wirraway and Boomerang Markings. Dandenong VIC, Australia, Kookaburra Technical Publications, 1970. ISBN 0-85880-007-1.
Wilson, Stewart. Wirraway, Boomerang & CA-15 in Australian Service. Sydney, Aerospace, 1991. ISBN 0-958797-88-9.
Zbiegniewski, Andre R. and Nowicki, Jacek. CAC Boomerang & CAC Wirraway, Wydawnicto Militaria 43. Warszawa, Wydawnicto Militaria, 1997. ISBN 83-86209-57-7. (Polish)

v t e Australian Defence Force aircraft serial-number prefixes
Italics indicate prefixes not used.
RAAF Series One 1921–34	A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12
RAAF Series Two 1935–63	A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 A19 A20 A21 A22 A23 A24 A25 A26 A27 A28 A29 A30 A30 A31 A32 A33 A34 A35 A36 A37 A37 A37 A38 A39 A40 A41 A42 A43 A44 A44 A45 A46 A47 A48 A49 A50 A51 A52 A53 A54 A55 A56 A57 A58 A59 A60 A61 A62 A63 A64 A65 A66 A67 A68 (I) A68 (II) A69 A70 A71 A72 A73 A74 A75 A76 A77 A78 A79 A80 A81 A82 A83 A84 A85 A86 A87 A88 A89 A90 A91 A92 A93 A94 A95 A96 A97 A98 A99 A100
RAN Series¹	N1 N2 N3 N4 N5 N6 N7 N8 N9 N10 N11 N12 N13 N14 N15 N16
RAAF Series Three Tri-Service series 1964–present	A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 A16 A17/N17 A18 A19 A20 A21 A22/N22 A23 N24 A25 A26 A27 N28 N29 A30 A31 A32 A33 A34 A35 A36 A37 A38 A39 A40/N40 A41 N42 A43 A44 A45 A46 A47 N48 N49 A51 N52 A53 A54 A55 A56 A69
Lists	Aircraft of the RAAF Aircraft of the RAN Aircraft of the Australian Army
¹ Prior to adoption of Tri-Service prefixes.