When Japan entered the
war, the Royal Australian Air Force was in desperate need of aircraft.
At that time, its total strength amounted to only 175 front-line
aircraft, most of which were obsolete. The fighter sector consisted of
old-fashioned Brewster Buffaloes, which were clearly inadequate
compared to their more modern and powerful adversaries. There was a
great fear that the country would be invaded, and, faced with the fact
that it was impossible for Australia's principal allies (Great Britain
and the United States) to provide better equipment within a short space
of time, the Australian aeronautical industry decided that it would
build a combat plane capable of facing the emergency independently.
This was the CA-12 Boomerang, a small, robust, and agile fighter that
the Commonwealth Aircraft Corporation (CAC) designed and built within a
very brief space of time and that gave invaluable service from 1943
onward, proving to be unbeatable in a tactical role.
A Commonwealth Aircraft CA-13 Boomerang of 5th Squadron Royal
Australian Air Force - Bougainville, New Guinea 1943
The Boomerang, the only
entirely Australian-designed aircraft to see combat during World War
II, was created by Lawrence Wackett on the basis of experience acquired
during the production on license of the North American NA-16/NA-26 (the
multirole two-seater that gave rise to the prolific series of
Texan-Harvard trainers in the United States), which was christened
Wirraway. Clauses in the contract with North American also allowed for
eventual modifications to the basic model, and, driven by the urgency
of the situation, CAC's chief designer decided to develop the fighter
using the basic structure of this aircraft as a starting point. This
proved to be a wise choice, as well as benefiting from the advantages
of using an airframe that had already been carefully tested, it meant
that most of the existing production infrastructures could be employed.
The program was launched on December 21, 1941, and the prototype took
to the air on May 29 of the following year. It kept the Wirraway's
wings, landing gear and tail fins. However, the rest of the fuselage
was entirely new and had been improved to house the large and powerful
Pratt & Whitney Twin Wasp radial engine.
Tests revealed the
CA-12 Boomerang to be basically without faults, easy to fly and very
manoeuvrable, Production was launched immediately on the basis of an
initial order for a first lot amounting to 150 aircraft placed in
February 1942. These production series aircraft were delivered to the
units from October 10 onward, and following an intensive period of
preparation with the pilots, they were consigned to the combat units.
On April 4, 1943, the first fighter unit (84th Squadron) was declared
operative in New Guinea. Production of the initial series continued
until June of the same year, and the Boomerang Mk I was followed by 95
aircraft belonging to the Mk II series, which were slightly modified
and designated CA-13. The final series included 49 CA-19 Boomerang Mk
IIs, with further improvements, and the last of these was delivered in
The total of 250
aircraft also included a single CA-14 built in order to improve the
plane's performance at altitude. This aircraft was provided with a
supercharged engine and had modified tail planes. However, it never
went into production, because the availability of the greatly superior
Spitfire Mk VIII made it unnecessary.
Despite its overall
inferiority compared to the powerful and effective Japanese fighters,
the Boomerang was used with particular intensity as an interceptor
throughout 1943. Toward the end of the following year, the aircraft
were gradually withdrawn from this role, following the arrival of the
more effective British and American combat planes. The Boomerangs thus
passed to the units cooperating with the army and were successfully
employed as tactical support planes. They distinguished themselves in
missions of this type up to the last day of the war.
service in October 1942 when the RAAF's No.2 Operational Training Unit
at Mildura, Victoria, received its first aircraft. The Boomerang became
operational with No. 84 Squadron, which was the first to receive the
new fighters, in April 1943. Initial contact with Japanese bombers was
made during the following month when No. 85 Squadron equipped with
Boomerangs. Other squadrons followed, including Nos 4 and 5, where
Boomerangs replaced Wirraways in the army co-operation role. As higher
performance fighters became available, the Boomerangs were replaced,
having proved to be extremely manoeuvrable, tough and blessed with a
rapid rate of climb. They had acquitted themselves well in roles for
which they were not designed and were remembered with affection by
their pilots. Only one true Boomerang, a CA-12, survives in a museum.
A three sided diagram of a Commonwealth CA-14 Boomerang
CA-12 (later named
Boomerang Mk I) - Japan's entry into World War II found Australia ill
prepared, with the only fighters on RAAF strength being a few
obsolescent Brewster Buffaloes based in Malaya. However, the licence
under which CAC (Commonwealth Aircraft Company) built the Wirraway
permitted modifications to the design and Lawrence Wackett used that
aircraft's entire wing, landing gear and tail unit married to a new
fuselage to produce a single-seat fighter, the Commonwealth Aircraft
CA-12, later named Boomerang Mk I. An order was placed for 105 in
February 1942, and because many Wirraway components were used the
prototype was built in only three months, flying for the first time on
29 May 1942.
CA-13 Boomerang Mk II -
Production of this first batch was completed in June 1943, and a second
batch of 95 aircraft designated CA-13 Boomerang Mk" followed, these
incorporating a number of minor modifications.
CA-14/CA-14A - A single
CA-14 was built with a General Electric turbocharger to improve high-
altitude performance; it was modified later as the CA-14A to have a
square fin and rudder, but availability of the faster Spitfire Mk Vllls
rendered these improvements unnecessary.
CA-19 Boomerang Mk II -
The final production batch consisted of 49 designated CA-19 Boomerang
Mk II, again with minor modifications, and the last of these was
delivered in February 1945.
(Commonwealth Aircraft CA-13 Boomerang Mk II)
Commander Lawrence J. Wackett
Commonwealth Aircraft Corporation at Fisherman's Bend, Australia
1,200 hp (895 kW) Pratt & Whitney R-1830-S3C4-G Twin Wasp radial
Maximum speed 305 mph (491 km/h) at 15,500 ft (4725 m); service ceiling
34,000 ft (10365 m); initial climb rate 2,940 ft (896 m) per minute.
miles (2575 km) with maximum fuel.
equipped 5,375 lbs (2437 kg) with a maximum take-off weight of 8,249
lbs (3742 kg).
36 ft 0 in (10.97 m); length 25 ft 6 in (7.77 m); height 9 ft 7 in
(2.92 m); wing area 225.0 sq ft (20.90 sq m).
7.7 mm (0.303 in) Browning machine-guns and two 20 mm Hispano cannon in
(later Boomerang Mk I), CA-13 Boomerang Mk II, CA-14/CA-14A, CA-19.
flight (prototype) 29 May 1942; first delivery August 1942; final
delivery early 1944.