Commonwealth Aircraft Corporation: Aussie WWII Battlers & Aviation Pioneers

The Australian aviation industry was in a fledgling state in the 1930’s. With the potential for war brewing in Europe, discussions between the Australian government and numerous companies such as BHP and General Motors Holden began in 1935 to establish a modern aviation company to produce military aircraft and engines.

Within a few short years and accelerated by wartime conditions the Australian aviation industry went from a small and very humble operation to some 44,000 people (plus 10,000 subcontractors) working at its peak in 1944 in four main aircraft factories and numerous annexes (up from just 5,000 people in 1940). These people would help the war effort enormously by producing approximately 3,500 aircraft for the Royal Australian Air Force (RAAF) to train its pilots and take the fight to the Axis enemies. The Department of Aircraft Production (more on this manufacturer in a future post) along with the Commonwealth Aircraft Corporation were the mainstay of the Australian aviation industry during this crucial time in history.

Commonwealth Aircraft Corporation

Lieutenant L.J. Wackett , Australian Flying Corps, circa March 22nd, 1916 (Photo Source: Australian War Memorial)

The Commonwealth Aircraft Corporation (CAC) of Australia was incorporated on October 17^th, 1936 and by September 1937 a factory had been constructed at Fishermen’s Bend in Port Melbourne, Victoria on 140 acres of land purchased by the Victorian government (they also established an airfield at the same location). Lawrence Wackett (1896-1982), the “father of the Australian aircraft industry” was appointed General Manager of CAC and he was integral to the design and development of the early aircraft produced by the company, including the two-seat, low wing monoplane, CAC Wirraway trainer and general purpose aircraft (later to be used in combat roles and as a squadron “hack” aircraft).

With a wealth of aviation experience, Lawrence Wackett was perfect for the job. He had flown with the Australian Flying Corps as combat pilot from 1915-1919 (awarded the Distinguished Flying Cross for bravery in 1918), served as an officer in the new Royal Australian Air Force from 1921, during which time he qualified as an aeronautical engineer and studied aircraft design, to later command the RAAF Experimental Section in Randwick, Sydney, NSW (established January 1924). During this time he developed four experimental military aircraft which were used for testing and training purposes but none went into production (Widgeon I & II flying boats and Warrigal I & II trainers).

The RAAF Experimental Section was closed in 1930 and Wackett resigned from the RAAF with the rank of Wing Commander. He continued his work on aircraft design with private firms but also continued to work with the RAAF on various projects.

CAC factory – Fishermen’s Bend – Port Melbourne (Photo Source: Monash University/Tony Lyons)

CAC Drawing Office – Fishermen’s Bend – Port Melbourne (Photo Source: Monash University/Tony Lyons)

CA-1/3/5/7/8/9/16 Wirraway

In 1936 Wackett lead a technical team to the United States and Europe to find a suitable aircraft to be constructed in Australia. The team selected the North American NA-16 trainer which would later be developed into the NA-33 training aircraft known as the AT-6/T-6 Texan, SNJ and Harvard (USAAF/USAF, US Navy and Commonwealth nations). The CAC Wirraway was a licence-built derivative of this aircraft and a single NA-16 (fixed undercarriage) and NA-33 aircraft were purchased and transported from the United States to Australia in 1937 to act as prototypes for the Wirraway design (receiving Australian serial numbers A20-1 and A20-2).

CAC Wirraway (A20-21) of RAAF No. 21 Squadron flying over Melbourne circa February 1940. The pilot of this aircraft is Flying Officer D.J. Doughty and the gunner is Sergeant Ellis (Photo Source: Australian War Memorial)

The CAC Wirraway used the same basic engine as the T-6 Texan/Harvard, a 600hp Pratt & Whitney R-1340 Wasp 9 cylinder air-cooled radial engine (licence-built by CAC) but had a number of key design differences from the original North American NA-16/NA-33 aircraft. These included a D shaped tail, a revised tailplane, a revised wing with more rounded wingtips, a larger air intake under the radial engine, two forward firing 0.303 in (7.62 mm) Vickers Mk.V machine guns synchronized to fire through the propeller arc and a single 0.303 Vickers Mk.I machine gun mounted in the rear cockpit and a strengthened airframe structure with underwing bomb racks to allow for dive bombing (the weapons were a sign of the times that Australia lacked modern combat aircraft and could not yet fund the development of fighters and bombers).

North American Harvard (top) & CAC Wirraway comparison – 2016 Tyabb Airshow

Note the variances in the tailplane and wing design of the Harvard (top) and Wirraway (bottom) – Temora Aviation Museum – February 2008

The first flight of a Wirraway (A20-3) took place on March 27^th, 1939 and this aircraft was then tested for a number of months by CAC. The first two production aircraft (A20-4 and A20-5) were delivered to the RAAF on July 10^th, 1939. By September 1939 Australia was at war with Germany and by September 1941 the CAC factory was producing 45 Wirraway aircraft a month.

Wirraway aircraft under construction at a CAC factory at Fishermen’s Bend in 1940 (Photo Source: Australian War Memorial)

The demand for military aircraft soon escalated with the entry of Japan into World War Two in December 1941. The CAC Wirraway became an important aircraft to the war effort and was integral to Australia’s contribution to the Empire Air Training Scheme (EATS) which trained thousands of pilots and aircrew in Australia and other Commonwealth Nations.

RAAF CAC Wirraway formation circa 1944 (Photo Source: State Library of Queensland)

The Wirraway was never intended to primarily be a combat aircraft but it was armed and in the early fighting in New Guinea in 1942, Australia had few fighters and bombers to combat the Japanese (most experienced crew were flying RAF provided combat aircraft in Europe and North Africa at that stage of the war), so the Wirraway and its crews had to bravely step into the void. Despite a relatively low top speed of 354 km/h and light machine gun armament some RAAF Wirraway’s was used as an emergency fighter and others to attack Japanese troops, simply because there was no other option. By January 1942 they were involved in air combat with no success and heavy losses.

An RAAF CAC Wirraway with underwing bombs during World War Two (Photo Source: Australian War Memorial)

On January 6th, 1942 the first air combat between Australia and Japan involved Wirraway’s intercepting Japanese seaplanes over New Britain, no aircraft were shot down in this incident. Two weeks later just 8 Wirraway’s had to be thrown into combat against more than 100 Japanese aircraft attacking Rabaul in New Guinea, sadly only 2 of the RAAF aircraft survived unscathed and none were able to shoot down a Japanese aircraft.

These RAAF pilots were incredibly brave going up against battle hardened Japanese pilots in superior fighter aircraft such as the Mitsubishi A6M Zero. A total mismatch in speed and firepower!

This all changed on December 26^th, 1942 though when RAAF Pilot Officer John S. Archer of No. 4 Squadron was flying his CAC Wirraway on a reconnaissance flight near Buna, New Guinea when he spotted and dived on what was reported as a Japanese Zero fighter 1,000 feet below. With machine guns blazing and against all odds he shot it down!

Members of No. 4 (Wirraway) Squadron, RAAF with the Wirraway (A20-103) aircraft that Pilot Officer John S (Jack) Archer was flying when he shot down a Japanese Zero aircraft. Joe Booker is pointing to a Japanese flag that was painted on the nose of the aircraft to commemorate shooting down the Zero. (photo source: Australian War Memorial)

RAAF Pilot Officer John S. (Jack) Archer of No. 4 Squadron seated in Wirraway A20-103 on January 8th, 1943 in New Guinea (Photo Source: Australian War Memorial)

Archer achieved the only known air to air victory in a CAC Wirraway. A post war investigation revealed that the aircraft shot down was actually a Nakajima Ki-43-II Hayabusa or Oscar of the Imperial Japanese Army Air Force 11th Sentai, rather than an Imperial Japanese Navy Mitsubishi A6M2 Zero. The mistake is understandable as back then everything was probably reported as a Zero!

Archer later said he just acted on impulse and was lucky to get a good shot in first. For his act of bravery he was awarded the Silver Star by none less than United States General Douglas MacArthur, Allied Supreme Commander of the Southwest Pacific Area!

The historical significance of this Wirraway (serial number A20-103) was recognized and today it is displayed in the Australian War Memorial for future generations to learn the important role this aircraft played in World War Two.

CAC Wirraway (serial number A20-103) at the Australian War Memorial. This aircraft flown by RAAF Pilot Officer John S. (Jack) Archer was the only known Wirraway to shoot down a Japanese aircraft in World War Two (photos taken during my January 2016 visit to the museum)

755 Wirraway aircraft were produced by the Commonwealth Aircraft Corporation at Fishermen’s Bend from 1939 to 1946, with the last serving the RAAF until 1959. Very few survive today (less than 15 in the world with ) because the wings were made of aluminium, which was a vital metal post war and they were reduced to aluminium ingots! Luckily you can still see a number of these survivors in museums around the country and there are also a few still flying in Australia.

The exposed and accident prone Wirraway A20-10 at the Australian National Aviation Museum at Moorabbin in 2010 (ADF-Serials report during RAAF service it was involved in an accident in 1953, forced landed in 1955 and was involved in another accident that same year). It was sold to the museum in the 1960’s.

CAC Wirraway at the Classic Fighters Museum in Parafield, South Australia (photo taken during my 2008 visit to the museum)

CAC Wirraway – Bull Creek Aviation Museum – Perth, WA (photo taken in 2004)

CAC Wirraway A20-502 – produced in 1942 it went on to fly over 1,100 hours and 953 sorties with the RAAF during World War Two, many over Japanese held territory whilst based in Bouganville from 1943 to 1945. Her crews affectionately nicknamed her “The Rocket” (photo taken at the Ballarat Aviation Museum in 2011)

CAC Wirraway 722 at the 2016 Tyabb Airshow

CA-6 Wackett

CAC were also working on another trainer design from a 1938 RAAF requirement, the low-wing monoplane CAC Wackett. This was the first in-house designed aircraft for CAC and was named in honour of its designer, Lawrence Wackett. The first of 2 prototypes flew in October 1939. The first of 200 production CA-6 Wackett trainers fitted with 175hp Warner Scarab radial engines was flown on February 6th, 1941 and they started to enter RAAF service in March 1941 to supplement de Havilland Tiger Moth biplane basic trainers. The last CAC Wackett was delivered to the RAAF by April 22nd, 1942. An effective training aircraft, it would go on to serve with Empire Air Training Scheme units until retired in 1946.

RAAF CAC CA-6 Wackett trainers

The last CAC CA-6 Wackett trainer (A3-200) on a test flight flown by a very jovial test pilot over Fishermen’s Bend in April 1942 (Photo Source: CAC)

Given it was a trainer for new pilots, around 33% of the CAC Wackett aircraft produced had been lost in accidents and service attrition. Upon retirement from the RAAF in 1946 the rest were sold to civilian customers, with around 30 also going to the Dutch for their Dutch East Indies operations that would later be transferred to Indonesia upon that nation’s independence.

CA-12/13 Boomerang

By 1942 the RAAF desperately needed modern fighter aircraft to combat the Japanese on the frontline. Unfortunately in 1942 these types of assets were tied up in the fighting in Europe and the Middle East and the supply of new fighters from Great Britain and the United States was limited. It would take some time for new aircraft to be shipped from overseas or produced locally under licence. To make up the shortfall the Australian Government funded the development of a home-grown fighter which was fortunately already in the design stage at the Commonwealth Aircraft Corporation (CAC) and the CAC Boomerang was the outcome.

CAC Boomerang “Sinbad II” (A46-126) from No. 5 Squadron during World War Two (Photo Source: Australian War Memorial)

The CAC Wirraway was the starting point for development of the CAC Boomerang fighter design (note the similar shaped wings), which was the first combat aircraft to ever be designed and built in Australia (as an “emergency fighter” a lot of hurdles had to be overcome to achieve this). Less than 2 months after Japan entered the war, the Australian government ordered the Boomerang into production on February 2nd, 1942. The first flight occurred incredibly, just a few months later on May 29th, 1942 (utilising many Wirraway components enabled the Boomerang to go from the CAC drawing board to first flight in only 14 weeks)!

Great view of the Boomerang wing (Photo Source: Australian War Memorial via ADF-Serials)

Given no fighters were in production in Australia during those early war years, high performance aircraft engines were simply not locally available. A solution needed to be found to put in the Boomerang. There was really only one viable option. DAP (Bristol) Beaufort torpedo bombers were now being manufactured locally and the Pratt & Whitney R-1830 Twin Wasp radial engine used in the bomber was deemed suitable for the Boomerang (CAC licence built the Pratt & Whitney R-1830 engine for the Beaufort and Boomerang).

The Boomerang was in production from 1942 to 1945 with 250 being manufactured. The first entered RAAF service with No. 2 Operational Conversion Unit (No. 2 OCU) on October 19th, 1942 and the first operational fighters were issued to No. 83 Squadron on April 10th, 1943 to replace the Bell P-39 Airacobra on home defence duties (Number 84 and 85 Squadrons soon followed – the latter was flying obsolete Brewster Buffalo fighters).

Boomerang fighters on the CAC Fishermen’s Bend production line in 1943 (Photo Source: Library of Congress)

A Boomerang sits on the CAC tarmac at Fishermen’s Bend in 1942 (Photo Source: Australian War Memorial)

The first combat test for a CAC Boomerang was on May 20th, 1943 when a Number 85 Squadron aircraft flown by Flight Lieutenant Roy Goon was scrambled to intercept Japanese bombers off Exmouth, Western Australia. Spotting the fighter, the Japanese dropped their bombs wide of their intended target and flew away before he could engage them!

Japanese air raids continued along the north of Australia and Boomerangs were deployed for air defence but unfortunately the top speed of the Boomerang at only 490 kph / 305 mph and poor high altitude performance was inadequate against Japanese aircraft, especially faster fighters such as the Mitsubishi A6M Zero and Nakajima Ki-43 Oscar. Ultimately they could head off an enemy and deter their attack but not pursue and shoot the enemy down.

Flying from Mareeba, QLD in March 1944 – Four CAC Boomerang fighter aircraft of RAAF No. 5 (Tactical Reconnaissance) Squadron in ‘four finger’ formation which was the standard formation used on operational missions (Photo Source: Australian War Memorial)

Although soon replaced in the fighter role by more capable aircraft such as the Curtiss P-40 Kittyhawk (from March 1942 onwards) and Supermarine Spitfire (from August 1942 onwards), these performance issues were not the end of the Boomerang though. With its twin 20mm cannons and 4 x .303 machine guns this little fighter could still pack a mean punch. Firepower accompanied with ruggedness and heavy armour plating protecting the pilot along with good maneuverability and performance at low altitude resulted in the Boomerang being very suitable for low-level close support missions in places such as New Guinea and Borneo. The Boomerang then assumed this new army co-operation role with No. 4 & 5 Squadrons with great respect from the troops down below.

RAAF CAC Boomerangs of No. 5 (Tactical Reconnaissance) Squadron flying from Mareeba, Queensland in March 1944 (Photo Source: Australian War Memorial)

RAAF CAC Boomerangs on the Bougainville airstrip circa 1944 (Photo Source: State Library of QLD)

CAC Boomerangs of RAAF No. 4 Squadron at Sepinggang Airfield, Borneo in 1945 (Photo Source: Australian War Memorial)

The CAC Boomerang was retired by the RAAF in 1945 as it had become well and truly obsolete. The little Aussie fighter had played its role in winning the war though and given its significance to the Australian aviation industry, luckily today a number of CAC Boomerang airframes survive and are on display in various museums in Australia including the RAAF Museum at Point Cook, Victoria. There are also 2 flying in Australia, with plans for more to be restored to airworthiness.

CAC Boomerang – RAAF Museum, Point Cook, Victoria (photo taken during my visit to the museum in February 2016)

Temora Aviation Museum CAC Boomerang “Suzie-Q” at the 2016 Tyabb Airshow

I was lucky enough to be present at the Temora Aviation Museum in October 2009, when two CAC Boomerangs (A46-122 a CA-13 “Suzy-Q” and A46-63 a CA-12 “Miss Imogen” from 1943 which first flew again on June 26th, 2009) flew together, probably for the first time since the end of World War Two. It was a great moment!

CAC Boomerang “Suzie-Q” – Temora Aviation Museum October 2009

CAC Boomerang “Miss Imogen” – Temora Aviation Museum October 2009

A pair of CAC Boomerangs fly together for probably the first time since World War Two at the Temora Aviation Museum on October 2009

CA-4/11 Woomera

The CAC CA-4/CA-11 Woomera was an exciting and advanced aviation bomber aircraft project designed by Lawrence Wackett to compete and outclass the Bristol Beaufort torpedo bomber, that had been ordered in large numbers by the Australian government in 1939. The government approved funding in June 1940 for CAC to develop a strike-reconnaissance bomber that also could also operate as a dive bomber. The first prototype, the CA-4 (A23-1001) with a three-man crew (pilot, navigator/bombardier, and wireless operator/air gunner) and Sperry autopilot was designed so that it was also capable of operating as a torpedo bomber. The first flight was successfully completed on September 19th, 1941.

CAC CA-4 Woomera light bomber prototype at Fishermen’s Bend – this one first flew in 1941 but exploded mid-air in 1943!

The CA-4 Woomera prototype flew well,  had a maximum speed of 435 km/h (270 mph) and was heavily armed in a very unique manner for its time. The nose of the aircraft housed 4 x 0.303 machine guns that were operated by the pilot, then there were two powered remotely controlled gun  turrets, with 2 x 0.303 machine guns at the rear of each engine nacelles (they were remotely controlled by the wireless operator/air gunner from the rear cockpit using a sighting periscope) which were a very advanced feature for so early in the war! The engine nacelles could also each house 2 x 250 lb bombs and 4 x  25 lb bombs could be carried under each wing. In addition 2 torpedos or 2 x 500 lb bombs could be carried below the centre section or for long-range missions these could be replaced by fuel drop tanks.

CAC workers constructing the CA-4 Woomera prototype (A23-1001) at Fishermen’s Bend 1941 (Photo Source: State Library of South Australia PRG 247/143/30)

All was looking good for the CA-4 Woomera prototype as it had performed well enough in early test flights, was equivalent to contemporary aircraft performance and could outperform the Bristol Beaufort. So well the government placed an order in early 1942 for 105 Woomera bombers even though the flight testing was not complete (the Japanese crisis was paramount at that stage and the RAAF needed capable aircraft!). The production models were to be redesignated as the CAC CA-11 Woomera (they were planned to start rolling out of the factory at a rate of 20 per month from January 1943). I say “were” as this unfortunately for CAC, was not to be.

The CA-4 prototype was handed over to the RAAF on April 20th, 1942 for further flight testing, especially in the dive bombing mode (interestingly on the RAAF history paperwork records from that time it is listed as the “Wackett Bomber”). There was an embarrassing mishap on November 12th, 1942 when in front of the Prime Minister during a test flight the CA-4’s undercarriage failed and a belly landing had to be made! RAAF photos from that day show the prototype resting on its belly in the grass at RAAF Laverton. Luckily there was no structural damage, just minor damage to the engines and propellers. The aircraft was returned to CAC for repairs. This was not the last mishap though and the next was a tragic blow to CAC and the RAAF.

CAC CA-4 Woomera bomber on rollout, a test flight fitted with torpedoes and a runway mishap!

Whilst on a test flight on January 16th, 1943 the CA-4 prototype suffered a mid-air explosion and subsequent fire. Squadron Leader Jim Harper was the pilot on that day and he had detected a fuel leak in the port engine and attempted to shut it down. In the process he activated the feather switch which somehow triggered an explosion and the fire erupted (the switch is believed to have caused a spark which ignited accumulated fuel). The crew attempted to bail out of the aircraft but only Harper parachuted safely. CAC test pilot Jim Carter (flying as a passenger for familiarisation purposes to take over future test flights) and CAC draftsman Lionel Dudgeon (flying as an observer) sadly both died in the incident. The aircraft crashed into the countryside near Kilmore and was later salvaged for parts.

All was not a total loss as improvements were made to the Woomera design and a new CA-11 prototype (A23-1) was produced in 1944 for extensive flight testing by CAC until it was handed over to the RAAF on November 22nd, 1944. It differed from the lost CA-4 prototype in a number of ways including an extended cockpit canopy with an improved moulded perspex sighting turret to operate the remote control rear facing gun turrets on the engine nacelles. Armament was bumped up too with 2 x 20 mm cannons and 2 x 0.303 machine guns in the nose plus a new flexible-mounted Vickers 0.303 machine gun in the lower fuselage. The fin, rudder and tailplane were completely redesigned to improve airflow and aerodynamic problems with the previous prototype. Initially the CA-11 prototype was fitted with two 1,200 hp Pratt and Whitney R1830 Wasp radial engines but these were replaced with more powerful 1,300 hp Pratt and Whitney R2000 Wasps and the prototype was redesignated as the CA-11A.

CAC CA-11 Woomera prototype in 1944

Alas for CAC, time had marched on and by 1944 the RAAF was in a very different position from that of 1942. There were now plenty of bomber aircraft available from the United States, the torpedo bomber role was ably covered by the DAP (Bristol) Beaufort, even a new dive bomber was not required and ultimately the DAP (Bristol) Beaufighter filled the strike-reconnaissance bomber role so well there was really no longer a requirement for the CAC CA-11 Woomera. The CA-11 prototype was approved for scrapping for components on January 16th, 1946. A sad end to an entirely Australian designed aircraft but metal was precious back then and there was apparently no room for sentimentality it seems (oh if only they had kept it for a museum collection! All I have seen is the CA-11 gun turret displayed at the Australian National Aviation Museum at the Moorabbin Airport ).

CAC CA-11 Woomera gun turret displayed at the Australian National Aviation Museum at the Moorabbin Airport (April 2016)

By 1945 CAC production switched to the construction of the CAC CA-18 Mustang (a licence-built North American P-51D Mustang). The P-51D was a proven war winner with no risk to manufacture, so it made sense to start producing this model to replace older RAAF fighters. More on this aircraft and other CAC developments in my next post.

 

References:

ADF-Serials: CAC Woomera

Australian Dictionary of Biography – Lawrence Wackett

Australian War Memorial – CAC Wirraway

Beaufort Restoration – The Story of the Commonwealth Aircraft Corporation

RAAF Museum: CAC Wackett, CAC Wirraway, CAC Boomerang, CAC Woomera

RAAF Radschool Association Magazine – Vol 27 – The Woomera Bomber of WWII

Wikipedia: Commonwealth Aircraft Corporation, CAC Wackett, CAC Wirraway, CAC Woomera, CAC Boomerang, Lawrence Wackett, P-51 Mustang