Much of Australian industry was evolved and put to the test during World War 2 (1939-1945). Its aviation sector eventually produced a handful of viable developments including the nationally-important CAC "Boomerang" by the Commonwealth Aircraft Corporation which had been established in 1936. In 1943, as the Pacific War continued to rage on near the Australian border, a new initiative was put into action involving a single-seat, single-engine monoplane fighter utilizing all-metal stressed-skin construction. Power for the aircraft was to come from the American-made Pratt & Whitney R2800-10W "Double Wasp" turbocharged radial piston engine of 2,300 horsepower output. The engine proved a monumental success during the war as it powered such famous types as the Martin B-26 "Marauder" medium bomber, the Curtiss C-46 "Commando" transport, and the Republic P-47 "Thunderbolt" fighter. Unfortunately this also meant that the engine continued to be in great demand outside of Australia.
The new endeavor was the CA-15 intended for the interceptor and bomber escort roles. CAC engineers, fresh off the success of their Boomerang program, elected for a well-streamlined and deep fuselage with the engine accordingly situated at front, the cockpit at center and a conventional single-finned tail unit at rear. The wing mainplanes were low-mounted and straight near midships and featured clipped tips. The pilot sat under a teardrop-style canopy offering excellent vision above and to the sides of the aircraft - though the design suffered as most wartime fighters did - the long nose and mainplanes obstructed much of vision towards critical quadrants about the aircraft. A "tail-dragger" retractable undercarriage was installed and a four-bladed propeller unit was fitted to the engine. The CA-15 showcased some of the form of the classic North American P-51 Mustang through its general appearance which included a ventral air scoop.
When it became apparent that the Double Wasp radial engine was not to be had in the numbers required, the decision was made to adopt an inline engine instead and this became the British Rolls-Royce Griffon 61 series liquid-cooled system. This added some complexity to the internal workings and overall operation of the aircraft. The shift in powerplant also did little to move the program along.
In August of 1945, the Empire of Japan formally capitulated and brought an end to the War in the Pacific for September. The CA-15 had still not yet flown and the massive military drawdown that followed the conflict cast a shadow on the slowly evolving indigenous Australian fighter project. Nevertheless, work on the product continued to the point that a first flight was finally had on March 4th, 1946. The aircraft featured its inline set in the nose and a streamlined spinner managed the four-bladed propeller unit. The CA-15 was a good initiative for the country and its most advanced wartime design to appear. In testing, it was able to see speeds reaching near 450 miles per hour.
On December 10th of that year, the sole working prototype suffered a failure of its undercarriage hydraulics when attempting to land at Point Cook - leaving the main legs only partially lowered. After dumping fuel, the test pilot crash landed the aircraft. The pilot survived with a few bumps and scrapes but the aircraft suffered considerable damage in the exercise. Despite the setback, CA-15 was repaired and readied to be flown again and topped diving speeds over 500 miles per hour in further flights.
While the program continued forward, albeit at a much-reduced pace in peacetime, the product was no longer in need and served mainly in a data collecting role for most of its time aloft. The global shift to jet-powered aircraft did many fighter programs such as the CA-15 in at the end of the war and in the period immediately following. With that, the only completed prototype of the CA-15 was discarded and ultimately scrapped, lost to the pages of Australian aviation history. The project was formally ended in 1950.
As finalized, the CA-15 was given a length of36.1 feet and a wingspan of 36 feet with a height nearing 14.1 feet. Empty weight was 7,540 pounds and Maximum Take-Off Weight (MTOW) reached 12,340 pounds. Officially performance numbers included a maximum speed of 448 miles per hour, a range of 1,150 miles, a service ceiling of 39,000 feet and a rate-of-climb of 4,900 feet per second.
While never officially named, the CA-15 ultimately garnered itself the nickname of "Kangaroo" in keeping with Australian aircraft naming conventions.
Proposed armament included 0.50 caliber (12.7mm) heavy machine guns, three per wing, with 250 rounds afforded per gun unit. The wings were also to receive provision for five high-explosive rockets each (ten total) and a hardpoint to carry up to 2 x 1,000 pound conventional drop bombs.