Country of origin:

Australia

Description:

Single-seat fighter bomber

Power Plant:

One 1,518 kw (2,035 hp) Rolls Royce Griffon twelve-cylinder VEE liquid-cooled engine

Specifications:

Armament:

Six 12.7 cm (0.50 in) machine guns; provision for two 227 kg (500 lb) bombs on external racks; provision for ten rocket projectiles under the wings

History:

The CAC CA-15 was the second single-seat fighter designed and built in Australia for service in the Pacific Theatre of Operations, the CAC Boomerang being the first. Specification 2/42 was conceived for a long-range, medium-altitude, high-performance fighter in 1943. Consideration was given to developing the Boomerang to take the Pratt & Whitney R-2800 Double Wasp, an 18-cylinder engine providing 1,716 kw (2,300 hp) and driving a 3.65 m (12 ft) diameter propeller. However, this idea was dropped and a new aircraft was designed.

Work on the prototype commenced and by August 1944 the fuselage was 60 per cent complete and the wings were 20 per cent complete. At this stage it was decided to fit the Pratt & Whitney R-2800-57W engine with a General Electric C2 turbocharger with water injection but in the event this engine did not become available. Consideration was also given to the installation of the Bristol Centaurus 12SM engine, or the Pratt & Whitney R-2800-22W engine but finally, because of availability problems, a Rolls Royce Griffon Mk 61 with a two-stage two-speed blower was obtained from the United Kingdom and installed, this on the drawing board indicating a max speed of 797 km/h (495 mph) would be available.

Fuel capacity was two 500 litre (110 Imp gal) tanks in the wings, and 182 litres (40 Imp gals) in a tank in the fuselage. Two 909 litre (200 Imp gal) drop tanks were to be fitted under the wings, making a total of 3,000 litres (660 Imp gals).

The prototype A62-1001 (c/n 1054) was not completed until early 1946, making its first flight on 4 March that year. By this time turbojet-powered fighters such as the Gloster Meteor and de Havilland Vampire were becoming available and the urgency of the program had disappeared, particularly following the cessation of hostilities.

The aircraft was delivered to No 1 Aircraft Performance Unit at Laverton, VIC on 2 June 1946 where a number of familiarisation flights were made by air force pilots. Testing continued until an emergency landing was made due to hydraulic failure on 10 December 1946 at Point Cook, VIC. The aircraft was rebuilt but this further delayed the program. The aircraft was returned to the RAAF on 19 May 1948 and testing continued until 1950 when further development was cancelled.

When seen at a distance the CA-15 could have been confused with the North American P-51D Mustang, which was also built by CAC under licence as the CA-17. However, the CA-15 had a smaller wingspan, increased length and a nine-degree dihedral setting of the tailplane. Another feature was the airscoop for the radiator. It also had the larger Rolls Royce Griffon engine and, because of the positioning of the cockpit, vision over the nose was improved.

A cartridge system was employed for engine starting. Accessories such as the generator, hydraulic pumps, and air compressor were grouped around a shaft driven auxiliary gear box.

One problem encountered was with the armament. Various combinations of 20 mm cannon and 12.7 mm (0.50 in) machine guns were considered and eventually the decision was made to install six of the latter with 280 rounds per gun. Provision was also made for ten rocket projectiles under the wings.

Range was expected to be 4,087 km (2,540 miles) at 1,524 m (5,000 ft) at 1,600 rpm.

Familiarisation flights were made by No 1 Aircraft Performance Unit (APU) pilots, including Wg Cmdrs J H Harper and G D Marshall, Sqdn Ldrs D R Cuming, G C Brunner, C V J Stark and G H Shields, and Flt Lt J A Archer.

Colour scheme was natural metal all over, with a matt-black anti-dazzle patch on the cowling ahead of the cockpit. RAAF Pacific blue and white roundels were placed on each side of the fuselage and in all four wing positions and the letter “P” for ‘prototype’ was inserted in a circle on each side of the fuselage.

Pilots reported that they were delighted with the orderly and rational manner in which the cockpit instruments and controls were installed. It was said to be a pleasant un-complicated aircraft to fly with no apparent vices and, due to the wide wheel track (4.26 m / 14 ft), was exceptionally stable even whilst taxiing over excessively rough ground.

Test Pilot Jim Schofield was reported to have said that the CA-15 could be landed normally on three points with no tendency to swing or bounce. There was some swing on take-off, this being due to the propeller running left-handed whereas most pilots were accustomed to right-hand rotation, but the tendency to swing was easily checked and fully controllable. Unofficially the CA-15 was known as the ‘Kangaroo’.

A newspaper report of the time made reference to the CA-15, stating “in flight over Melbourne…a record speed of 502.2 mph (808 km/h) was attained on 25 May 1948”, the aircraft being flown by Flt Lt Archer, achieving this speed after a modest dive from 2,743 m (9,000 ft) to 1,524 m (5,000 ft).

Eventually the aircraft was converted to components and the engine returned to the United Kingdom.

In early 2019 a Melbourne-based group announced it was building a replica of the CA-15, the cockpit and part of the fuselage being placed on display at the Australian International Air Show at Avalon, VIC in Feb / March that year.