Country of origin:

Australia

Description:

Three-seat fighter bomber

Power Plant:

[CA-11]

Two CAC-built 895 kw (1,200 hp) Pratt & Whitney R-1830-S3C4G Twin-Wasp fourteen-cylinder two-row air-cooled radial engines

Specifications:

Armament:

Two 20 mm Hispano cannon and two 7.7 mm (0.303 in) machine guns in nose; one Vickers K gas-operated Mk I machine gun in ventral step; two 7.7 mm (0.303 in) Browning Mk II machine guns in remotely-controlled barbettes at the rear of each engine nacelle; provision for four 113 kg (250 lb) bombs in engine nacelle bays; eight 11 kg (25 lb) bombs under outboard wing panels; two 45.7 cm (18 in) torpedoes

History:

In June 1940 the Australian Government War Cabinet voted money for the development of an aeroplane for the RAAF which was capable of dive-bombing, torpedo-carrying, general bombing and reconnaissance duties. The design team, led by Wg Cdr L J Wackett, produced the Woomera, which had a crew of three: a pilot/front gunner, a second pilot/turret gunner/wireless operator, and a navigator/bomb-aimer /ventral defence gunner. It was twin-engined with a number of interesting features which included remotely-controlled power-operated barbettes at the rear of each engine nacelle, each mounting two hydraulically-operated Browning machine guns; a Sperry automatic pilot and Mk IX Course Setting Bombsight; and provision for the carriage of two Mk 12A or Mk 13 torpedoes released electrically.

Late in 1940 a mock-up of the CAC CA-4 was built; and later approval was given for the construction of a prototype (A23-1001 – c/n 435). It is noteworthy the appellation “Woomera” was not allotted to the CA-4 and was only allotted to the CA-11 and future production aircraft.

On completion the CA-4 commenced taxiing trials on 14 September 1941, followed by a first flight on 19 September. Performance trials continued for some time and on 20 April 1942 it was delivered to No 1 Aircraft Depot, Laverton, VIC. Preliminary trials conducted by the Council for Scientific & Industrial Research (CSIR) revealed that at a weight of 8,278 kg (18,250 lb) it had a maximum speed at 4,694 m (15,400 ft) of 430 km/h (267 mph), a rate of climb of 402 m/min (1,320 ft/min) and a time to climb to 7,620 m (25,000 ft) of 25.8 minutes. It suffered a taxiing accident on 22 December 1942 and was returned to CAC.

Armament trials were carried out at the Special Duties & Performance Flight. On 15 January 1943 the aircraft flown by Sqdn Ldr J H Harper, left Fishermens Bend, VIC with CAC test pilot J Carter and Mr L Dudgeon, CAC draftsman, as observer on a test flight when a fuel leak was observed in the port engine. The pilot operated the electric feathering switch but an explosion and fire occurred. The aircraft was at 305 m (1,000 ft) at the time and the crew attempted to escape the aircraft. There was insufficient time for Carter and Dudgeon to escape and they were lost in the crash near Kilmore, VIC, the aircraft being destroyed.

Work then proceeded on the CA-11, which was more representative of the production aircraft. This was a re-design of the CA-4 and was produced in accordance with RAAF Specification 2/42, dated 8 March 1942, which called for 105 production examples (serials A23-1 to A23-105). As with the CA-4 it would carry two 45.7 cm (18 in) torpedoes, bombs slung inside the engine nacelles, and four 11 kg (25 lb) bombs under each outer wing panel; but in lieu of the four 7.7 mm (0.303 in) machine guns in the nose it had two of these replaced with 20 mm cannon. Fuel capacity was 2,709 litres (596 Imp gals), and to supplement this two 1,332 litre (293 Imp gal) auxiliary fuel tanks could be fitted under the centre-section where the bombs or torpedoes would be accommodated. The barbettes were retained but the gunner sat in a moulded perspex sighting turret.

Progress on the CA-11, which became known as the Woomera, was slow. A further RAAF manufacturing specification was issued reducing the original order to 20 production examples (A23-1 to A23-20) and the first of these (A23-1 – c/n 1225) flew on 7 July 1944 at 11.50 hours in the hands of CAC test pilot Gregory R Board. A second flight of 70 mins was made on 10 July, and a third on the 13. The fifth test flight was made by Sqdn Ldr D R Cuming of No 1 Aircraft Performance Unit (APU), Laverton, the aircraft being delivered to that unit, after further testing at Fishermens Bend, on 21 November 1944. However, by this time the war against Japan was progressing well. The Japanese were no longer in a position to regain the offensive. Because adequate numbers of American-built aircraft, Australian production Beaufighters and Beauforts, and the soon to enter production Mosquito, were progressing well, the Woomera project was cancelled.

The CA-11 Woomera remained at Laverton until 20 December 1945 when it was transferred to No 1 Central Repair Depot at Werribee, VIC for storage. The following January approval was given for its conversion to components. At this stage the second aircraft (A23-2) was virtually complete. This machine, to be known as the CA-11A, was intended to be fitted with two 1,007 kw (1,350 hp) Pratt & Whitney R-2000 Wasp engines, plans for the manufacture of which at Lidcombe, NSW were in train. Subsequently A23-2 and the remaining aircraft on the production line were sold for scrap.

In the 1960s substantial parts were located at the rear of the premises of Ready Mixed Concrete at Nunawading, VIC and, although they did not carry construction number plates, the numbers 5, 6, 8, 9, 10, 12, 15, 16, 17, 18 and 20 were painted on the airframes. At that time thirteen airframes were located.

Had the design received urgent priority at the very beginning, and had the problems encountered in the test program been quickly overcome, the Woomera might well have developed into a successful combat aircraft rather than another promising Australian design. It is a pity that it, like the CA-15, was not saved for a museum for future generations to see the work of the fledgling Australian design team at a time when Australia was in danger.