CAC, under Sir Lawrence Wackett, began work on its own design, hoping to out-perform the Beaufort by building a machine that could serve as both a torpedo-bomber and dive bomber.

[3] Faced with the crisis caused by the Japanese entry into the war in December 1941, the RAAF accepted the design even before testing was complete, and ordered 105 examples of the CAC bomber on 8 March 1942.

On 15 January 1943, the prototype CA-4 Wackett Bomber, A23-1001, crashed on a test flight to assess powerplant performance and evaluate aerodynamic effects of a new fixed leading edge slat.

During the return to the CAC airfield at Fisherman's Bend, the pilot, Squadron Leader Jim Harper, had detected a fuel leak in the port Pratt & Whitney R-1830 engine.

The three-man crew subsequently attempted evacuation at 1,000 feet (300 m), yet only Harper succeeded in parachuting free, while the CAC test pilot Jim Carter and power plant group engineer Lionel Dudgeon were both killed.