In 1949, the Royal Australian Air Force (RAAF) began assessing replacements for its locally-built Commonwealth Aircraft Corporation (CAC) Mustangs and De Havilland Australia (DHA) Vampires.

The Commonwealth Aircraft Corporation (CAC), which had developed an extensive and proven in-house design capability during World War II, submitted a detailed proposal for a twin-jet, all-weather fighter with a two-seat cockpit, the CA-23.

[2] Over the life of the project, many mock-up models were made at different scales, with hundreds of detailed drawings, plus wind tunnel tests proving the delta wing was more than satisfactory.

The testing results were so promising and ground breaking for a delta wing design that RAE requested permission to distribute the data to major UK aircraft manufacturers and Avro Canada.

Along with this decision, a series of negative reports by the U.K. Ministry of Supply were cited about the CA-23, which contained false assumptions and data comparisons, that led to terse rebuttal letter from Sir Lawrence J Wackett to U.K.

Swept Wing Advisory Committee to 15 British Aircraft manufacturers and Avro Canada has always raised questions and theories around the similarities with the English Electric Lightning and especially the Sukhoi Su-7.