One of a batch of incomplete DH-94s shipped to Australia following the decision to terminate production in the UK. The aircraft were completed by DH Australia and delivered to the RAAF which did not want them. Most served as station or squadron hacks with A21-4 at Cootamundra until January 1945 when it was grounded pending disposal. Became VH-AFT in May 1945.

A21-4 was the display jet for the 2016 Australian Formula 1.

The "Purple Cobras" formation at the Avalon Airshow 2009, Trade Day Three

'Purple Cobra Lead' waits at the holding point for F-16 'Wild 1' to backtrack after landing ex display at the Australian International Airshow. This aircraft was built as a Block 15 Hornet and delivered to the RAAF on 20 June 1986. Served initially with 2 OCU and later 77 Squadron, whose 'Grumpy Monkey' unit marks it wears. Deployed to Diego Garcia in 2002 and shared with 3 Squadron. Returned to Australia in May 2002 and currently in service with 77 Squadron.