The fleet of more than 40 Taipan helicopters was grounded while investigators probed the night-time crash, which occurred during war-game exercises off the Whitsunday Islands.

The aircraft was originally due to be retired at the end of 2024.

The Taipans "will not return to flying operations" before that withdrawal date, Australia's defence ministry said in a statement.

The government said it was introducing a new fleet of 40 UH?60M Black Hawk helicopters, three of which had already started flying in September.

"The government's highest priority is the safety and well-being of our people," said Defence Minister Richard Marles.

"We continue to support the families of the four soldiers who lost their lives earlier this year, and the broader defence community."

Australian officials have previously complained about the European-made Taipans, citing difficulties with maintenance and getting spare parts.

The fleet was grounded for a month earlier this year after one of the helicopters suffered engine failure during a night-time training exercise, forcing the crew to ditch into the ocean.