The families of four Australian Defence Force personnel killed in the fatal Taipan helicopter crash have launched a class action against the Commonwealth and aircraft manufacturer Airbus.

The legal action centres on the July 2023 Taipan army helicopter crash off the Whitsunday Islands, Queensland, which claimed the lives of Captain Daniel Lyon, Lieutenant Max Nugent, Warrant Officer Joseph Laycock and Corporal Alexander Naggs.

WATCH THE VIDEO ABOVE: Families launch legal action over fatal helicopter crash

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It’s understood about 10 family members are involved in the class action, alleging failings led to the deaths of the four men.

The development comes less than a week after relatives gathered in Airlie Beach for the unveiling of a permanent memorial honouring the four servicemen, who died when their MRH-90 Taipan helicopter crashed during the multinational military exercise Talisman Sabre.

Captain Daniel Lyon, Lieutenant Max Nugent, Warrant Officer Joseph Laycock and Corporal Alexander Naggs were killed when their Taipan helicopter crashed during a nightly military exercise off the Queensland coast. Credit: 7NEWS

The Taipan helicopter crashed into waters off Lindeman Island during Exercise Talisman Sabre, killing all four crew members. Credit: 7NEWS

The families of the four soldiers killed in the 2023 Taipan helicopter crash have launched a class action against the Commonwealth and Airbus. Credit: 7NEWS

The Taipan fleet was grounded immediately after the crash before the federal government announced it would be retired early.

Australia has since replaced the aircraft with UH-60M Black Hawk helicopters.

Investigations into the fatal crash have been ongoing, while the circumstances surrounding the disaster continue to be examined.

No further details about the allegations contained in the class action have been released.