The sole survivor of the Anzac Day helicopter crash is trying to prosecute the Defence Force - and the chief of defence.

Sergeant Stevin Creeggan - who is still in the air force - served the New Zealand Defence Force with legal papers on July 18.

It is understood the prosecution against the NZDF and Defence Force chief, Lieutenant General Rhys Jones, if permitted by a judge, would focus on the Defence Force's failure to protect the welfare of an employee in the workplace.

Sergeant Creeggan, 39, suffered severe chest, leg and spinal injuries in the 2010 Anzac Day Iroquois helicopter crash at Pukerua Bay.

After the crash, he spent a year in a wheelchair and using a frame before being able to walk unassisted. He still cannot remember the crash or several days after it.

The three other airmen in the chopper - Flight Lieutenant Hayden Madsen, co-pilot Flying Officer Daniel Gregory, and Corporal Benjamin Carson - died at the scene.

In normal circumstances, an employment health and safety prosecution would need to be filed within six months of the accident. Beyond that window, if Sergeant Creeggan is to bring charges against NZDF and Lieutenant General Jones, the court must first grant leave to proceed with the court case out of time.

Those requirements would be the same whether charges were laid under a private prosecution or by the Labour Department.

If the case were to be approved by the court, Sergeant Creeggan could push for reparations from the Crown, according to Nikki Pender of Wellington law firm Legal Empowerment. But the injured airman would first need to get past the delay in time.

"You need the extension of time to be able to lay charges. [An extension] depends on how long the Department of Labour took to investigate, or if they did," she said.

Neither the then-Labour Department, now part of the Business, Innovation and Employment Ministry, nor the Civil Aviation Authority investigated the crash.

The NZDF-headed court of inquiry investigation - the only inquiry into the crash - found that the crew did not take evasive action fast enough when they found themselves lost in low cloud.

Wing Commander Logan Cudby, who headed the court of inquiry, said Defence Force protocols were also to blame for causing a situation where the crew piloting the doomed Iroquois were not up to the task.

"Orders, instructions and procedures were too complex, contradictory, convoluted and in some cases out-of-date to be useful," he said.

Ms Pender said, if prosecuted and found guilty, the Defence Force could be liable to pay reparations to Sergeant Creeggan "into the tens of thousands". As a Crown agency, it cannot be fined.

NZDF has refused to comment on Sergeant Creeggan's application "as it is a matter before the courts". Sergeant Creeggan, pictured right, could not be contacted.

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