The sole survivor of the Anzac Day helicopter crash has been allowed to lay health and safety charges against the Defence Force.
Sergeant Stevin Creeggan had been travelling with three other members of the Defence Force in an Air Force Iroquois when it crashed in bad weather above Pukerua Bay north of Wellington in 2010.
Flying Officer Daniel Gregory, Flight Lieutenant Hayden Madsen and Corporal Ben Carson died in the crash.
Sergeant Creeggan, who suffered serious injuries, was found 25 metres away from the wreckage.
In June, he applied to lay criminal charges against the Defence Force and the Chief of Defence for breaches of the Health and Safety in Employment Act.
Wellington District Court Judge Bill Hastings has now allowed the application, making Sergeant Creeggan the first ever individual to successfully apply for leave to lay charges under the Act outside the six-month time limit.
Sergeant Creeggan's lawyer Charles McGuinness said Judge Hastings had considered the reasons for the delay in seeking charges, including the failure of the then Department of Labour to investigate because of confusion over its jurisdiction.
The reasons also included Sergeant Creeggan's serious injuries and the Defence Force's court of inquiry process, which took over 20 months to issue its redacted report to the public.
Mr McGuinness said consideration was also given to the interests of justice and the public interest in a prosecution, with Judge Hastings finding that both were satisfied.
"Stevin is seeking one key outcome - that all possible steps are taken to ensure an accident like this never happens again and members of the armed forces are kept as safe as practicable," he said.
"Judge Hastings' decision is an important step towards this goal."
Lawyer Sarah Cates, who also worked on Mr Creeggan's case, said transparency was also among Judge Hastings' considerations.
"The transparency of a prosecution based on alleged health and safety breaches, as opposed to the Court of Inquiry process was also relevant in the decision,'' she said.
Mr McGuinness said Sergeant Creeggan was very happy about the outcome.
It had been a long battle, but there were small victories along the way, including clarification that the Ministry of Business, Innovation and Employment was responsible for investigating and enforcing health and safety obligations in the armed forces, including aircraft.
Judge Hastings also heard argument about whether the office of the Chief of Defence or the person in that office was the most appropriate to be prosecuted, but determined the issue could be decided later.