Prime Minister of New Zealand Jacinda Arden. File picture: Seth Wenig/AP

Wellington - New Zealand Prime Minister Jacinda Ardern on Thursday apologized to the families of the 257 people who died when an Air New Zealand Antarctic sightseeing flight crashed into Mount Erebus on Ross Island on 29 November 1979.

"After forty years, on behalf of today's government, the time has come to apologize for the actions of an airline then in full state ownership; which ultimately caused the loss of the aircraft and the loss of those you loved," Ardern said at a service for the families  in Auckland.

Air New Zealand board chair Therese Walsh also apologized.

"I apologize on behalf of an airline which 40 years ago failed in its duty of care to its passengers and staff," she said. 

"And I apologize again on behalf of the airline for the way in which the families of those lost on Mt Erebus were treated in the aftermath of the accident," she added. 

The plane's pilots were blamed for the accident in an initial report but a Royal Commission of Inquiry found in 1981 that the dominant cause of the accident was the airline's actions in reprogramming the aircraft's navigation system without advising the aircrew.

"The pilots were not responsible for this tragedy, I stand here today to state that again," Ardern said. 

"But those findings were not accepted by our government then. That was wrong, it caused trauma on top of grief, and persecution on top of pain."

It is the first time the government and airline issued apologies to the families. 

dpa