Today's military helicopter crash, which claimed three lives, happened almost 38 years to the day after the Air Force's only other fatal Iroquois chopper crash.

Three people died after the RNZAF Iroquois helicopter, which was en route from Ohakea Air Base in Rangitikei region to Anzac day services in Wellington, crashed into a gully on the hills high above State Highway 1 near Pukerua Bay, about 40km north east of Wellington, shortly before 6am.

One man suffered serious injuries and was in a stable condition in Wellington Hospital's Emergency Department.

The crash was the second fatal accident involving Air Force Iroquois helicopters since they started service in New Zealand in 1966. On April 27, 1972, three people died when a helicopter crashed into sandhills near the Kaipara harbour.

Since 1966, there have been four other crashes in the fleet of 14 Iroquois, according to the RNZAF website.

One helicopter suffered serious damage in a groundstrike on Mt Cook on November 28, 1982, while it was trying to retrieve trapped climbers during a search and rescue mission.

Another was damaged while lifting an aerial at Kaipara in July 1990.

A third was damaged when it was involved in a mid-air collision with another aircraft in Australia on October 6, 1991.

Those aircraft have since been rebuilt.

In the latest incident involving an Air Force Iroquois, the helicopter was written off after an engine failure in March 1995 resulted in the aircraft landing short of the Waiouru helipad, and overturning in the Ngamatea swamp.

The Air Force is in the process of replacing the ageing helicopters with eight NH90 utility choppers.

The French-made aircraft were due to arrive early this year and would be fully commissioned by 2013 as part of a $771 million deal.