Investigators have started detailed work to find the cause of a Northland helicopter crash which claimed two lives.
Two staff from the Transport Accident Investigation Commission (TAIC) spent yesterday conducting interviews and were to visit the Glenbervie Forest site where the Robinson 44 crashed in thick bush.
As tributes were paid to the second man killed in the crash - forestry worker Derek Hammond - the Department of Conservation announced it was suspending the use of Robinson machines.
DoC said its decision was prompted by the crash and the placing of Robinson helicopters on a TAIC "watchlist".
DoC health and safety director Harry Maher said the decision had been made to protect staff, including volunteers and contractors working directly for it.
"The safety of our people is paramount, so in light of the recent accident we are suspending the use of these helicopters for operations where DoC staff, volunteers and contractors are passengers."
Monday's crash brought the number of people killed in New Zealand crashes involving Robinson helicopters to 20 since 1996.
About 300 Robinson choppers are registered in New Zealand and the brand makes up 40 per cent of the nation's helicopter fleet.
Hammond, 49, died in the crash with pilot Allan Jessop. Hammond worked for Rayonier Forests as a supervisor and one of his favourite parts of the job he loved was flying in the choppers during aerial surveying work.
William Hammond, one of three brothers, also died in a forestry accident years ago in Australia.
Younger brother Les said Derek loved building hotrods and spending time with friends and family. Derek and his partner Jackie had no children, and he is survived by his mother Teresa Hammond.
"Mum's just like everyone else right now, trying to come with terms with this," Les Hammond said. "Derek was funny all the time, he always had a laugh," said family friend Kevin Morgan, from Te Kopuru. "He was into everything. He loved his hunting and his cars. He was a real family man."
Several messages posted on social media refer to Hammond's generosity, selflessness and support of his friends and family
TAIC investigators yesterday talked to the Glenbervie Forest manager, the helicopter company, witnesses, police and others.
The wreckage was due to be airlifted from the crash site yesterday, depending on the progress of the site examination, weather and transport plans, a TAIC spokesman said.
The wreckage would be trucked to TAIC's technical facility in Wellington for detailed examination.
A safety investigator from Robinson Helicopter Company in the US will also take part in the site examination and later work.
International convention allows an aircraft's maker to join inquiries after an accident involving it.
Roger Stevenson, owner of Skywork Helicopters, has welcomed DoC's decision to stop using Robinsons and said he and others in the industry had lobbied authorities on several aspects of commercial helicopter use.