Stephen Anthony Nicholson Combe (42), of Wanaka, and James Louis Patterson Gardner (18), of Queenstown, were killed yesterday when the helicopter in which they were travelling crashed in the Lochy River valley in the Eyre Mountains, southwest of Queenstown.
The men were employees of Queenstown company Over the Top, which operated the helicopter, a Robinson R44.
Transport Accident Investigation Commission (Taic) investigator Ian McClelland said the team would focus on assessing the site and determining the best way of recovering the wreckage.
When that was completed, it would begin collecting evidence such as the aircraft's maintenance records and pilot records, and conduct interviews with Over The Top staff.
The wreckage was in bush on "moderately steep'' terrain, but could be reached on foot.
Whether the wreckage was recovered today depended on how long it took to survey the site.
When asked about the Robinson R44's safety record, Mr McClelland said it was "probably the single most common helicopter in service, and so they will feature statistical-wise in accidents''.
The aircraft was reported overdue to the Rescue Co-ordination Centre (RCCNZ) about 2.30pm yesterday, and was discovered by search and rescue crews shortly after 4pm.
Det Sgt Brian Cameron said the helicopter's distress beacon was detected, which helped lead the searching aircraft to the crash site.
Mr Combe was born in South Africa and raised in Britain. He was married with two young sons.
Mr Combe was no stranger to danger. He was a former British Royal Marine captain and served in Sierra Leone, Kosovo and Iraq, retiring after spending three months in Basra in 2003 with the 847 Naval Air Squadron.
Mr Patterson Gardner was fresh out of school and was believed to have been preparing to go to university.
Mr Patterson Gardner was the son of Over the Top chief executive officer Louisa (Choppy) Patterson, who had operated the company for more than 26 years without accident.
He knew Prime Minister John Key and had posted to his Facebook page a photo of the pair together at the driving range overlooking Queenstown.
Mr Key paid tribute to the pilot last night:''It was a privilege to meet James on a number of occasions. He was a fine young man.
''It will be devastating for the family and my heart goes out to them.''
The company said in a statement today it had temporarily suspended its commercial operations while it focused on providing support to family and staff.
"It's a hugely difficult time for everyone at Over the Top - both will be sorely missed by all the team and our thoughts are with the family and friends of Stephen and James."
The company was working closely with authorities.
Southern Lakes Helicopters (Te Anau) owner/pilot Sir Richard Hayes said the pair were well known and well liked in the local aviation community.
''Speaking on behalf of the aviation community, we're absolutely devastated and shocked that such a tragedy has happened.
''Stephen was a respected and experienced pilot. James is only a young guy - only just finished school, I believe.
''The industry is going to reel from this one, because it is very close to home.
''The Queenstown aviation community is a pretty close-knit family here. Everyone knows everyone else. We're all like extended family.''
The deaths have been referred to the coroner and postmortem examinations would take place in Christchurch today.
