A "gentle wisp of smoke" rising above the dense forest canopy led an air rescue operation to the fiery remains of a helicopter crash in which two men died.

Pilot Allan Jessop, aged 42, from Tangiteroria, and forestry worker Derek Hammond, 49, from Kauri, perished when the Robinson 44 helicopter plunged to the ground in rugged country, deep inside the forest.

Peter Turnbull, the chief pilot for Northland Rescue Helicopter (NRH), said the first call-out to the Glenbervie Forest crash came after the Wellington-based Rescue Co-ordination Centre picked up a solitary "ping" from the chopper's on-board locator beacon yesterday afternoon.

The single beep gave an accurate location, and the Northland service was alerted.


Mr Turnbull said it was not uncommon for an emergency locator device to be bumped and set-off manually and the rescue crew was hoping it was the case this time, or that the chopper had landed safely.

The forest at the crash site was so dense no wreckage could be seen from the air but the co-pilot spotted "a gentle wisp of smoke" at the right co-ordinates, Mr Turnbull said.

"We knew then it had crashed and what we were dealing with."

A second NRH helicopter was dispatched with a winch and a paramedic who, once on the ground, saw there were two fatalities.

A police search and rescue specialist recovery team walked into the site over rugged terrain well off the network of forest tracks and access roads.

The bodies were recovered today.

Mr Jessop's widow Kirsty said it was too soon to talk publicly about her husband or the work he was doing when he died.

Through a family member, Mrs Jessop said she was shocked but coping with the news.


The family said they knew few details about the incident.

"We can't say anything until we know more," the spokesman said.

Devastated friends described Mr Jessop, a father of two, of Tangiteroria, as "one of the good ones" and a "nice guy".

The chopper was carrying out a survey operation when it crashed.

A Rayonier spokeswoman confirmed the company did not own the Robinson 44 and had contracted Mr Jessop.

Whangarei police today handed over the crash site to the Civil Aviation Authority (CAA) to carry out its investigation.

The Transport Accident Investigation Commission (TAIC) could yet make a separate inquiry.

Only last week the TIAC placed Robinson helicopters on a list of transport safety concerns; however, neither the CAA nor TAIC has commented on or established the cause of yesterday's fatal air accident, nor any connection with the aircraft's make.

Mr Turnbull said he could not comment on the circumstances but, "Robinsons are vulnerable to turbulence".

They are prone to "mast bumping", where the main rotor head makes contact with the rotor mast, and the machine breaks apart.

"It's a design problem and you can't train against it. When you skid out in a car there is about five seconds. You can train and recover. When this [rotor] comes to bits in a helicopter there's about one second and it's over," Mr Turnbull said.

The burned-out helicopter wreckage could remain at the site for some time for examination before being carried or winched out, a TAIC spokesman said.

Allan and Kirsty Jessop merged their HeliNorth agricultural spray business, which they started in 2007, with nationwide company Precision Helicopters Ltd in 2013.

It is understood the Jessops recently sold their share in the business and Mr Jessop was working for another company.