An experienced Northland helicopter pilot sent to rescue people escaping a large bush fire probably experienced spatial disorientation flying into plumes of thick smoke before crashing into the sea, an investigator has found.
During a coroner's inquest, Civil Aviation investigator Paul Breuilly presented a report on the crash in which he said there was no evidence a technical malfunction had contributed to the crash that killed pilot John "Prickles" de Ridder, 69, and Department of Conservation (DoC) ranger William Macrae, 54, of Awanui.
Mr de Ridder had been using a monsoon bucket to dump sea water on the blaze which started on the Karikari Peninsula on November 30, 2011. He had then been directed by fire staff on the ground, who had been contacted by fire communication staff in Auckland, to help five people trapped on the beach after they were forced to flee their homes under threat by the fire.
Mr de Ridder had landed, removed the monsoon bucket, collected Mr Macrae and headed back in to the fire. Two boats in the area at the time rescued the people who had sought refuge in the sea. Concerns were then raised over the helicopter which had gone missing. In the report, Mr Breuilly raised concerns over the pilot being directed from firefighting work to search and rescue mode, in a helicopter that was not fitted with rescue equipment.
"The implications of a change in role ... may not have been fully appreciated by those making the requests, those relaying them and those asked to deal with them."
He said inadequate field command and control structure contributed to the failure to adequately assess the safety risks when the helicopter changed to rescue operation.
"It is likely the pilot felt compelled to respond to the emergency situation that had developed," Mr Breuilly said.
A DoC official tasked with investigating the fire also raised concerns over the way a helicopter was redirected by someone in Auckland, who had no knowledge of the environment and blaze at the time. Ross Atkinson, a principal compliance officer who has worked for DoC in Northland for more than 20 years, requested audio tapes from the fire communications centre in Auckland as part of his investigation into the tragedy.
The audio of communications between firefighters on the ground and an operator at the fire communication centre in Auckland was played in court. Over fours hours worth of communication was condensed into a 26-minute tape.
In his opinion there were a number of things that contributed to the accident. Mr Atkins said there was chaotic command and control on the fire ground. Fire crews were evacuating people from house to beach which was the safest place to be as there was no fuel for the fire to burn.
A fire communication operator, apparently influenced by direct communication with panicking members of the public, issued an inappropriate command outside standard procedure.
"A normally safe pilot along with an experienced firefighter extended themselves into a high risk situation in the belief they were issued a command because lives were in peril."
The hearing has been adjourned until next year.