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An investigation into the crash-landing of a helicopter on Mt Ruapehu's crater lake in 2006 has found its load was nearly 20kg too heavy and the pilot had insufficient mountain flying experience.
Taupo pilot Bruce Lilburn and his four passengers were injured when the Hughes 500 they were travelling in went down on the northern edge of the lake.
Lilburn had picked up two Department of Conservation (DOC) officers who had been doing routine work near the crater lake.
He took with him his loader driver from an earlier job and another DOC worker.
The Transport Accident Investigation Commission (TAIC) report said one worker questioned whether the helicopter would handle five people and Lilburn responded that they would "see how it goes", or words to that effect.
The pilot did not ask for the weight of any passengers or their packs, although he helped load them on to the helicopter.
Take-off was normal but as soon as the helicopter started moving forward it stopped climbing and he knew something was wrong.
The helicopter hit the water, throwing both front-seat passengers from it. Another worker was submerged but escaped through an open rear door.
Lilburn broke his ankle and one passenger fractured neck vertebrae.
The TAIC report said the take-off weight was estimated to be 18kg over the maximum allowable, and the pilot did not have the mountain flying experience and knowledge of the helicopter's performance necessary for him to undertake the flight safely.
Although the pilot's options for dealing with the load problem were reduced by the two unnecessary passengers, the report said he could have returned them to the park before picking up the remaining workers.
The report made mention of two passengers who had not been wearing seatbelts, saying their injuries would not have been as severe if they had worn restraints.
No technical defect was found with the helicopter, although damage caused by the accident meant the possibility of reduced engine performance could not be ruled out.
TAIC made several safety recommendations to the Director of Civil Aviation which included a closer examination of how pilots were trained and how well the industry was complying with Civil Aviation Authority rules.
It also recommended the need for life jackets on flights where a forced landing on water was possible be addressed, and said a culture of non-compliance where seat restraints were concerned be examined.
Following the accident, Lilburn was hailed a hero after he trekked for an hour with a broken foot to get help for his four injured passengers.
Using an ice-axe, he scaled a near-vertical 30 metre eroding ice shelf above the crash site, and then made his way down the mountain.
However, in December Lilburn was committed for trial over the incident after a charge of operating an aircraft in a manner causing unnecessary danger was laid under the Civil Aviation Act .
He was remanded at large for callover in the Rotorua High Court on March 4.
- NZPA