Australia's national transport safety investigator has released its preliminary report into "one of the worst" aviation tragedies in Victorian history, revealing a helicopter pilot encountered a "wall of cloud" prior to the crash.
Five people on board an Airbus helicopter were killed after it crashed into Mount Disappointment in March this year, while on its way to Ulupna in Victoria's north.
On board were pilot Dean Neal, 32, and passengers Paul Troja, 73, Linda Woodford, 50, Ian Perry, 59, and Nicholas Vasudeva, 53.
The helicopter had been flying in convoy with another as part of a private charter operated by Microflite, when it disappeared just after 9am on March 31.
Its wreckage was discovered less than two hours later.
A preliminary investigation by the Australian Transport Safety Bureau (ATSB) has revealed the helicopter hit an old-growth tree at about 2,500 feet, before plummeting to the ground and catching fire.
The report said there was no evidence from the wreckage that the helicopter had any pre-existing defect.
"The two helicopters were flying under visual reference rules, that is flying using visual references rather than instruments," ATSB chief commissioner Angus Mitchell said.
The pilot who flew the first helicopter told investigators scattered cloud coverage at 1,500 feet forced them to take a more direct route over Mount Disappointment to Ulupna, instead of flying the recommended route to Kilmore Gap.
Before the two helicopters could cross Mount Disappointment, the first pilot reported being confronted by a "wall of cloud", and broadcast to Mr Neal their intention to turn around.
They believed Mr Neal may have been confused by the message and thought the conditions were safe to continue.
Just before 8am, the first pilot took a sharp left turn after broadcasting "U-turn, U-turn, U-turn" to Mr Neal.
Moments later, Mr Neal's helicopter was seen flying below and to the left of the first helicopter. It would be the last time the helicopter would be seen before its wreckage was discovered.
Passengers of the first helicopter, who had flown with Mr Neal before, told the investigation the 32-year-old pilot was very cautious regarding weather conditions.
They reported that heavy cloud rolled in as the convoy approached Mount Disappointment, with one telling the investigation they "could not see anything, it was like a white-out".
Another recalled hearing Mr Neal radio to the first pilot after the "U-turn" broadcast, "aren't we going to cut through?"
Families hope lessons are learned
Ms Woodford's older brother Andrew said he wanted lessons to be learnt so other families were spared the pain his has been put through.
"The whole thing about investigations and reports is to determine the cause and if it can be discovered, as humans we can learn from failure.
"The odds are so low to perish in a helicopter, it's less than bee stings in Australia."
He said the families of those on board had been warned the interim report was due to be released.
"I've had it for a week, I've had a few phone calls with the guy from the ATSB, they've been awesome," he said.
"They prepared us for what was going to be in it and how it was going to be presented.
"I asked if there was going to be any confronting photos I had to protect Mum from."
Mr Woodford lives in Tasmania and said the long investigation process, on top of losing his sister had been difficult.
"The whole shock factor was pretty hard initially," he said.
"Then having to deal with the coroner, ATSB, and police on top of the finality of not being able to see your sister again, who you speak to regularly.
"At the end of the day it's pretty painful."
In a tearful press conference days after the crash Mr Neal's parents described their son as a conscientious pilot and remarkable man.
"Our broken hearts go to the families and friends of those who were flying with him," his father Rodney Neal said at the time.
Among those on board were leaders in the Victorian meat and agriculture industries, including two members of agricultural technology business AXIChain.
Ms Woodford, its chief executive, was remembered as a visionary while the company's finance consultant, Mr Perry, was described as a committed family man and respected member of the agriculture industry.
Members of the meat industry said Mr Troja had played a big role in developing the sector both in Australia and overseas.
Mr Vasudeva, who was a managing director of a financial solutions company, was remembered as "generous" and "fiercely intelligent".
The ATSB says a final report into the crash will be released after the investigation has concluded.
"The ATSB will analyse data from the helicopter's on board camera and avionics equipment," Mr Mitchell said.
"Should a critical safety issue be identified at any time, the ATSB will immediately notify relevant parties so appropriate and timely safety action can be taken."
