TWO helicopter pilots did not know they had collided as they fought the December bushfires at Macquarie Woods until they later stopped to refuel, a report from the Australian Transport Safety Bureau says.
The preliminary report was released yesterday and detailed the investigation into the sequence of events that led to the crash about 6.40pm on December 8.
It said that after the pilot of the first helicopter had landed to refuel, he noticed damage to the "trailing edge of the helicopter's vertical fin".
"In addition, the plastic navigation light cover on top of the vertical fin was broken," the report said.
It said the pilot reported the damage to the pilot of the second helicopter but examination of the second machine showed there was no obvious damage.
“There was significant bushfire activity in NSW on the day of the occurrence. The pilots had been tasked by the Rural Fire Service of NSW and were operating under the operational control of that organisation,” the report said.
The report details how the helicopters were filling up their buckets with water from two separate dams close by each other.
“The pilot of [the first helicopter] later reported that, as he initiated the water drop from an altitude of about 100 feet above ground level, he felt a ‘slight jolt’ through the helicopter and immediately rolled right, away from the fire line,” it said.
“In his peripheral vision, he saw a yellow coloured object flash past the left door and initially thought it was a water bombing aeroplane that had not reported its bombing run.
“The pilot of [the first helicopter] considered that his helicopter was performing normally and continued with the firefighting task. Similarly [the second] also continued on task.
“Immediately before the occurrence, the pilot of [the second helicopter] was refilling his bucket from the westernmost dam. The pilot of [the first] completed his refill first and informed the pilot of [the second] that he was departing the dam. The pilot of [the second] subsequently reported that he was also departing his dam.”
The report said both pilots had mistakenly thought the other helicopter was a couple of hundred metres away. It said damage displayed the “characteristics of a high energy impact”.
The investigation is continuing.