A helicopter that crashed, killing two people, had already been reported missing once earlier in the day, after it continued on when six others landed because of deteriorating weather.
It, too, landed for a period, but authorities searching for it got to the site just after it took off again. It would crash less than half an hour later.
The Australian Transport Safety Bureau preliminary report notes the helicopter crashed into the ground at Kiandra Flats in Kosciuszko National Park on April 3 after a steep left descending turn. The pilot and passenger - a 64-year-woman and a 75-year-old man, both from Sydney - were fatally injured. It was the second helicopter crash in the area in three weeks.
In this case, the seven-seat Bell Jet Ranger 206 LongRanger left Majura, north of Canberra Airport as one of seven helicopters on a flying tour. They were following a common itinerary but operating independently.
The six other helicopters landed on a property near Wee Jasper due to deteriorating weather, while the pilot of the helicopter that would later crash continued south, before landing alongside Long Plain Road in the Brindabella region.
The helicopter was certified for day visual flight rules only, meaning the aircraft can only fly in clear weather conditions.
When the Jet Ranger didn't arrive at Wee Jasper, the other pilots contacted authorities, who launched a search.
Bureau director of transport safety Stuart Macleod said the pilot was able to contact other members of the tour group, with the help of a passing motorist, and the search was called off.
Almost 3.5 hours after landing, flight tracking data shows the helicopter took off again, about 3pm.
"Police officers dispatched to locate the helicopter as part of the earlier search arrived at the site just after it took off, and observed the helicopter depart to the south at low level, in overcast conditions with low cloud and light rain," Mr Macleod said.
Tracking data shows the helicopter flew below 500 feet above ground level, following geographical features along low-lying terrain.
"About 10 minutes into this second flight, the pilot turned north-west and took up a track towards Tumut, which they had indicated to the tour group as their intended refuelling destination," Mr Macleod said.
"They then encountered higher terrain and turned around to head southward, again following lower lying terrain for another 10 minutes, before reaching Anglers Reach, at which point they turned back on a track towards Tumut."
The helicopter climbed to 7000 feet above sea level and continued for several minutes, before descending to 6800 feet, and almost immediately began climbing again.
"After climbing to 7400 ft, the helicopter commenced the steep turn, its ground speed increased to 134 kt, and its descent rate exceeded 3800 ft per minute."
The helicopter crashed at 3.26pm in an area of tussock grass and protruding rock.
A second search was initiated the next morning when the helicopter did not meet the tour group as planned in Victoria. A ground team, assisted by aircraft tracking data, found the accident site that evening.
An examination of the site found the helicopter's engine was providing power at impact, and there was no evidence of an in-flight break-up or a pre-existing defect with the drive train or flight controls.
"As the investigation progresses, the ATSB will further review and analyse pilot and maintenance records, recovered wreckage components, the flight tracking data, witness information and meteorological data," Mr Macleod said.
A final report, which will detail analysis and findings, will be released at the conclusion of the investigation.
"However, should a critical safety issue be identified at any time as the investigation progresses, the ATSB will immediately notify relevant parties so appropriate and timely safety action can be taken."
