On 7 October 2014, the pilot of a Bell 206B3 helicopter registered VH-CLR, departed Cairns, Queensland with one passenger on-board to conduct a charter flight to Mount Cook, about 9 km south-east of Cooktown Airport, Queensland.
To assess the landing area at Mount Cook, the pilot made 3-4 practice approaches and a practice landing prior to continuing to Cooktown to pick up the remaining passengers. The landing area was a rocky ledge jutting out from the south-eastern side near the top of Mount Cook.
The pilot conducted two flights to drop off a total of five passengers. He reported that the wind during these two flights was about 10 knots from the south-east. When he returned to pick up the first load of passengers, the wind had increased to about 14-15 knots.
During the approach to land, the pilot reported that he felt the helicopter was stable and appeared unaffected by the increased wind. As the helicopter prepared to touch down, both the ground co-ordinator and a passenger moved closer to it. Just prior to touching down on the right skid, the pilot felt the helicopter momentarily lift, most likely from a gust of wind, and drift to the right. The helicopter rolled rapidly onto its right side and slid a short distance forward, prior to coming to rest.
The helicopter fell onto the ground controller and nearby passenger. The ground controller sustained serious injuries. The pilot and passenger received minor injuries and the helicopter was substantially damaged.
The roll onto the right side by the helicopter is consistent with the phenomenon known as dynamic rollover. When a helicopter rests on one skid, the aircraft may begin rolling, and under certain circumstances it cannot be controlled.
The operator has advised the ATSB that they have taken several Safety Actions since the occurrence. These are detailed in the report.