On 18 August 2011, an Aérospatiale Industries AS355F2 helicopter, registered VH-NTV, was operating in an area east of Lake Eyre, South Australia (SA). On board were the pilot and two passengers. The helicopter landed on an island in the Cooper Creek inlet, about 145 km north of Marree, SA, at about 1715 Central Standard Time.
At about 1900, the helicopter departed the island, and soon after takeoff it collided with terrain. The pilot and the two passengers were fatally injured, and the helicopter was destroyed by the impact forces and a fuel-fed fire.
Update 26 November 2012
The Global Positioning System (GPS) data that was recovered from the accident site indicates that the helicopter took off normally, before being established on a heading of 035 °M at 1,500 ft above mean sea level (AMSL). After maintaining 1,500 ft for 17 seconds, the helicopter commenced a gradual turn to the right and started to descend. The descending right turn continued for about 35 seconds until the last GPS plot at an altitude of about 728 ft, or about 725 ft above the elevation of the accident site. The location of the accident site was consistent with a continuation of the recorded flight path.
The Australian Transport Safety Bureau (ATSB) is examining various scenarios to explain the helicopter’s flight path, including spatial disorientation and pilot incapacitation. As part of these activities, the ATSB has arranged for simulations to be conducted of the flight by external agencies. Given the time required to conduct and analyse these simulations, the final report is now not expected to be released until the first quarter of 2013.
Although the reasons for the flight path have not yet been determined, the ATSB is concerned about the conduct of visual flight rules (VFR) flights in dark night conditions – that is, conditions with minimal celestial illumination, terrestrial lighting cues or visible horizon. The ATSB is reviewing the regulatory requirements and guidance for the conduct of night VFR flights, and the training and ongoing assessment of pilot skills to conduct such flights. The ATSB is also preparing an ‘Avoidable Accidents’ educational report focussing on night VFR accidents.
The information contained in this web update is released in accordance with section 25 of the Transport Safety Investigation Act 2003 and is derived from initial investigation of the occurrence. Readers are cautioned that new evidence will become available as the investigation progresses that will enhance the ATSB’s understanding of the occurrence as outlined in the web update. As such, no analysis or findings are included in this update.
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Update 15 August 2012
Since the Preliminary Report was issued on 16 September 2011, the ATSB investigation has:
- examined the helicopter's maintenance and airworthiness records
- examined the helicopter's engines, instruments and other recovered components
- tested fuel samples from the drums that were used to refuel the helicopter
- recovered and analysed data from a GPS device on board the helicopter
- reviewed the pilot's experience and medical status
- analysed witness statements and conducted further witness interviews as required.
The download and analysis of the GPS data required an extensive period of time, as well as input from overseas investigation agencies.
Overall, the analysis of the circumstances of the accident has been difficult due to the limited evidence available.
The ATSB has completed its data collection activities and is preparing its draft final report, which will be issued to Directly Involved Parties for their comments.
