Preliminary report published: 6 June 2018
On 17 April 2018, the pilot of a Garlick Helicopter UH-1H, registered VH-HUE, was conducting long-line lifting operations near Talbingo in the Snowy Mountains region of New South Wales. This operation was part of a proposed expansion of the Snowy Mountains Hydro-electric Scheme, known as the Snowy 2.0 project. The onsite ground crew consisted of two loadmasters, who had VHF/UHF radio communications with the helicopter, and three additional workers.
Accident site location approximately 24 km SSE of Talbingo Township. Source: Google Earth
After completing a number of earlier lifts, the pilot was positioning the helicopter to lift the motor of a drill rig. As the helicopter approached, the load master advised by radio that he needed some more time to prepare the rigging for the next lift and requested that the pilot to hold off for a short time. The pilot repositioned the helicopter approximately 700 metres north-east and maintained a hover while waiting for clearance to commence a forward approach to the intended lift. The pilot recalled that weather conditions were ideal in the valley with a slight breeze and good visibility (Figure 2). Wind observations recorded approximately 45 minutes later at Cabramurra (18 km away), were 11 km/hr from the west.
While waiting for radio clearance to lift the drill rig motor, the pilot recalled that he had time to conduct a full systems check and that all instruments indicated the helicopter was operating in the normal range. At about 1415 EST, the load master requested the pilot approach the site in preparation for lifting the drill rig motor. As the pilot approached overhead, the load master radioed to the pilot that he wanted to re-check the rigging and to temporarily delay the approach. In order to minimise the rotor downwash on the people below, the pilot raised the collective to climb the helicopter, and the 100 foot long-line, above the tree canopy.
As the helicopter started to climb, the pilot heard a loud mechanical ‘screaming’ noise, and he started making plans for an emergency landing. Almost immediately, the pilot also heard an audible alarm, followed by a noticeable yaw. Around this time, a light coloured gas or mist was evident near the engine area of the helicopter (Figure 2).
A light coloured mist or smoke is visible trailing from the helicopter in this photograph taken near the time of the ‘Mayday’ call. Source: GHD.
The pilot elected to conduct the emergency landing in the Yarrangobilly River bed, south-west of the lifting area and workers. Concurrently, the pilot transmitted a ‘Mayday’ call over the radio. The ground workers observed the helicopter turn to the south-west, away from the lifting site and descend toward the river. The helicopter subsequently collided with the river bed. Two areas along the flight path with broken tree branches were identified, consistent with being struck by the helicopter main rotor blades.
The pilot, who was wearing a helmet and secured in a lap belt, sustained serious injuries and the helicopter was destroyed.
Drill pad shown in top right of photo including path of helicopter shown. Source: GHD.
At interview, the pilot advised he had flared the helicopter prior to the impact with the second tree, but could not recall the remainder of the impact sequence until exiting the helicopter. Examination of the wreckage and ground impact marks indicated that the helicopter had impacted the ground in a nose high, slightly right side down attitude. During the impact with terrain, the tail boom of the helicopter detached from the fuselage. The fuselage then came to a rest inverted and nose low a short distance away, balancing on the main rotor head assembly.
Wreckage of VH-HUE looking downstream away from the drill pad, in the approximate direction of flight. Source: ATSB
Four of the workers on the ground gathered fire extinguishers and immediately moved in the direction of the helicopter. One of the loadmasters stayed at the lifting site and called for help via satellite telephone and radio.
The four workers travelled on foot down river to access the accident site. Upon arrival, fuel was visible leaking down the outside of the fuselage. Some smoke was also observed in the area and, due to concerns of a potential fire in the engine bay, fire extinguishers were deployed toward this area to mitigate this risk. Meanwhile, two workers assisted the pilot to exit the helicopter and supported him in moving upstream, safely away from the wreckage, before commencing first aid.
The pilot of another helicopter (also operating in support of the Snowy 2.0 project), heard the Mayday call, flew to the lifting site, and dropped off three additional workers to assist. These workers gathered additional first aid supplies to help provide first aid to the injured pilot and also assisted with rescue coordination. As communication was limited from the site, the pilot of the helicopter took off and climbed the helicopter to relay messages from the ground by flight radio and UHF. This pilot remained overhead for the duration of the rescue efforts and medical extraction of the pilot.
The pilot of a third helicopter (also conducting Snowy 2.0 operations) had also become aware of the accident. This helicopter flew to Cabramurra to transport Snowy Hydro medical support workers to the accident site. Upon arrival at the accident site, the two medical personnel, consisting of a nurse and paramedic, commenced further medical treatment of the injured pilot.
During this time, a medical helicopter was deployed from Canberra to lift the pilot from the site. Approximately 2 hours after the accident, the injured pilot was winched from the accident site and transported to a Canberra hospital.
The immediate rescue efforts of the ground workers afforded the best opportunity to assist the pilot escaping the helicopter, conduct first aid and mitigate the risk of a serious fire.
While the helicopter was destroyed, the fuselage remained unaffected by fire (Figure 5).
Wreckage of VH-HUE looking upstream toward the drill pad, showing the nose of the helicopter and pilot’s seat. Source: ATSB
Due to the unstable nature of the wreckage, on-site examination was limited. Consequently, the helicopter was lifted from the accident site (Figure 6) and transported by road to a secure hangar for further examination.
Wreckage of VH-HUE being lowered by an s-61 ‘Sea-King’ to Cabramurra ALA for transfer to a secure hangar. Source: ATSB
The ATSB investigation is continuing and will include the following:
- Examination of the fuselage, flight and engine instruments, controls and linkages, engine and auxiliary components, and the pilot occupied space.
- Technical failure mechanisms for the engine and/or drive train
- Cabin safety and survivability factors
- Helicopter maintenance history
The ATSB wishes to thank the significant contribution of the following organisations and their staff: New South Wales Rural Fire Service, Snowy Hydro Limited, GHD and Jindabyne Landscaping. These organisations assisted with transport to the accident site and operational support during the investigation process. The ATSB also acknowledges the support of Encore Aviation, Charles Taylor Adjusting, Heli Survey Jindabyne and Coulson Helicopters in supporting the lifting of the helicopter wreckage from the accident site.
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 the 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 accident as outlined in this web update. As such, no analysis or findings are included in this update.