Preliminary report published: 30 January 2019

What happened

On 24 November 2018, at about 0800 Central Standard Time,^[1] a Robinson R22 helicopter, registered VH-KZV, collided with terrain about 125 km east-north-east of Alice Springs Airport. The pilot was fatally injured and the passenger was seriously injured. The helicopter was substantially damaged.

The pilot held a private helicopter pilot licence and was employed by a cattle station for general flying duties, which included cattle mustering. On the morning of the accident, the pilot and passenger were tasked to assist with the recovery of a motor vehicle, located about 63 km east-north-east of Ambalindum Station (departure point). A station hand assisted them with preparing the helicopter for departure. The station hand could not recall the actual time of departure, but estimated it was between 0730 and 0745.

At about 0811, the pilot’s Spot Tracker device transmitted its location in SOS mode.^[2] A local helicopter company in Alice Springs was subsequently tasked by the Joint Rescue Coordination Centre to transport a paramedic to the reported location and conduct a search and rescue. In addition, Ambalindum Station dispatched two employees by road to investigate. The search helicopter pilot located the wreckage of the R22 at the reported location, and the paramedic subsequently attended to the accident pilot and passenger. At about 1045 the paramedic found the pilot deceased and the passenger in a serious condition. The rescue helicopter departed to collect the two station employees who were enroute to assist with the emergency response. The rescue helicopter pilot and the paramedic, with the assistance of the two station employees, retrieved the passenger and transported him to Ambalindum Station for treatment by a retrieval doctor, before transporting him to Alice Springs Hospital for further medical attention.

Figure 1: Robinson R22 helicopter, VH-KZV, main wreckage site

Source: ATSB

The ATSB attended the accident site on 26 and 27 November 2018. The helicopter’s clock had stopped at about 0756. The helicopter had impacted the ground on a downslope, in an easterly direction, and continued down the slope, producing debris as it struck rocks and trees, before crossing a dry creek bed. The helicopter came to rest on the far side of the creek bed, in a southerly direction, with the port side of the helicopter resting against the upslope of the far bank. The main rotor disc struck and separated the rear section of tailcone as a consequence of the accident sequence. Significant torsional deflection of the tail rotor driveshaft intermediate flexible coupling indicated that it was rotating when the strike occurred.

The ATSB found no pre-existing defect with the rotors, transmission, sprag clutch, drive belts or flight controls, which would have prevented normal operation. The main fuel tank had sufficient fuel for flight. A fuel test on site and at the point of departure did not identify any visual contaminates, including water. In addition, fuel samples were collected from the helicopter and departure point fuel pump, for future chemical analysis testing if required. The engine and a majority of the airframe was retrieved from the accident site and transported to Alice Springs. The engine was then removed from the wreckage and transported to Brisbane for further examination under the supervision of the ATSB. Several components and cockpit warning lamps were retained for examination.

Weather and terrain

The accident site was within the MacDonnell Ranges at an elevation of about 1,850 ft, 31 km east of Ambalindum Station. At the time of the accident the weather forecast included moderate turbulence throughout the area. At 0800 the Alice Springs Airport recorded a wind speed of 18 kt, with gusts to 29 kt, from 330 degrees, and a temperature of 29 °C. The Arltunga weather station, located about 40 km west of the accident site, recorded two observations each day. At 0800 it recorded a wind speed of 14 kt^[3] from 360 degrees, and a temperature of 30 °C.

Engine tests and inspections

On 8 and 9 January 2019, inspections and tests were conducted on the recovered engine. Representatives from the workshop, Civil Aviation Safety Authority, insurance company and helicopter owner were present.^[4] No fault was identified that would have prevented normal engine operation. Damage to the engine cooling fan and the presence of dirt inside the number 2 cylinder indicated the engine was operating at the time of initial impact. Scoring damage to the V-belt actuator was identified. The helicopter manufacturer advised the ATSB that the identified damage was consistent with the upper sheave rotating on contact with the actuator as the structure distorted on impact and that the actuator was in the extended position.^[5]

Further investigation

To date, the ATSB has examined the wreckage, interviewed witnesses, consulted with the helicopter manufacturer and collected weather data and analysis from the Bureau of Meteorology.

The ATSB will conduct further enquiries into:

• flight planning
• the weight and balance of the helicopter
• examination of individual components and warning lamps
• analysis of data recording devices
• pilot training and qualifications.

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The information contained in this 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 update.

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1. Central Standard Time (CST): Coordinated Universal Time (UTC) +9.5 hours.
2. The Spot Tracker is a global positioning system tracking device, which uses a satellite network to provide tracking and text messaging. The cattle station owners issued one to each of their employees. The SOS mode of activation indicated an emergency.
3. Mean wind speed recorded over a 10 minute period.
4. The helicopter manufacturer, engine manufacturer and maintenance organisation were invited by the ATSB but did not attend.
5. Normal position for flight.