Preliminary report published 7 November 2019The information contained in this investigation update is derived from the initial investigation of the occurrence. Readers are cautioned that there is the possibility that new evidence may become available that alters the circumstances as depicted in the report.
What happened
On 6 September 2019, at 1430 Eastern Standard Time,[1] the pilot of a UH-1H helicopter registered VH‑UVC (UVC) departed Archerfield Airport, Queensland, with four passengers on board. The pilot was conducting a private flight for the purpose of repositioning the helicopter to Bankstown Airport, New South Wales.
At about 1600, the pilot landed at Coffs Harbour, New South Wales to refuel the helicopter. Following refuelling, the pilot departed at about 1648 and tracked to the south. At 1755, the pilot made contact with Williamtown Tower, requesting clearance to track south via the Visual Flight Rules[2] lane. The pilot also requested a climb to higher altitude, to take advantage of favourable winds. The Williamtown Tower controller advised the pilot to contact Williamtown Approach (Approach) for clearance.
At 1757, the pilot of UVC made contact with Approach and requested clearance. At 1758, the Approach controller identified UVC’s position as 7.4 km (4 nautical miles) to the north-east of Broughton Island (Figure 1), and advised the pilot he could operate at whatever altitude was required provided it was not below 2,400 ft. The pilot responded with a request to operate between 3,000 and 3,500 ft. At 1758 UVC was cleared to track coastal southbound at a block altitude between 3,000 and 3,500 ft.
At 1759, following an inquiry from the Approach controller, the pilot advised that Bankstown was his intended destination. At 1800, the pilot was advised that if any further track and altitude changes were required to advise accordingly. While no response was required, the pilot did not acknowledge the transmission. At 1801, the controller again contacted UVC to offer alternative tracking if required. The pilot responded requesting to remain on the eastern side of the romeo five seven eight alpha (R578A) restricted area. The controller clarified this request and, in response, the pilot advised if it was not available he would continue on the VFR coastal route. The pilot was then cleared to track as required for Bankstown Airport. The track clearance was acknowledged by the pilot at 1802.
At 1805, the Approach controller contacted the pilot to confirm that operations were normal, having observed that the altitude of UVC had dropped to 2,700 ft. The pilot acknowledged the altitude drop, commenting on a sudden wind gust affecting the helicopter’s altitude. The controller responded by providing clearance for the pilot to operate between 2,400[3] and 3,500 ft. This was acknowledged by the pilot who also commented on the turbulent conditions that were being experienced. The controller acknowledged the conditions and made a further offer of assistance should the pilot require it.
UVC was later observed on Williamtown Air Traffic Control radar to make a left turn to the south, depart the coastal VFR lane and head offshore. According to Automatic Dependent Surveillance - Broadcast (ADS-B)[4] data supplied by Airservices Australia, the helicopter’s position at the beginning of the turn at 1811, was 2.3 km west-south-west of Anna Bay.[5]
The aircraft continued to track offshore to the south-west for about 1 min 20 sec, maintaining between 3,000 and 3,600 ft before commencing a rapidly descending, left turn. Surveillance data showed that the aircraft commenced this descent from 3,400 ft at about 1812:56, and the last data point identified the aircraft passing 525 ft at 1813:18. Figure 2 shows the final flight segment based on ADS-B data, including the turn out to sea.
Two attempts by the Approach controller to contact the pilot at 1813 were unsuccessful. The controller then broadcast advice to the pilot that surveillance identification had been lost and to immediately check altitude. Further advice of the area’s QNH[6], the lowest safe altitude in the area, and an instruction to climb immediately were broadcast. The controller followed that transmission with several more unsuccessful attempts to contact the pilot.
Recorded data
The aircraft was fitted with a Mode S transponder that broadcast ADS-B data. This information included the position and altitude of the aircraft and was received by Airservices Australia as well as other third‑party ADS‑B receivers (Aireon and FlightRadar24) and provided to the ATSB.Also on board were two mobile devices with the OzRunways application installed. This application provides the option for live flight tracking by transmitting the device’s position and altitude and that information was also obtained by the ATSB.
Site and wreckage
Initial indications of the possible location of the helicopter were found on the evening of 6 September at 1917. Search personnel in aircraft reported an oil slick on the sea surface, about 5.5 km to the south-south-west of Anna Bay. Two more oil slicks were observed that night in the same vicinity.There were numerous reported sightings of possible helicopter wreckage that evening and the following morning with a small piece of floating wreckage, identified as part of the rear cabin lower bulkhead, retrieved by officers on a New South Wales Police Force search vessel on 7 September.
Two items that were also identified as wreckage from the helicopter subsequently washed ashore on Stockton Beach, and were collected by police on 18 September.Following an extensive sea search, hampered by poor sea and weather conditions, the helicopter wreckage field was located on 26 September 2019. The wreckage field was situated about 5.4 km to the south-west of Anna Bay, in about 30 metres of water. A large section of the helicopter tailboom was recovered from the wreckage field for further examination (Figure 3).
Pilot details
The pilot held Private and Commercial Pilot (Helicopter) Licences and was qualified to fly by day under the Visual Flight Rules. The pilot also held a single-engine helicopter class rating and a gas turbine engine design feature endorsement. The pilot last conducted a single-engine helicopter flight review in October 2018 that was valid until 31 October 2020. His logbook indicated he had a total of 1,440.5 flying hours experience.
The pilot held a Class 1 aviation medical certificate that was valid until 26 Apr 2020.
Weather and available light
Forecast meteorological conditions for the Williamtown area for 6 September 2019 included moderate to severe turbulence and wind gusts up to 38 knots from the north-west from 1000. From 1800, severe turbulence was forecast with wind gusts up to 45 knots occurring from the west-north-west and layers of scattered[7] cloud at 4,000 ft and broken[8] cloud at 12,000 ft above ground level. Light showers of rain were also forecast.
Comments between Williamtown Approach and Tower controllers at 1753 made reference to visibility in the area, which was noted to be about 6‑7 km.Last light[9] for the Anna Bay area, was calculated to occur at 1801 however, the presence of cloud cover, dust or masking terrain to the west would have resulted in last light occurring at an earlier time.