Pilot incapacitation and collision with terrain involving Kawasaki Heavy Industries BK117, VH-JWB 9 km west of Ulladulla, New South Wales, on 17 August 2018 ATSB Transport Safety Report Aviation Occurrence Investigation (Defined) AO-2018-057 Final – 21 May 2021 Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Publishing information Published by: Australian Transport Safety Bureau Postal address: PO Box 967, Civic Square ACT 2608 Office: 62 Northbourne Avenue Canberra, ACT 2601 Telephone: 1800 020 616, from overseas +61 2 6257 2463 Accident and incident notification: 1800 011 034 (24 hours) Email: [email protected] Website: www.atsb.gov.au © Commonwealth of Australia 2021 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this publication is owned by the Commonwealth of Australia. 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Addendum Page Change Date Safety summary What happened On the afternoon of 17 August 2018, the pilot of a Kawasaki Heavy Industries BK117 helicopter, registered VH-JWB, was conducting fire-bombing operations approximately 9 km west of Ulladulla, New South Wales (NSW). The pilot was on the third flight for the day and was conducting repeated water bombing of a fire on Plot Road, Woodburn, NSW. On the fifth fire-bombing circuit, at this location, the pilot filled the slung Bambi Bucket (bucket) without incident from a nearby dam and departed towards the fire area. Shortly after, the aircraft diverted off course, the bucket and longline became caught in trees and the helicopter collided with terrain. The pilot was fatally injured and the helicopter was destroyed. What the ATSB found The ATSB found that it was likely the pilot suffered an incapacitating medical event. As a result, the pilot unintentionally diverted off track, leading to the bucket becoming tangled in the trees and causing the helicopter to collide with terrain. The pilot’s post-mortem identified a focus of acute inflammatory change in the heart muscle, a condition known as lymphocytic myocarditis. This condition is capable of causing sudden impairment or complete incapacitation. The pilot is unlikely to have known they suffered from this condition. There are no risk factors for the development of this condition and it cannot be detected by medical screening. The pilot’s post-mortem also identified coronary heart disease which is also capable of causing sudden impairment and incapacitation. This condition was being effectively managed by medication. Despite the pilot suffering from these two heart-related conditions, there was insufficient evidence to determine if they contributed to the accident. The ATSB also determined that the pilot was known to use an over the counter medication for the treatment of hay fever that, although labelled as non-sedating, was not approved for use while conducting flying operations. Finally, the pilot did not wear the upper torso restraint correctly. Although on this occasion the accident was unsurvivable, the use of such a shoulder harness restraint generally reduces the likelihood of fatal head injuries. Safety message Pilots are reminded that some medical conditions may be undetectable by the normal aviation medical screening process. Pilots should remain vigilant for any medical symptoms which may be the precursor to a more serious medical event. Pilots should also exercise caution when using over-the-counter medications as their availability does not mean they are automatically safe for use while conducting aviation activities. › i ‹ Contents Safety summary ........................................................................................................................ i The occurrence ........................................................................................................................1 Context ......................................................................................................................................4 Pilot information 4 General information 4 Fatigue assessment 4 Meteorological information 4 Aircraft information 4 General 4 Airworthiness and maintenance 4 Weight and Balance 5 Engines 5 Hydraulic System 5 Bambi Bucket 5 Cargo Hook 5 Operational information 5 Fuel 6 Wreckage and accident site information 6 Accident site 6 Wreckage examination 7 Recorded information 8 Medical and pathological informational 8 Post-mortem examination 8 Lymphocytic myocarditis 8 Coronary heart disease 9 Observed behaviour 9 Medication 10 Carbon monoxide 10 Survival aspects 12 Related occurrences 12 Safety analysis ...................................................................................................................... 13 Introduction 13 Pilot incapacitation 13 Possible sources of incapacitation 13 Lymphocytic myocarditis 14 Coronary heart disease 14 Over the counter medication 14 Upper torso restraint 14 Findings ................................................................................................................................. 15 Contributing factors 15 Other factors that increased risk 15 General details ...................................................................................................................... 16 Sources and submissions .................................................................................................. 17 Australian Transport Safety Bureau .................................................................................. 19 › ii ‹ ATSB – AO-2018-057 The occurrence On 17 August 2018, a Kawasaki Heavy Industries BK 117 (BK 117),1 registered VH-JWB (JWB), was performing aerial work in the Ulladulla area, New South Wales (NSW). The operator had been tasked by the NSW Rural Fire Service (RFS) to support fire-fighting activities in the Bombaderry area, near Nowra, on 15 August 2018, then in the Ulladulla area from the afternoon of 16 August 2018 (Figure 1). The fire-bombing operations were being flown out of the Milton Showground during the day, with the fire-bombing aircraft flown back to Nowra, for overnight parking. Figure 1 - Accident location Source: Google Earth, annotated by the ATSB On the morning of 17 August 2018, JWB departed Nowra for the Milton Showgrounds. The pilot was the sole occupant and conducted a number of flights that day, refuelling from the showground at 1030 Eastern Standard Time2 and again at 1225. 1 The Kawasaki Heavy Industries BK 117 is a twin-engine medium utility–transport helicopter jointly developed and manufactured by Messerschmitt-Bölkow-Blohm of Germany and Kawasaki of Japan. 2 Eastern Standard Time (EST): Coordinated Universal Time (UTC) + 10 hours. › 1 ‹ ATSB – AO-2018-057 In the afternoon, JWB and another BK 117, VH-FHB (FHB), were tasked to assist ground-based fire crews extinguish fires near Plot Road, Milton (Figure 2). Both helicopters were operated with a Bambi Bucket3 (bucket) on a longline.4 The operation involved flying circuits between the fire area and a nearby dam, where the buckets were re-filled with water. Figure 2 - Area of operations Figure 2 shows the area of operations with circuit direction arrows that are indicative of the average track of JWB during the previous 4 circuits. Source: Google Earth, annotated by the ATSB At 1400 the RFS Air Attack co-ordinator conducted an ‘operations normal’ radio call with all aircraft operating in the Ulladulla fire area. The pilot of JWB responded normally and did not report any difficulties. At about 1407, the pilot of FHB observed JWB’s pilot fill the bucket at the dam before releasing a small quantity of water, consistent with normal operations. JWB then departed the dam in a south-easterly direction towards the fire. The pilot then moved FHB over the same dam to fill its bucket. On completion of filling the bucket, the pilot looked for JWB but could not sight the helicopter. A witness on Plot Road, approximately 100 m east of the accident site, observed JWB tracking in a north-easterly direction, contrary to the established flight pattern. A number of witnesses in the 3 A Bambi Bucket, also known as a helicopter bucket, is a specialised bucket suspended on a cable carried by a helicopter to deliver water for aerial firefighting 4 A longline is a long cable suspended from a hard point on the belly of the aircraft and connected to an external load such as a Bambi Bucket. › 2 ‹ ATSB – AO-2018-057 same area then observed the bucket and longline become tangled in trees at the edge of a clearing, and the helicopter collide with terrain (Figure 3). The pilot was fatally injured and the helicopter was destroyed. › 3 ‹ ATSB – AO-2018-057 Context Pilot information General information The pilot was a New Zealand citizen who