Aviation safety investigations & reports

Collision with terrain involving BK117 helicopter, VH-JWB, near Ulladulla, New South Wales, on 17 August 2018

Investigation number:
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final Report

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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.

Download final report
[Download  PDF: 1.08MB]

The occurrence


Safety analysis


Sources and submissions

General details
Date: 17 August 2018   Investigation status: Completed  
Time: 1400 EST   Investigation level: Defined - click for an explanation of investigation levels  
Location   (show map): near Ulladulla, Jervis Bay SW 38 km   Investigation phase: Final report: Dissemination  
State: New South Wales   Occurrence type: Collision with terrain  
Release date: 21 May 2021   Occurrence category: Accident  
Report status: Final   Highest injury level: Fatal  

Aircraft details

Aircraft details
Aircraft manufacturer Kawasaki Heavy Industries  
Aircraft model BK117 B-2  
Aircraft registration VH-JWB  
Serial number 1094  
Operator Sydney Helicopters  
Type of operation Aerial Work  
Sector Helicopter  
Damage to aircraft Destroyed  
Departure point Milton Showgrounds, Ulladulla  
Last update 21 May 2021