What happened
On 28 February 2022, a Robinson R44 II helicopter, registration VH-IDW, was engaged in a specialized mission to collect crocodile eggs near King River, Northern Territory. The operation was conducted under a specific CASA authorization that permitted a person to be suspended outside the aircraft in a harness system.
Following a period of radio silence lasting over an hour, a nearby pilot initiated a search and discovered the crash site. The egg collector was found fatally injured on the ground, having been detached from the aircraft's sling system. The helicopter had struck the terrain in an upright position, causing substantial damage. The pilot of VH-IDW sustained serious injuries.
The investigation
The investigation focused on the sequence of events leading to the engine stoppage and the subsequent impact. Investigators found that the engine had stopped prior to the aircraft hitting the ground. While there was no evidence of mechanical failure in the airframe, harness, or attachment systems, the aircraft was found with almost no fuel remaining in the main tank and none in the auxiliary tank.
Discrepancies were noted regarding the refueling process at Mount Borradaile. While the pilot intended to refuel at that location, there was conflicting evidence as to whether VH-IDW actually received fuel during its brief stop. The investigation also examined the pilot's physiological state, noting the presence of cocaine metabolites in toxicology results, and noted that the helicopter's emergency locator transmitter had been removed from its mount.
Findings
- The engine stopped due to fuel exhaustion.
- The pilot released the egg collector during the autorotation at an altitude that was likely above a survivable height, leading to the one fatality.
- The pilot's inability to identify the declining fuel state contributed to the engine failure.
- Inadequate safety management systems failed to address the risks of human external cargo operations.
- Regulatory oversight by CASA lacked the necessary structured risk management to ensure that authorizations for sling operations included adequate safety mitigations, such as height and speed limits.