Incident Overview
Images from the accident site showed that the aircraft collided with a white‑bellied sea eagle (Haliaeetus leucogaster). The pilot had limited opportunity to detect the bird as they were looking down and to the left of the helicopter’s trajectory, placing the bird probably in their peripheral vision where detection of small objects is very limited. Even if they had been looking ahead, the inherent limitations of the see-and-avoid principle may have prevented timely avoidance. The closure rate to the soaring bird was around 94 kt, and the difference in speed made their relative trajectory almost direct. These factors further reduced the pilot’s ability to see the bird and change flight path in time, likely rendering the collision unavoidable under the circumstances.
Windshield Impact Resistance
Analysis of bird strike data highlights significant safety risks to windshields. In the United States, 14.4% of windshield impacts caused serious injuries and 1.8% caused fatalities. Australian occurrences included 3 fatal and 3 serious injuries. Comparison of US and Australian data indicated a higher chance of both birdstrike and strike resulting in windshield damage per flight hour in Australia. Helicopter operations face elevated risk due to low‑altitude operations and often less robust windshield designs. If a bird penetrates the windshield, it can directly impact occupants, potentially causing injury or incapacitation of flight crew, which may lead to loss of control or further hazards. Advancements in windshield design, such as laminated materials and reinforced structures, have mitigated many impacts, but the data highlights vulnerabilities in extreme cases. Manufacturers like Robinson and Bell have released birdstrike‑rated windshields that provide higher impact resistance, rated to withstand a 1 kg bird strike at the aircraft’s never‑exceed speed. The occurrence scenario involving a 3 kg bird colliding with the helicopter would likely exceed the windshield’s design limits. Operators are encouraged to consider installing impact‑resistant windshields if operating in areas with a high probability of birdstrike, noting some disadvantages.
Helmets
Helicopter pilots often wear helmets as a safety measure due to frequent exposure to dynamic conditions where turbulence, rapid manoeuvres, and potential accidents pose risks of head injury. Passengers often do not wear helmets, as the risk is lower for occasional travellers, particularly considering other safety measures in commercial passenger transport. Frequent helicopter passengers fall between these extremes, naturally exposed to higher risk due to increased number of flights. The pilot reported being a helmet advocate and had discussed potential benefits with the passenger, but the decision was left to the passenger’s discretion. Helmets provide an additional layer of protection against birdstrikes, as seen in the Glasair Sportsman GS‑2 incident (AO‑2016‑001). A helmet with a sturdy visor can shield the face and head from small‑object impacts, reducing injury risk from a shattered windshield. Aviation helmets are engineered to absorb and disperse kinetic energy from impacts with larger objects such as a bird, potentially mitigating injury severity. The helmet’s hard outer shell and padded inner liner reduce force transmitted to the skull, lowering risk of traumatic brain injuries, concussions, or skull fractures. However, a helmet would not have prevented the passenger’s injuries in this case due to the impact location. Wearing a helmet as standard practice would provide some protection against other potential hazards.
Pilot Response
The pilot maintained control of the aircraft despite the sudden disruption and potential aerodynamic effects of the compromised windscreen. They promptly identified the nearest suitable landing site with access to medical facilities and executed a controlled descent and landing. The pilot’s effective response and adherence to emergency procedures ensured the injured passenger was positioned for immediate medical response.