What happened
On 6 October 2022, a Bell 206B helicopter, registered VH-PHP, was flying at a low altitude over Maitland Vale, New South Wales, when it experienced a significant roll and a rapid descent. The aircraft struck a riverbank, which resulted in the total destruction of the helicopter and one fatality.
Prior to the impact, the aircraft had deviated from its intended VFR lane. During this period of unplanned maneuvering, the helicopter's speed dropped to 22 kt and its altitude decreased to 120 ft above the ground before the pilot climbed away. The pilot failed to respond to air traffic control communications during this time, despite having functional navigational aids available via a mobile device.
The investigation
The ATSB examined several potential causes for the deviation from the flight path, including mechanical failure, weather, and pilot distraction.
Regarding the aircraft's serviceability, investigators found no structural or mechanical defects that would have prevented normal flight. Evidence of engine and driveshaft rotation indicated the powerplant and rotor system were functional at the time of the accident. Furthermore, the mast fracture was consistent with impact with the ground rather than excessive maneuvering.
Meteorological data and witness reports indicated that weather conditions were suitable for VFR operations, ruling out weather as a contributing factor. While the pilot was using a Bluetooth headset for phone calls, investigators determined that any distraction was unlikely to be of sufficient magnitude to cause such a prolonged loss of situational awareness.
Findings
- The pilot likely experienced an incapacitating event while flying at low altitude, which led to the collision with the terrain.
- The pilot had a medical history of severe coronary artery disease, a condition that can cause dizziness or loss of consciousness.
- The pilot had not disclosed the use of prescription medications to the Civil Aviation Safety Authority (CASA), preventing necessary safety oversight.
- The presence of metabolites from both prescription and controlled substances in the pilot's bloodstream may have impacted flight performance.