What happened
During an aerial photography mission near Hinton, Alberta, a Bell 206B helicopter was flying at a very low altitude to film Canadian National (CN) train traffic. The pilot was maneuvering the aircraft over the rolling stock, descending to a height of approximately 12 feet above the train cars to capture footage. While overtaking the locomotives, the helicopter struck two steel electrical conductors that crossed the railway tracks at a 90-degree angle.
The impact with the wires, which were positioned about 35 feet above the tracks, caused the aircraft's pitch control rods to be severed. This resulted in an immediate loss of flight control. The helicopter entered a steep, nose-down descent, eventually striking the ground roughly 600 feet beyond the point of the wire strike. The accident resulted in one serious injury and two minor injuries.
The investigation
Investigators examined the flight path, the aircraft's equipment, and the circumstances leading to the impact. The investigation established that the pilot had performed aerial reconnaissance for previous filming runs but had not scouted the specific section of track used during the final pass. Additionally, the wires were difficult to detect because they were oxidized and blended into the background of the terrain and trees.
The aircraft was not equipped with a wire strike protection system (WSPS). Furthermore, analysis of the pilot's lap belt revealed that the webbing had likely deteriorated due to long-term sun exposure, causing it to fail during the impact. The investigation also noted that while the film director had requested low and fast flight for the best footage, the pilot had been previously cautioned by rail staff to be cautious with altitude to avoid startling train crews.
Findings
- The pilot lost control of the aircraft because the pitch control rods failed following the strike of the electrical wires.
- The pilot did not conduct a reconnaissance flight of the final flight path to identify potential obstacles.
- The helicopter lacked a wire strike protection system that might have mitigated the impact.
- The wires were visually difficult to distinguish from the surrounding environment prior to the collision.