What happened
At approximately 0700 Pacific daylight time, a Bell 206B helicopter, registration C-FGGC, was departing the Trans North helicopter base at Carmacks, Yukon. The pilot was tasked with supporting power pole positioning in the area. After lifting off from the pad, the pilot performed a 180-degree left pedal turn, directing the aircraft over the Yukon River on an easterly heading.
Shortly after the turn, the aircraft struck the water surface approximately 600 feet from the helipad. The impact lasted roughly 14 seconds from the start of the flight path. While the rear section of the helicopter and the fuel tank floated downstream, the forward fuselage, engine, and transmission were submerged. The pilot, who was the sole occupant, died from drowning.
The investigation
Investigators examined the wreckage and analyzed video footage recorded from a nearby riverbank. The examination of the mast revealed an overload failure, with 45-degree shear lips indicating that power was being transmitted at the moment of impact. No mechanical or control deficiencies were found in the engine, transmission, or hydraulic servos that would have prevented a normal climb.
Environmental conditions were analyzed, noting that the sun was positioned low on the horizon, approximately 15 degrees above the pilot's horizontal reference. This position, combined with the sun's reflection off the river, created significant glare. Additionally, the investigation looked into the physiological effects of the aircraft's rapid acceleration from zero to 40 knots during the 14-second flight duration.
Findings
- The pilot's forward vision was obscured by intense sunlight and glare reflecting off the river surface.
- The pilot likely lost visual reference with the terrain, leading to a descent into the water.
- Somatogravic illusion likely caused the pilot to perceive the aircraft as climbing when it was actually in a slight descent.
- The decision to depart directly over the river, rather than accelerating along the shoreline, increased the risk of ditching in the event of a loss of visual reference.