Incident Overview
A helicopter was involved in an accident while flying over an open area of flat, glassy water. The pilot, who did not hold an instrument rating, was intentionally operating at a very low altitude due to falling snow and low ceilings, which created whiteout/greyout conditions.
Sequence of Events
As the pilot continued toward his destination, he progressively descended to maintain visual reference with the water's surface. Eventually, the helicopter's skids dragged through the water, almost immediately followed by the tail rotor colliding with the water. Shortly thereafter, the helicopter's airframe impacted the water's surface.
Contributing Factors
The official investigation source describes the pilot's actions and the environmental conditions but does not state a specific probable cause.