Helicopter rolls over in whiteout during landing attempt (N7402F)

What happened

The pilot reported becoming disorientated due to whiteout conditions caused by blowing snow while attempting to land. To mitigate the visibility issue, the pilot lowered the collective pitch control with the intention of stopping the accumulation of blowing snow on the aircraft.

During this maneuver, the left side of the helicopter penetrated the surface of a four foot thick snow cover. The penetration caused the aircraft to roll over onto its side. Recent weather data indicated that six inches of snow had fallen shortly before the incident.

The investigation

The investigation relied primarily on the pilot's statement regarding the sequence of events and the environmental conditions. No mechanical failure was identified as a contributing factor; the rollover was directly attributed to the interaction between the aircraft and the snow crust.