Robinson Helicopter R44 II N704T accident near Skwentna, Alaska

Probable cause

The pilot's failure to maintain adequate altitude/clearance from terrain while maneuvering in adverse weather conditions, which resulted in a dynamic rollover.

NTSB analysis

The pilot reported that, he was flying uphill over an area of snow-covered, mountainous terrain, when he encountered flat light and whiteout conditions, which made it difficult to discern topographical features. In an attempt to maintain visual reference with the ground, he turned the helicopter to the right to fly back down the hill. Subsequently, the right landing gear skid contacted terrain and the helicopter entered a dynamic rollover to the right, resulting in substantial damage to the fuselage, tail boom, and powertrain system. The pilot reported that there were no preaccident mechanical malfunctions or anomalies that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for ANC23LA032 for the full record.