Primary finding
Probable cause
The pilot's failure to maintain helicopter control during a descent, which resulted in a collision with terrain.
Investigator assessment
Analysis narrative
The helicopter pilot reported that, he set-up for an approach over hilly terrain with a strong tailwind. Descending on a left base the helicopter began to drift due to the wind, so the pilot added collective pitch to control the descent rate however, the helicopter rapidly descended despite the control input. The pilot initiated a run-on landing to the unimproved featureless tundra that appeared level. Upon ground contact the helicopter dynamically rolled over on its right side. The fuselage was substantially damaged. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.