Aviation accident LAX00FA160

A snow ingestion caused loss of engine power due to the pilot's inadequate preflight inspection and failure to remove the accumulated snow from the engine inlet area. Also causal was the pilot's failure to maintain main rotor rpm while maneuvering to avoid power lines directly in his path during the autorotation necessitated by the loss of power. While the failure to maintain proper rotor rpm is listed as causal, the Safety Board acknowledges that the pilot's successful avoidance of the power lines, which required expenditure of rotor energy, likely precluded a more severe accident.