What happened
During a visual approach to a landing zone situated at 12,800 feet MSL in mountainous terrain, the pilot executed a series of right turns, transitioning from downwind to base and then to final approach. This sequence of maneuvers placed the helicopter into a downslope wind condition.
As a result of these conditions, the aircraft settled and began a left turn around its vertical axis. The helicopter subsequently impacted the side of the mountain at a location below the intended landing zone. Upon impact, the tail boom separated from the main structure, and the fuselage rolled down the mountainside. During this descent, the passengers were ejected from the aircraft.
The investigation
The investigation found no evidence of any preimpact mechanical failure or malfunction. Records indicated that while the maximum gross weight for the aircraft was 4,960 pounds, the actual gross weight at the time of the accident was 4,375 pounds.