Accident Narrative
A helicopter was conducting a visual approach to a landing zone located at an elevation of 12,800 feet MSL in mountainous terrain. During the approach, the pilot executed a right turn from downwind to base to final. This maneuver placed the helicopter in a down-slope wind condition. The helicopter then settled, turned left around its vertical axis, and struck the side of the mountain below the intended landing zone. The impact caused the tail boom to separate from the fuselage. The fuselage rolled down the mountainside, and during this sequence, the passengers were ejected from the aircraft.
Investigation Findings
Investigators examined the wreckage and operational circumstances. The investigation found no evidence of any pre-impact failure or malfunction of the helicopter. The accident sequence was consistent with a loss of control due to the aerodynamic effects of the down-slope wind condition encountered during the turn.
Weight Information
The helicopter's maximum gross weight was 4,960 pounds. At the time of the accident, the actual gross weight was 4,375 pounds, which was below the maximum limit.