Accident Overview
A pilot reported that after departing a site located on top of a mountain at approximately 12,200 feet mean sea level, the helicopter experienced a loss of partial power about 30 seconds into the flight. The power loss necessitated a forced landing. The incident occurred shortly after takeoff from the elevated site.
Investigation Findings
Examination of the helicopter's turbocharger revealed that the compressor impeller retaining nut had backed off from its intended position. This allowed the compressor impeller to come into contact with the compressor shroud. The contact led to the seizure of the impeller, which in turn caused the failure of the turbocharger. The loss of turbocharger function resulted in the partial power loss that forced the pilot to execute an emergency landing.
No further details about the aircraft type, registration, operator, or the condition of occupants were provided in the report. The investigation focused solely on the mechanical failure of the turbocharger as described.