Accident Overview
The pilot was cruising at an altitude of 1,000 feet above mean sea level (MSL) when the engine unexpectedly decelerated to flight idle. Unable to maintain powered flight, the pilot performed an autorotation, which resulted in the aircraft contacting trees within a densely wooded area.
Investigation Findings
Following the accident, the engine was disassembled and examined. The examination revealed that the power control line, part number 6848471-B, was broken at its attaching 'B' nut sleeve. This type of failure can cause the engine to decelerate from a cruise power setting to flight idle. No other issues were found during further disassembly that could have contributed to the deceleration.
Conclusion
The investigation determined that the broken power control line was the only anomaly identified, with no other problems observed in the engine or related systems.