Accident Overview
A helicopter sustained a complete loss of engine power during flight, prompting the pilot to perform an autorotation. The maneuver ended with the aircraft contacting unsuitable terrain. The event occurred after the engine lost power unexpectedly.
Investigation Findings
Post-crash examination of the engine identified the cause of the power loss. An oil channel within the engine had become blocked with debris, leading to the failure of the number 4 bearing and connecting rod. This mechanical failure resulted in the loss of engine power.
Engine Condition
The engine had been overhauled 6 years and 228.5 flight hours prior to the accident. Lycoming, the engine manufacturer, conducted an examination of the engine after the accident. Their analysis determined that the overhaul had not been performed in accordance with Lycoming's directives and specifications.