Incident Overview
According to the official accident investigation, the pilot reported that approximately 40 minutes after takeoff, there was a drop in oil pressure. Almost immediately afterward, the helicopter's engine failed while the aircraft was over a wooded area. The pilot attempted an emergency landing in a small clearing, but the helicopter struck trees before reaching the opening.
Engine Examination
An investigation of the engine revealed that the No. 5 connecting rod had failed at the crankshaft end. Specifically, a rod cap bolt had broken, causing the cap to straighten out and the rod to separate from the crankshaft. A large hole was found in the crankcase, and the oil tank was empty. However, oil was noted inside the engine and on all bearings and journals except the No. 5 connecting rod. Additionally, all main bearings and all rod bearings and journals, except those for the No. 5 connecting rod, appeared normal.
Investigation Findings
No further details regarding the helicopter's registration, type, operator, or occupants were provided in the source. The investigation did not specify the extent of damage to the helicopter, injuries, or the time of day. No mention was made of weather conditions or air traffic control involvement.