Accident Summary
The accident occurred when the propeller RPM surged. As the pilot attempted to reduce power, the engine began to vibrate violently. When the throttle was closed, the engine stopped. The pilot performed a forced landing to a desert area covered with mesquite and sage brush. During the landing rollout, the aircraft impacted several large clusters of mesquite and a fence, resulting in substantial damage to both wings and the horizontal stabilizers.
Engine Examination
Examination of the engine, which had accumulated 580 hours since new or overhaul, revealed that two connecting rods had failed due to lack of lubrication. Further inspection found that a bearing had spun, blocking the flow of engine oil.
Prior Incident
The airplane had been involved in an incident 108 hours before the accident, during which the engine was operated with low oil quantity and low oil pressure.