What happened
While operating in cruise flight, the pilot reported that the engine began to vibrate significantly. During this event, both oil pressure and revolutions per minute (RPM) decreased simultaneously. Recognizing the mechanical failure, the pilot initiated a forced landing procedure toward an open field. As the aircraft touched down and proceeded through the landing roll, it collided with trees located in the vicinity of the runway.
The investigation
A post-accident examination of the engine was conducted to determine the root cause of the power loss. The inspection revealed that the head of the number 2 cylinder had fractured. Maintenance records were reviewed and indicated that the engine had accumulated only 262 hours since its last overhaul.
Findings
The mechanical failure was identified as a fractured cylinder head. This structural failure led directly to the loss of engine power during cruise flight, necessitating the emergency landing. The short time since the last overhaul suggests a potential manufacturing defect or material fatigue rather than wear-and-tear from operation.