Incident Overview
According to the pilot's report, the flight encountered a rough running engine, prompting a decision to conduct a precautionary landing on a grass strip. The pilot stated that he was unable to discern the height of the grass on the runway prior to landing.
Loss of Control and Impact
During the landing roll, directional control was lost, leading to a ground loop. The aircraft subsequently collided with grass that was approximately six feet tall. The impact spread the main landing gear, separated the tail wheel, and caused both wings to strike the ground.
Post-Crash Examination
An examination of the airframe, flight controls, engine assembly, and accessories revealed no evidence of any pre-crash mechanical failure or malfunction. The aircraft's systems were found to be intact and functional prior to the event.
Conclusion
The incident occurred as a result of the pilot's encounter with tall grass during a precautionary landing, which compromised directional control and led to a ground loop.