What happened
During cruise flight, the pilot experienced a decrease in engine revolutions per minute (RPM). In response to the power loss, he executed a precautionary landing in an open field. While rolling out on the ground after touchdown, the airplane nosed over.
The investigation
Post-accident examination of the engine revealed that the right magneto was inoperative. Further inspection of the failed magneto component identified the specific point of failure: the condenser lead wire had failed at the condenser connection point.
Findings
The sequence of events indicates that engine power loss due to an electrical fault precipitated the emergency landing. The subsequent ground loop or nose-over during the rollout was a direct consequence of the forced landing in unprepared terrain.