Incident Summary
About 8 to 10 minutes after takeoff, while still climbing at approximately 5,000 feet, the airplane experienced a loss of engine power. The pilot observed that the engine gauges indicated about 1,000 rpm while the manifold pressure remained at 25 inches. The pilot turned back toward the airport and attempted to restart the engine, but all attempts were unsuccessful. Subsequently, the pilot performed a forced landing to a clearing short of the airport property. The airplane sustained substantial damage.
Investigation Findings
A postcrash examination of the airplane revealed that the dual magneto had detached from its mounted position and was hanging by the ignition harness behind the engine. The magneto itself had not incurred any damage. The magneto drive gear was found lying in the accessory housing along with one hold-down plate. The retaining nuts, washers, and lock washers were not recovered. When tested, the magneto operated on all eight distributor outputs. The impulse coupler was not damaged, and the distributor wiring was intact. Engine continuity was confirmed, with proper valve action and compression on all cylinders. Engine oil was present, and there was evidence of some oil having leaked at the back of the engine. No anomalies were noted with either the induction or fuel systems. The airplane had last received an annual inspection in August 2005, during which an overhauled engine had been installed. It had accumulated 10 hours since that inspection.