Incident Summary
While in cruise flight over a remote wilderness area, the aircraft's engine began to sputter and subsequently lost power. The pilots attempted to restart the engine without success and initiated a search for a suitable landing area. The pilot successfully performed a forced landing on a gravel and sand bar adjacent to a river.
Damage
The aircraft sustained structural damage during the landing. The firewall was damaged, a wing strut was compromised, and the leading edge of the horizontal stabilizer incurred damage.
Engine Conditions and Inspection
Prior to the loss of power, the pilots reported that both the oil pressure and cylinder head temperature gauges indicated normal operating ranges, with no warnings or anomalies noted. An inspection of the engine was conducted following the incident. Examination revealed that the master rod end had fractured. No metal particles were found in the oil filter or the oil sump. Further inspection identified that the supercharger impeller shaft bearings, also known as the blower bushing, had failed. These bearings require proper lubrication; according to the source, if they fail, raw oil can be pumped into the induction system, potentially causing various engine problems, including detonation.