Incident Summary
A certificated commercial pilot was in cruise flight with eight passengers on board when a loud bang was heard. The engine began to run rough and lose power. While the pilot performed engine emergency procedures, smoke was detected in the cabin and oil pressure decreased rapidly.
Forced Landing and Damage
The pilot executed a forced landing in a marshy, muskeg-covered area. During the landing, the airplane nosed over. Substantial damage was sustained to the right wing strut, engine firewall, and empennage.
Post-Incident Examination
Following the incident, the engine was disassembled for examination. The exhaust valve within the number one cylinder was found fractured.