Mayday Call and Emergency Descent
The pilot issued a Mayday call, reporting the airplane was at 4,000 feet mean sea level (msl) and descending without engine power. An approach controller acknowledged the distress call and attempted to direct the pilot to a nearby airport.
Forced Landing and Impact
Instead of proceeding to the airport, the pilot elected to perform a forced landing to a field. During the landing, the airplane impacted a private residence.
Witness Observations
A witness located about 4 miles north of the accident site reported seeing the accident airplane flying normally before hearing a "bang." Subsequently, the witness heard about 5 seconds of intermittent engine noise, followed by white smoke trailing behind the airplane as it continued flying.
Physical Evidence
The propeller was found approximately 3.4 miles from the location where the airplane came to rest. Examination of the airframe revealed no mechanical anomalies. Examination of the engine revealed damage consistent with an engine overspeed. Examination of the propeller, propeller flange, and associated hardware revealed signatures consistent with insufficient propeller retention bolt torque.