The pilot reported that, while the Cessna 180A was on approach and about three miles from the airport, the engine lost all power.
He continued the descent while maintaining the best glide airspeed and performing the engine restart procedures, which included applying carburetor heat.
Despite the pilot’s efforts, the engine would not restart, and he initiated a forced landing to a small field near Polson, Montana.
During the landing, the landing gear collapsed, and the right wing hit terrain.
Post-accident examination of the engine and airframe revealed no mechanical anomalies that would have precluded normal operation.
About the time of the accident, a weather reporting facility located 37 nautical miles north of the accident site recorded a temperature and dew point that were conducive to the accumulation of carburetor icing at glide power. However, it could not be determined whether carburetor ice caused the power loss.
Probable cause: A total loss of engine power during approach for reasons that could not be determined because postaccident examination revealed no anomalies that would have precluded normal operation.
NTSB Identification: WPR15LA191
This June 2015 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.