What happened
The pilot was operating the aircraft in cruise flight at 4,500 feet when the engine began to vibrate and experienced a partial loss of power. In an attempt to resolve the issue, the pilot diverted toward a nearby airport and attempted troubleshooting by adjusting the fuel mixture and activating the carburetor heat. While these actions briefly restored power, the engine subsequently suffered a total loss of power.
Determining that the aircraft could not reach the intended airport, the pilot elected to perform an emergency landing in a field. During the landing roll, the nose landing gear struck a rut in the terrain, causing the airplane to nose over and come to rest in an inverted position. The occupants were not injured.
The investigation
Post-accident inspections revealed that there was plenty of fuel remaining on board the aircraft. An examination of the engine by a mechanic found no mechanical anomalies or malfunctions. Environmental conditions at the time of the accident included a temperature of 22 degrees Celsius (72 degrees Fahrenheit) and a dew point of 14 degrees Celsius (57 degrees Fahrenheit). Analysis of carburetor icing probability charts indicated that these specific atmospheric conditions were conducive to moderate icing during cruise power or serious icing during glide power.