Incident Overview
A pilot reported that while in cruise flight at an altitude of 6,000 feet, the engine began running roughly. The pilot engaged the carburetor heat control, after which the engine operated normally for a few seconds before losing power completely. The pilot subsequently executed a forced landing in a bean field. The pilot expressed the belief that carburetor icing was the cause of the power loss.
Post-Accident Engine Examination
Following the incident, the engine was tested and found to run at 800 revolutions per minute (rpm). A magneto check revealed a 25 rpm drop on each magneto. All cylinders exhibited thumb compression, indicating adequate compression.
Weather Conditions
The surface weather observation at 1455 hours from the Indianapolis International Airport (IND), located approximately 22 nautical miles southwest of the accident site, recorded a temperature of 48 degrees Fahrenheit and a dew point of 32 degrees Fahrenheit. According to the Transport Canada "Carburetor Icing" chart, these conditions correspond to moderate to serious carburetor icing.