Incident Overview
During an agricultural spraying operation, the pilot reported that the engine began to skip and backfire. He decided to terminate the current swath run and climb out of the field. At that point, the engine quit entirely. The pilot climbed the aircraft to the maximum achievable altitude before initiating a glide toward a nearby soybean field. The landing phase resulted in damage to the aircraft.
Investigation Findings
A subsequent investigation revealed that the carburetor heat ducting was disconnected, which rendered the carburetor heat system inoperative. This condition likely affected the engine's performance during the flight.
Weather Conditions
The nearest weather reporting facility recorded a temperature of 86°F and a dew point of 70°F. According to icing probability charts, these conditions were conducive to serious carburetor icing at glide power and visible icing at cruise power. The combination of the inoperative carburetor heat and the ambient weather likely contributed to the engine malfunction.