What happened
The pilot had been operating the aircraft in the local vicinity for approximately one hour. During this time, the flight remained within the practice area before the pilot began the return journey. At the time of the incident, the aircraft was descending at an altitude of 1100 feet above ground level (AGL). As the pilot prepared to land, he advanced the mixture control to the full rich position. Immediately following this adjustment, the engine lost power completely.
In response to the power loss, the pilot attempted standard emergency procedures. He cycled the throttle and mixture controls back and forth in an effort to restore engine function. Additionally, he switched between fuel tanks to rule out fuel starvation or contamination issues. Despite these efforts, the engine did not respond to any inputs. The pilot then executed a left turn and managed to land the aircraft safely in a nearby cornfield.
The investigation
Following the incident, the owner of the aircraft conducted an examination of the engine to determine the cause of the failure. However, the inspection did not reveal any mechanical evidence that would explain the reported loss of power. No internal damage or fuel system blockages were found during this initial assessment.
Weather conditions at the time of the accident were recorded with a surface temperature of 78°F and a dew point of 63°F. According to carburetor icing probability charts, this specific combination of temperature and dew point is conducive to moderate carburetor icing at cruise power settings and serious icing at descent power settings. The pilot stated that he had not used carburetor heat during the flight, which aligns with the environmental conditions favorable for ice formation in the carburetor.
Findings
The primary contributing factor was the failure to use carburetor heat when conditions were conducive to icing. The combination of high humidity and moderate temperatures created an environment where ice could accumulate in the carburetor, particularly during power reductions such as those made when preparing for landing. The lack of visible mechanical damage supports the conclusion that the engine failure was caused by external environmental factors rather than internal mechanical malfunction.