Incident Overview
A pilot experienced a total loss of engine power during a descent and executed a forced landing in a cornfield, during which the airplane nosed over shortly after the main landing gear contacted the ground. The incident occurred after the pilot had released parachutists at an altitude of 10,100 feet mean sea level (msl) over the drop zone.
Flight Details
The pilot reported that following the parachute release, he initiated a descent to the south to maintain better cloud clearances and avoid company traffic. Before descending, he applied carburetor heat. While descending through an altitude between 3,000 and 4,000 feet msl, the pilot attempted to advance the throttle but received no engine response. He then performed engine restart procedures, which were unsuccessful. The forced landing was carried out in a cornfield, and the aircraft nosed over almost immediately after touchdown.
Post-Accident Examination
An examination of the airframe and engine revealed no preexisting anomalies. The engine was subsequently run and operated normally, aside from minor vibration attributed to both propeller blades being bent aft from the nose-over.
Weather Conditions and Icing Potential
The observed weather at the time included wind from 360 degrees at 8 knots, clear skies, visibility of 10 miles, temperature 86°F, dew point 66°F, and an altimeter setting of 30.02 inHg. According to the Transport Canada Carburetor Icing Graph, these conditions fell within the region labeled "Serious icing - descent power." The FAA Advisory Circular (AC) 20-113, titled "Pilot Precautions and Procedures To Be Taken In Preventing Aircraft Reciprocating Engine Induction System and Fuel System Icing Problems," states that pilots should regularly use heat under conditions known to be conducive to atmospheric icing. It also recommends applying heat for a short time before beginning a prolonged descent with the engine throttled, leaving it on during the descent, and periodically advancing the power lever to ensure power recovery.
Conclusion
The forced landing resulted from a total loss of engine power, with no mechanical anomalies identified. The weather conditions were conducive to serious carburetor icing during descent, as indicated by the relevant icing graph and advisory circular.