Accident Details
During a precautionary landing to a road, the pilot applied carburetor heat while on the downwind leg but removed it shortly afterward. While on final approach, the pilot reported that the airplane began descending too rapidly. He stated that he applied power, but the engine did not respond. The pilot also noted that the airplane drifted to the right as it neared the road, and applying left aileron did not correct the drift. He could not recall whether he had applied right rudder when using left aileron. The pilot attributed the ailerons' lack of response to the airplane's low speed. The airplane subsequently landed in snow beside the road and nosed over.
Investigation Findings
An on-scene investigation revealed no mechanical anomalies that would have prevented normal flight. According to the pilot/operator handbook for the Bellanca 7GCBC, carburetor heat should be used only when atmospheric conditions indicate that icing is probable. At the time of the accident, the temperature was 17°F and the dew point was 12°F. The FAA's carburetor icing chart indicates that carburetor icing was probable under those conditions.
Carburetor Icing Considerations
The pilot's use of carburetor heat, followed by its removal, may have been influenced by the handbook's guidance. The ambient temperature and dew point were within a range where carburetor icing is likely, based on published charts.