What happened
The pilot was flying at an altitude of 7,000 feet when he reported encountering rain. Shortly after, he notified air traffic control that he could no longer maintain his altitude due to a loss of engine power. He mentioned that the manifold pressure had dropped to approximately 14 inches and that he had just emerged from the clouds. At 18:49, following a discussion with controllers about available airports, the pilot reported a complete failure of engine power while at 4,000 feet. He stated he intended to divert to Henderson Airport but indicated that he was still inside cloud cover.
The aircraft subsequently impacted a heavily wooded hillside located approximately 4.5 miles southeast of Asheville Regional Airport, positioned on the extended centerline of Runway 16. The weather conditions at Asheville were characterized by a temperature and dew point of 49 degrees Fahrenheit, indicating saturated air. Forecasts for temperatures at 6,000 feet and 9,000 feet were 39 degrees and 32 degrees respectively. Two other pilots in the vicinity reported encountering icing conditions at altitudes between 8,000 and 9,000 feet.
The investigation
Examination of the wreckage revealed that the carburetor heat door was found jammed in the cold, or off, position. The control knob for the carburetor heat was also confirmed to be in the cold position at the time of the accident. These mechanical findings were critical in determining the sequence of events leading to the crash.
Findings
The investigation determined that the Piper PA-32 suffered a total loss of power due to carburetor icing. The presence of rain and low temperatures aloft created ideal conditions for ice accumulation within the carburetor. The failure to apply carburetor heat, combined with the mechanical jamming of the heat door, prevented the pilot from mitigating the icing condition. This resulted in the engine stopping while the aircraft was in instrument meteorological conditions, leading to the controlled flight into terrain.
Safety message
Pilots operating aircraft equipped with carburetors must monitor weather conditions closely and apply carburetor heat as a preventive measure when flying in visible moisture at temperatures conducive to icing. Relying solely on engine instruments may not provide sufficient warning of impending ice accumulation.