Primary finding
Probable cause
The loss of engine power due to carburetor icing and the pilot's failure to continue the use of carburetor heat after experiencing carburetor ice.
Investigator assessment
Analysis narrative
The pilot was flying a potential buyer of the airplane on a pre-buy inspection flight. Just after leveling the airplane in cruise flight, the engine lost power momentarily. He applied carburetor heat, and the engine regained normal power. While returning to the airport, he turned the carburetor heat back off, and then on again, and the engine again lost power. He stated that this time, the engine power could not be restored, and with no suitable landing sites available within gliding distance, he ditched the airplane into the water paralleling the shoreline. During the ditching, the airplane nosed over, and sustained substantial damage to the left wing. Based on the temperature and dew point at the time of the accident, the conditions were favorable for serious carburetor icing at any power setting.
Source record
Factual narrative
The pilot was flying a potential buyer of the airplane on a pre-buy inspection flight. Just after leveling the airplane in cruise flight, the engine lost power momentarily. He applied carburetor heat, and the engine regained normal power. While returning to the airport, he turned the carburetor heat back off, and then on again, and the engine again lost power. He stated that this time, the engine power could not be restored, and with no suitable landing sites available within gliding distance, he ditched the airplane into the water paralleling the shoreline. During the ditching, the airplane nosed over, and sustained substantial damage to the left wing. Based on the temperature and dew point at the time of the accident, the conditions were favorable for serious carburetor icing at any power setting.