This September 2009 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Piper Cherokee. Injuries: None. Location: Mansfield, Mass. Aircraft damage: Substantial.
What reportedly happened: The pilot performed a preflight inspection prior to departure, including topping off the fuel tanks. There was no observed fuel contamination. He took off, then went to a nearby area to practice maneuvers for a few minutes. He performed a stall, after which the engine started to sputter and run rough. He activated the carburetor heat and switched fuel tanks. This did not restore engine power so he decided to make an emergency landing on a highway. During the landing, the left wing hit a barrier, resulting in substantial damage.
Examination of the airplane revealed sufficient fuel in the right tank. The left tank was breached. Examination of the engine revealed no mechanical anomalies. A review of the FAA carburetor ice probability chart revealed that the temperature and dew point at the time of the accident were conducive to “serious icing” conditions at glide power.
Probable cause: A loss of engine power due to carburetor icing as a result of the pilot’s delayed use of carburetor heat.
For more information: NTSB.gov, NTSB Identification: ERA09LA496