Piper PA28-151 N32146 accident near Mansfield, Massachusetts

Probable cause

A loss of engine power due to carburetor icing as a result of the pilot's delayed use of carburetor heat.

NTSB analysis

The pilot performed a preflight inspection prior to departure, including "topping off" the fuel tanks, and he observed no contamination in the fuel. After departure, the pilot maneuvered in the local area for about 20 minutes. He performed a stall maneuver and shortly after the airplane’s engine started to "sputter and run rough." The pilot attempted unsuccessfully to troubleshoot the problem, including turning on the carburetor heat and switching fuel tanks. When he realized that he would be unable to make it to a nearby airport, the pilot prepared for a forced landing to the highway below. During the landing, the left wing struck a barrier resulting in substantial damage. Examination of the airplane revealed sufficient fuel in the right tank and the left tank was breached. Examination of the engine revealed no mechanical anomalies. Review of the Federal Aviation Administration 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.

Text from the NTSB. Open the NTSB docket for ERA09LA496 for the full record.