Carb icing suspected in engine failure

Aircraft: Lancair 320. Injuries: 1 Minor. Location: Temple Bar, Ariz. Aircraft damage: Substantial.

What reportedly happened: According to the pilot, the airplane was in cruise flight at 5,500 feet MSL when he decided to descend to 3,500 feet MSL to avoid a layer of haze ahead.

At 4,000 feet, the engine began to lose power. The pilot’s attempts to restore power were not successful, so he made a forced landing. The pilot noted that he did not apply carburetor heat.

Weather conditions at the time of the accident were such that the route of flight was directly into a cold front with increasing moisture and relative humidity. A weather station about 11 nautical miles from the accident reported a temperature of 32°F and dew point of 30° F. These weather conditions were conducive to the formation of serious carburetor icing at cruise power.

Probable cause: The pilot’s failure to use carburetor heat in cruise flight while operating in an area conducive to carburetor icing, which resulted in a loss of engine power.

NTSB Identification: WPR11LA193

This April 2011 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.


Leave a Reply

Your email address will not be published. Required fields are marked *