Cirrus Design Corp SR22 N34TG incident near Elkin, North Carolina

Probable cause

A total loss of engine power due to the failure of the No. 2 piston as a result of a fatigue crack of undetermined origin.

NTSB analysis

The pilot stated that he was at a cruise altitude of 6,000 feet mean sea level when he heard a loud bang. Oil began to flow over the windshield and the pilot decided to activate the Cirrus Airframe Parachute System. The airplane descended under the parachute into a cornfield. Examination of the engine revealed the No. 2 piston had failed. Metallurgical examination of the No. 2 piston showed it had failed due to a fatigue crack that originated adjacent to the piston pin in the pin boss area. The exact location of the fatigue crack and the cause of fatigue crack initiation could not be determined due to extensive damage in the area of origin. Damage to the other components submitted for examination likely occurred as a result of the failure of the piston once the fatigue crack reached a critical size. While the pin boss is an area under high stress and it is possible that operational factors, such as improper timing, could initiate a fatigue crack, the investigation could not determine the cause of the fatigue crack.

Text from the NTSB. Open the NTSB docket for ERA09IA331 for the full record.