Event Summary
On June 8, 2009, at approximately 2015 eastern daylight time, a Cirrus SR22, registration N34TG, experienced an engine failure near Elkin, North Carolina. The certificated commercial pilot was not injured, and the airplane sustained minor damage. The personal flight was conducted under 14 CFR Part 91 with an instrument flight rules flight plan filed. Visual meteorological conditions prevailed.
Pilot Information
The pilot, aged 63, held a commercial pilot certificate with ratings for airplane single-engine land and instrument airplane, last updated on March 30, 2007. His most recent FAA third-class medical certificate was issued on January 16, 2009, with a limitation for lenses for near vision. He reported 2,531 total flight hours, including 900 hours in the SR22.
Aircraft Information
The four-seat, low-wing, fixed-gear airplane, serial number 0386, was manufactured in 2002. It was powered by a Continental IO-550-N7 engine producing 310 horsepower, equipped with a Hartzell three-bladed propeller. The most recent annual inspection was conducted on October 30, 2008, at an airplane total time of 876.4 hours. The current Hobbs time was 928.9 hours.
Sequence of Events
The pilot reported being in cruise flight at 6,000 feet mean sea level when he heard a loud bang followed by violent vibration. All engine instruments were within normal ranges prior to the event. He contacted air traffic control and requested vectors to Elkin Municipal Airport. The vibration continued, oil flowed over the windshield, and forward vision was lost. The pilot activated the Cirrus Airframe Parachute System (CAPS) at 6,000 feet, and the airplane descended under parachute into a cornfield.
Examination Findings
Examination by an FAA inspector revealed the airplane descended through trees into a cornfield. The airframe and flight control systems showed no evidence of preimpact mechanical malfunction. The engine had a 6-inch diameter hole at the top rear of the engine case, below the right magneto. The right magneto was broken away from its mount. Fragments of the No. 2 piston were found externally on the engine case. The engine still contained 4 quarts of oil in the sump.
The engine was removed and sent to Teledyne Continental Motors for examination under NTSB oversight. Fragments of the No. 2 piston, rings, and pin boss were found throughout the engine case and oiling system. These fragments, along with the remainder of the piston assembly, were sent to the NTSB Materials Laboratory for metallurgical examination.
Metallurgical Examination
The examination revealed that the No. 2 piston failed due to a fatigue crack that originated adjacent to the 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. No other valve train abnormalities were noted within the engine.