ANC07LA011

The commercial certificated pilot was on a cross-country personal flight in instrument meteorological conditions under Title 14, CFR Part 91. In cruise flight at 10,000 feet, the engine lost power. The pilot declared an emergency, and requested vectors to the nearest airport. The pilot said the airplane broke out of the clouds about 300 feet above ground level, and he landed gear-up in a muddy field. An inspection of the airplane revealed that the engine crankshaft had fractured. Multiple fatigue fracture initiation points were discovered along the radius of the number 2 crankshaft journal. The engine had accrued about 998 hours in service since major overhaul. The airplane sustained structural damage to the fuselage and wings.

On December 31, 2006, about 1100 eastern standard time, a Cessna T210N airplane, N5093A, sustained substantial damage during an emergency off airport landing, following a complete loss of engine power during cruise flight, about 1.5 miles north of Southwest Georgia Regional Airport, Albany, Georgia. The airplane was being operated by the pilot as a instrument flight rules (IFR) cross-country personal flight under Title 14, CFR Part 91, when the accident occurred. The commercial certificated pilot and sole passenger received serious injuries. Instrument meteorological conditions prevailed, and an IFR flight plan was filed. The flight departed Winter Haven's Gilbert Airport, Winter Haven, Florida, about 0930, and was bound for the Smyrna Airport, Smyrna, Tennessee.

During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on January 4, the FAA air safety inspector who examined the airplane said the pilot reported a total loss of engine power during cruise flight. She said the pilot diverted to the nearest airport, but was unable to make the runway. The inspector reported the pilot landed, with the landing gear retracted, in a cultivated field north of the airport, and that the airplane received substantial damage to the wings and fuselage. After the airplane was recovered, the airplane engine was given a limited examination by the inspector, accompanied by a representative of the engine manufacturer. The inspector said the engine's crankshaft appeared to be broken.

Under direction of the NTSB, the engine was removed from the airplane, and shipped to the engine manufacturer's materials laboratory for disassembly, and inspection. The disassembly revealed the crankshaft had fractured. An inspection of the crankshaft revealed that the crankshaft cracked through the number 3 cheek from the aft radius of the number 2 main journal. There were no signs of bearing rub in the area above the radius, however progressive damage precluded examination of the other half of the fracture. Inspection of the crankshaft under magnification showed multiple fatigue initiation points along the journal radius. There was no evidence of tool marks, or metallurgical defects. The serial number on the crankshaft indicated that it was manufactured in 1976. The engine in its present configuration, was assembled in 1990. Engine logbooks indicate that the engine was overhauled in March 1996, and at the January 2006 annual inspection, had accumulated 998 hours in service since the preceding major overhaul.