Socata TB 9 TAMPI N135ER accident near Milner, Georgia

Probable cause

The failure of the No. 3 cylinder exhaust valve for undetermined reasons.

NTSB analysis

After takeoff the flight proceeded toward the destination airport. While in a descent between 7,000 and 6,500 feet msl, the engine began to vibrate and shake. The pilot continued toward the destination airport and reduced power to 2,000 rpm, but the vibrating/shaking continued. The pilot slowly reduced the power to idle, and after recognizing that he would be unable to land at the airport, he maneuvered the airplane for a forced landing in a field. He realized that the flight was too high to land in the first field, and he maneuvered the airplane toward a second field. He secured the engine about 100 feet above ground level (agl), and lowered full flaps. While descending through 20 feet agl, the airplane collided with the tops of pine trees. The airplane then impacted the ground and came to rest upright. Examination of the engine revealed the exhaust valve of the No. 3 cylinder was missing and not recovered. The top of the No. 3 piston exhibited heavy impact damage associated with the broken exhaust valve. The No. 3 cylinder had accumulated approximately 1,918 hours since overhaul at the time of the accident.

Text from the NTSB. Open the NTSB docket for ERA09LA510 for the full record.