Cessna T210L N398MA accident near Borger, Texas

Probable cause

The failure of the No. 4 connecting rod due to inadequate oil lubrication.

NTSB analysis

The pilot reported that, while in cruise flight, the engine began to surge with intermittent power and that the airplane's speed and the engine's manifold pressure and oil pressure decreased. While the pilot was diverting the airplane to the nearest airport, the engine stopped producing power. The pilot established a glide toward the airport, but, when he realized that the airplane would not be able to reach the airport, he chose to perform a forced landing to a field. During the forced landing, the airplane struck a transmission wire and subsequently collided with terrain. A postaccident examination of the engine revealed that the No. 4 connecting rod had separated from its rod journal and that the rod cap bearing had partially melted into the rod journal. The No. 4 connecting rod cap and cap bolts exhibited signatures consistent with a lack of oil lubrication. No other anomalies were discovered with the engine that would have precluded normal operation. The examinations did not reveal any abnormalities that would have prevented adequate oil lubrication of the No. 4 connecting cap and cap bolts. The reason for the lack of lubrication could not be determined.

Text from the NTSB. Open the NTSB docket for CEN14LA031 for the full record.