Cessna T210M N6149B accident near Independence, Missouri

Probable cause

Latent dimensional discrepancies related to the engine crankcase main bearing saddle bores, which precipitated the fatigue failure of the crankshaft and a complete loss of engine power. Contributing to the accident was the engine manufacturer's failure to properly identify and address the crankcase discrepancies when the engine was rebuilt.

NTSB analysis

The pilot reported that he was in cruise flight when the engine began to run rough and lose power. Smoke began to enter the cockpit, and engine oil covered the windshield. The engine ultimately lost all power. The pilot executed a forced landing to a roadway, and the left wing struck a bridge guardrail. Examination of the engine revealed a fatigue failure of the crankshaft initiating at the No. 6 connecting rod journal. Further examination determined that several crankcase main bearing saddles were oversized compared to the required specifications. As a result, the crankshaft was not adequately supported within the crankcase during operation, which precipitated the fatigue failure of the crankshaft. Records indicated that the engine was initially manufactured with one oversized saddle bore. The manufacturer subsequently rebuilt the engine, which was installed on the accident airplane. At the time of the accident, the engine had accumulated 1,303.5 hours since it was rebuilt.

Text from the NTSB. Open the NTSB docket for CEN11FA202 for the full record.