Cessna T210N N6179Y accident near Baggs, Wyoming

Probable cause

The failure of a connecting rod cap retaining bolt during cruise flight, which resulted in a loss of engine power.

NTSB analysis

The pilot reported that during cruise flight, he heard and felt a solid “thump” that seemed to come from the engine compartment. Shortly thereafter, the oil pressure dropped and the engine eventually lost power. The pilot initiated a power-off forced landing on a rough and rutted dirt road. Although the initial touchdown was successful, due to the condition of the road, the pilot was unable to keep the airplane on the road surface, and it entered rough and uneven terrain. The nose of the airplane then dug into the terrain, and the airplane nosed over. The postaccident engine examination found that most of the engine oil had exited through a hole in the crankcase. Further examination found that the No. 1 connecting rod cap retaining bolt failed, ultimately resulting in the separation of the connecting rod from the crankshaft. The damage to the fracture surface on the portion of the retaining bolt that was recovered and the missing remainder of the bolt precluded any determination of bolt failure mode.

Text from the NTSB. Open the NTSB docket for WPR11LA038 for the full record.