Cessna 177RG N5AW accident near Tallapoosa, Georgia

Probable cause

The failure of the No. 2 rod end cap bolt, which resulted in a total loss of engine power.

NTSB analysis

The airplane was in cruise flight at 4,000 feet when the pilot declared an emergency due to low engine oil pressure and requested radar vectors to the nearest airport. The pilot received radar vectors to fly direct to the nearest airport. Shortly thereafter, the pilot advised the air traffic controller that he was unable to reach the airport and was going to land in a field. According to a witness adjacent the field, the airplane flew at a low altitude over his home, and it made a sharp, banking turn in an attempt to land in the field. The airplane was unable to land in the clearing and collided with a tree line at the end of a field, and a postcrash fire ensued.

During the postaccident examination of the engine the left and right crankcase halves were found fractured between the No. 1 and No. 2 cylinder base pads. The No. 2 crankshaft journal was visible through the crankcase fracture, and no connecting rod was observed on the journal. Further examination of the No. 2 cylinder rod cap and the related bolt pieces revealed that the rod cap was fractured. Examination revealed that the bearing shells for the No. 3 and No. 4 cylinders displayed severe abrasive wear on the bearing surfaces. It is likely that due to the failure of the No. 2 rod end cap bolt, the rod end cap came loose, which resulted in a fracture of the case halves and subsequent loss of engine oil. After the loss of engine oil, the engine seized, which resulted in a total loss of engine power.

Text from the NTSB. Open the NTSB docket for ERA12FA084 for the full record.