NTSB Factual Report

On November 2, 2009, at 1403 eastern standard time, a Piper PA-28-180, N8364W, sustained substantial damage during a forced landing to a field about 2 miles southeast of the Branch County Memorial Airport (EOB), Coldwater, Michigan. The airplane experienced a total loss of engine power when the engine seized during cruise flight at 2,500 feet above mean sea level (msl). The pilot, the sole occupant, received minor injuries. The 14 Code of Federal Regulations Part 91 flight departed Pontiac, Michigan, about 1300 and was en route to Champaign, Illinois. Visual meteorological conditions prevailed and a visual flight rules (VFR) flight plan was filed.

The pilot reported that while he was in cruise flight the oil temperature started rising so he decided to land at EOB. When he was about five miles from the airport, the engine started making noise and then the propeller “froze.” He executed a forced landing to a field and the airplane sustained substantial damage.

A Federal Aviation Administration (FAA) airworthiness inspector examined the airplane. The engine was a 180 horsepower Lycoming O-360-A3A. A hole was observed on the top of the engine crankcase at the #4 cylinder position. The #4 cylinder was removed. The #4 piston connecting rod was found disconnected from the crankshaft, and it was deformed and bent into a “U” shape. The #4 connecting rod cap was separated from the #4 connecting rod. One of the connecting bolts was found sheared in half with the nut still attached to one end of the bolt. The other connecting rod bolt was not located in the connecting rod or in the rod cap. A connecting rod bolt was found in the bottom of the engine. The bolt threads exhibited some impact damage, but otherwise, the connecting rod bolt was intact and was not bent. The nut for the connecting rod bolt was not located in the engine. The connecting rod bolts for the #3 connecting rod and rod cap were found sheared in half, but the nuts were still attached to the connecting rod bolts.

The engine logbook indicated that four new pistons were installed on May 31, 2003. The logbook entry did not indicate that the connecting rods had been replaced. On May 1, 2007, the #4 cylinder was replaced, but there was no indication in the logbook entry that the #4 piston or connecting rod had been repaired or replaced. On September 12, 2007, the #3 cylinder was replaced, but there was no indication in the logbook entry that the #3 piston or connecting rod had been repaired or replaced.

NTSB Probable Cause

A loss of engine power due to the separation of the No. 4 piston connecting rod as a result of inadequate torque of the connecting rod bolt.