What happened
While climbing at 5,500 feet, the engine began to vibrate and lose power. The pilot observed an increase in oil temperature accompanied by a decrease in oil pressure, which was followed by a total loss of engine power. In response to the failure, the pilot performed a forced landing into a field. During the landing maneuver, the aircraft's left wing impacted a tree.
The investigation
Examination of the aircraft revealed oil streaks on the engine cowling and a 6-inch hole in the top of the engine crankcase near the number 2 cylinder. Investigators found that the number 2 connecting rod had broken into four pieces. The connecting rod journal was black in color with a smeared appearance, and fretting was observed on the mating surfaces of the number 2 main bearing saddles. Additionally, the bearing shells had shifted toward the rear of the engine by approximately 1/4 of an inch.
At the time of the accident, the aircraft had been operated for 26 hours since its most recent annual inspection, which had occurred about one month prior. The engine had been in service for approximately 1,700 hours since being rebuilt by TCM roughly nine years before the event. The number 2 and 4 cylinders had been replaced approximately 830 hours before the accident.