NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
The pilot reported that, during cruise flight, the airplane’s engine began making an unusual ticking sound and the oil pressure was low. The oil pressure continued to drop, and the engine began to “knock” louder until it experienced a total loss of power. The pilot attempted to glide to an airport, but the airplane had insufficient altitude and landed in a field short of the intended runway. Postaccident examination of the engine revealed that the No. 4 connecting rod had failed, and displayed signatures consistent with a lack of lubrication. The other connecting rods also exhibited signs of a lack of lubrication, and the oil pickup screen contained debris. The engine had sufficient oil in the sump, and examination of the components of the oil system failed to reveal any preimpact anomalies. The engine manufacturer recommended that engines be overhauled at least every 12 years due to possible deterioration of engine components and abnormal wear on soft metal bearing surfaces during engine start procedures. The accident engine had not been overhauled for 23 years; however, the investigation was unable to determine if or to what extent the damage to the engine was a result of the connecting rod failure or may have occurred before the failure.