What happened
The flight was proceeding at an altitude of 3,000 feet mean sea level when the engine began running roughly. The crew immediately noticed that oil pressure had dropped to zero. In response to the mechanical failure, the pilot maneuvered the aircraft toward a nearby bean field in an attempt to execute a forced landing.
Before the aircraft could reach the intended landing area, the engine ceased operation entirely. During the descent, the airframe collided with a ditch and subsequently nosed over upon impact.
The investigation
Following the accident, investigators disassembled the engine to determine the root cause of the failure. Examination of the internal components revealed that an estimated three to four quarts of oil were present within the engine case, indicating a significant loss of lubricant during flight.
Mechanical inspection identified critical structural failures within the engine assembly. The number one and number two connecting rods were found to be broken. Additionally, the number four piston showed clear evidence of having been subjected to extremely high temperatures, consistent with severe friction caused by oil starvation.
Findings
The primary factors contributing to this accident were the in-flight loss of oil pressure and the subsequent failure of internal engine components. The broken connecting rods and overheated piston indicate that the engine suffered catastrophic mechanical failure due to lack of lubrication.