What happened
The incident occurred while the aircraft was operating in cruise flight conditions. During this phase of flight, the pilot experienced an abrupt loss of oil pressure. This mechanical failure immediately resulted in a complete loss of engine power and the subsequent seizure of the engine crankshaft.
With no power available to maintain altitude or continue the planned route, the pilot initiated a forced landing procedure. The aircraft was landed in a muddy agricultural field located near the flight path. The impact with the uneven, soft terrain caused substantial damage to the airframe during the landing process.
The investigation
Following the accident, investigators conducted a detailed post-accident examination of the engine components to determine the root cause of the power loss. The inspection focused on identifying mechanical failures that could explain the sudden seizure and pressure drop.
The technical analysis revealed specific internal damage within the engine assembly. Investigators found that the number 5 connecting rod bearing exhibited excessive clearance. This abnormal gap in the bearing is a critical mechanical fault that compromises oil film integrity and load-bearing capacity, directly leading to the observed failure mode.
Findings
The primary factor contributing to this accident was the mechanical failure of the engine's internal lubrication and support system. The excessive clearance in the number 5 connecting rod bearing allowed for metal-to-metal contact or insufficient oil pressure maintenance, which precipitated the crankshaft seizure. This sequence of events left the pilot with no option but to execute an emergency landing in unprepared terrain.