Beech A36 N1875W accident near Pinckneyville, Illinois

Probable cause

The total loss of engine power due to oil starvation. The reason for the oil starvation could not be determined based on available evidence.

NTSB analysis

While at an altitude of 8,000 ft mean sea level, the pilot noticed the engine oil pressure began to fluctuate. The pilot then requested to divert to the nearest airport, and shortly thereafter, the engine began to shake and lost total power. Unable to make the airport, the pilot executed a forced landing to a field. During the landing, the airplane’s nose wheel landing gear impacted a ditch. The nose landing gear collapsed, and the airplane came to rest upright. The airplane sustained substantial damage to the left wing and fuselage.

Postaccident examination of the engine revealed that connecting rods 2 through 5 were fractured and separated from the crankshaft, and the connecting rod bearings were destroyed. Heat distress signatures were noted on the crankshaft connecting rod locations. The connecting rod bearings number 1 and 6 displayed significant scoring consistent with a lack of oil lubrication. It is likely the engine failure was the result of oil starvation to the connecting rod bearings, however, the reason for the oil starvation could not be determined based on the available evidence.

Text from the NTSB. Open the NTSB docket for CEN21LA221 for the full record.