Cessna A185E N36ZN accident near York, Pennsylvania

Probable cause

Oil starvation of the number 1 connecting rod bearings, which resulted in a total loss of engine power.

NTSB analysis

The pilot had just purchased the airplane and was flying it to his home airport. He made a stop, added fuel, checked the oil, and continued to his home airport. About an hour after departure, he noticed a drop in oil pressure and then heard a clanking sound in the engine before it lost total power. He diverted to the nearest airport but landed short of the runway in a field. The airplane slid into the airport perimeter fence, resulting in substantial damage to the left wing.

Postaccident examination of the engine revealed that it contained only 2 quarts of oil out of a total capacity of 12 quarts. There were oil leaks around all the cylinder pushrod housings, with the leak around the No. 1 cylinder being the worst. All spark plugs were dark, indicating oil burn. The No. 1 connecting rod was fractured and separated from the crankshaft, and the connecting rod bearings were destroyed. Heat distress signatures were found on the crankshaft connecting rod location and the No. 1 connecting rod bearings displayed significant scoring consistent with a lack of oil lubrication. Based on this information, it is likely the loss of engine power was the result of oil starvation to the connecting rod bearings.

Text from the NTSB. Open the NTSB docket for ERA23LA034 for the full record.