Beech 35-B33 N8983M accident near Baker, Nevada

Probable cause

A total loss of engine power during the initial climb due to the failure of the No. 5 connecting rod bearing.

NTSB analysis

The accident flight occurred after a mechanic replaced the exhaust pushrod for the No. 1 cylinder. After takeoff and during the initial climb, the engine lost total power. The airplane sustained substantial damage during a forced landing in desert terrain.

Postaccident examination of the engine revealed that the No. 5 connecting rod strap exhibited fracture signatures consistent with fatigue cracks in multiple areas. The connecting rod also exhibited signs of heat distress. The No. 5 connecting rod bearing was severely worn, deformed, flattened, and darkened, consistent with high heat exposure. The general heat tinting and damage on the bearing, connecting rod, and crankshaft journal indicated that the No. 5 connecting rod bearing likely experienced frictional heating from insufficient clearance between the bearing and the journal. The insufficient clearance could have been produced by excessive wear on the bearing or journal, bearing surface damage such as spalling, or insufficient lubrication.

Text from the NTSB. Open the NTSB docket for WPR21LA358 for the full record.