Accident Sequence
The pilot reported that during cruise flight, a burning smell was first noticed, followed shortly by a low oil pressure indication. Subsequently, a vibration was felt, and the engine briefly oversped to 3,000 rpm before losing all power. The pilot executed a forced landing in a field, during which the airplane collided with multiple ground obstacles.
Post-Accident Examination
Examination of the engine at the accident site revealed that the No. 6 connecting rod had penetrated the engine crankcase. An excess of engine oil was found on the bottom of the airplane. Further inspection identified an oil filter gasket, Lycoming part number LW-13388, that was extruded at the base of the filter assembly. This extrusion had allowed virtually all engine oil to escape.
Maintenance History
Lycoming Mandatory Service Bulletin MSB-543 and Emergency Airworthiness Directive (AD) 2000-18-53, which was later superseded by AD 2002-12-17, applied to the potential problem of the oil filter gasket. These directives required repetitive inspections and gasket replacement or replacement of the gasket adapter plate with a different part number. The investigation found no evidence of compliance with either AD.