What happened
While en route at 13,500 feet mean sea level, the airplane experienced engine vibrations. These vibrations prompted the pilot to shut down the engine and execute an off-airport landing. During the forced landing roll, the aircraft struck brush and hidden rocks.
The investigation
An on-scene examination of the aircraft showed engine oil covering the bottom of the plane. A post-accident inspection of the engine determined that a catastual internal failure had occurred. Investigators discovered that an oil filter gasket had been pinched and extruded around the oil filter base plate, which allowed engine oil to escape.
Records show that on August 30, 2000, Textron Lycoming issued Mandatory Service Bulletin MSB-543A regarding the replacement of oil filter converter plate gaskets. Following this, the FAA issued Emergency Airworthiness Directive AD 2000-18-53 on September 5, 2000, to mandate compliance. A subsequent revision to the service bulletin on October 4, 2000, provided an alternate means of compliance and included a requirement for marking the converter plate by vibropeening the numbers "543" onto a designated location. The converter plate involved in this accident had not been marked.
The last documented annual inspection took place on July 27, 2000, at 2,418.9 total hours, with 235.9 hours since the engine major overhaul. That inspection entry noted that Airworthiness Directives were checked through 2000-15. At the time of the accident, the FAA Aircraft Registration database listed the aircraft registration status as "Sale Reported."