On January 8, 1995, a Mooney 20J (registration N205MD) was involved in an aviation accident near St. Petersburg, FL. Investigators recorded the probable cause as: Failure of the No. 3 connecting rod bolt due to oil starvation for undetermined reasons. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot reported rough engine and decreasing oil pressure, leading to a forced landing in a bay after the engine began shaking violently. Examination revealed a connecting rod bolt failure due to oil starvation.
Incident Overview
The pilot reported that during a takeoff over a bay, the aircraft climbed to 1,000 feet mean sea level and leveled off. Shortly thereafter, the engine began running rough and the oil pressure started decreasing. The pilot notified the control tower of the intention to return to the airport. However, when the power was reduced, the engine started shaking violently. The pilot subsequently executed a forced landing into the bay.
Post-Incident Examination
The airplane was recovered, and the engine underwent examination by the manufacturer in the presence of the Federal Aviation Administration (FAA). Disassembly of the engine revealed a separation of the No. 3 connecting rod cap and bolts. Further examination of the components by the National Transportation Safety Board (NTSB) laboratory identified a failure of the No. 3 connecting rod bolt due to oil starvation. The reasons for the oil starvation could not be determined.
Probable cause
Failure of the No. 3 connecting rod bolt due to oil starvation for undetermined reasons.