On August 7, 1995, a Beech C23 (registration N9310S) operated by James D. Gregory was involved in an aviation accident near Dublin, NH. Investigators recorded the probable cause as: The engine failure resulted from metal particles generated by the loose fitting piston pin plugs, causing progressive contamination of the engine lubrication system. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot experienced a total loss of engine power while cruising at 4,500 feet, necessitating a forced landing. The nose gear collapsed and firewall buckled. Postaccident inspection revealed piston pins below service limits and contamination from loose pin plugs.
Incident Overview
A pilot was cruising at an altitude of 4,500 feet when a low oil pressure indication appeared, followed by a complete loss of engine power. The pilot executed a forced landing onto an open field. During the landing, the nose landing gear collapsed, and the firewall buckled.
Postaccident Findings
An FAA inspector reported that all piston pins had been reused during the last engine overhaul, which occurred 121 hours prior to the accident. A subsequent postaccident examination revealed that all piston pins measured below service limits. Additionally, investigators determined that the engine failure resulted from metal particles generated by loose fitting piston pin plugs. These particles caused progressive contamination of the engine lubrication system, leading to the power loss.
Damage Assessment
The aircraft sustained damage to the nose gear and firewall as a result of the forced landing.
Probable cause
The engine failure resulted from metal particles generated by the loose fitting piston pin plugs, causing progressive contamination of the engine lubrication system.