Incident Overview
A 1,622-hour private pilot was conducting a cross-country flight in a single-engine airplane at a cruising altitude of 3,500 feet. During cruise, the pilot heard a "metallic" noise, followed by a loss of oil pressure and oil spray on the windscreen. Shortly thereafter, smoke appeared and the engine lost power. The pilot initiated a forced landing to a state highway. However, just before touchdown, a gust of wind pushed the airplane off the highway, resulting in a collision with a ditch and a fence.
Examination Findings
Post-accident examination of the engine revealed a hole in the engine case above the number 4 cylinder. Further investigation determined that the oil pressure line installed between an after-market oil pressure gauge and the engine had separated at the fitting where it attached to the engine. The separation led to the loss of oil pressure and subsequent engine failure.
Maintenance History
A review of the maintenance logbooks indicated that the oil pressure line had been last replaced approximately 12 years prior to the accident and had accrued about 412 hours of operation at the time of failure. There was no logbook entry documenting when the new, larger oil pressure gauge had been installed.