CEN19LA163

The pilot of the experimental, amateur-built airplane reported that, while returning to the airport after a local flight, the engine speed "suddenly" decreased from about 5,000 rpm to 2,500 rpm. He trimmed the airplane for its best glide airspeed and began looking for a forced landing site. About 30 seconds later, the engine seized and lost power completely. The airplane touched down short of the pilot's intended landing point and nosed over resulting in substantial damage to the fuselage and empennage. An engine examination revealed that a lower connecting rod bearing had failed, resulting in the total loss of engine power. Maintenance records indicated that an engine overhaul was completed slightly more than 5 years before the accident flight. The engine manufacturer's maintenance schedule specified that an engine overhaul be completed every 5 years or 300 hours, whichever comes first. It is likely that, had the engine been overhauled in accordance with manufacturer guidance, the worn connecting rod bearing would have been detected during the overhaul and resulted in its replacement.

On June 11, 2019, about 2100 eastern daylight time, an amateur-built Griff Challenger II airplane, N582L, was substantially damaged during a forced landing following a loss of engine power near Switz City, Indiana. The pilot sustained serious injuries. The airplane was registered to and operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological condition prevailed, and the flight was not operated on a flight plan. The local flight departed from Shawnee Field (1I3), Bloomfield, Indiana, about 1930. The pilot reported that while returning to the airport at 2,000 ft mean sea level the engine speed "suddenly" decreased from about 5,000 rpm to 2,500 rpm. The engine water temperature began "rising fast." He trimmed the airplane for best glide airspeed and began looking for a forced landing site. About 30 seconds later, the engine lost power completely. The airplane touched down short of his intended landing point and nosed over. An engine examination was conducted under oversight of a Federal Aviation Administration inspector, with the assist of a technical representative of the engine manufacturer. The examination revealed a lower connecting rod bearing had failed. Metallic debris consistent with fragmented bearing material was recovered from the cylinder. The cylinder head and the piston exhibited mechanical peening damage. The connecting rod exhibited surface corrosion but appeared otherwise intact. Excessive play was noted between the connecting rod and the crankshaft journal consistent with the failure of the bearing. The airplane maintenance records noted that the engine was reinstalled after an overhaul on April 21, 2014 at 75.3 hours total airframe time. The most recent condition inspection was completed on August 15, 2018 at 130 hours total airframe time. The pilot reported the airframe time was 176 hours at the time of the accident. The engine manufacturer's maintenance schedule specified that an engine overhaul be completed every 5 years or 300 hours, whichever comes first. At the time of the accident, the engine was about 7 weeks beyond the 5-year overhaul limit. About 100 hours time-in-service had elapsed since the overhaul in 2014. An aircraft owner is not required comply with the engine manufacturer's recommended overhaul interval when operating under Part 91 unless the engine does not meet the requirements of a condition inspection.