CEN13LA397

The pilot reported that, upon leveling the airplane at the assigned cruise altitude, he heard three loud "bangs" and that the engine oil pressure and temperature indications exceeded the gauge limits. He was unable to maintain altitude and subsequently executed a forced landing to a field. A postaccident engine examination revealed that a portion of the No. 6 piston face had separated along the perimeter due to detonation within the cylinder during operation. The No. 5 connecting rod had separated near the crankshaft journal, and the lower portion of the engine crankcase exhibited a hole immediately above the oil sump. Metallic fragments were recovered from the oil sump, oil sump screen, and oil filter. Piston fragments likely interrupted the oil flow within the engine, which resulted in the failure of the No. 5 connecting rod.

On July 5, 2013, about 1230 eastern daylight time, a Piper PA-46-350P airplane, N502EU, was substantially damaged during a forced landing following a loss of engine power during cruise flight near Nappanee, Indiana. The pilot was not injured. The aircraft was registered to GTG LLC and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which was operated on an instrument flight rules flight plan. The flight had departed from the Elkhart Municipal Airport (EKM), Elkhart, Indiana, about 1210. The intended destination was the Indianapolis Executive Airport (TYQ), Indianapolis, Indiana. The pilot reported that the takeoff and climb out were uneventful. However, upon leveling at the assigned cruise altitude of 8,000 feet mean sea level, he heard three loud "bangs." The engine oil pressure and temperature indications exceeded the gauge limit. He was unable to maintain altitude and ultimately executed a forced landing to a field located about 4 miles north-northwest of Nappanee, Indiana. The airplane came to rest upright, with substantial damage to the right wing. A postaccident engine examination was conducted under the direct supervision of a Federal Aviation Administration inspector. The examination revealed that a portion of the no. 6 piston face has separated along the perimeter. The damage appeared consistent with exposure to detonation within the cylinder during operation. The no. 5 connecting rod separated near the crankshaft journal. The lower portion of the engine crankcase exhibited a hole immediately above the oil sump. Metallic fragments were recovered from the oil sump, the oil sump screen, and the oil filter. The accident airplane was powered by a 350-horsepower Lycoming TIO-540-AE2A engine, serial number L-9578-61A. The pilot reported that the airframe and engine had accumulated 1,584.3 hours total time at the time of the accident. Maintenance records indicated that on October 19, 2012, the no. 6 cylinder was removed and a new piston, new rings, and new gaskets were installed due to excessive oil consumption. The engine had accumulated 39.5 hours since the work was performed. The records noted that 8 days earlier, on October 11, 2012, the no. 4 cylinder was removed and new rings and gaskets were installed due to excessive oil consumption. The most recent annual inspection was performed on September 11, 2012, at 1,535.4 hours total airframe/engine time. The engine maintenance logbook did not contain any entries subsequent to the October 19th cylinder replacement.