CEN18IA273

The commercial pilot of the aerial application flight reported that the airplane was at 350 ft above ground level when the engine started running roughly and then lost total power. He executed a forced landing to a field, which resulted in minor damage to the right wing. A review of the engine maintenance logbooks indicated that the accident occurred 107.6 hours after all six cylinders were replaced. The engine teardown examination revealed a large hole in the crankcase near the No. 2 cylinder. The crankcase bearing supports exhibited signs consistent with bearing shift. The No. 2 and No. 3 lock tabs exhibited elongation, and all bearing support mating surfaces exhibited varying amounts of fretting, with the No. 2 and No. 3 surfaces displaying the most fretting. The No. 3 bearing had shifted a significant amount, and part of the bearing was separated. The No. 2 connecting rod bearings exhibited a significant amount of thermal damage consistent with heat distress. The No. 2 connecting rod was separated from its journal and exhibited damage consistent with lubrication distress. The No. 2 piston was separated from the connecting rod and remained in the cylinder. It is likely that, when all six cylinders were replaced, the engine's through-bolts did not have sufficient clamping force, which resulted in movement of the crankcase halves as evidenced by the fretting on the crankcase bearing supports. This led to the crankcase main bearings shifting, which resulted in oil starvation to the No. 2 connecting rod journal, failure of the No. 2 connecting rod, and the subsequent total loss of engine power.

On July 12, 2018, about 1647 eastern daylight time, a Cessna A188B, N2483J, made a forced landing after a loss of engine power near Rockford, Ohio. The pilot was not injured; the airplane sustained minor damage. The airplane was owned and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 137 as an aerial-application flight. Visual meteorological conditions prevailed at the time of the flight, which was not on a flight plan. The airplane departed about 1620 from the Lakefield Airport (CQA), Celina, Ohio, on a local flight. The pilot reported that he was flying at 350 ft above ground level when the engine started running rough and then stopped producing power. He executed a forced landing to a bean field, which resulted in minor damage to the right wing. The examination of the engine revealed that there was a hole in the engine case near the No. 2 cylinder. The engine was a 300-horsepower six-cylinder Continental IO-550-D engine. A review of the engine maintenance logbooks indicated that the last major overhaul was performed on February 2, 2014 and was installed on the airplane on April 1, 2014. All six cylinders were replaced on September 9, 2017 at a tachometer time of 1,225.8 hours. The logbook entry did not provide a reason for why all six cylinders were replaced. The last annual maintenance inspection was performed on April 2, 2018, at a tachometer time of 1,262.0 hours. The last oil change was performed on July 8, 2018, at a tachometer time of 1,315.6 hours. The tachometer time at the time of the accident was 1,333.4 hours, which as 107.6 hours since all six cylinders were replaced. The engine was shipped to Continental Motors for an engine teardown examination under the oversight of the National Transportation Safety Board. There were no signs of external impact to the engine. All six cylinders remained attached to their cylinder bays and there was no damaged noted to the cylinders. The crankcase bearing supports exhibited signs consistent with bearing shift. The No. 2 and No. 3 lock tabs exhibited elongation, and all bearing support mating surfaces exhibited varying amounts of fretting with the No. 2 and No. 3 surfaces displaying the most fretting. The No. 3 bearing had shifted a significant amount and a portion of the bearing was separated. It was noted that the crankshaft gear was improperly safety wired. The No. 2 connecting rod was separated from its journal and exhibited damage consistent with lubrication distress, and portions of the connecting rod were in the sump. The No. 2 connecting rod bearings exhibited a significant amount of thermal damage consistent with heat distress. The No. 2 piston was separated from the connecting rod and remained in the cylinder. The induction system remained attached to the engine; however, several induction coupling clamps were missing, and all the induction riser bolts that go on the inside portion of the attach flange were not installed.