ERA24LA222

The pilot reported that a preflight inspection revealed no anomalies, and he subsequently departed on a night cross-country flight. While in cruise flight at an altitude of 3,500 ft, he noticed a sudden drop in oil pressure, declared an emergency with air traffic control, and diverted to a nearby airport. While enroute to the diversion airport, the engine began running roughly and oil leaked into the cabin. When the pilot was unable to activate the runway lights at the diversion airport he aborted the landing approach and chose to divert to another airport; however, enroute to the second airport, the engine lost total power, and the airplane impacted terrain about 2.5 miles from the runway. Postaccident examination of the engine revealed that the No. 4 piston was seized in its cylinder and its connecting rod had separated from the crankshaft. In addition to the crankshaft’s No. 4 throw bearing, main bearings Nos. 2 and 3 also exhibited features consistent with oil starvation. The engine’s oil pump was undamaged and displayed no abnormal operating signatures. An unquantified amount of oil was found on the underside of the airplane’s fuselage, within the engine cowling, and remaining with the engine’s impact-damaged oil sump. Based on the pilot’s initial description that the engine had lost oil pressure during the flight, and the damage signatures observed that were consistent with oil starvation, it is likely that the loss of engine power was due to insufficient lubrication to the engine’s internal components. The reason for the oil starvation could not be determined.

On May 18, 2024, at 2115 eastern daylight time, a Cessna 177, N3268T, was substantially damaged when it was involved in an accident near Selma, Alabama. The commercial pilot was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported completing his pre-flight checks before beginning the cross-country flight. He specifically noted that he verified the oil level, confirming that the engine contained 7 quarts of oil. After ensuring that everything appeared normal, he departed. While cruising at an altitude of 3,500 ft, the pilot observed a sudden drop in oil pressure to approximately 30 psi. He declared an emergency with air traffic control and requested a diversion to Vaiden Field Airport (A08), Marion, Alabama. As the airplane descended, the engine began running roughly, and the pilot observed oil leaking into the cabin near the rudder pedals. As the pilot approached A08, he attempted to activate the runway lights using the airport’s common traffic advisory frequency, but the lights did not illuminate. Due to darkness and low ceilings, the pilot was unable to visually identify the airport and initiated a go-around. Air traffic control then provided vectors to Craig Field (SEM), Selma, Alabama; however, the engine lost total power about 7 miles west of SEM, and the airplane impacted terrain about 2.5 miles from the runway. An FAA inspector responded to the accident site and reported crush damage to the cockpit and cabin, with buckling observed on both wings. Examination of the engine revealed that the No. 4 piston was seized within its cylinder, and the corresponding connecting rod had fractured from the crankshaft. The engine oil pump showed no signs of malfunction, abnormal wear, or blockage. Cylinder Nos. 1 and 2 exhibited glazing, and the crankcase halves displayed signs of fretting with a large crack adjacent to the No. 4 cylinder. The crankshaft No. 4 throw bearing and connecting rod exhibited signs of extreme heat damage consistent with oil starvation. Portions of the connecting rod cap, bolts, and other components were found melted into the engine case, indicative of a severe heat event consistent with oil starvation. The Nos. 2 and 3 main bearing surfaces exhibited oil starvation signatures, and the camshaft was broken in half. The spark plugs were normal in color and exhibited no signs of damage. The engine oil sump was observed punctured consistent with ground impact. An unquantified amount of oil was present within the sump. Additionally, residual oil was observed in the engine cowling area and on various engine components. Dirt and debris were noted along the underside of the fuselage, extending from the forward to the aft sections. An undetermined amount of oil was observed within the dirt and debris. A review of the airplane's maintenance logbooks revealed that the engine had been overhauled approximately 180 flight hours before the accident. The logbooks didnot contain an entry indicating that a break-in inspection had been performed, a standard procedure following engine overhaul to prevent premature wear or damage. The pilot stated that he purchased the airplane from the previous owner in September 2022 at an engine time of 75 hours since overhaul. The maintenance facility that performed the overhaul had provided the previous owner with detailed instructions for the engine break-in procedure, including warnings regarding potential consequences of noncompliance. The instructions also stated that a warranty requirement of the overhaul was an inspection performed after 15 to 18 flight hours following overhaul. Review of airplane maintenance records revealed that the overhauled engine was installed on the accident airplane on May 22, 2018, at 0 hours since overhaul. An annual inspection was also performed on this date. The next annual inspection was performed on April 12, 2019, at 10.2 hours since overhaul. The maintenance log entry for this inspection specified that the engine oil was drained and refilled with 8 quarts of Aeroshell 100 (mineral oil), consistent with overhaul instructions to use mineral oil during the first 25 hours of operation; however, the entry did not mention any of the other inspection items specified in the 15- to 18-hour inspection. The subsequent annual inspections were performed in April 2020 and April 2021 at 29 hours and 67.2 hours since overhaul, respectively. There were no entries to indicate that the 15- to 18-hour inspection was performed in accordance with the maintenance facility’s instructions.