ERA24LA141

About 30 minutes into the flight, without warning, the airplane’s engine made a “loud noise” and stopped producing power. This was immediately followed by oil spraying onto the windscreen. Unable to divert to the closest airport due to distance and with no suitable places to land, the pilot deployed the whole airframe parachute system. The airplane came to rest between several trees and the airframe was substantially damaged. The pilot and passenger egressed the airplane without injury. Postaccident examination of the engine revealed a hole in the crown of the engine crankcase near the Nos. 3 and 4 cylinders. Further examination revealed the No. 4 piston connecting rod detached, with pieces found in the crankcase and oil sump. Additionally, the connecting rod bushings on all of the remaining piston connecting rods showed various signs of migration out of their respective locations; all bushings showed signs of chips and damage. Given these findings, it is likely that the bushings unseated themselves and migrated outward, resulting in imbalance, vibration, and the eventual failure of the No. 4 bushing and the subsequent total loss of engine power. A critical service bulletin (CSB) existed for the bushings that included augmented oil change procedures and inspections; however, the CSB was not adhered to, nor was it required to be due to the nature of the operation. The mechanic who had been maintaining the airplane assumed the procedures he was adhering to were sufficient, as they included routine oil changes at more frequent than recommended intervals, examination of the oil filter internal element, and having a laboratory analyze the engine’s used oil for the previous 14 months. The accident occurred 15 hours after the most recent oil change and the oil analysis report. Additionally, communications between the laboratory and mechanic, had indicated no substantive anomalies or other concerns indicating an imminent failure.

On March 16, 2024, about 1530 eastern daylight time, a Cirrus SR22, N469GB, was substantially damaged when it was involved in an accident near Reidsville, Georgia. The private pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated that he departed St. Simons Island Airport (SSI), St. Simons Island, Georgia, with an intended destination of W H 'Bud' Barron Airport (DBN), Dublin, Georgia, which was his home airport. During takeoff, climb, and initial cruise portion of the flight, all of the engine parameters and the airplane performance were normal. About 30 minutes into the flight, without warning, the engine made a “loud noise” and stopped producing power. This was immediately followed by oil spraying onto the windscreen. The pilot established the best glide speed and declared an emergency. He turned left and flew toward a diversion airport that was about 10 nm away but realized that the airplane would not reach it. As the airplane descended through 4,500 ft mean sea level (msl), he noticed that there was no suitable place to land. The entire area was hilly and covered with pine trees. When the airplane descended through 2,500 ft msl, he deployed the whole airframe parachute system. The system arrested the descent immediately above the pine trees; it settled down between several trees in a nose-low attitude and was held upright by the parachute lines and canopy that was caught in the trees. The pilot and passenger egressed the airplane without injury. Postaccident examination revealed that the engine crankcase was fractured. The No. 4 cylinder was damaged and peeled back from the No. 4 connecting rod. The engine crankshaft could not be rotated. The oil pump contained light scratches. The oil filter contained numerous particles of ferrous and nonferrous material. The induction system and plenum were damaged consistent with contact from the No. 4 connecting rod. The remaining engine components exhibited normal operating signatures. The engine crankcase contained a hole on the top of the crankcase between cylinder Nos. 3 and 4 (figure 1). Figure 1. Hole in the top of the crankcase near cylinder Nos. 3 and 4. Disassembly revealed the No. 4 connecting rod was fractured at the piston pin connection. Only fragments of the connecting rod were present in the engine. Further examination revealed that the No. 4 connecting rod bushings were in the oil sump. An examination of the remaining bushings revealed that they were broken, chipped, and dislocated on the remaining connecting rods (figure 2). Figure 2. The Nos. 5 and 3 connecting rods and bushings. Note how the bushing has migrated; it should be flush within the diameter of the hole. This misalignment was found in all of the remaining connecting rods. A Critical Service Bulletin (CSB), CSB07-01A, Connecting Rod Piston Pin Bushing Inspection, had already been issued by the engine manufacturer to remedy issueswith the bushings. The bulletin provided inspection instructions for the connecting rod piston pin bushing due to reports of piston pin bushing material being found in the oil sump or the oil filter. The CSB outlined procedures to strain the engine oil and inspect the oil filter media during oil changes to determine if any bushing material had separated from the connecting rods. If any bushing issues were suspected, the CSB includeed procedures to remove the engine cylinders and pistons to visually inspect the piston pin bushing for wear. The owner of the airplane had the engine oil changed about every 20 to 30 hours and it was under an oil analysis (OA) program. The previous 6 OA reports indicated trace amounts attributed to normal wear of the engine; however, during the most recent OA, conducted on February 16, 2024, about 15 hours before the accident flight, the mechanic who was maintaining the airplane informed the OA laboratory that “small amounts of metal were seen in the oil filter.” According to the mechanic, he did not follow the critical service bulletin because he assumed he was going over and above the procedures. The engine oil was changed every 30 hours or less. Each time he serviced the oil, he cut open the filter and pulled out the filter pleats examining it for unusual signs of metal or other ferrous material, and then sent the oil for analysis and received a detailed report. During the most recent oil change, he discovered trace material and advised the oil laboratory. The last year of reports did not show any “red flags,” and he was in communication with the lab on the findings. There was nothing to indicate a potential issue with the engine. At the time of the accident, the engine had accrued 1,507 hours total time since new.