The FAA on February 23, 2023 published a new, final airworthiness directive (AD 2023–04–08) highlighting a problem with new Continental engines manufactured between June 1, 2021, and Feb. 7, 2023. According to the agency, “The manufacturer has notified the FAA that 2,176 crankshaft assemblies are subject to the unsafe condition. The FAA estimates that of those 2,176 crankshaft assemblies, 1,632 are installed on aircraft of U.S. registry. The FAA estimates that 544 engines will need to remove one cylinder, 544 engines will need to remove two cylinders, and 544 engines will need to remove three cylinders for compliance with this AD.”
The new AD is based on Continental’s Mandatory Service Bulletin MSB23–01, Revision A, dated February 16, 2023. According to the bulletin, “It is possible one or more counterweight retaining rings were not properly seated in the crankshaft counterweight groove. This condition could allow the counterweight to depart from the crankshaft during engine operation resulting in catastrophic engine damage.”
