AD 2023-05-16, adopted March 15, 2023, supersedes AD 2023-04-08, adopted February 23, 2023. The FAA has provided guidance in the form of a flowchart to assist in complying with AD 2023-05-16. Every Continental engine model listed in section (c) of the AD, titled “Applicability” is affected by this AD. However, every affected engine does not require the inspection detailed in Continental Aerospace Technologies Mandatory Service Bulletin MSB23-01A. Operators of affected engines can follow the flowchart to determine whether their engine requires inspection.
FAA Releases AD 2023-04-08 on Certain Continental Engines Because of Possible Improperly Installed Crankshaft Counterweights
The FAA has adopted an airworthiness directive (AD 2023-04-08) for certain Continental Aerospace Technologies, Inc. (Continental) reciprocating engines. The AD is effective February 23, 2023. The AD was prompted by a report of possible improper installation of counterweight retaining rings in the engine crankshaft counterweight groove during manufacture. This condition, if not addressed, could result in loss of engine oil pressure, catastrophic engine damage, and possible engine seizure. The AD requires inspection of the crankshaft assembly for proper installation of the counterweight retaining rings in the counterweight groove, and corrective actions if improper installation is found.
Related Mandatory Service Bulletin MSB23-01 Issued by Continental
The FAA reviewed Continental Mandatory Service Bulletin MSB23-01, Revision A, dated February 16,2023 (MSB23-01A). This service information specifies procedures for inspection of the crankshaft assembly for improper installation of the counterweight retaining rings in the counterweight, and corrective actions if improper installation is found.
Differences Between the FAA’s AD and Continental’s MSB23-01
The FAA’s AD is more restrictive than Continental’s MSB. The Continental MSB specifies compliance for engines with less than 200 operating hours, while the FAA’s AD requires compliance for all affected engines, regardless of the operating hours. The FAA has determined that this unsafe condition of improperly installed counterweight retaining rings is likely to exist on affected engines.
While the manufacturer’s service information excludes engines accumulating 200 or more operating hours, the FAA has not, as of yet, been provided with adequate data to support that exclusion. In the event the FAA receives data to support the exclusion of engines with more than 200 operating hours, or make other changes to this AD, the FAA may consider further rulemaking.