AD FAA-2021-0259

The FAA proposes to supersede Airworthiness Directive (AD) 2013-26-01, which applies to all CFM International, S.A. (CFM) CFM56-3 and CFM56-7B model turbofan engines with a certain accessory gearbox assembly (AGB) not equipped with a handcranking pad oil dynamic seal assembly. AD 2013-26-01 requires an independent inspection to verify re-installation of the handcranking pad cover after removal of the pad cover for maintenance. Since the FAA issued AD 2013-26-01, a dual- engine oil loss event occurred, prompting CFM to revise its service information to provide procedures for reworking and reidentifying the AGB. The FAA has also evaluated the requirement to install a redesigned handcranking pad oil dynamic seal assembly in response to the dual- engine oil loss event. This proposed AD would continue to require independent inspection to verify re-installation of the AGB handcranking pad cover after maintenance. This proposed AD would require the replacement of the affected AGB as a terminating action to the inspection requirement. The FAA is proposing this AD to address the unsafe condition on these products.