Action
Final rule; request for comments.
Summary
We are superseding Airworthiness Directive (AD) 2018-18-01 for all CFM International S.A. (CFM) Model CFM56-7B turbofan engines. AD 2018-18-01 required initial and repetitive inspections of certain fan blades and, if they fail the inspection, their replacement with parts eligible for installation. This AD requires the same initial and repetitive inspections but revises the compliance time for the initial inspections and revises the installation prohibition based on the updated compliance time. This AD was prompted by further analysis by the manufacturer that indicated a need to reduce the initial fan blade inspection interval based on an ongoing root cause investigation of an April 2018 engine failure. We are issuing this AD to address the unsafe condition on these products.