Summary
This notice proposes the supersedure of an existing airworthiness directive (AD), applicable to all CFM International (CFMI) CFM56-3C-1 and certain CFM56-3B-2 engines, that currently requires the removal from service of certain fan disk and fan blade hardware, and limits the use of CFM56-3C-1 thrust levels. This action would require removal of additional fan blade hardware, require an Airplane Flight Manual (AFM) revision to impose thrust level limitations for airplanes equipped with affected engines, and require the installation of redesigned fan blades as a terminating action to the thrust level limitations of this AD. The current AD requirements for certain CFM56-3B-2 engines are unchanged and carried over into the proposed AD. This proposal is prompted by the availability of redesigned fan blades that are not subject to the thrust level limitations, and the need to clarify the AD requirements by deleting references to specific AFM's. The actions specified by the proposed AD are intended to prevent a fan blade failure that can result in complete loss of engine power.