Airworthiness Directives; Pratt & Whitney Division Engines

on, replacing the HPC drum rotor disk assembly with a part eligible for installation. The FAA also proposed to require removing and replacing certain HPC drum rotor disk assemblies before reaching certain life limits. The FAA is issuing this AD to address the unsafe condition on these products. Discussion of Final Airworthiness Directive Comments The FAA received comments from three commenters. The commenters were the Air Line Pilots Association, International (ALPA), All Nippon Airways (ANA), and The Boeing Company (Boeing). ALPA and Boeing supported the NPRM without change. The following presents the comments received on the NPRM and the FAA's response to each comment. Request To Clarify Acceptable Inspection Results and a Part Eligible for Installation ANA requested that the FAA revise the NPRM to clarify what action should be taken if evidence of shot peening is not discovered during the visual inspection of the HPC drum rotor disk assembly, and to clarify that affected HPC drum rotor disk assemblies that have passed the visual inspection required by the NPRM are still eligible for installation. Specifically, ANA requested that the FAA add the following language to paragraphs (g) and (h)(2) of the proposed AD: ``HPC drum rotor disk assemblies that have passed the inspection specified in paragraph (h)(1) of this AD with ``SB A72-373'' marking can be treated as a part eligibl