Discussion \n\n\n\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM was published in the Federal Register on June 29, 2011 (76 FR 38072). That NPRM proposed to require repetitive detailed inspections and high frequency eddy current (HFEC) inspections for cracks of the WCS spanwise beams, and repair if necessary. \n\nComments \n\n\n\tWe gave the public the opportunity to participate in developing this AD. The following presents the comments received on the proposal (76 FR 38072, June 29, 2011) and the FAA's response to each comment. \n\nRequests to Reference Service Bulletin Information Notice (IN) and Revised Service Bulletin \n\n\n\tAmerican Airlines (AAL) requested that we revise the NPRM (76 FR 38072, June 29, 2011) to refer to Boeing Service Bulletin Information Notice 777-57A0087 IN 01, dated March 24, 2011. AAL stated that this IN addresses information that is critical to the correct design and installation of repairs. If this IN is not incorporated, AAL asserted that the repairs could be designed and installed improperly. \n\tBoeing and Continental Airlines requested that we revise the NPRM (76 FR 38072, June 29, 2011) to refer to Boeing Service Bulletin 777- 57A0087, Revision 1, dated August 24, 2011. They stated that without incorporating the latest issue of this service bulletin, the repairs provided in the original issue of this service bulletin could be installed \n\n((Page 24356)) \n\nimproperly because the original issue of this service bulletin contains minor deficiencies. \n\tSince we issued the NPRM (76 FR 38072, June 29, 2011), Boeing has issued Service Bulletin 777-57A0087, Revision 1, dated August 24, 2011, which incorporates the changes outlined in Boeing Service Bulletin Information Notice 777-57A0087 IN 01, dated March 24, 2011. Therefore, we agree to refer to Boeing Service Bulletin 777-57A0087, Revision 1, dated August 24,2011, not the earlier Boeing Service Bulletin Information Notice 777-57A0087 IN 01, dated March 24, 2011. \n\tBoeing Service Bulletin 777-57A0087, Revision 1, dated August 24, 2011, was revised to, among other things, clarify and provide additional repair information. We have changed paragraphs (c), (g), and (h) of this AD to refer to Boeing Service Bulletin 777-57A0087, Revision 1, dated August 24, 2011. We have also added new paragraph (i) to this AD to give credit to operators for actions done before the effective date of this AD in accordance with Boeing Alert Service Bulletin 777-57A0087, dated November 11, 2010, since accomplishment of that service bulletin adequately addresses the unsafe condition. We have re-identified subsequent paragraphs accordingly. \n\nRequest To Clarify Inspection Terminology \n\n\n\tFedEx requested that we revise the NPRM (76 FR 38072, June 29, 2011) to refer to a detailed visual inspection, rather than a detailed inspection. The Accomplishment Instructions of Boeing Service Bulletin 777-57A0087, Revision 1, dated August 24, 2011, calls out a ''detailed inspection.'' FedEx indicated that, while it is clear that the inspection is meant to be a visual inspection, the term ''visual'' is not used anywhere in the definition in either Boeing Service Bulletin 777-57A0087, Revision 1, dated August 24, 2011, or in the NPRM. \n\tWe disagree. The term ''intensive'' in the definition of a detailed inspection indicates that the inspection demands a higher level of scrutiny than using only visual means to find unsatisfactory conditions that are more difficult to detect. The mention of ''elaborate procedures'' used in the definition of a detailed inspection raises the awareness that extraordinary means of gaining access by removing adjacent items, de-fueling tanks, etc., are necessary to perform the inspection, and hence, the inspection cannot be performed by visual means only. We have not changed the final rule in this regard. \n\nRequest To ProvideBoeing With AMOC Authoring Authority \n\n\n\tFedEx suggested that the FAA provide Boeing with AMOC authoring authority for the proposed rule NPRM (76 FR 38072, June 29, 2011) on an aircraft-by-aircraft basis. \n\tWe agree to clarify. Boeing Commercial Airplanes has received an Organization Designation Authorization (ODA), which provides Boeing with AMOC authoring authority. We included paragraph (j)(3) in the NPRM to reflect Boeing's authorization. We have not changed the final rule in regard to this issue. \n\nAdditional Change Made to This AD \n\n\n\tWe have revised the wording of paragraph (i) of this AD; this change has not changed the intent of that paragraph. \n\nConclusion \n\n\n\tWe reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously, and minor editorial changes. We have determined that these minor changes: \n\tAre consistent with the intent that was proposed in the NPRM (76 FR 38072, June 29, 2011) for correcting the unsafe condition; and \n\tDo not add any additional burden upon the public than was already proposed in the NPRM (76 FR 38072, June 29, 2011). \n\tWe also determined that these changes will not increase the economic burden on any operator or increase the scope of the AD. \n\nCosts of Compliance \n\n\n\tWe estimate that this AD affects 160 airplanes of U.S. registry. \n\tWe estimate the following costs to comply with this AD: \n\n\n\tEstimated Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost on U.S. \n\tAction Labor cost Parts cost Cost per product operators ---------------------------------------------------------------------------------------------------------------- Detailed inspection and high 50 work-hours x $85 per $0 $4,250 per $680,000 per \n\tfrequency eddy current hour= $4,250 per inspection cycle. inspection \n\tinspection of spanwise beam. inspection cycle. cycle. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tWe have received no definitive data that would enable us to provide cost estimates for the on-condition repair actions specified in this AD. We have no way of determining the number of aircraft that might need these repairs. \n\nAuthority for This Rulemaking \n\n\n\tTitle 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority. \n\tWe are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: ''General requirements.'' Under that section, Congresscharges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. \n\nRegulatory Findings \n\n\n\tThis AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. \n\tFor the reasons discussed above, I certify that this AD: \n\t(1) Is not a ''significant regulatory action'' under Executive Order 12866, \n\t(2) Is not a ''significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), \n\t(3) Will not affectintrastate aviation in Alaska, and \n\t(4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. \n\n((Page 24357)) \n\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.