Discussion \n\n\n\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to the specified products. That NPRM published in the Federal Register on January 22, 2010 (75 FR 3660). That NPRM proposed to require repetitive inspections for corrosion and cracking in the front spar lower chord at the fastener locations common to the side link support fitting at wing station (WS) 292, and corrective actions if necessary. \n\nActions Since Issuance of NPRM (75 FR 3660, January 22, 2010) \n\n\n\tThe NPRM (75 FR 3660, January 22, 2010) referred to Boeing Special Attention Service Bulletin 757-57-0065, dated May 14, 2009, as the appropriate source of service information for accomplishing the actions. Since issuance of the NPRM, Boeing has issued Special Attention Service Bulletin 757-57-0065, Revision 1, dated August 1, 2011. No more work is necessary for airplanes on which the original issue was used to accomplish the actions. Certain procedures specified in Revision 1 of this service bulletin have been clarified to provide additional instructions. \n\tWe have revised this AD to refer to Boeing Special Attention Service Bulletin 757-57-0065, Revision 1, dated August 1, 2011, as the appropriate source of service information for accomplishing the actions. In addition, we added a new paragraph (i) to this AD (and reidentified subsequent paragraphs accordingly) to give credit for using Boeing Special Attention Service Bulletin 757-57-0065, dated May 14, 2009, for accomplishing the actions. \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 and the FAA's response to each comment. \n\nSupportive Comment \n\n\n\tBoeing concurred with the content of the NPRM (75 FR 3660, January 22, 2010). \n\nRequest To Include Instructions for Airplanes With Unmodified Configurations at the Side Link Fitting \n\n\n\tFedEx stated that Figures 2 and 3 of the Boeing Special Attention Service Bulletin 757-57-0065, dated May 14, 2009, show a configuration of the airplane with the modification of the side link fitting accomplished. FedEx added that the procedures in that service information replace the side link \n\n((Page 12171)) \n\nfitting and install additional fasteners attaching the fitting to the lower chord. FedEx noted that it is possible to perform the proposed inspections prior to incorporation of the service information; however, for airplanes on which the configuration may not match that provided in the service information, and on which the inspection has not been accomplished, the inspection steps provided may not match the configuration. \n\tWe agree that Figures 2 and 3 of Boeing Special Attention Service Bulletin 757-57-0065, dated May 14, 2009, do not include diagrams of different configurations of the side link fitting for airplanes that may currently be in service. However, as specified under ''Actions Since Issuance of NPRM,'' (75 FR 3660, January 22, 2010) Boeing has issued Special Attention Service Bulletin 757-57-0065, Revision 1, dated August 1, 2011, which clarifies the steps in those figures. In addition, the number of fastener locations specified in the figures was incorrect and they now identify either three or four fastener locations; therefore, we have removed the number ''four'' preceding the phrase ''fastener locations'' throughout this AD. \n\nRequest To Include FAA-Approved Repair Data \n\n\n\tContinental Airlines (CAL) asked that the NPRM (75 FR 3660, January 22, 2010) include a requirement that any repairs must be approved either by the aircraft certification office (ACO) or an FAA-authorized Boeing Organization Designation Authority (ODA) using data that meets the certification basis of the airplane. FedEx stated that if cracks and corrosion are found, the airplane must be repaired prior to further flight; however, the NPRM and the referenced service information do not give repair instructions. FedEx asked that repair instructions be included in or referred to in the proposed AD requirements. FedEx also noted that in the event of findings, Boeing must be contacted for a repair prior to further flight. CAL also stated that if any corrosion or cracking is found, it is required to submit damage data to Boeing and await disposition and proper approval before accomplishing the repair and releasing the airplane. CAL added that this has the possibility of grounding airplanes beyond an acceptable time for operational requirements while the repair parts are obtained. \n\tWe agree that if repair data were available as part of the service information, it would allow a quicker return to service for airplanes on which damage is found during the inspections. However, at this time the repair data are not currently available; therefore, the data cannot be included in the AD. We have made no change to the AD in this regard.Request To Include Repair and Corrosion Limitations \n\n\n\tCAL stated that the referenced service information does not include any specified limits for the repair, and added that corrosion limitations and related actions should be included for existing approved crack repairs. CAL noted that Boeing Special Attention Service Bulletin 757-57-0065, dated May 14, 2009, states that several repairs have been accomplished addressing crack lengths to 0.080 inch, and the service history table in the Background section of this service information lists six instances of cracking with pre-existing, pre- approved repairs from Boeing. CAL added that all but one reported instance included oversizing of the discrepant holes and freeze plug installation. CAL believes that these existing repairs should be included either in the service information or the structural repair manual, and subsequently added as repair actions in the proposed AD prior to issuance. \n\tWe do not agree that the corrosion limitations and related actions should be included in this AD for existing approved crack repairs. Boeing maintains information related to pre-existing, pre-approved repairs. We have delegated authority to make findings concerning repairs related to this AD to the Boeing Commercial Airplanes ODA. Under the provisions of paragraph (j) of this AD, we will consider requests to accept the use of standard repairs developed by Boeing or the operator if sufficient data are submitted to substantiate that the repair would provide an acceptable level of safety. We have made no change to the AD in this regard. \n\nRequest To Extend Compliance Time \n\n\n\tEuropean Air Transport and DHL asked that we extend the interval for the repetitive inspections in the NPRM (75 FR 3660, January 22, 2010) to the next 4C check or 12,000 flight cycles from the date of the referenced service information, whichever occurs first. These commenters stated that they are already performing the inspection at the next 4C checkand at intervals of 12,000 flight cycles. These commenters added that the fuel tanks are only purged during a 4C check, which has an interval of 12,000 flight cycles, 24,000 flight hours, and 72 months, whichever occurs first. The commenters noted that, if the proposed interval is maintained, the fuel tanks will need to be purged during a 1C or 2C check, and this will create additional downtime and costs for the inspection. \n\tWe do not agree with the commenters' request. The repetitive inspection interval was determined using a damage tolerance analysis and is appropriate to adequately address the unsafe condition. Under the provisions of paragraph (j) of this AD, operators may request approval of an alternative method of compliance (AMOC) if sufficient data are submitted to substantiate that the request would provide an acceptable level of safety. We have not changed the AD in this regard. \n\nRequest To Supersede Related ADs \n\n\n\tFedEx asked that we supersede related AD 2003-18-05, Amendment 39- 13296 (68 FR 53496, September 11, 2003); and AD 2004-12-07, Amendment 39-13666 (69 FR 33561, June 16, 2004). FedEx stated that the NPRM (75 FR 3660, January 22, 2010) should be approved as ancillary inspections to these ADs. FedEx added that this would maintain current AD maintenance documents and prevent future misinterpretation of the AD modification and inspection requirements. \n\tWe agree that the subject inspections are in the same area as the modifications required by AD 2003-18-05 (68 FR 53496, September 11, 2003) and AD 2004-12-07 (69 FR 33561, June 16, 2004). We also agree that accomplishing the inspections required by this AD could be cited as related actions to the actions included in AD 2003-18-05 and AD 2004-12-07. In the event that those ADs are superseded, this AD could be included as related rulemaking. \n\tThe actions required by those ADs (mandating strut modifications) are complex and require compliance times which would not correlate with the compliance times in this AD. Therefore, we do not agree that this AD should supersede AD 2003-18-05 (68 FR 53496, September 11, 2003) and AD 2004-12-07 (69 FR 33561, June 16, 2004). We have not changed the AD in this regard. \n\nAdditional Change Made to This Final Rule \n\n\n\tWe have revised the heading for and wording in 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 \n\n((Page 12172)) \n\npublic 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 (75 FR 3660, January 22, 2010) for correcting the unsafe condition; and \n\tDo not add any additional burden upon the public than was already proposed in the NPRM (75 FR 3660, January 22, 2010). \n\tWe also determined that these changes will not increase the economic burden on any operator or increase the scope of the AD. \n\nExplanation of Change to Costs of Compliance \n\n\n\tSince issuance of the NPRM (75 FR 3660, January 22, 2010), we have increased the labor rate used in the Costs of Compliance from $80 per work-hour to $85 per work-hour. The Costs of Compliance information, below, reflects this increase in the specified labor rate. \n\nCosts of Compliance \n\n\n\tWe estimate that this AD affects 668 airplanes of U.S. registry. We also estimate that it will take about 6 work-hours per airplane to comply with this AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $340,680 per inspection cycle, or $510 per airplane, per inspection cycle. \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, Congress charges 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 DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), \n\t(3) Will not affect intrastate 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\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.