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. The NPRM published in the Federal Register on September 20, 2012 (77 FR 58334). The NPRM proposed to require an inspection for damage of wire bundles and hydraulic tubing on the right side of the forward bulkhead of the MLG wheel well; installation of new clamps; and corrective actions, as applicable. \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 (77 FR 58334, September 20, 2012) and the FAA's response to each comment. \n\nRequest To Refer to Revised Service Information \n\n\n\tUnited Airlines (United) requested that we refer to the latest revision of the service information in this final rule. \n\tWe agree with United's request, since Boeing has issued Special Attention Service Bulletin 737-29-1113, Revision 1, dated March 29, 2013. That service information removes airplanes from the effectivity, which were reworked during production and on which the change specified in Boeing Special Attention Service Bulletin 737-29-1113, Revision 1, dated March 29, 2013, has already been incorporated. We have revised paragraph (g) of this final rule to refer to that revised service information, added a new paragraph (h) to this final rule to allow credit for previous actions done using Boeing Special Attention Service Bulletin 737-29-1113, dated March 23, 2011. Subsequent paragraphs have been redesignated accordingly. \n\nRequest To Clarify Source of Applicability Exclusions \n\n\n\tAmerican Airlines (American), Delta Airlines (Delta), and United requested that we revise the NPRM (77 FR 58334, September 20, 2012) to clarify the source of the airplane line numbers excluded from the applicability paragraph which do not appear in Boeing Special Attention Service Bulletin 737-29-1113, dated March 23,2011, or in Boeing Service Bulletin Information Notice 737-29-1113 IN 01, dated May 20, 2011, and correct the source of the applicability information in the ''Differences Between the Proposed AD and the Service Information'' paragraph. \n\tWe partially agree. Boeing identified those airplanes that were reworked during production, and communicated the excluded line numbers to the FAA prior to the issuance of the NPRM (77 FR 58334, September 20, 2012). Boeing Special Attention Service Bulletin 737-29-1113, Revision 1, dated March 29, 2013, reduced the number of affected airplanes. We have revised paragraph (c) of this final rule to identify those airplanes which are affected by this AD. Because the ''Differences Between Proposed AD and the Service Information'' paragraph is not restated in the preamble of the final rule, we have not made any change to the final rule in that regard. \n\nRequest To Simplify Applicability \n\n\n\tUnited requested that the applicability statement of the NPRM(77 FR 58334, September 20, 2012) be simplified to clearly state which airplanes are affected by the AD. \n\tWe agree with United's request. We have revised paragraph (c) of this final rule to match the line numbers as listed in Boeing Special Attention Service Bulletin 737-29-1113, Revision 1, dated March 29, 2013. We have coordinated this change with Boeing. \n\nRequest To Clarify Applicability \n\n\n\tUnited requested that the applicability statement of the NPRM (77 FR 58334, September 20, 2012) be clarified since it differs from the service bulletin. United stated that Boeing Special Attention Service Bulletin 737-29-1113, dated March 23, 2011, contains a conditional statement for the required clamp installation based on whether there is sufficient separation between the wire bundle and hydraulic tubing. United reasoned that operators may elect not to install new clamps if they find sufficient separation between the wire bundling and hydraulic tubing. \n\tWe disagree with United's request because the NPRM (77 FR 58334, September 20, 2012) did not include the implied conditional applicability. This final rule applies to all airplanes listed in paragraph (c) of this AD regardless of separation between the hydraulic tubing and wire bundles. We have changed paragraph (c) of this AD to match the line numbers as listed in Boeing Special Attention Service Bulletin 737-29-1113, Revision 1, dated March 29, 2013, since this new revision of the service bulletin was released since the issuance of the NPRM. \n\nRequest To Verify Excluded Airplane Line Numbers (L/Ns) Are Correct \n\n\n\tAmerican and Delta requested that the FAA verify the excluded airplane L/Ns are correct in paragraph (c) ''Applicability'' of the NPRM (77 FR 58334, September 20, 2012) because there were discrepancies between the NPRM, Boeing Service Bulletin Information Notice (IN) 737- 29-1113 IN 01, dated May 20, 2011, and Boeing Special Attention Service Bulletin 737-29-1113, dated March 23, 2011. American and Delta stated they had airplanes that should not be included in the effectivity since they did not have the hydraulic tubing that is referred to in the service information installed. American and Delta confirmed through a review of the applicable airplane illustrated parts catalogs that certain L/Ns did not have the hydraulic tubing \n\n((Page 59800)) \n\ninstalled (i.e. American L/Ns 3307, 3328, 3334, 3340, and 3347; Delta L/N 3338). American stated that two of its airplanes did have the hydraulic tubing installed (American L/Ns 3291 and 3298). \n\tWe agree to provide clarification. The airplane L/Ns listed by both American and Delta are excluded airplane L/Ns. The FAA has verified with Boeing that the correct airplane L/Ns are listed in the NPRM (77 FR 58334, September 20, 2012) and match the airplane L/Ns in Boeing Special Attention Service Bulletin 737-29-1113, Revision 1, dated March 29, 2013. As stated previously, we have revised paragraph (c) of this final rule to identify thoseairplanes that are affected by this AD. This change has been coordinated with Boeing. \n\nRequest To Add Inspection for Clamps Already Installed \n\n\n\tUnited requested that the NPRM (77 FR 58334, September 20, 2012) be revised to include an inspection to look for clamps already installed prior to performing the required work, and if found, to check the part number of the subject clamp. United stated that if the clamp is not a part number listed in Boeing Special Attention Service Bulletin 737-29- 1113, Revision 1, dated March 29, 2013, it should be replaced. United stated it found at least one aircraft with clamps installed on the right side of the forward bulkhead of the MLG wheel well and that it has revised its work instructions to include the clamp installation and part number inspection. \n\tWe disagree with United's request to add an inspection to look for clamps already installed prior to performing the required work because Boeing has confirmed that the airplane mentioned by United is among those listed as an excluded line number, meaning it was already reworked during production. Because both this final rule and Boeing Special Attention Service Bulletin 737-29-1113, Revision 1, dated March 29, 2013, require installation of new clamps with the correct part number, we have not made any change to this final rule in that regard. \n\nStatement Regarding Installation of Winglets \n\n\n\tAviation Partners Boeing (APB) stated that the installation of winglets per supplemental type certificate (STC) ST00830SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/408E012E008616A7862578880060456C?OpenDocument&Highlight=st00830se) does not affect the actions specified in the NPRM (77 FR 58334, September 20, 2012). \n\tWe concur. We have redesignated paragraph (c) of the NPRM (77 FR 58334, September 20, 2012) as paragraph (c)(1) in this final rule, added paragraph (c)(2) to this final rule, which states that STC ST00830SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/408E012E008616A7862578880060456C?OpenDocument&Highlight=st00830se) does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST00830SE is installed, a ''change in product'' alternative method of compliance (AMOC) approval request is not necessary to comply with the requirements of Section 39.17 of the Federal Aviation Regulations (14 CFR 39.17). For all other AMOC requests, the operator must request approval of an AMOC in accordance with the procedures specified in paragraph (i) of this AD. \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 this AD with the changes described previously and minor editorial changes. We have determined that these minor changes: \n\t(Agr)re consistent with the intent that was proposed in the NPRM (77 FR 58334, September 20, 2012) for correcting the unsafe condition; andDo not add any additional burden upon the public than was already proposed in the NPRM (77 FR 58334, September 20, 2012). \n\tWe also determined that these changes will not increase the economic burden on any operator or increase the scope of this AD. \n\nCosts of Compliance \n\n\n\tWe estimate that this AD affects 520 airplanes of U.S. registry. \n\tWe estimate the following costs to comply with this AD: \n\n\n\tEstimated Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost per Cost on U.S. \n\tAction Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Inspection and installation......... 2 work-hours x $85 per $0 $170 $88,400 \n\thour = $170. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tWe have received no definitive data that would enable us to provide labor cost estimates for the on-condition actions (repairing or replacing of damaged wire bundles and damaged hydraulic tubing) specified in this AD. \n\tAccording to the manufacturer, some of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected individuals. We do not control warranty coverage for affected individuals. As a result, we have included all costs in our cost estimate. \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\n((Page 59801)) \n\n\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.