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 published in the Federal Register on June 12, 2012 (77 FR 34876). That NPRM proposed to require a detailed inspection of the clamps on the power feeder cable of the APU to determine if certain clamps are installed, and related investigative and corrective actions 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 and the FAA's response to each comment. American Airlines and United Airlines stated they will incorporate the requirements of the NPRM (77 FR 34876, June 12, 2012). \n\nRequest To Remove Paragraph (h) of the NPRM (77 FR 34876, June 12, 2012) \n\n\n\tBoeing requested that paragraph (h) of the NPRM (77 FR 34876, June 12, 2012), ''Exception to the Service Bulletin,'' be removed from the NPRM. Boeing stated that paragraph (h) of the NPRM requires repair of the APU power feeder, insulation blankets, and clamps, if no primer discoloration or structural damage is found. Boeing stated that paragraph (h) of the NPRM is redundant to steps 3.B.6.f.(2) of the Accomplishment Instructions of Boeing Alert Service Bulletin 777- 24A0119, dated November 11, 2011, which accomplishes the replacement and repair of all damaged components found during the progressive detailed inspection outlined in that service bulletin. \n\tWe disagree with Boeing's request to remove paragraph (h) of this AD. Step 3.B.6.f.(2) of the Accomplishment Instructions of Boeing Alert Service Bulletin 777-24A0119, dated November 11, 2011, is part of the requirements of step 3.B.6.b. of that service bulletin, which states, ''If visual indications of heat damage are found, do steps 6.c through 6.f.'' However, if no primer discoloration or structural deterioration is detected after doing the inspection specified in 3.B.6.a. of that service bulletin, the service information does not specify which step to accomplish next, which is repairing the APU power feeder cable and insulation blanket, and replacing the existing clamps. We have not changed this final rule in this regard. \n\nRequest To Clarify the ''Differences Between the Proposed AD and the Service Information'' Section of the NPRM (77 FR 34876, June 12, 2012) \n\n\n\tFedEx requested clarification regarding the statement in the ''Differences Between the Proposed AD and the Service Information'' section of the NPRM (77 FR 34876, June 12, 2012), and the statement in Boeing Alert Service Bulletin 777-24A0119, dated November 11, 2011, to contact Boeing for repair instructions. FedEx stated that, in the ''Differences Between the Proposed AD and the Service Information'' section, the repairs will be addressed in one of the following ways: In accordance with a method approved by the FAA, or using data that meets the certification basis of the airplane, and \n\n((Page 70356)) \n\nhas been approved by Boeing Commercial Airplanes Organization Designation Authorization (ODA). FedEx stated that it would like to know if any repair design by the airline will require an alternative method of compliance (AMOC), and whether Boeing will provide repair methods in a revised service bulletin, or if the airline will have to provide Boeing with information on the damage and request a repair. FedEx stated that standard repair methods, if listed in the service information, would expedite the repair, especially if the repair would need to be ''bought off'' by an airline certified structures inspector. \n\tWe agree to clarify the intent of the ''Differences Between the Proposed AD and the Service Information'' section in the NPRM (77 FR 34876, June 12, 2012). Any deviation from the Accomplishment Instructions of Boeing Alert Service Bulletin 777-24A0119, dated November 11, 2011, requires an AMOC approval. Also, as stated in paragraph (i)of this AD, where that service bulletin specifies to contact Boeing for the repair, the repair must be done in accordance with the procedures specified in paragraph (j) of this AD, which is the ''Alternative Methods of Compliance (AMOCs)'' paragraph of this AD. The AMOC requests, whether the structural repair design is developed by the airline or by Boeing engineering, could either be approved by the Manager of the Seattle Aircraft Certification Office, or by the Boeing ODA that has been authorized by the Manager, Seattle ACO, to approve AMOC requests specifically for this AD. We understand FedEx's concern on the potential delays due to the absence of standard structural repair methods in Boeing Alert Service Bulletin 777-24A0119, dated November 11, 2011; however, we have not received any information from the manufacturer on whether that service bulletin will be revised. We have not changed this final rule in this regard. \n\nConclusion \n\n\n\tWe reviewed the relevant data, consideredthe comments received, and determined that air safety and the public interest require adopting the AD as proposed. \n\nCosts of Compliance \n\n\n\tWe estimate that this AD affects 164 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 Clamp Replacement.... 8 work-hours x $85 per $500 $1,180 $193,520 \n\thour = $680. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tWe estimate the following costs to do any necessary repairs that would be required based on the resultsof the inspection. We have no way of determining the number of aircraft that might need this repair: \n\n\n\tOn-Condition Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost per \n\tAction Labor cost Parts cost product ---------------------------------------------------------------------------------------------------------------- Inspection and Repair of the Pressure 48 work-hours x $85 per hour = $0 $4,080 \n\tBulkhead. $4,080. ---------------------------------------------------------------------------------------------------------------- \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:(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.