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 May 1, 2012 (77 FR 25647). That NPRM proposed to require repetitive lubrication of the MLG pivot joints; repetitive detailed inspections of the outer diameter chrome on the center axles of the MLG for chicken-wire cracks, corrosion, and chrome plate distress; repetitive magnetic particle inspections of the outer diameter chrome on the center axles of the MLG for cracks; 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 (77 FR 24647, May 1, 2012), and the FAA's response to each comment. \n\nSupport for the NPRM (77 FR 25647, May 1, 2012) \n\n\n\tUnited Airlines agrees with the intent of the NPRM (77 FR 24647, May 1, 2012). \n\nRequests to Extend Compliance Time \n\n\n\tFedEx and Air France requested that we revise the compliance time for the inspection specified in paragraph (g) of the NPRM (77 FR 25647, May 1, 2012) to coincide with the time between overhaul (TBO) of the MLG for their respective fleets. The applicable compliance time specified in the NPRM for the FedEx fleet would be 3,000 days; the TBO for the FedEx fleet is 3,650 days. The applicable compliance time specified in the NPRM for the Air France fleet would be 3,750 days; the TBO for the Air France fleet is 4,015 days. FedEx noted that, of the 28 cracked axles found during overhaul, none was fractured. \n\tWe disagree to revise the compliance time. In developing an appropriate compliance time for this AD, we considered not only the safety implications, but the manufacturer's recommendations and the practical aspect of accomplishing the required actions within an interval of time that corresponds to typical scheduledmaintenance for affected operators. Under the provisions of paragraph (l) of this final rule, however, we might consider requests for adjustments to the compliance time if data is submitted to substantiate that such an adjustment would provide an acceptable level of safety. We have not changed the final rule regarding this issue. \n\nRequests for Alternative Provisions \n\n\n\tBoeing, FedEx, and All Nippon Airways requested that we revise paragraph (i) of the NPRM (77 FR 25647, May 1, 2012) to include an additional exception to the service information. The commenters requested that we allow the use of MIL-PRF-32014 grease as an alternative to the Royco 11MS grease for the lubrications specified in paragraph (g) of the NPRM. Boeing Alert Service Bulletin 777-32-0082, dated December 9, 2010 (referenced in the NPRM as the appropriate source of service information for this lubrication), replaces the Royco 11MS grease with \n\n((Page 60286)) \n\nMIL-PRF-32014 grease for lubricating and installing the MLG pivot joint components. \n\tBoeing asserted that MIL-PRF-32014 grease provides the same lubricating properties as Royco 11MS grease. Boeing and FedEx noted that use of MIL-PRF-32014 grease across the fleet will avoid intermixing grease types and prevent the need to track which grease has been applied on each airplane. FedEx reported it has already standardized to MIL-PRF-32014 grease to ensure that there is no intermixing of greases. Boeing reported that Boeing Alert Service Bulletin 777-32A0082, dated December 9, 2010, will be revised to allow use of MIL-PRF-32014 grease as an optional grease type, but this revision will not be available when the AD is issued. \n\tWe agree with the request. Both greases have the same lubricating properties and will work with the original and new bushing materials. We have added new paragraph (i)(2) in this final rule (and redesignated paragraph (i) of the NPRM (77 FR 25647, May 1, 2012) as paragraph (i)(1) of this final rule) to allow theuse of either MIL-PRF-32014 or Royco 11MS grease for the lubrications required by paragraph (g) of this AD. \n\nRequests To Include Terminating Action \n\n\n\tFedEx, Air France, United Airlines, and All Nippon Airways requested that we revise paragraph (j) of the NPRM (77 FR 25647, May 1, 2012) to provide terminating action for the repetitive inspections specified in paragraph (g) of the NPRM. FedEx stated that airplanes after incorporation of Boeing Service Bulletin 777-32-0085, dated April 14, 2011, have the same configuration as new production airplanes. Air France stated that incorporation of Boeing Service Bulletin 777-32- 0085, dated April 14, 2011, and the incorporation of Item 32-CMR-01 of Section 9, Airworthiness Limitations of the Boeing 777 Maintenance Planning Document (MPD) into the airplane maintenance program terminates the repetitive inspections specified in paragraph (g) of the NPRM by modifying the MLG and including the repetitive lubrication in the airplane maintenance program. \n\tWe agree that accomplishment of the actions specified in Boeing Service Bulletin 777-32-0085, dated April 14, 2011, involves a final inspection, modification to the MLG, and modification of the airplane maintenance program to terminate the repetitive inspections of paragraph (g) of this AD. Paragraph (j)(2) of this AD provides the optional terminating action. It is, therefore, unnecessary to revise that paragraph. We have made no changes to the AD in this regard. \n\nRequest To Clarify Specific Terminating Actions \n\n\n\tAir France noted that the optional terminating action specified in paragraph (j)(2) of the NPRM (77 FR 25647, May 1, 2012) does not specify the inner cylinder assembly upgrade with bushing replacement, as specified in Part 2, Option 2, of the Accomplishment Instructions of Boeing Service Bulletin 777-32-0085, dated April 14, 2011. \n\tWe agree to revise the AD. Instead of identifying every action, however, we have revised paragraph (j)(2) in this final rule to require all applicable actions specified in the Accomplishment Instructions of Boeing Service Bulletin 777-32-0085, dated April 14, 2011. \n\nRequest for Warranty Support \n\n\n\tAir France expressed concern regarding the cost of the inspection and modification program, with no industry support from Boeing. Air France noted that an unsafe condition due to normal operation would be considered a major design defect. Air France requested that Boeing propose industry support to cover the maintenance burden of the design defect. \n\tAir France did not request any change to the AD. Further, we do not control warranty coverage for affected individuals. We have, therefore, not changed the AD regarding the estimated costs. \n\nRequest To Extend Compliance Time for On-Condition Action \n\n\n\tAir France reported that it found the service information instructions to be complex, with a high risk of grounding airplanes due to on-condition findings and a lack of Boeing support regarding the innercylinder assembly. Air France requested that Boeing add service extension limits in case of on-condition findings. \n\tAir France did not specifically request a change to the AD. We cannot allow continued operation if cracking is detected, due to the safety implications and consequences of such cracking. We have not changed the final rule regarding this issue. \n\nRequest To Clarify On-Condition Actions \n\n\n\tBoeing requested that we revise the NPRM (77 FR 25647, May 1, 2012) to clarify the related investigative and corrective actions for the inner cylinder. Boeing noted minor differences between the wording of the NPRM and the wording of Boeing Alert Service Bulletin 777-32A0082, dated December 9, 2010. Boeing requested that we revise the NPRM to more closely align with the Accomplishment Instructions of that service bulletin. \n\tWe partially agree. We agree that Boeing's proposed changes are consistent with the procedures provided in the service information specified in the preambleof the NPRM (77 FR 24647, May 1, 2012). But this level of detail is not provided in the regulatory language of this AD. Instead, the AD refers to the service information for the required procedures. It is not necessary to revise the final rule to account for this request. \n\nRequest To Correct Service Bulletin Reference \n\n\n\tBoeing noted an incorrect reference to service information specified in the NPRM (77 FR 25647, May 1, 2012). Where the NPRM referred to ''Boeing Service Bulletin 777-32A0085,'' the correct service bulletin number is ''777-32-0085.'' We have revised paragraph (j)(2) of this AD accordingly. \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\t(Agr)re consistent with the intent that was proposed in the NPRM (77 FR 25647, May 1, 2012) for correcting the unsafe condition; and \n\tDo not add any additional burden upon the public than was already proposed in the NPRM (77 FR 25647, May 1, 2012). \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((Page 60287)) \n\n\n\n\n\n\n\tEstimated Costs ---------------------------------------------------------------------------------------------------------------- \n\tParts Cost on U.S. \n\tAction Labor cost cost Cost per product operators ---------------------------------------------------------------------------------------------------------------- Lubrication of MLG pivot joints... 4 work-hours x $85 $0 $340 per lubrication $54,400 per \n\tper hour = $340 percycle. lubrication cycle. \n\tlubrication cycle. Detailed and magnetic particle 39 work-hours x $85 0 $3,315 per $530,400 per \n\tinspections. per hour = $3,315 inspection cycle. inspection cycle. \n\tper inspection cycle. Inner cylinder lug bore inspection 6 work-hours x $85 0 $510 per inspection $81,600 per \n\tper hour = $510 per cycle. inspection cycle. \n\tinspection cycle. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tWe estimate the following costs to do any necessary repairs or replacements that would be required based on the results of the inspections. We have no way of determining the number of aircraft that might need these repairs or replacements. \n\n\n\tOn-Condition Costs ---------------------------------------------------------------------------------------------------------------- \n\tAction Labor cost Parts cost Cost per product ---------------------------------------------------------------------------------------------------------------- Replacing center axle............. 25 work-hours x $85 $54,030................... $56,155. \n\tper hour = $2,125. Refinishing the lug bore and 12 work-hours x $85 Up to $3,526.............. Up to $4,546. \n\tfaces, and installing new per hour = $1,020. \n\tbushings. Replacing the inner cylinder 46 work-hours x $85 Up to $254,847............ Up to $258,757. \n\tassembly cylinder assembly. per hour = $3,910. ---------------------------------------------------------------------------------------------------------------- \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.