Discussion \n\n\n\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to the specified products. The NPRM published in the Federal Register on July 11, 2012 (77 FR 40828). The NPRM proposed to require replacing certain MLG upper torque link bolts with a new or serviceable part. \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 40828, July 11, 2012) and the FAA's response to each comment. \n\nRequest To Revise the Unsafe Condition \n\n\n\tBoeing requested that we revise the unsafe condition in the NPRM (77 FR 40828, July 11, 2012). Boeing stated that it disagrees with the SUMMARY section of the NPRM where it states that the safe life limit (SLL) of the bolt is reduced significantly due to ''incorrect'' fabrication. Boeing stated that it approved the fabrication of the bolts from bar stock with amachined head; however, this did not reduce the SLL at that point in time. Boeing stated that the fabrication therefore is not incorrect, and that the SLL reduction was due to fabrication from bar stock with a machined head. \n\tWe partially agree with Boeing's request. We agree that the cause of the unsafe condition is not incorrect fabrication. \n\tWe disagree with the commenter's statement that the fabrication method of the bolt is correct because with a reduced SLL the discrepant bolts do not meet the type design. The correct fabrication process of the bolt, from forged blank with an upset forged head, would not have reduced the SLL. We have changed the cause of the unsafe condition throughout this final rule to state that the SSL of the bolt is reduced significantly because those bolts were ''fabricated from bar stock with a machined head.'' \n\nRequest To Allow Maintenance Records Review \n\n\n\tFedEx requested that in paragraph (g) of the NPRM (77 FR 40828, July 11, 2012) operators be allowed to show compliance by a records review. \n\tWe agree with the commenter that a review of an airplane's maintenance record is acceptable if the part number of the bolt can be conclusively determined from that review. We have changed paragraph (g) of this final rule accordingly. \n\nRequest To Revise Applicability of the NPRM (77 FR 40828, July 11, 2012) \n\n\n\tFedEx stated that paragraphs (g) and (h) of the NPRM (77 FR 40828, July 11, 2012) state to inspect the 18 airplanes \n\n((Page 61162)) \n\nlisted in the Effectivity section of Boeing Alert Service Bulletin DC10-32A260, dated September 30, 2011. FedEx stated that this wording requires an inspection of the airplane, and since the bolts are easily replaced, the airplane effectivity listed in the service information is not accurate. FedEx stated that it has identified two additional airplanes that have the recalled bolts installed, and that the NPRM would require the operator to inspect an airplane that does not have a recalled bolt installed. FedEx stated that the NPRM should be worded to require the tracking and removal of the recalled bolts listed in that service information without any reference to the airplane effectivity. In addition, FedEx stated that the NPRM should change the SLL of the bolt and then allow the bolts to be tracked and removed in the same manner as any life-limited part. FedEx stated that paragraph (f) of the NPRM should state clearly that an airplane does not require an inspection if a recalled bolt is not installed. \n\tWe infer that FedEx is requesting that we revise the applicability of this final rule because the AD applicability refers to the effectivity in Boeing Alert Service Bulletin DC10-32A260, dated September 30, 2011. We disagree with the commenter regarding revising the applicability of this AD. We confirmed with Boeing that the two additional airplanes mentioned previously are not included in the service information effectivity, as the affected bolts were removed inMarch 2012 and are no longer serviceable. We also disagree that this final rule should be revised to require a reduced SLL of the bolt, and the tracking and removal of the recalled bolts listed in the service information. According to 14 CFR 39.1, Airworthiness Directives apply to aircraft, aircraft engines, propellers, or appliances, and we are required to provide airplane effectivity in an AD. We have not changed this AD in this regard. \n\nRequest To Revise the Parts Installation Paragraph \n\n\n\tFedEx requested that we revise paragraph (h) of the NPRM (77 FR 40828, July 11, 2012), which stated that no one may install a recalled bolt on an airplane after the effective date of the AD. FedEx stated that the intent of this requirement is to prevent a replacement bolt from being installed. FedEx stated that the requirement can be interpreted as preventing removal and re-installation of a recalled bolt during maintenance, which could result in grounding an airplane at a remote station until a new bolt is available. FedEx stated that the operator should have the flexibility to remove a recalled bolt and re- install it on the same airplane or another airplane to meet operational requirements. FedEx stated that paragraph (h) of the NPRM should be changed to state that no one may install a replacement bolt. FedEx stated that the intent of paragraph (h) of the NPRM could also be accomplished by requiring all recalled bolts to be removed from spares and the spare gear assemblies. \n\tWe agree with the commenter. We agree that an operator should have the flexibility to re-install recalled bolts on the same airplane if the bolts have not reached their revised SLL of 6,590 flight cycles. We also agree that an operator should have the flexibility to install the reduced life bolt on an airplane not listed on the service bulletin effectivity list, provided the reduced life bolt is replaced prior to accumulation of 6,590 flight cycles. Therefore, we have removed paragraph (h) of the NPRM (77 FR 40828, July 11, 2012) from this AD because this would allow the reinstallation of a reduced life bolt on other Model DC-10-10 and MD-10-10 airplanes. Subsequent paragraphs have been redesignated accordingly. We have also clarified paragraph (g) of this AD to specify that any replacement bolts identified in paragraph 3.B.1 of the Accomplishment Instructions of Boeing Alert Service Bulletin DC10-32A260, dated September 30, 2011, must be replaced prior to the revised SLL. \n\nRequest To Clarify Compliance Time \n\n\n\tFedEx Express and Boeing requested clarification of the compliance time. FedEx stated that paragraph (g) of the NPRM (77 FR 40828, July 11, 2012) states that the recalled bolts must be removed at 6,590 cycles since installation. FedEx stated the wording does not correlate with the service information and the service information changes the SLL for these recalled bolts from ''47,300 to 6,590 cycles.'' FedEx stated that this will force the recalled bolts to be removed at 6,590 cycles since new. FedEx added that the wording of the NPRM allows a bolt to be flown at 6,590 cycles since installation. FedEx stated that the NPRM assumes every bolt has been installed only once in one airplane. FedEx stated that a review of its records show that several of these bolts have been installed on more than one airplane. \n\tBoeing stated that the compliance time should be ''before 6,590 flight cycles are accrued on the part, except as specified in paragraph (h)'' regardless of bolt installation. Boeing stated that this reasoning takes into account multiple installations. In addition, Boeing stated that the SLL is 6,590 flight cycles, regardless of part installation. \n\tWe partially agree with the commenters' request to clarify the compliance time. The FAA intended the term ''bolt installation'' as installation of the bolt since new. We disagree with FedEx's statement that this AD and the service information use different terms in the compliance time because the term ''within 6,590 flight cycles from bolt installation'' is similar to the compliance time in section 1.E., ''Compliance,'' of the service information, which states, ''before 6,590 flight cycles from bolt installation.'' In addition, we have removed paragraph (h) of the NPRM (77 FR 40828, July 11, 2012) from this AD to address a previous comment; therefore, the additional language is unnecessary. Subsequent paragraphs have been redesignated 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 this 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 July 11, 2012 (77 FR 40828, July 11, 2012) for correcting the unsafe condition; and \n\tDo not add any additional burden upon the public than was already proposed in the NPRM July 11, 2012 (77 FR40828, July 11, 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 17 airplanes of U.S. registry. \n\tWe estimate the following costs to comply with this AD: \n\n((Page 61163)) \n\n\n\n\n\n\n\tEstimated Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost per Cost on U.S. \n\tAction Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Bolt Replacement.................... 2 work-hours x $85 per $9,340 $9,510 $161,670 \n\thour = $170. ---------------------------------------------------------------------------------------------------------------- \n\nAuthority for This Rulemaking \n\n\n\tTitle49 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.