((Page 10751)) \n\nDiscussion \n\n\n\tThe FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747- 200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR series airplanes. The NPRM published in the Federal Register on May 18, 2020 (85 FR 29673). The NPRM was prompted by reports of inboard foreflap departures from the airplane. The NPRM proposed to require repetitive replacement of certain parts; a general visual inspection to determine production configuration for certain parts; a repetitive lubrication of certain parts and a repetitive general visual inspection of certain parts for any exuding grease; repetitive detailed inspections of certain parts for loose or missing attachment bolts, cracks or bushing migration, cracks or gouges, or broken, binding, or missing rollers; repetitive detailed inspections of certainparts for cracks or corrosion; repetitive lubrication; and on-condition actions if necessary. \n\tThe FAA is issuing this AD to address departures of the inboard foreflap assembly from the airplane, which could result in damage to the airplane and adversely affect the airplane's continued safe flight and landing. \n\nComments \n\n\n\tThe FAA gave the public the opportunity to participate in developing this final rule. The following presents the comments received on the NPRM and the FAA's response to each comment. \n\nSupport for the NPRM \n\n\n\tThe Air Line Pilots Association, International (ALPA) and Boeing expressed support for the NPRM. \n\nRequest To Incorporate Inspection and Overhaul Program \n\n\n\tAtlas Air (Atlas) requested that the FAA revise the proposed AD to incorporate and provide credit for Atlas's flap inspection and overhaul program. Atlas explained that after four flap failure events, their flap mitigation team formulated a program of actions that successfully address the unsafe conditions cited in the NPRM. \n\tThe FAA acknowledges that alternative methods may exist to address the potential unsafe condition, but disagrees with the request to revise this AD to incorporate specific actions from the Atlas flap mitigation program. That program is unique to an individual operator, and Atlas has not provided the FAA substantiating data demonstrating that these proposed changes provide an equivalent level of safety. Atlas may apply for an AMOC with substantiating data. The FAA has not changed this AD with regard to this request. \n\nRequest for Change in Inspection Requirement \n\n\n\tCargolux (CLX) requested that the proposed inspection, as specified in Boeing Alert Requirements Bulletin 747-57A2367 RB, dated November 15, 2019, Table 1, Action 2, no longer include identifying nuts with part number BACN10HR7CD. CLX explained that determining the part number by inspection is difficult due to access restrictions, and operators may have to replace the subject nuts to be compliant with the proposed AD. \n\tThe FAA disagrees with the requested exemption because it is unnecessary. Boeing Alert Requirements Bulletin 747-57A2367 RB, dated November 15, 2019, Table 1, Action 2, specifies a ''general visual inspection of the inboard foreflap assembly stop, stop attachment bolts, stop lug attachment bolts, and rollers.'' The subject nuts are not specifically identified. Additionally, the service bulletin does not mandate a specific method of compliance for this inspection. It refers to Part 2 of Boeing Alert Service Bulletin 747-57A2367, dated November 15, 2019, where the subject nut is listed, as an accepted procedure. In accordance with Note 6 of the Accomplishment Instructions, ''when the words 'refer to' are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used.'' The FAA has not changed this AD regarding this request. \n\nRequest To Allow Alternative Part Numbers \n\n\n\tCLX requested that approved alternative, substitute, or interchangeable part numbers for specified parts be allowed when demonstrating compliance. CLX is concerned that operators may have trouble obtaining parts if the parts have been replaced and there are interchangeable parts available in lieu of the required part number. \n\tThe FAA disagrees with the request. The design approval holder (DAH) identified the parts necessary to address the unsafe condition. Kits with those replacement part numbers may be acquired from the DAH. Additionally, CLX did not provide the FAA any substantiating data to demonstrate that any alternative/substitute part provides an acceptable level of safety. CLX may submit an AMOC request with supporting data that demonstrates an acceptable level of safety for a replacement part not specified in the service information. The FAA has not changed this AD regarding this request. \n\nRequest To Specify Document as Aid \n\n\n\tRoyal Dutch Airlines (KLM) and CLX requested that Boeing document 747-FTD-57-10002 be specified in the proposed AD as an aid for the general visual inspection described in Boeing Alert Requirements Bulletin 747-57A2367 RB, dated November 15, 2019, to identify part numbers currently installed on the airplane. KLM and CLX claimed that dirt, grease, or sealant may prevent part numbers from being identified by way of a general visual inspection and that the document provided by Boeing should be used as a visual aid. \n\tThe FAA agrees with using visual aids or other documentation to help identify part numbers during the inspection. However, the FAA disagrees with revising the AD to require the specified document. Boeing Alert Requirements Bulletin 747-57A2367 RB, dated November 15, 2019, refers to a procedure in Boeing Alert Service Bulletin 747- 57A2367, dated November 15, 2019, as an accepted procedure for the general visual inspection to identify the parts production configuration. Note 6 of the Accomplishment Instructions states that ''when the words 'refer to' are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used.'' The FAA has not changed this AD regarding this request. \n\nRequest To Allow Optional Records Check \n\n\n\tBoth KLM and CLX requested that a maintenance records check be allowed as an option to the general visual inspection specified in Boeing Alert Requirements Bulletin 747-57A2367 RB, dated November 15, 2019, for the purpose of identifying parts currently installed on the airplane. Both KLM and CLX stated that operators should be able to determine whether their maintenance records are accurate. \n\tThe FAA disagrees with the request. The service information was coordinated with the DAH and it was determined that a physical check, as specified in Boeing Alert Requirements Bulletin 747-57A2367 RB, dated November 15, 2019, is required. This AD has not been changed regarding this request. \n\nRequest To Accept Work Package From Previous Service Bulletin \n\n\n\tUnited Parcel Service (UPS) requested that the FAA also accept \n\n((Page 10752)) \n\naccomplishment of Work Package 3 of Boeing Alert Service Bulletin 747- 27-2366, Revision 3, dated March 22, 2016, in lieu of the initial inspection specified by Table 4 of Boeing Alert Requirements Bulletin 747-57A2367 RB, dated November 15, 2019. UPS asserted that there is significant overlap between the two flap inspections. \n\tThe FAA does not agree with the request. The inspections specified in Boeing Alert Requirements Bulletin 747-57A2367 RB, dated November 15, 2019, include additional structure to inspect, compared to Boeing Alert Service Bulletin 747-27-2366, Revision 3, dated March 22, 2016, and also specify corrective action if damage is detected. The requirements of this AD have been coordinated with the DAH. UPS did not provide the FAA any substantiating data to demonstrate that the less stringent inspections from Boeing Alert Service Bulletin 747-27-2366, Revision 3, dated March 22, 2016, provide an acceptable level of safety. The FAA has not changed this AD as a result of this comment. \n\nConclusion \n\n\n\tThe FAA reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting this final rule as proposed, except for minor editorial changes. The FAA has determined that these minor changes: \n\tAre consistent with the intent that was proposed in the NPRM for addressing the unsafe condition; and \n\tDo not add any additional burden upon the public than was already proposed in the NPRM. \n\nRelated Service Information Under 1 CFR Part 51 \n\n\n\tThe FAA reviewed Boeing Alert Requirements Bulletin 747-57A2367 RB, dated November 15, 2019. This service information describes procedures for repetitive replacement of certain parts; a general visual inspection to determine production configuration for certain parts; a repetitive lubrication of certain parts and a repetitive general visual inspection of certain parts for any exuding grease; repetitive detailed inspections of certain parts for loose or missing attachment bolts, cracks or bushing migration, cracks or gouges, or broken, binding, or missing rollers; repetitive detailed inspections of certain parts for cracks or corrosion; repetitive lubrication; and on-condition actions if necessary. On-condition actions include replacements and repair. This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section. \n\nCosts of Compliance \n\n\n\tThe FAA estimates that this AD affects 125 airplanes of U.S. registry. The FAA estimate the following costs to comply with this AD: \n\n\n\tEstimated Costs for Required Actions ---------------------------------------------------------------------------------------------------------------- \n\tCost on U.S. \n\tAction Labor cost Parts cost Cost per product operators ---------------------------------------------------------------------------------------------------------------- Repetitive replacement......... Up to 10 work-hours x $35,719 Up to $36,569 per Up to $4,571,125 \n\t$85 per hour = Up to replacement cycle. per replacement \n\t$850 per replacement cycle. \n\tcycle. General visual inspection for 1 work-hour x $85 per 0 $85............... $10,625. \n\tparts production configuration. hour = $85. Repetitive detailed inspections 4 work-hours x $85 per 0 $340 per $42,500 per \n\thour = $340 per inspection cycle. inspection cycle. \n\tinspection cycle. Repetitive inspection for 1 work-hour x $85 per 0 $85 per $10,625 per \n\tlubrication and repetitive hour = $85 per lubrication. lubrication. \n\tlubrication.lubrication. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tThe FAA estimates the following costs to do any necessary on- condition actions that would be required. The FAA has no way of determining the number of aircraft that might need these on-condition actions: \n\n\n\tEstimated Costs of On-Condition Replacements ------------------------------------------------------------------------ \n\tLabor cost Parts cost Cost per product ------------------------------------------------------------------------ Up to 8 work-hour x $85 per Up to $17,720....... Up to $18,400. \n\thour = $680. ------------------------------------------------------------------------ \n\n\n\tThe FAA has received no definitive data that would enable the FAA to provide cost estimates for the on-condition repairs specified in this AD. \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\tThe FAA is 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) Will not affect intrastate aviation in Alaska, and \n\t(3) 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\n((Page 10753)) \n\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.