Background \n\n\n\tThe EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2020-0122, dated May 29, 2020 (EASA AD 2020-0122) (also referred to as the Mandatory Continuing Airworthiness Information, or the MCAI), to correct an unsafe condition for certain Airbus SAS Model A320-271N, A321-211, and A321-271N airplanes. \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 Airbus SAS Model A320-271N, A321-211, and A321-271N airplanes. The NPRM published in the Federal Register on September 17, 2020 (85 FR 58014). The NPRM was prompted by reports of missing OHSC X-fixation brackets or brackets that were incorrectly installed during assembly. The NPRM proposed to require a special detailed inspection of the OHSC X-fixation brackets for missing or incorrectly installed brackets, and installation or replacement if necessary; or modification of eachOHSC, as specified in an EASA AD. \n\tThe FAA is issuing this AD to address this condition, which could lead to OHSC failure under certain loading conditions, and possibly result in injury to occupants and impede egress during an emergency evacuation. See the MCAI for additional background information. \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\nRequest To Use a Borescope for the Inspection Requirement \n\n\n\tDelta Air Lines (DAL) requested that the FAA allow the use of a borescope as an alternative device to the endoscope for the inspection of the OHSC X-fixation brackets as specified in paragraph (1) of EASA AD 2020-0122. DAL stated that Airbus has provided its concurrence in Airbus Technical Request 80838467/006, dated October 15, 2020. \n\tThe FAA agrees that use of a borescope to do this inspection will provide an adequate level of safety. The FAA has added paragraph (h)(3) to this AD, which allows for the use of a borescope for the inspection of the OHSC X-fixation brackets required in this AD. \n\nRequest To Disregard the Description of the Bin Assembly in the Referenced Service Information \n\n\n\tDAL requested that the FAA add an exception to paragraph (h) of the proposed AD to disregard the description of the bin assembly. DAL commented that where paragraph 3.C.1(b) through 3.C.1(ae) of the referenced modification service information specified in paragraph (3) of EASA AD 2020-0122 states to ''replace bin assembly 1F FL EE'' (and other bin assemblies), the bin assembly description is information only and does not point to a location on the airplane. DAL commented that Airbus has provided its concurrence in Airbus Technical Request 80838467/006, dated October 15, 2020. \n\tThe FAA agrees that the bin assembly identifier, such as ''1F FL EE,'' is related to the bin assembly description in the referenced modification service information specified in EASA AD 2020-0122. The bin assembly identifiers are provided for information only. The FAA does not agree with removing these references for the bin assemblies because they describe the part that correlates with the part number. Further, the FAA has verified with Airbus that Airbus tech request 80838467/006, dated October 15, 2020, does not recommend removing the part description. However, the FAA has clarified use of the bin assembly identifiers in paragraph (h)(4) of this AD. \n\nRequest for a One-Time Identification of the OHSC \n\n\n\tDAL requested that the FAA clarify that the OHSC housing must be reidentified only one time although the service information referenced in paragraph (3) of EASA AD 2021-0122 specifies to reidentify the OHSC housing at each bin assembly replacement step. DAL stated that Airbus confirmed in Airbus Technical Request 80838467/006, dated October 15, 2020, that each OHSC housing has more than one bin assembly,so the reidentification step is needed only one time for the OHSC housing, not when each bin assembly is replaced. \n\tThe FAA agrees with the commenter. The complete OHSC module, which mainly consists of one housing, one or more bins, the light cover, and one or more air outlets, has one part number. Only one identification label is needed for the whole module, and the bins have their own identification labels with their own part numbers. The FAA has revised this AD to add paragraph (h)(5) of this AD to clarify that the OHSC module is a one-time reidentification no matter how many bins have been modified. \n\nRequest To Disregard a Part Number Not Installed on the Airplane \n\n\n\tDAL requested that the FAA add an exception to paragraph (h) of the proposed AD explaining that the part number of the COMPARTMENT ASSY may be disregarded if it is not installed on the airplane, as long as the OHSC X-fixation brackets are replaced as specified in paragraph (3) of EASA AD 2020-0122. DAL statedthat the part numbers of the COMPARTMENT ASSY can be mismatched due to differences in the airplane applicability; therefore, mismatched part numbers in this step occur when the COMPARTMENT ASSY in the airplane are removed. DAL stated that Airbus has provided its concurrence in Airbus Technical Request 80838467/006, dated October 15, 2020. \n\tThe FAA disagrees with the commenter's request. An AD may not require actions on a part or component that is not installed on the airplane. Any COMPARTMENT ASSY installed after the effective date of this AD must be in compliance with the requirements of this AD. The COMPARTMENT ASSY is reidentified using the referenced modification service information specified in EASA AD 2020-0122. When the COMPARTMENT ASSY is reidentified, the referenced modification service information shows the list of the old and new part numbers to address \n\n((Page 21925)) \n\nthe re-identified parts. The FAA has not revised this AD in this regard. \n\nRequest To Include Certain Equivalencies for Certain Tasks \n\n\n\tDAL requested that the proposed AD include certain equivalencies for the Ref. Tasks identified in the referenced inspection service information specified in EASA AD 2020-0122. DAL stated that the Ref. Task identified in the referenced inspection service information specified in EASA AD 2020-0122 specifies that the actions be accomplished ''in accordance with'' a specific Ref. Task. DAL stated that Airbus has provided its concurrence in Airbus Technical Request 80838467/006, dated October 15, 2020. \n\tThe FAA agrees to revise this AD to include certain equivalencies for the Ref. Tasks identified in step 3.C.1(c) of the referenced inspection service information specified in EASA AD 2020-0122. The FAA has included the Ref. Task equivalencies in paragraphs (h)(6)(i) through (xvi) of this AD. \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 with the changes described previously and 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\tThe FAA also determined that these changes will not increase the economic burden on any operator or increase the scope of this final rule. \n\nRelated Service Information Under 1 CFR Part 51 \n\n\n\tEASA AD 2020-0122 specifies procedures for a special detailed inspection of the OHSC X-fixation brackets for missing or incorrectly installed brackets, and corrective actions (installation or replacement OHSC X-fixation brackets) if necessary; or modification of each OHSC by installing new X-fixation brackets and reidentifying the OHSC housing. This material 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 31 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: \n\n\n\tEstimated Costs for Required Actions ---------------------------------------------------------------------------------------------------------------- \n\tLabor cost Parts cost Cost per product Cost on U.S. operators ---------------------------------------------------------------------------------------------------------------- Up to 29 work-hours x $85 per hour = Up $0 Up to $2,465.............. Up to $76,415. \n\tto $2,465. ---------------------------------------------------------------------------------------------------------------- \n\n\n\n\n\tEstimated Costs for Optional Actions ------------------------------------------------------------------------ \n\tLabor cost Parts cost Cost perproduct ------------------------------------------------------------------------ Up to 36 work-hours x $85 per Up to $539,060.... Up to $542,120. \n\thour = Up to $3,060. ------------------------------------------------------------------------ \n\n\n\tThe FAA estimates the following costs to do any necessary on- condition action that would be required based on the results of any required actions. The FAA has no way of determining the number of aircraft that might need this on-condition action: \n\n\n\tEstimated Costs of On-Condition Actions ------------------------------------------------------------------------ \n\tCost per \n\tLabor cost Parts cost product ------------------------------------------------------------------------ Up to 29 work-hours x $85 per hour = * $ * $ \n\tUp to $2,465......................... ------------------------------------------------------------------------ \n* The FAA has received no definitive data thatwould enable us to\n\n\tprovide parts cost estimates for the on-condition action specified in \n\tthis AD. \n\n\n\tAccording to the manufacturer, some or all of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected operators. The FAA does not control warranty coverage for affected operators. As a result, the FAA has included all known 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\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\n((Page 21926)) \n\n\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.List of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.