Background The 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 A318, A319, A320, and A321 airplanes. The NPRM published in the Federal Register on October 31, 2023 (88 FR 74376). The NPRM was prompted by AD 2023-0138, dated July 13, 2023 (EASA AD 2023-0138) (also referred to as the MCAI), issued by EASA, which is the Technical Agent for the Member States of the European Union. The MCAI states that new airworthiness limitations are necessary. In the NPRM, the FAA proposed to require revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations, as specified in EASA AD 2023-0138. The FAA is issuing this AD to address safety-significant latent failures (that are not annunciated), which, in combination with one or more other specific failures or events, could result in a hazardous or catastrophic failure condition. You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2023-2138. Discussion of Final Airworthiness Directive Comments The FAA received a comment from The Air Line Pilots Association, International (ALPA), who supported the NPRM without change. The FAA also received comments from Delta Air Lines. The following presents the comments received on the NPRM and the FAA's response to each comment. Request for Clarification of Paragraph (i) Referencing Service Information Delta requested clarification of the statement in paragraph (i) of the proposed AD that references later-approved revisions within the "Ref. Publications" section of EASA AD 2023-0138. Delta requested adding an exception in paragraph (h) of the proposed AD that replaces the language in the EASA AD 2023-0138 section "Ref. Publications" from "the above-mentioned document, or of an ALS revision" to "the above-mentioned document, or of an ALS revision or variation." Delta stated this change would help clarify whether an AMOC (alternative method of compliance) is required to use future variations of Airbus A318/A319/A320/A321 ALS Part 3 Certification Maintenance Requirements (CMR), Revision 08 (Var 8.3 or later). Delta also requested clarification of the statement within the section "Ref. Publications" of EASA AD 2023-0138, referred to in paragraph (i) of the proposed AD, that references later-approved revisions "which include the technical content of the variation." Delta wanted to know if a later-approved variation or revision is acceptable to use if the technical content of the variation is updated in some way, and not exactly the same. The commenter requested this clarification to better understand the allowance provided by the provisions of the "Ref. Publications" section of EASA AD 2023-0138. The FAA disagrees with changing paragraph (h) of this AD. The later version of Airbus A318/A319/A320/A321 ALS Part 3 Certification Maintenance Requirements (CMR) would be acceptable for compliance as long as EASA has also approved it. Any subsequent issue of that document containing the technical information presented in that variation that has been approved by the certifying authority can be used without the need to obtain an AMOC. For confirmation regarding the appropriateness of using service information associated with this AD, Delta may contact their local FAA office for further guidance. Conclusion This product has been approved by the aviation authority of another country and is approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, it has notified the FAA of the unsafe condition described in the MCAI referenced above. The FAA reviewed the relevant data, considered the comments received, and determined that air safety requires adopting this AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on this product. Except for minor editorial changes, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator. Related Service Information Under 1 CFR Part 51 The FAA reviewed EASA AD 2023-0138, which specifies new or more restrictive airworthiness limitations for airplane structures and safe life limits. 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. Costs of Compliance The FAA estimates that this AD affects 1,680 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: The FAA has determined that revising the existing maintenance or inspection program takes an average of 90 work-hours per operator, although the agency recognizes that this number may vary from operator to operator. Since operators incorporate maintenance or inspection program changes for their affected fleet(s), the FAA has determined that a per-operator estimate is more accurate than a per-airplane estimate. Therefore, the agency estimates the average total cost per operator to be $7,650 (90 work-hours ? $85 per work-hour). Authority for This Rulemaking Title 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. The 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. Regulatory Findings This 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. For the reasons discussed above, I certify that this AD: (1) Is not a "significant regulatory action" under Executive Order 12866, (2) Will not affect intrastate aviation in Alaska, and (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 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. The Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: PART 39-AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 [Amended] 2. The FAA amends § 39.13 by adding the following new airworthiness directive: 2024-04-07 Airbus SAS: Amendment 39-22686; Docket No. FAA-2023-2138; Project Identifier MCAI-2023-00870-T. (a) Effective Date This airworthiness directive (AD) is effective April 22, 2024. (b) Affected ADs This AD affects AD 2023-04-06, Amendment 39-22353 (88 FR 13665, March 6, 2023) (AD 2023-04-06). (c) Applicability This AD applies to Airbus SAS airplanes, identified in paragraphs (c)(1) through (4) of this AD, certificated in any category, with an original airworthiness certificate or original export certificate of airworthiness issued on or before May 12, 2023. (1) Model A318-111, -112, -121, and -122 airplanes. (2) Model A319-111, -112, -113, -114, -115, -131, -132, -133, -151N, -153N, and -171N airplanes. (3) Model A320-211, -212, -214, -216, -231, -232, -233, -251N, -252N, -253N, -271N, -272N, and -273N airplanes. (4) Model A321-111, -112, -131, -211, -212, -213, -231, -232, -251N, -252N, -253N, -271N, -272N, -251NX, -252NX, -253NX, -271NX, and -272NX. (d) Subject Air Transport Association (ATA) of America Code 05, Time Limits/Maintenance Checks. (e) Unsafe Condition This AD was prompted by a determination that new or more restrictive airworthiness limitations are necessary. The FAA is issuing this AD to address safety-significant latent failures (that are not annunciated), which, in combination with one or more other specific failures or events, could result in a hazardous or catastrophic failure condition. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Requirements Except as specified in paragraph (h) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, European Union Aviation Safety Agency (EASA) AD 2023-0138, dated July 13, 2023 (EASA AD 2023-0138). (h) Exceptions to EASA AD 2023-0138 (1) This AD does not adopt the requirements specified in paragraphs (1) and (2) of EASA AD 2023-0138. (2) Paragraph (3) of EASA AD 2023-0138 specifies revising "the approved AMP" within 12 months after its effective date, but this AD requires revising the existing maintenance or inspection program, as applicable, within 90 days after the effective date of this AD. (3) The initial compliance time for doing the tasks specified in paragraph (3) of EASA 2023-0138 is at the applicable "associated thresholds" as incorporated by the requirements of paragraph (3) of EASA AD 2023-0138, or within 90 days after the effective date of this AD, whichever occurs later. (4) This AD does not adopt the provisions specified in paragraphs (4) of EASA AD 2023-0138. (5) This AD does not adopt the "Remarks" section of EASA AD 2023-0138. (i) Provisions for Alternative Actions and Intervals After the existing maintenance or inspection program has been revised as required by paragraph (g) of this AD, no alternative actions ( e.g., inspections), and intervals are allowed unless they are approved as specified in the provisions of the "Ref. Publications" section of EASA AD 2023-0138. (j) Terminating Action for Certain Tasks Required by AD 2023-04-06 Accomplishing the actions required by this AD terminates the corresponding requirements of AD 2023-04-06 for the tasks identified in the service information referenced in EASA AD 2023-0138 only. (k) Additional AD Provisions The following provisions also apply to this AD: (1) Alternative Methods of Compliance (AMOCs): The Manager, International Validation Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or responsible Flight Standards Office, as appropriate. If sending information directly to the International Validation Branch, send it to the attention of the person identified in paragraph (l) of this AD. Information may be emailed to: 9-AVS-AIR-730-AMOC@faa.gov. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. (2) Contacting the Manufacturer: For any requirement in this AD to obtain instructions from a manufacturer, the instructions must be accomplished using a method approved by the Manager, International Validation Branch, FAA; or EASA; or Airbus SAS's EASA Design Organization Approval (DOA). If approved by the DOA, the approval must include the DOA-authorized signature. (l) Additional Information For more information about this AD, contact Timothy Dowling, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 206-231-3367; email Timothy.P.Dowling@faa.gov. (m) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51. (2) You must use this service information as applicable to do the actions required by this AD, unless this AD specifies otherwise. (i) European Union Aviation Safety Agency (EASA) AD 2023-0138, dated July 13, 2023. (ii) [Reserved] (3) For EASA AD 2023-0138, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221 8999 000; email ADs@easa.europa.eu; website easa.europa.eu. You may find this EASA AD on the EASA website at ad.easa.europa.eu. (4) You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195. (5) You may view this material at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations, or email fr.inspection@nara.gov. Issued on February 16, 2024. Victor Wicklund, Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.