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 Department of Transportation Federal Aviation Administration 14 CFR Part 39
[Docket No. FAA-2023-1711; Project Identifier MCAI-2023-00093-T; Amendment 39-22639; AD 2023-25-12]
RIN 2120-AA64
 AGENCY: Federal Aviation Administration (FAA), DOT.
 ACTION: Final rule.
 SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all Airbus SAS Model A318-112 airplanes; Model A319-115, -132, -133, -151N, -153N, and -171N airplanes; Model A320-211, -212, -214, -231, -232, -251N, -252N, -253N, -271N, -272N, and -273N airplanes; and Model A321-112 airplanes. This AD was prompted by a report that the fatigue life limit of the motoreductor installed on the on-board entrance stairs is not demonstrated for the complete airplane design service goal (DSG). This AD requires repetitive replacement of the motoreductor for onboard entrance stairs, and it limits the installation of affected parts under certain conditions, as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.
 DATES: This AD is effective February 7, 2024. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of February 7, 2024.
 ADDRESSES:  *AD Docket:*
                         You may examine the AD docket at 
                        *regulations.gov*
                         under Docket No. FAA-2023-1711; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this final rule, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590. *Material Incorporated by Reference:* For material incorporated by reference in this AD, 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 material on the EASA website at 
                        *ad.easa.europa.eu.*
                    You may view this material 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. It is also available in the AD docket at*regulations.gov*
                         under Docket No. FAA-2023-1711.
 FOR FURTHER INFORMATION CONTACT: Tim Dowling, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 206-231-3667; email 
                        *timothy.p.dowling@faa.gov.*


SUPPLEMENTARY INFORMATION: Background The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all Airbus SAS Model A318-112 airplanes; Model A319-115, -132, -133, -151N, -153N, and -171N airplanes; Model A320-211, -212, -214, -231, -232, -251N, -252N, -253N, -271N, -272N, and -273N airplanes; and Model A321-112 airplanes. The NPRM published in the 
                    **Federal Register**
                     on August 17, 2023 (88 FR 55953). The NPRM was prompted by AD 2023-0014, dated January 18, 2023, issued by EASA, which is the Technical Agent for the Member States of the European Union (EASA AD 2023-0014) (also referred to as the MCAI). The MCAI states that computations conducted on the Model A320 family program showed that the fatigue life limit of the motoreductor, installed on the on-board entrance stairs and acting as one of the two (stair) immobilization systems, is not demonstrated for the complete airplane design service goal (DSG). Therefore, a motoreductor failure could remain undetected during the period between the demonstrated life limit of the motoreductor and the airplane DSG (and subsequent extended service goal). A failed motoreductor, if not corrected, could lead to an airstairs deployment in flight, possibly resulting in loss of control of the airplane. In the NPRM, the FAA proposed to require repetitive replacement of the motoreductor for onboard entrance stairs, and limit the installation of affected parts under certain conditions, as specified in EASA AD 2023-0014. The FAA is issuing this AD to address the unsafe condition on these products. You may examine the MCAI in the AD docket at 
                    *regulations.gov*
                     under Docket No. FAA-2023-1711. Discussion of Final Airworthiness Directive Comments The FAA received comments from a commenter, American Airlines (AAL). The following presents the comments received on the NPRM and the FAA's response to each comment. Request for Revision of the Applicability Paragraph AAL requested revising paragraph (c) of the proposed AD to narrow the scope of affected airplanes to only those that have had certain modifications accomplished for installing airstairs on the affected Airbus SAS model airplanes (identified as Group 1 airplanes in EASA AD 2023-0014). AAL acknowledged that the FAA carried over EASA AD 2023-0014's applicability statement on all serial numbers of the affected Airbus SAS models. AAL also noted that the replacement action is only necessary if the airplane is equipped with the airstairs. The FAA agrees that the replacement actions are only required for airplanes equipped with the affected airstairs (Group 1 airplanes). However, the FAA has determined it is necessary to retain the proposed applicability that is based on EASA's determination of the effectivity of EASA AD 2023-0014. Airplanes that have airstairs installed after the effective date would be subject to the requirements of this AD. Removing airplanes identified as Group 2 airplanes in EASA AD 2023-0014 (airplanes not equipped with the 
                    ( print page 234)
                    affected airstairs) would remove this AD from those airplanes' records and possibly increase the risk that the affected airstair part could be installed during a later modification of the Group 2 airplane into a Group 1 airplane without the operator's awareness that the requirements of this AD would then apply to that airplane. A Group 2 airplane with on-board entrance stairs becomes a Group 1 airplane. Operators can check the airplane's maintenance records to monitor the Group status and determine the applicable requirements for that airplane. The FAA has not changed this AD as a result of this comment. 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 comment 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 EASA AD 2023-0014 specifies procedures for repetitive replacement of the motoreductor for Airbus on-board entrance stairs, including a detailed inspection to determine the threshold for replacement. 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. Costs of Compliance The FAA estimates that this AD will affect 954 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: Estimated Costs for Required Actions
Labor cost
Parts cost
Cost per product
Cost on U.S. 
                             operatorsUp to 8 work-hours × $85 per hour = $680 per replacement cycle
$49,590 per replacement cycle
Up to $50,270 per replacement cycle
Up to $47,957,580 per replacement cycle.
 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
 2.The FAA amends § 39.13 by adding the following new airworthiness directive: **2023-25-12 Airbus SAS:**
                             Amendment 39-22639; Docket No. FAA-2023-1711; Project Identifier MCAI-2023-00093-T. (a) Effective Date This airworthiness directive (AD) is effective February 7, 2024. (b) Affected ADs None. (c) Applicability This AD applies to all Airbus SAS airplanes identified in paragraphs (c)(1) through (4) of this AD, certificated in any category. (1) Model A318-112 airplanes. (2) Model A319-115, -132, -133, -151N, -153N, and -171N airplanes. (3) Model A320-211, -212, -214, -231, -232, -251N, -252N, -253N, -271N, -272N, and -273N airplanes. (4) Model A321-112 airplanes. (d) Subject Air Transport Association (ATA) of America Code 52, Doors. (e) Unsafe Condition This AD was prompted by a report that the fatigue life limit of the motoreductor, installed on the on-board entrance stairs, is not demonstrated for the complete airplane design service goal (DSG). The FAA is issuing this AD to address a motoreductor failure, which could be undetected until DSG is reached. The unsafe condition, if not addressed, could result in an airstairs deployment in flight, possibly resulting in loss of control of the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Requirements Except as specified in paragraphs (h) and (i) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, European Union Aviation Safety Agency (EASA) AD 2023-0014, dated January 18, 2023 (EASA AD 2023-0014). Thereafter, before the accumulation of 39,400 total flight cycles on 
                            ( print page 235)
                            any motoreductor, part number 4255417, 4394656, or 4339747, replace it with a serviceable part as defined in EASA AD 2023-0014. (h) Exceptions to EASA AD 2023-0014 (1) Where EASA AD 2023-0014 refers to its effective date, this AD requires using the effective date of this AD. (2) This AD does not adopt the “Remarks” section of EASA AD 2023-0014. (i) No Reporting Requirement Although the service information referenced in EASA AD 2023-0014 specifies to submit certain information to the manufacturer, this AD does not include that requirement. (j) 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 (k) 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 responsible Flight Standards 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. (3) 
                            *Required for Compliance (RC):*
                             Except as required by paragraph (j)(2) of this AD, if any service information contains procedures or tests that are identified as RC, those procedures and tests must be done to comply with this AD; any procedures or tests that are not identified as RC are recommended. Those procedures and tests that are not identified as RC may be deviated from using accepted methods in accordance with the operator's maintenance or inspection program without obtaining approval of an AMOC, provided the procedures and tests identified as RC can be done and the airplane can be put back in an airworthy condition. Any substitutions or changes to procedures or tests identified as RC require approval of an AMOC. (k) Additional Information For more information about this AD, contact Tim Dowling, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 206-231-3667; email 
                            *timothy.p.dowling@faa.gov.* (l) 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 2023-0014, dated January 18, 2023 (EASA AD 2023-0014). (ii) [Reserved] (3) For EASA AD 2023-0014, 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/​ibrlocations.html,*
                             or email 
                            *fr.inspection@nara.gov.* Issued on December 14, 2023. Victor Wicklund, Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.


[FR Doc. 2023-28847 Filed 1-2-24; 8:45 am] BILLING CODE 4910-13-P