AD 2026-20-04

62299 Federal Register / Vol. 91, No. 189 / Thursday, October 1, 2026 / Rules and Regulations (2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards District Office/certificate holding district office. (k) Additional Information For more information about this AD, contact Katherine Le, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (817) 222– 5178; email: katherine.le@faa.gov. (l) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference of the material listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51. (2) You must use this material as applicable to do the actions required by this AD, unless the AD specifies otherwise. (i) European Union Aviation Safety Agency (EASA) AD 2025–0159, dated July 24, 2025. (ii) [Reserved] (3) For EASA material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: ADs@easa.europa.eu; website: easa.europa.eu. You may find the EASA material on the EASA website at ad.easa.europa.eu. (4) You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 10101 Hillwood Parkway, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222–5110. (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 September 23, 2026. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2026–20103 Filed 9–30–26; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2026–2730; Project Identifier AD–2025–01579–T; Amendment 39–23477; AD 2026–20–04] RIN 2120–AA64 Airworthiness Directives; The Boeing Company Airplanes AGENCY : Federal Aviation Administration (FAA), DOT. ACTION : Final rule. SUMMARY : The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 757–300 series airplanes. This AD was prompted by a crack growth analysis that indicated that existing maintenance planning data (MPD) and supplemental structural inspection program (SSIP) tasks do not provide adequate inspection opportunities to detect cracks in the upper frames around the uppermost fastener common to the fail-safe chord at the fuselage frame splices. This AD requires an inspection or maintenance record check for existing repairs, repetitive inspections of the upper frames around the uppermost fastener common to the fail-safe chord at the fuselage frame splices for any cracks, and applicable on-condition actions. The FAA is issuing this AD to address the unsafe condition on these products. DATES : This AD is effective November 5, 2026. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of November 5, 2026. ADDRESSES : AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA–2026–2730; 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, 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 Boeing material identified in this AD, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110–SK57, Seal Beach, CA 90740–5600; telephone 562–797–1717; website myboeingfleet.com . • 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 at regulations.gov under Docket No. FAA–2026–2730. FOR FURTHER INFORMATION CONTACT : Wayne Ha, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 562–627–5238; email: wayne.ha@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 The Boeing Company Model 757–300 series airplanes. The NPRM was published in the Federal Register on April 2, 2026 (91 FR 16593). The NPRM was prompted by a report that crack growth analysis indicated that existing MPD and SSIP tasks do not provide adequate inspection opportunities to detect cracks in the upper frames around the uppermost fastener common to the fail-safe chord at the fuselage frame splices between stringers S–13 to S–14, from station (STA) 1380 to STA 1620. In the NPRM, the FAA proposed to require an inspection or maintenance record check for existing repairs, repetitive inspections of the upper frames around the uppermost fastener common to the fail-safe chord at the fuselage frame splices for any cracks, and applicable on-condition actions. The FAA is issuing this AD to address cracking in the upper frames around the uppermost fastener common to the fail-safe chord at certain fuselage frame splices, which could lead to multiple upper frame failures. The unsafe condition, if not addressed, could result in the inability of a principal structural element to sustain limit loads and the loss of continued safe flight and landing. Discussion of Final Airworthiness Directive Comments The FAA received a comment from Boeing who supported the NPRM without change. The FAA received additional comments from Aviation Partners Boeing (APB) and United Airlines (United). The following presents the comments received on the NPRM and the FAA’s response to each comment. Effect of Winglets on Accomplishment of the Proposed Actions APB stated that accomplishing Supplemental Type Certificate (STC) ST01518SE does not affect the actions specified in the proposed AD. APB stated that Boeing has delegation from APB to review and approve data in areas affected by STC ST01518SE for the blended winglet configuration. The provisions of paragraph (i)(2) in the proposed AD remain applicable to The Boeing Company Model 757–300 series airplanes modified by STC ST01518SE, with blended winglets or production wingtips installed. The FAA concurs with the commenter. The FAA has redesignated paragraph (c) of the proposed AD as paragraph (c)(1) of this AD and added paragraph (c)(2) to this AD to state that installation of STC ST01518SE does not affect the ability to accomplish the actions required by this AD. Therefore, VerDate Sep<11>2014 21:53 Sep 30, 2026 Jkt 268001 PO 00000 Frm 00003 Fmt 4700 Sfmt 4700 E:\FR\FM\01OCR1.SGM 01OCR1 lotter on DSK8BHNXB4PROD with RULES1

62300 Federal Register / Vol. 91, No. 189 / Thursday, October 1, 2026 / Rules and Regulations for airplanes on which STC ST01518SE is installed, a ‘‘change in product’’ alternative method of compliance (AMOC) approval request is not necessary to comply with the requirements of 14 CFR 39.17. Request To Correct Typographical Error in Service Material United requested that the FAA revise Table 2 of Boeing Alert Requirements Bulletin 757–53A0122 RB, dated September 26, 2025, to correct the references to stringers S–13L and S–14L in certain steps. United stated that Table 2 applies to the right side in both the compliance and actions required for compliance sections and, therefore, the stringer references should be S–13R and S–14R. The FAA agrees that Table 2 of Boeing Alert Requirements Bulletin 757– 53A0122 RB, dated September 26, 2025, contains typographical errors in certain stringer references. The FAA has added an exception in paragraph (h)(3) of this AD to correct the typographical errors. Conclusion The FAA reviewed the relevant data, considered any 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 these products. Except for minor editorial changes, and any other changes described previously, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator. Material Incorporated by Reference Under 1 CFR Part 51 The FAA reviewed Boeing Alert Requirements Bulletin 757–53A0122 RB, dated September 26, 2025. This material specifies procedures for performing a general visual inspection or a maintenance records check of the forward and aft sides of the upper frames at the frame splices between S– 13 and S–14 on the left and right sides, from STA 1380 to STA 1620, for any repair and applicable on-condition actions. On-condition actions include contacting Boeing for alternative inspection and corrective action instructions and doing the alternative inspection and applicable corrective actions in the repaired areas. This material also specifies procedures for repetitive detailed inspections of the upper frames around the uppermost fastener common to the fail-safe chord at the frame splices between S–13 and S–14 on the left and right sides, from STA 1380 to STA 1620, for any crack and applicable on- condition actions. On-condition actions include contacting Boeing for repair instructions and doing the repair. 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 affects 37 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: E STIMATED C OSTS Action Labor cost Parts cost Cost per product Cost on U.S. operators General visual inspection or maintenance records check. Up to 70 work-hours × $85 per hour = $5,950. $0 Up to $5,950 ........................... Up to $220,150. Detailed inspection ................... 4 work-hours × $85 per hour = $340 per inspection cycle. 0 $340 per inspection cycle ....... $12,580 per inspection cycle. The FAA has received no definitive data on which to base the cost estimates for the alternative inspections and on- condition actions specified in this AD. 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: 2026–20–04 The Boeing Company: Amendment 39–23477; Docket No. FAA–2026–2730; Project Identifier AD– 2025–01579–T. (a) Effective Date This airworthiness directive (AD) is effective November 5, 2026. (b) Affected ADs None. VerDate Sep<11>2014 21:53 Sep 30, 2026 Jkt 268001 PO 00000 Frm 00004 Fmt 4700 Sfmt 4700 E:\FR\FM\01OCR1.SGM 01OCR1 lotter on DSK8BHNXB4PROD with RULES1

62301 Federal Register / Vol. 91, No. 189 / Thursday, October 1, 2026 / Rules and Regulations (c) Applicability (1) This AD applies to all The Boeing Company Model 757–300 series airplanes, certificated in any category. (2) Installation of Supplemental Type Certificate (STC) ST01518SE does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST01518SE is installed, a ‘‘change in product’’ alternative method of compliance (AMOC) approval request is not necessary to comply with the requirements of 14 CFR 39.17. (d) Subject Air Transport Association (ATA) of America Code 53, Fuselage. (e) Unsafe Condition This AD was prompted by a crack growth analysis that indicated that the existing maintenance planning data and supplemental structural inspection program tasks do not provide adequate inspection opportunities to detect cracks in the upper frames around the uppermost fastener common to the fail-safe chord at certain fuselage frame splices. The FAA is issuing this AD to address cracking in the upper frames around the uppermost fastener common to the fail-safe chord at certain fuselage frame splices, which could lead to multiple upper frame failures. The unsafe condition, if not addressed, could result in the inability of a principal structural element to sustain limit loads and the loss of continued safe flight and landing. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions Except as specified by paragraph (h) of this AD: At the applicable times specified in the ‘‘Compliance’’ paragraph of Boeing Alert Requirements Bulletin 757–53A0122 RB, dated September 26, 2025, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 757–53A0122 RB, dated September 26, 2025. Note 1 to paragraph (g): Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin 757–53A0122, dated September 26, 2025, which is referred to in Boeing Alert Requirements Bulletin 757–53A0122 RB, dated September 26, 2025. (h) Exceptions to Requirements Bulletin Specifications (1) Where the Compliance Time column of the tables in the ‘‘Compliance’’ paragraph of Boeing Alert Requirements Bulletin 757– 53A0122 RB, dated September 26, 2025, refers to the original issue date of Requirements Bulletin 757–53A0122 RB, this AD requires using the effective date of this AD. (2) Where Boeing Alert Requirements Bulletin 757–53A0122 RB, dated September 26, 2025, specifies contacting Boeing for repair instructions or for alternative inspections: This AD requires doing the repair, or doing the alternative inspections and applicable on-condition actions, using a method approved in accordance with the procedures specified in paragraph (i) of this AD. (3) Where Table 2 in the ‘‘Compliance’’ paragraph and the Accomplishment Instructions of Boeing Alert Requirements Bulletin 757–53A0122 RB, dated September 26, 2025, states ‘‘S–13L and S–14L’’, for this AD replace that text with ‘‘S–13R and S– 14R’’. (i) Alternative Methods of Compliance (AMOCs) (1) The Manager, AIR–520, Continued Operational Safety 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 manager of the Continued Operational Safety Branch, send it to the attention of the person identified in paragraph (j)(1) of this AD. Information may be emailed to: 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) An AMOC that provides an acceptable level of safety may be used for any repair, modification, or alteration required by this AD if it is approved by The Boeing Company Organization Designation Authorization (ODA) that has been authorized by the Manager, AIR–520, Continued Operational Safety Branch, FAA, to make those findings. To be approved, the repair method, modification deviation, or alteration deviation must meet the certification basis of the airplane, and the approval must specifically refer to this AD. (j) Additional Information (1) For more information about this AD, contact Wayne Ha, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 562–627–5238; email: wayne.ha@faa.gov. (2) Material identified in this AD that is not incorporated by reference is available at the address specified in paragraph (k)(3) of this AD. (k) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference of the material listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51. (2) You must use this material as applicable to do the actions required by this AD, unless the AD specifies otherwise. (i) Boeing Alert Requirements Bulletin 757–53A0122 RB, dated September 26, 2025. (ii) [Reserved] (3) For Boeing material identified in this AD, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110– SK57, Seal Beach, CA 90740–5600; telephone 562–797–1717; website myboeingfleet.com . (4) 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. (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 September 22, 2026. Brian Knaup, Acting Deputy Director, Integrated Certificate Management Division, Aircraft Certification Service. [FR Doc. 2026–20120 Filed 9–30–26; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2026–11789; Project Identifier MCAI–2026–00908–R; Amendment 39–23480; AD 2026–20–07] RIN 2120–AA64 Airworthiness Directives; Leonardo S.p.a. Helicopters AGENCY : Federal Aviation Administration (FAA), DOT. ACTION : Final rule; request for comments. SUMMARY : The FAA is adopting a new airworthiness directive (AD) for certain Leonardo S.p.a. Model AB139 and AW139 helicopters. This AD was prompted by a report of a nozzle exhaust duct clamp separating from the engine nozzle duct and coming to rest on the tail rotor (TR) drive shaft. This AD requires repetitively inspecting certain clamp assemblies and, depending on the results of the inspection, replacing parts. This AD also prohibits the installation of an affected clamp assembly, unless certain requirements are met. The FAA is issuing this AD to address the unsafe condition on these products. DATES : This AD is effective October 16, 2026. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of October 16, 2026. The FAA must receive comments on this AD by November 16, 2026. ADDRESSES : You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: • Federal eRulemaking Portal: Go to regulations.gov. Follow the instructions for submitting comments. • Fax: (202) 493–2251. VerDate Sep<11>2014 21:53 Sep 30, 2026 Jkt 268001 PO 00000 Frm 00005 Fmt 4700 Sfmt 4700 E:\FR\FM\01OCR1.SGM 01OCR1 lotter on DSK8BHNXB4PROD with RULES1