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 757-200, -200PF, and -200CB series airplanes. The NPRM was published in the Federal Register on July 8, 2025 (90 FR 30030). The NPRM was prompted by a report of improper grinding of the inner diameter of the MLG outer cylinders, resulting in possible heat damage to the outer cylinders. In the NPRM, the FAA proposed to require a records check or inspection to determine if an affected outer cylinder is installed and replacing all affected outer cylinders. The FAA is issuing this AD to address heat damage to the MLG outer cylinders. The unsafe condition, if not addressed, could cause failure of a principal structural element to sustain its limit load or collapse of the MLG, which could result in loss of control of the airplane or runway departure. Discussion of Final Airworthiness Directive Comments The FAA received comments from the Air Line Pilots Association, International (ALPA) and Boeing who supported the NPRM without change. The FAA received an additional comment from Aviation Partners Boeing (APB). The following presents the comment received on the NPRM and the FAA's response to the comment. Effect of Winglets on Accomplishment of the Proposed Actions APB stated that the installation of winglets per Supplemental Type Certificate (STC) ST01518SE does not affect accomplishment of the actions specified in the proposed AD. The FAA agrees that STC ST01518SE does not affect the ability to accomplish the actions required by this AD. The FAA has not changed the AD in this regard. Conclusion The FAA reviewed the relevant data 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, 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 757-32A0216 RB, dated January 26, 2024. This material specifies procedures for performing a maintenance records check or an inspection of the left and right MLG outer cylinders to determine if any affected part numbers and serial numbers are installed and replacing any affected outer cylinder. 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 399 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: Estimated Costs Action Labor cost Parts cost Cost per product Cost on U.S. operators Inspection or maintenance records check for affected parts 3 work-hours × $85 per hour = $255 $0 $255 $101,745 The FAA estimates the following costs to do any replacement that would be required based on the results of the inspection or maintenance records check. The agency has no way of determining the number of airplanes that might need this replacement: On-Condition Costs Action Labor cost Parts cost Cost per product Replacement of MLG outer cylinder (20 affected parts) 137 work-hours × $85 per hour = $11,645 $325,000 $336,645 per MLG outer cylinder. 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: 2025-19-11 The Boeing Company: Amendment 39-23151; Docket No. FAA-2025-1357; Project Identifier AD-2025-00618-T. (a) Effective Date This airworthiness directive (AD) is effective November 6, 2025. (b) Affected ADs None. (c) Applicability This AD applies to The Boeing Company Model 757-200, -200PF, and -200CB series airplanes, certificated in any category. (d) Subject Air Transport Association (ATA) of America Code 32, Landing Gear. (e) Unsafe Condition This AD was prompted by a report of improper grinding of the inner diameter of the main landing gear (MLG) outer cylinders, resulting in possible heat damage to the outer cylinders. The FAA is issuing this AD to address heat damage to the MLG outer cylinders. The unsafe condition, if not addressed, could cause failure of a principal structural element to sustain its limit load or collapse of the MLG, which could result in loss of control of the airplane or runway departure. (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 757-32A0216 RB, dated January 26, 2024, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 757-32A0216 RB, dated January 26, 2024. Note 1 to paragraph (g): Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin 757-32A0216, dated January 26, 2024, which is referred to in Boeing Alert Requirements Bulletin 757-32A0216 RB, dated January 26, 2024. (h) Exceptions to Requirements Bulletin Specifications Where the "Boeing Recommended Compliance Time" column in the table under the "Compliance" paragraph of Boeing Alert Requirements Bulletin 757-32A0216 RB, dated January 26, 2024, refers to the original issue date of Boeing Alert Requirements Bulletin 757-32A0216 RB, this AD requires using the effective date of this AD. (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 certification office, 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) Related Information (1) For more information about this AD, contact Stefanie Roesli, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3964; email: stefanie.n.roesli@faa.gov. (2) Material identified in this AD that is not incorporated by reference is available at the address specified in paragraph (k)(3) 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 757-32A0216 RB, dated January 26, 2024. (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 19, 2025. Peter A. White, Deputy Director, Integrated Certificate Management Division, Aircraft Certification Service.