Comments Invited The FAA invites you to send any written data, views, or arguments about this final rule. Send your comments using a method listed under the ADDRESSES section. Include Docket No. FAA-2025-0746 and Project Identifier AD-2025-00674-T at the beginning of your comments. The most helpful comments reference a specific portion of the final rule, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend this final rule because of those comments. Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this final rule. Confidential Business Information CBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this AD contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this AD, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as "PROPIN." The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this AD. Submissions containing CBI should be sent to Taylor Stanley, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 407-852-7677; email: taylor.stanley@faa.gov. Any commentary that the FAA receives that is not specifically designated as CBI will be placed in the public docket for this rulemaking. Background The FAA has received a report that a Model 747-8F series airplane operated with a right-hand outboard elevator that was received and installed without balance weights. The operator ordered left- and right-side outboard elevators, part number (P/N) 183U3300-13 and P/N 183U3300-14 respectively, and received outboard elevators, P/N 654U6625-2411 and P/N 654U6625-2412, with associated paperwork that identified the parts were interchangeable with P/N 183U3300-13 and P/N 183U3300-14 and included balance weights. However, P/N 654U6625-2411 and P/N 654U6625-2412 do not contain balance weights. Therefore, the parts are not directly interchangeable and must be balanced prior to installation and flight. A total of 10 spare assemblies, P/N 654U6625-2411 and P/N 654U6625-2412 (5 each), have been delivered to operators since 2022. Outboard elevators without balance weights, if not addressed, could result in abnormal vibration, buffeting, flutter, or oscillation that could result in loss of continued safe flight and landing. Further, outboard elevators without balance weights could result in personal injury to maintenance personnel during installation or removal of the outboard elevators. FAA's Determination The FAA is issuing this AD because the agency has determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. Material Incorporated by Reference Under 1 CFR Part 51 The FAA reviewed Boeing Alert Safety Advisory 747-BSA-55-001, dated April 24, 2025. The material specifies procedures for a maintenance records check to determine if outboard elevators, P/N 654U6625-2411 and P/N 654U6625-2412, are installed, a general visual inspection of the outboard elevators to determine if balance weights are installed, and applicable on-conditions actions. On-condition actions include a maintenance records check to determine if the balance procedure of the outboard elevator was done, a general visual inspection of the outboard elevator for the installation of the balance weights, and corrective action instructions. 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. AD Requirements This AD requires accomplishing the actions identified as "RC" (required for compliance) in the Accomplishment Instructions of Boeing Alert Safety Advisory 747-BSA-55-001, dated April 24, 2025, already described, except for any differences identified as exceptions in the regulatory text of this AD. See "Differences Between this AD and the Referenced Material" for a discussion of the general differences included in this AD. For information on the procedures and compliance times, see Boeing Alert Safety Advisory 747-BSA-55-001, dated April 24, 2025, at regulations.gov under Docket No. FAA-2025-0746. Differences Between This AD and the Referenced Material The effectivity of Boeing Alert Safety Advisory 747-BSA-55-001, dated April 24, 2025, is limited to Model 747-400, -400D, -400F, -8, and -8F series airplanes. However, the applicability of this AD includes all The Boeing Company Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400, -400D, -400F, -8, -8F, 747SR, and 747SP series airplanes. Because the affected elevators are rotable parts, the FAA has determined that these parts could later be installed on airplanes that were initially delivered with acceptable parts, thereby subjecting those airplanes to the unsafe condition. The FAA has confirmed with Boeing that the Accomplishment Instructions in Boeing Alert Safety Advisory 747-BSA-55-001, dated April 24, 2025, can be used for the expanded group of airplanes to address the unsafe condition. Justification for Immediate Adoption and Determination of the Effective Date Section 553(b) of the Administrative Procedure Act (APA) (5 U.S.C. 551 et seq. ) authorizes agencies to dispense with notice and comment procedures for rules when the agency, for "good cause," finds that those procedures are "impracticable, unnecessary, or contrary to the public interest." Under this section, an agency, upon finding good cause, may issue a final rule without providing notice and seeking comment prior to issuance. Further, section 553(d) of the APA authorizes agencies to make rules effective in less than thirty days, upon a finding of good cause. An unsafe condition exists that requires the immediate adoption of this AD without providing an opportunity for public comments prior to adoption. The FAA has found that the risk to the flying public justifies forgoing notice and comment prior to adoption of this rule because left-hand and right-hand outboard elevators installed without balance weights, if not addressed, could result in abnormal vibration, buffeting, flutter, or oscillation that could result in loss of continued safe flight and landing. Further, outboard elevators without balance weights could result in personal injury to maintenance personnel during installation or removal of the outboard elevators. Additionally, the compliance time in this AD is shorter than the time necessary for the public to comment and for publication of the final rule. Accordingly, notice and opportunity for prior public comment are impracticable and contrary to the public interest pursuant to 5 U.S.C. 553(b). In addition, the FAA finds that good cause exists pursuant to 5 U.S.C. 553(d) for making this amendment effective in less than 30 days, for the same reasons the FAA found good cause to forgo notice and comment. Regulatory Flexibility Act The requirements of the Regulatory Flexibility Act (RFA) do not apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt a rule without prior notice and comment. Because the FAA has determined that it has good cause to adopt this rule without notice and comment, RFA analysis is not required. Costs of Compliance The FAA estimates that this AD affects 170 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 Records check to determine part number or inspection to determine if balance weights are installed Up to 4 work-hours × $85 per hour = $340 $0 Up to $340 Up to $57,800. The FAA estimates the following costs to do any necessary on-condition actions that would be required based on the results of the records check or inspection. The FAA has no way of determining the number of aircraft that might need these actions: On-Condition Costs * Action Labor cost Parts cost Cost per product Records check to determine if balance procedure was done 1 work-hour × $85 per hour = $85 $0 $85 Inspection to determine if balance weights are installed 4 work-hours × $85 per hour = $340 0 340 * The FAA has received no definitive data on which to base the cost estimates for the corrective action instructions 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, and (2) Will not affect intrastate aviation in Alaska. 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: 2025-09-08 The Boeing Company: Amendment 39-23029; Docket No. FAA-2025-0746; Project Identifier AD-2025-00674-T. (a) Effective Date This airworthiness directive (AD) is effective May 5, 2025. (b) Affected ADs None. (c) Applicability This AD applies to all The Boeing Company Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400, -400D, -400F, -8, -8F, 747SR, and 747SP series airplanes, certificated in any category. (d) Subject Air Transport Association (ATA) of America Code 55, Stabilizers. (e) Unsafe Condition This AD was prompted by a report that a right-hand outboard elevator was received and installed without balance weights. The FAA is issuing this AD to address left-hand and right-hand outboard elevators delivered without balance weights. The unsafe condition, if not addressed, could result in abnormal vibration, buffeting, flutter, or oscillation that could result in loss of continued safe flight and landing. Further, outboard elevators without balance weights could result in personal injury to maintenance personnel during installation or removal of the outboard elevators. (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 paragraph 1.E., "Compliance," of Boeing Alert Safety Advisory 747-BSA-55-001, dated April 24, 2025, do all applicable actions identified as "RC" (required for compliance) in, and in accordance with, the Accomplishment Instructions of Boeing Alert Safety Advisory 747-BSA-55-001, dated April 24, 2025. For airplanes not identified in Boeing Alert Safety Advisory 747-BSA-55-001, dated April 24, 2025, do the actions for Group 1 airplanes specified in Boeing Alert Safety Advisory 747-BSA-55-001, dated April 24, 2025. (h) Exceptions to Safety Advisory Specifications (1) Where the "Boeing Recommended Compliance Time" columns of the tables in the "Compliance" paragraph of Boeing Alert Safety Advisory 747-BSA-55-001, dated April 24, 2025, refer to "the Original Issue date of this safety advisory," this AD requires using the effective date of this AD. (2) Where Boeing Alert Safety Advisory 747-BSA-55-001, dated April 24, 2025, specifies contacting Boeing for corrective action instructions: This AD requires doing the instructions using a method approved in accordance with the procedures specified in paragraph (j) of this AD. (i) Special Flight Permit Special flight permits may be issued in accordance with 14 CFR 21.197 and 21.199 to operate the airplane to a location where the actions required by this AD can be performed, provided the Manager, AIR-520, Continued Operational Safety Branch, FAA, concurs with issuance of the special flight permit. Send requests for concurrence by email to AMOC@faa.gov. (j) 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 (k) 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. (3) Except as required by paragraph (h)(2) of this AD: For material that contains steps that are labeled as Required for Compliance (RC), the provisions of paragraphs (j)(3)(i) and (ii) of this AD apply. (i) The steps labeled as RC, including substeps under an RC step and any figures identified in an RC step, must be done to comply with the AD. If a step or substep is labeled "RC Exempt," then the RC requirement is removed from that step or substep. An AMOC is required for any deviations to RC steps, including substeps and identified figures. (ii) Steps not labeled 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 RC steps, including substeps and identified figures, can still be done as specified, and the airplane can be put back in an airworthy condition. (k) Related Information For more information about this AD, contact Taylor Stanley, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 407-852-7677; email: taylor.stanley@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) Boeing Alert Safety Advisory 747-BSA-55-001, dated April 24, 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 April 25, 2025. John P. Piccola, Jr., Director, Integrated Certificate Management Division, Aircraft Certification Service.