2025-21-02: Flight controls

1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. 2. The FAA amends § 39.13 by: a. Removing Airworthiness Directive (AD) 2022-15-06, Amendment 39-22126 (87 FR 47334, August 3, 2022); and b. Adding the following new AD: 2025-21-02 The Boeing Company: Amendment 39-23174; Docket No. FAA-2024-2144; Project Identifier AD-2024-00424-T. (a) Effective Date This airworthiness directive (AD) is effective January 2, 2026. (b) Affected ADs This AD replaces AD 2022-15-06, Amendment 39-22126 (87 FR 47334, August 3, 2022) (AD 2022-15-06). (c) Applicability This AD applies to all The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series airplanes, certificated in any category. (d) Subject Air Transport Association (ATA) of America Code 27, Flight controls. (e) Unsafe Condition This AD was prompted by high electrical resistance within the gust suppression sensor (GSS) transorb modules due to corrosion on the transorb threads and insufficient engagement of the anti-rotation teeth. The FAA is issuing this AD to address high electrical resistance in both transorb modules, which can result in two actuator control electronics (ACEs) being exposed to damaging lightning transient voltages in excess of the qualification levels, potentially inducing erroneous or oscillatory outputs to flight control surfaces. The unsafe condition, if not addressed, could result in loss of control of the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Retained Requirement To Disconnect, Cap, and Stow Transorb Module Connectors, With Revised Affected Airplanes For airplanes with an original airworthiness certificate or original export certificate of airworthiness issued on or before the effective date of this AD: This paragraph restates the requirements of paragraph (g) of AD 2022-15-06, with revised affected airplanes. At the later of the times specified in paragraphs (g)(1) and (2) of this AD: Disconnect the connectors and cap and stow the wires to bundles/connectors W7314/D02006P and W7579/D02005P from the transorb module part numbers CLPT-12SP-06, CLPT-12SP-07, and CLPT-12SP-67. Note 1 to the introductory text of paragraph (g): Guidance on locating wire bundles/connectors W7314/D02006P and W7579/D02005P can be found in Section 05-55-43 of the Boeing 777 aircraft maintenance manual. Note 2 to the introductory text of paragraph (g): Guidance on capping and stowing the wires once they are disconnected can be found in Section 20-10-11 of the Boeing Standard Wiring Practices Manual. (1) Before the accumulation of 75,000 total flight hours or 23,000 total flight cycles, whichever occurs first. (2) Within 3 months after August 18, 2022 (the effective date of AD 2022-15-06). (h) New Requirement To Disconnect, Cap, and Stow Certain Other Transorb Module Connectors For airplanes with an original airworthiness certificate or original export certificate of airworthiness issued on or before the effective date of this AD: At the later of the times specified in paragraphs (h)(1) and (2) of this AD: Disconnect the connectors and cap and stow the wires to bundles/connectors W6313/D02098P or W7314/D02099P from the transorb module part numbers CLPT-12SP-06, CLPT-12SP-07, and CLPT-12SP-67. Note 3 to the introductory text of paragraph (h): Guidance on locating wire bundles/connectors W6313/D02098P and W7314/D02099P can be found in Section 05-55-43 of the Boeing 777 aircraft maintenance manual. Note 4 to the introductory text of paragraph (h) : Guidance on capping and stowing the wires once they are disconnected can be found in Section 20-10-11 of the Boeing Standard Wiring Practices Manual. (1) Before the accumulation of 75,000 total flight hours or 23,000 total flight cycles, whichever occurs first. (2) Within 3 months after the effective date of this AD. (i) New Required Actions (1) For airplanes with an original airworthiness certificate or original export certificate of airworthiness issued on or before the effective date of this AD: At the later of the times specified in paragraph (i)(1)(i) or (ii) of this AD, do an inspection to determine if any airplane has a transorb module with part number CLPT-12SP-06, CLPT-12SP-07, or CLPT-12SP-67 installed. A review of airplane maintenance records is acceptable in lieu of the inspection if the part numbers can be conclusively determined from that review. (i) Within 24 months after the effective date of this AD. (ii) Within 24 months after the date of issuance of the original standard airworthiness certificate or the original export certificate of airworthiness. (2) If, during any inspection or records review required by paragraph (i)(1) of this AD, any transorb module with part number CLPT-12SP-06, CLPT-12SP-07, or CLPT-12SP-67 is found: Except as specified by paragraph (j) of this AD, at the applicable times specified in the "Compliance" paragraph of Boeing Alert Requirements Bulletin 777-27A0125 RB, dated February 3, 2023, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 777-27A0125 RB, dated February 3, 2023. Doing the replacement required by this paragraph terminates the requirements of paragraphs (g) and (h) of this AD. Note 5 to paragraph (i)(2): Guidance for accomplishing the actions required by paragraph (i)(2) of this AD can be found in Boeing Alert Service Bulletin 777-27A0125, dated February 3, 2023, which is referred to in Boeing Alert Requirements Bulletin 777-27A0125 RB, dated February 3, 2023. (j) Exception to Requirements Bulletin Specifications Where the Compliance Time column of the table in the "Compliance" paragraph of Boeing Alert Requirements Bulletin 777-27A0125 RB, dated February 3, 2023, refers to the original issue date of Requirements Bulletin 777-27A0125 RB, this AD requires using the effective date of this AD. (k) Parts Installation Prohibition As of the effective date of this AD, no person may install a transorb module, part numbers CLPT-12SP-06, CLPT-12SP-07, and CLPT-12SP-67, on any airplane. (l) 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 (m)(1) of this AD. Information may be emailed to: AMOC@faa.gov. (2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards Office. (3) 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. (4) AMOCs approved for AD 2022-15-06 are approved as AMOCs for the corresponding provisions of paragraph (g) of this AD. (m) Related Information (1) For more information about this AD, contact Raja Vengadasalam, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3859; email: raja.vengadasalam@faa.gov. (2) Material identified in this AD that is not incorporated by reference is available at the address specified in paragraph (n)(3) of this AD. (n) 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 777-27A0125 RB, dated February 3, 2023. (ii) [Reserved] (3) For the 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 October 7, 2025. Lona C. Saccomando, Acting Deputy Director, Integrated Certificate Management Division, Aircraft Certification Service. Issued on October 7, 2025. Lona C. Saccomando, Acting Deputy Director, Integrated Certificate Management Division, Aircraft Certification Service. [FR Doc. 2025-21477 Filed 11-26-25; 8:45 am]BILLING CODE 4910-13-P