2023-21-09: 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 adding the following new airworthiness directive: 2023-21-09 The Boeing Company: Amendment 39-22581; Docket No. FAA-2023-0436; Project Identifier AD-2022-00395-T. (a) Effective Date This airworthiness directive (AD) is effective December 18, 2023. (b) Affected ADs None. (c) Applicability This AD applies to all The Boeing Company Model 777-200, 777-200LR, 777-300, 777-300ER, 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 a report of a "FLAPS DRIVE" caution message in flight due to the torque trip indicator of the No. 2 trailing edge (TE) flap transmission assembly being in the set position, which resulted in an air turn-back. The FAA is issuing this AD to address a broken ratchet pawl assembly in combination with an upstream torque tube disconnect, which can cause failure of the no-back brake to hold flap surfaces in a commanded position, and possible debris in the transmission assembly, which can prevent the pawl from engaging the ratchet plate or cause other damage to the transmission assembly. The unsafe condition, if not addressed, could result in asymmetric loss of the lift that can prevent 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 777-27A0123 RB, Revision 1, dated January 16, 2023, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 777-27A0123 RB, Revision 1, dated January 16, 2023. Note 1 to paragraph (g): Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin 777-27A0123, Revision 1, dated January 16, 2023, which is referred to in Boeing Alert Requirements Bulletin 777-27A0123 RB, Revision 1, dated January 16, 2023. (h) Exception to Service Information Specifications Where the Compliance Time columns of the tables in the "Compliance" paragraph of Boeing Alert Requirements Bulletin 777-27A0123 RB, Revision 1, dated January 16, 2023, use the phrase "the original issue date of Requirements Bulletin 777-27A0123 RB," this AD requires using "the effective date of this AD." (i) Credit for Previous Actions This paragraph provides credit for the actions specified in paragraph (g) of this AD, if those actions were performed before the effective date of this AD using Boeing Alert Requirements Bulletin 777-27A0123 RB, dated October 11, 2021. (j) Parts Installation Limitation As of the effective date of this AD, no person may install, on any airplane, an affected TE flap transmission or gearbox assembly, as identified in Appendix J of Boeing Alert Requirements Bulletin 777-27A0123 RB, Revision 1, dated January 16, 2023, unless the assembly has been inspected and all applicable corrective actions have been performed in accordance with Boeing Alert Requirements Bulletin 777-27A0123 RB, Revision 1, dated January 16, 2023. Affected TE flap transmission or gearbox assemblies on which, prior to the effective date of this AD, the inspection and all applicable corrective actions have been performed as specified in Boeing Alert Requirements Bulletin 777-27A0123 RB, dated October 11, 2021, are acceptable for installation. (k) 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 (l) of this AD. Information may be emailed to: [email protected]. (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. (l) Related Information For more information about this AD, contact Anthony Caldejon, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; telephone: 206-231-3534; email: [email protected]. (m) 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 the AD specifies otherwise. (i) Boeing Alert Requirements Bulletin 777-27A0123 RB, Revision 1, dated January 16, 2023. (ii) [Reserved] (3) For service information 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 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 service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, [email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html. Issued on October 19, 2023. Caitlin Locke, Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2023-25046 Filed 11-9-23; 8:45 am]BILLING CODE 4910-13-P