2023-17-14: Wings

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) 2022-18-11, Amendment 39-22162 (87 FR 58259, September 26, 2022); and b. Adding the following new AD: 2023-17-14 The Boeing Company: Amendment 39-22541; Docket No. FAA-2023-1814; Project Identifier AD-2023-00773-T. (a) Effective Date This airworthiness directive (AD) is effective September 15, 2023. (b) Affected ADs This AD replaces AD 2022-18-11, Amendment 39-22162 (87 FR 58259, September 26, 2022) (AD 2022-18-11). (c) Applicability This AD applies to all The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series airplanes, certificated in any category, excluding the airplanes identified in paragraphs (c)(1) and (2) of this AD. (1) Boeing Model 777-200 series airplanes having a maximum taxi weight equal to or less than 547,000 pounds. (2) Boeing Model 777F series airplanes with manufacturer line numbers of 1743 and subsequent. (d) Subject Air Transport Association (ATA) of America Code 57, Wings. (e) Unsafe Condition This AD was prompted by a report of a crack found in a front spar lower chord undergoing an underwing longeron replacement, and the determination that AD 2022-18-11 did not specify the appropriate thickness for the application of cap seals to fasteners penetrating the center wing fuel tank. The FAA is issuing this AD to detect and correct such cracking, which in combination with cracking in the front spar web, could result in a fuel leak and fire hazard. In addition, cap seals applied below the necessary thickness may fail to contain a spark resulting from a lightning strike, possibly resulting in a fuel tank explosion. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Retained Required Actions, With No Changes This paragraph restates the requirements of paragraph (g) of AD 2022-18-11, with no changes. Except as specified by paragraph (h) of this AD: At the applicable times specified in the "Compliance" paragraph of Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021. Actions identified as terminating action in Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021, terminate the applicable required actions of this AD, provided the terminating action is done in accordance with the Accomplishment Instructions of Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021. Note 1 to paragraph (g): Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin 777-57A0122, dated October 8, 2021, which is referred to in Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021. (h) Exceptions to Service Information Specifications (1) Where the Compliance Time columns of the tables in the "Compliance" paragraph of Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021, use the phrase "the original issue date of Requirements Bulletin 777-57A0122 RB," this AD requires replacing those words with "October 31, 2022, the effective date of AD 2022-18-11." (2) Where Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021, specifies contacting Boeing for repair instructions: This AD requires repair using a method approved in accordance with the procedures specified in paragraph (j) of this AD. (3) Where the "Compliance" paragraph of Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021, uses the phrase "Tables 1 through 50," this AD requires replacing those words with "Tables 1 through 54." (4) During application of any cap seal to a fastener, fastener head, and fastener threads and collars, as required by this AD, the cap seal must be applied with a thickness equal to or greater than the dimensions specified in figure 1 to paragraph (h)(4) of this AD. Figure 1 to paragraph (h)(4) - Cap seal minimum thickness (all dimensions in inches) ER31AU23.000 (5) Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021, does not require the application of cap seals to underwing longeron fasteners, fastener heads, and fastener threads and collars for the airplane groups and configurations identified in paragraphs (h)(5)(i) through (iv) of this AD. For those airplane groups and configurations, however, this AD requires application of a cap seal to the underwing longeron fasteners at the locations identified in Figures 81 and 144 of Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021, during installation of the underwing longeron. (i) Groups 7 and 8, Configurations 5 through 8, on the left side. (ii) Group 9, Configurations 1 and 2, on the left side. (iii) Groups 7 and 8, Configurations 2, 6, 10, and 14, on the right side. (iv) Group 9, Configurations 1 and 3, on the right side. (6) Where Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021, requires inspections that may require the removal of fastener cap seals, this AD requires that if the cap seal is removed, a cap seal of BMS 5-45 sealant be reapplied with a thickness equal to or greater than the dimensions specified in figure 1 to paragraph (h)(4) of this AD before further flight after completion of the inspection. (7) The Effectivity of Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021, does not include Boeing Model 777F series airplanes having line numbers 1713, 1717, 1720, and 1724 through 1742 inclusive. However, for those airplanes, this AD requires accomplishment of the applicable actions specified in the Boeing Alert Requirements Bulletin for Group 6. (i) Actions for Previously Modified Airplanes For airplanes on which the applicable actions of Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021, have been accomplished before the effective date of this AD: Within 30 days after the effective date of this AD, review the maintenance records to determine the procedures used to apply cap seals during accomplishment of the actions in Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021. (1) If all of the conditions specified in paragraphs (i)(1)(i) through (iii) of this AD are met, no further work is required by paragraph (i) of this AD. (i) If the underwing longeron was removed for any reason during accomplishment of the actions in Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021, a cap seal was applied to the underwing longeron fasteners, fastener threads, and fastener collars at the locations identified in Figures 81 and 144 of Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021, during installation. (ii) All cap seals were applied using procedures with thickness dimensions greater than or equal to those given in figure 1 to paragraph (h)(4) of this AD. (iii) All cap seals that were removed to accomplish any inspection in accordance with Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021, were replaced with cap seals of BMS 5-45 sealant of thickness dimensions greater than or equal to those given in figure 1 to paragraph (h)(4) of this AD. (2) If any cap seal was applied using procedures with thickness dimensions less than those given in figure 1 to paragraph (h)(4) of this AD, or if the maintenance records do not definitively specify the procedures used: At the applicable time specified in paragraph (i)(2)(i) or (ii) of this AD, replace the cap seal in accordance with the Accomplishment Instructions of Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021, using a cap sealing procedure with thickness greater than or equal to the dimensions given in figure 1 to paragraph (h)(4) of this AD. (i) For airplanes equipped with a flammability reduction means approved by the FAA as compliant with the fuel tank flammability reduction (FTFR) requirements of 14 CFR 25.981(b) or 26.33(c)(1), or an ignition mitigation means approved by the FAA as compliant with the FTFR requirements of 14 CFR 25.981(c) or 26.33(c)(2): Within 180 days after the effective date of this AD, (ii) For airplanes not described in paragraph (i)(2)(i) of this AD: Within 90 days after the effective date of this AD. (3) For any cap seal that was not applied, or for any cap seal that was removed for inspections and not replaced, or if the maintenance records do not definitively specify the procedures used: At the applicable time specified in paragraph (i)(3)(i) or (ii) of this AD, apply a cap seal of BMS 5-45 sealant using an accepted method with thickness greater than or equal to the dimensions given in figure 1 to paragraph (h)(4) of this AD. Note 2 to paragraph (i)(3): Guidance for applying a cap seal can be found in the Boeing Model 777 Aircraft Maintenance Manual section 28-11-00. (i) For airplanes equipped with a flammability reduction means approved by the FAA as compliant with the fuel tank flammability reduction (FTFR) requirements of 14 CFR 25.981(b) or 26.33(c)(1), or an ignition mitigation means approved by the FAA as compliant with the FTFR requirements of 14 CFR 25.981(c) or 26.33(c)(2): Within 180 days after the effective date of this AD. (ii) For airplanes not described in paragraph (i)(3)(i) of this AD: Within 90 days after the effective date of this AD. (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: [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. (4) AMOCs approved for AD 2022-18-11 are approved as AMOCs for the corresponding provisions of Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021, that are required by paragraph (g) of this AD. (k) Related Information For more information about this AD, contact Kevin Nguyen, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3555; email: [email protected]. (l) 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 this AD specifies otherwise. (3) The following service information was approved for IBR on October 31, 2022 (87 FR 58259, dated September 26, 2022). (i) Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021. (ii) [Reserved] (4) 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; internet myboeingfleet.com. (5) 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. (6) 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 [email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html. Issued on August 28, 2023. Victor Wicklund, Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. Issued on August 28, 2023. Victor Wicklund, Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2023-18835 Filed 8-28-23; 4:15 pm]BILLING CODE 4910-13-P