2023-03-15: Air conditioning

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) 2021-07-09, Amendment 39-21486 (86 FR 17899, April 7, 2021); and b. Adding the following new AD: 2023-03-15 The Boeing Company: Amendment 39-22340; Docket No. FAA-2022-1058; Project Identifier AD-2022-00256-T. (a) Effective Date This airworthiness directive (AD) is effective April 14, 2023. (b) Affected ADs This AD replaces AD 2021-07-09, Amendment 39-21486 (86 FR 17899, April 7, 2021) (AD 2021-07-09). (c) Applicability This AD applies to The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes, certificated in any category, as identified in Boeing Alert Requirements Bulletin 747-21A2577 RB, Revision 2, dated February 10, 2023. (d) Subject Air Transport Association (ATA) of America Code: 21, Air conditioning. (e) Unsafe Condition This AD was prompted by reports of sealant deteriorating on the outside of the center wing fuel tank and analysis showing that sealant could deteriorate inside the fuel tank due to excess heat from trim air diffuser ducts or sidewall riser duct assemblies (collectively referred to as TADDs), and by the determination that existing requirements do not adequately address the unsafe condition. The FAA is issuing this AD to address potential hot air leakage from original fiberglass fabric material or high temperature composite material TADDs that can cause damage to the center wing fuel tank secondary fuel barrier coating and primary sealant, which can cause fuel leakage into an ignition zone, possibly resulting in a fire or explosion. (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 747-21A2577 RB, Revision 2, dated February 10, 2023, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 747-21A2577 RB, Revision 2, dated February 10, 2023. Note 1 to paragraph (g): Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin 747-21A2577, Revision 2, dated February 10, 2023, which is referred to in Boeing Alert Requirements Bulletin 747-21A2577 RB, Revision 2, dated February 10, 2023. (h) Exceptions to Service Information Specifications (1) Where the Compliance Time column of the tables in the "Compliance" paragraph of Boeing Alert Requirements Bulletin 747-21A2577 RB, Revision 2, dated February 10, 2023, uses the phrase "the Revision 1 date of Requirements Bulletin 747-21A2577 RB," this AD requires using "the effective date of this AD." (2) Where Boeing Alert Requirements Bulletin 747-21A2577 RB, Revision 2, dated February 10, 2023, specifies contacting Boeing for repair instructions: This AD requires doing the repair before further flight using a method approved in accordance with the procedures specified in paragraph (k) of this AD. (i) Parts Installation Prohibition As of the effective date of this AD, no person may install an original fiberglass fabric material TADD assembly, having a part number listed in Appendix A of Boeing Alert Requirements Bulletin 747-21A2577 RB, Revision 2, dated February 10, 2023, on any airplane. (j) 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 the service information identified in paragraph (j)(1) or (2) of this AD. (1) Boeing Alert Requirements Bulletin 747-21A2577 RB, dated February 18, 2020, which was incorporated by reference in AD 2021-07-09. (2) Boeing Alert Requirements Bulletin 747-21A2577 RB, Revision 1, dated March 9, 2022, which is not incorporated by reference in this AD. (k) Alternative Methods of Compliance (AMOCs) (1) The Manager, Seattle ACO 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, Seattle ACO 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 2021-07-09 are approved as AMOCs for the corresponding provisions of Boeing Alert Requirements Bulletin 747-21A2577 RB, Revision 2, dated February 10, 2023, that are required by paragraph (g) of this AD. (l) Related Information For more information about this AD, contact Nicole S. Tsang, Aerospace Engineer, Cabin Safety and Environmental Systems Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3959; 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 747-21A2577 RB, Revision 2, dated February 10, 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; internet myboeingfleet.com . You may view this referenced 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. (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 [email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html. Issued on February 25, 2023. Christina Underwood, Acting Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2023-04848 Filed 3-9-23; 8:45 am]BILLING CODE 4910-13-P