2021-21-09: Fuselage

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) 2005-05-18, Amendment 39-14007 (70 FR 12410, March 14, 2005); and b. Adding the following new AD: 2021-21-09 The Boeing Company: Amendment 39-21769; Docket No. FAA-2021-0503; Project Identifier AD-2021-00163-T. (a) Effective Date This airworthiness directive (AD) is effective December 13, 2021. (b) Affected ADs This AD replaces AD 2005-05-18, Amendment 39-14007 (70 FR 12410, March 14, 2005) (AD 2005-05-18). (c) Applicability (1) This AD applies to The Boeing Company Model 737-600, -700, -700C, -800, and -900 series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 737-53A1251, Revision 2, dated January 20, 2021. (2) Installation of Supplemental Type Certificate (STC) ST00830SE does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST00830SE is installed, a "change in product" alternative method of compliance (AMOC) approval request is not necessary to comply with the requirements of 14 CFR 39.17. (d) Subject Air Transport Association (ATA) of America Code 53, Fuselage. (e) Unsafe Condition This AD was prompted by a report of cracks found at several of the fastener rows in the web lap splices at the dome apex of the aft pressure bulkhead, and the determination that airplanes not affected by AD 2005-05-18 are subject to this unsafe condition. The FAA is issuing this AD to address fatigue cracks in the webs of the aft pressure bulkhead, which could result in rapid decompression of the airplane. (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 Service Bulletin 737-53A1251 Revision 2, dated January 20, 2021, do all applicable actions identified as "RC" (required for compliance) in, and in accordance with, the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1251, Revision 2, dated January 20, 2021. For Group 1 airplanes, as defined in Boeing Alert Service Bulletin 737-53A1251, Revision 2, dated January 20, 2021: Step 3.B.2. of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1251, Revision 2, dated January 20, 2021, is an RC step, and the provisions of paragraphs (j)(5)(i) and (ii) of this AD apply. (h) Exceptions to Service Information Specifications (1) Where Boeing Alert Service Bulletin 737-53A1251, Revision 2, dated January 20, 2021, uses the phrase "the Revision 1 date of this service bulletin," this AD requires using "the effective date of this AD." (2) Where Boeing Alert Service Bulletin 737-53A1251, Revision 2, dated January 20, 2021, specifies contacting Boeing for repair instructions or for alternative inspections: This AD requires doing the repair, or doing the alternative inspections and applicable on-condition actions using a method approved in accordance with the procedures specified in paragraph (j) of this AD. (i) Credit for Previous Actions (1) For airplanes having line numbers 1 through 1166 inclusive: This paragraph provides credit for the corresponding actions of Boeing Alert Service Bulletin 737-53A1251, Revision 2, dated January 20, 2021, that are required by paragraph (g) of this AD, if those actions were performed before the effective date of this AD using Boeing Service Bulletin 737-53-1251, dated June 3, 2004, which was incorporated by reference in AD 2005-05-18. (2) This paragraph provides credit for the corresponding actions of Boeing Alert Service Bulletin 737-53A1251, Revision 2, dated January 20, 2021, that are required by paragraph (g) of this AD, if those actions were performed before the effective date of this AD using Boeing Alert Service Bulletin 737-53A1251, Revision 1, dated September 22, 2020, which is not incorporated by reference in this AD. (j) 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 (k)(1) 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 2005-05-18 are approved as AMOCs for the corresponding provisions of Boeing Alert Service Bulletin 737-53A1251, Revision 2, dated January 20, 2021, that are required by paragraph (g) of this AD. (5) Except as specified by paragraph (h) of this AD: For service information that contains steps that are labeled as Required for Compliance (RC), the provisions of paragraphs (j)(5)(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 (1) For more information about this AD, contact Wayne Lockett, Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3524; email: [email protected]. (2) Service information identified in this AD that is not incorporated by reference is available at the addresses specified in paragraphs (l)(3) and (4) of this AD. (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 the AD specifies otherwise. (i) Boeing Alert Service Bulletin 737-53A1251, Revision 2, dated January 20, 2021. (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 https://www.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 [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html. Issued on October 8, 2021. Gaetano A. Sciortino, Deputy Director for Strategic Initiatives, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2021-24225 Filed 11-5-21; 8:45 am]BILLING CODE 4910-13-P