AD 2018-17-23

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This AD was prompted by a report indicating that during a fleet survey on a retired Model 737 airplane, cracking was found common to the number 3 windshield assembly, aft sill web. This AD requires, at certain locations, repetitive high frequency eddy current (HFEC) inspections of the number 3 windshield assembly, aft sill web; and applicable on-condition actions. We are issuing this AD to address the unsafe condition on these products.

Final rule.

Adoption of the Amendment \n\n\n\tAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n0 1. The authority citation for part 39 continues to read as follows: \n\n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n\n\nSec. 39.13 (Amended) \n\n0 2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD): \n\n2018-17-23 The Boeing Company: Amendment 39-19377; Docket No. FAA- 2018-0272; Product Identifier 2018-NM-005-AD. \n\n(a) Effective Date \n\n\n\tThis AD is effective October 4, 2018. \n\n(b) Affected ADs \n\n\n\tNone. \n\n(c) Applicability \n\n\n\t(1) This AD applies to all The Boeing Company Model 737-100, - 200, -200C, -300, -400, and -500 series airplanes, certificated in any category. \n\t(2) Installation of Supplemental Type Certificate (STC) ST01219SE does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST01219SE 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. \n\n(d) Subject \n\n\n\tAir Transport Association (ATA) of America Code 53, Fuselage. \n\n(e) Unsafe Condition \n\n\n\tThis AD was prompted by a report indicating that during a fleet survey on a retired Model 737 airplane, cracking was found common to the number 3 windshield assembly, aft sill web. We are issuing this AD to address such cracking at this location, which could adversely affect the structural integrity of the windshield assembly. \n\n(f) Compliance \n\n\n\tComply with this AD within the compliance times specified, unless already done. \n\n(g) Required Actions for Group 1 Airplanes \n\n\n\tFor airplanes identified as Group 1 in Boeing Alert Requirements Bulletin 737-53A1377 RB, dated December 11, 2017: Within 120 days after the effective date of this AD, do an inspection to correct the unsafe condition, using a method approved in accordance with the procedures specified in paragraph (j) of this AD. \n\n(h) Required Actions for Group 2 Airplanes \n\n\n\tFor airplanes identified as Group 2 in Boeing Alert Requirements Bulletin 737-53A1377 RB, dated December 11, 2017: Except as required by paragraph (i) of this AD, at the applicable times specified in the ''Compliance'' paragraph of Boeing Alert Requirements Bulletin 737-53A1377 RB, dated December 11, 2017, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 737-53A1377 RB, dated December 11, 2017. \n\n\n\tNote 1 to paragraph (h) of this AD: Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin 737-53A1377, dated December 11, 2017, which is referred to in Boeing Alert Requirements Bulletin 737-53A1377 RB, dated December 11, 2017. \n\n(i) Exceptions to Service Information Specifications \n\n\n\t(1) For purposes of determining compliance with the requirements of this AD: Where Boeing Alert Requirements Bulletin 737-53A1377 RB, dated December 11, 2017, uses the phrase ''the original issue date of Requirements Bulletin 737-53A1377 RB,'' this AD requires using ''the effective date of this AD.'' \n\t(2) Where Boeing Alert Requirements Bulletin 737-53A1377 RB, dated December 11, 2017, specifies contacting Boeing for \n\n((Page 44202)) \n\nrepair instructions, this AD requires repair using a method approved in accordance with the procedures specified in paragraph (j) of this AD. \n\n(j) Alternative Methods of Compliance (AMOCs) \n\n\n\t(1) The Manager, Los Angeles 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 local Flight Standards District 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: 9-ANM-LAACO-AMOC-Requests@faa.gov. \n\t(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. \n\t(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 Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Los Angeles ACO Branch, 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. \n\n(k) Related Information \n\n\n\tFor more information about this AD, contact David Truong, Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627- 5224; fax: 562-627-5210; email: david.truong@faa.gov. \n\n(l) Material Incorporated by Reference \n\n\n\t(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. \n\t(2) You must use this service information as applicable to do the actions required by this AD, unless the AD specifies otherwise. \n\t(i) Boeing Alert Requirements Bulletin 737-53A1377 RB, dated December 11, 2017. \n\t(ii) Reserved. \n\t(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. \n\t(4) You may view this service information at the FAA, Transport Standards Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195. \n\t(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, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

Discussion \n\n\n\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. The NPRM published in the Federal Register on April 16, 2018 (83 FR 16243). The NPRM was prompted by a report indicating that during a fleet survey on a retired Model 737 airplane, cracking was found common to the number 3 windshield assembly, aft sill web. The NPRM proposed to require, at certain locations, repetitive HFEC inspections of the number 3 windshield assembly, aft sill web; and applicable on-condition actions. \n\tWe are issuing this AD to address such cracking common to the number 3 windshield assembly, aft sill web, which could adversely affect the structural integrity of the windshield assembly. \n\nComments \n\n\n\tWe gave the public the opportunity to participate in developing this final rule. The following presents the comments received on the NPRM and the FAA's response to each comment. \n\nEffect of Winglets on Accomplishment of the Proposed Actions \n\n\n\tAviation Partners Boeing stated that accomplishing the Supplemental Type Certificate (STC) ST01219SE does not affect the actions specified in the NPRM. \n\tWe agree with the commenter. We have redesignated paragraph (c) of the proposed AD as paragraph (c)(1) of this AD and added paragraph (c)(2) to this AD to state that installation of STC ST01219SE does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST01219SE 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. \n\nRequest To Clarify Inspection Location \n\n\n\tBoeing requested that the language in the ''Related Service Information under 1 CFR part 51'' paragraph be clarified in the proposed AD. Boeing requested that we replace ''repetitive HFEC inspections of the number 3 windshield and of the aft sill web'' with ''repetitive HFEC inspections of the number 3 windshield aft sill web.'' Boeing stated that there is no requirement in Boeing Alert Requirements Bulletin 737-53A1377 RB, dated December 11, 2017, to inspect the windshield with an HFEC inspection. Boeing commented that the only HFEC requirement in Boeing Alert Requirements Bulletin 737- 53A1377 RB, dated December 11, 2017, is to accomplish the HFEC inspections of the number 3 windshield aft sill web. \n\tWe agree with the request to clarify the inspection location, for the reasons provided. We have revised the ''Summary and Related Service Information under 1 CFR part 51'' section, as well as the SUMMARY, of this final rule accordingly. For consistency within this AD and in response to the following Boeing comment, this AD specifies the ''number 3 windshield assembly, aft sill web.'' \n\nRequest To Clarify Location of Cracking \n\n\n\tBoeing requested that weclarify the unsafe condition in paragraph (e) of the NPRM. Boeing requested that we replace the language ''common to the windshield and aft sill web'' with ''common to the number 3 windshield assembly, aft sill web.'' Boeing stated that the cracking in the aft sill web is at the fastener common to the aft sill web and the outer chord of the number 3 windshield assembly and is not actually common to the windshield. \n\tWe agree with the request, for the reasons provided. We have revised paragraph (e) of this AD, as well as the SUMMARY and the Discussion section of this final rule, accordingly. \n\nRequest To Clarify Certain Language in the ''Exceptions to Service Information Specifications'' Paragraph \n\n\n\tBoeing requested that we revise paragraph (i)(2) of the ''Exceptions to Service Information Specifications'' paragraph in the proposed AD. Boeing requested that we replace the language ''specifies contacting Boeing'' with ''specifies contacting Boeing for repair instructions.'' Boeing commented that this addition adds clarity. \n\tWe agree with the request and have revised this AD to clarify the requirements accordingly. \n\nExplanation of Change to Applicability Description \n\n\n\tThe applicability of the proposed AD referred to affected airplanes identified in Boeing Alert Requirements Bulletin 737-53A1377 RB, dated December 11, 2017. The effectivity in the service information is identified in terms of line numbers. Since those line numbers include all airplanes of the affected models, we have revised the applicability in this AD as all Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. \n\nConclusion \n\n\n\tWe reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting this final rule with the changes described previously and minor editorial changes. We have determined that these minor changes: \n\tAre consistent with the intent that was proposed in the NPRM for addressingthe unsafe condition; and \n\tDo not add any additional burden upon the public than was already proposed in the NPRM. \n\tWe also determined that these changes will not increase the economic burden on any operator or increase the scope of this final rule. \n\nRelated Service Information Under 1 CFR Part 51 \n\n\n\tWe reviewed Boeing Alert Requirements Bulletin 737-53A1377 RB, dated December 11, 2017. The service information describes procedures for repetitive HFEC inspections of the number 3 windshield assembly, aft sill web at station 254.6, between stringers S-9 and S-11 on the left- and right-hand sides; and applicable on-condition actions. This service information is reasonably available because the interested parties \n\n((Page 44201)) \n\nhave access to it through their normal course of business or by the means identified in the ADDRESSES section. \n\nCosts of Compliance \n\n\n\tWe estimate that this AD affects 63 airplanes of U.S. registry. We estimate the following costs to complywith this AD: \n\n\n\tEstimated Costs for Required Actions ---------------------------------------------------------------------------------------------------------------- \n\tCost on U.S. \n\tAction Labor cost Parts cost Cost per product operators ---------------------------------------------------------------------------------------------------------------- HFEC inspection................. 4 work-hours x $85 $0 $340 per inspection $21,420 per \n\tper hour = $340 per cycle. inspection cycle. \n\tinspection cycle. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tWe have received no definitive data that would enable us to provide cost estimates for the on-condition actions specified in this AD. \n\nAuthority for This Rulemaking \n\n\n\tTitle 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority. \n\tWe are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: ''General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. \n\tThis AD is issued in accordance with authority delegated by the Executive Director, Aircraft Certification Service, as authorized by FAA Order 8000.51C. In accordance with that order, issuance of ADs is normally a function of the Compliance and Airworthiness Division, butduring this transition period, the Executive Director has delegated the authority to issue ADs applicable to transport category airplanes and associated appliances to the Director of the System Oversight Division. \n\nRegulatory Findings \n\n\n\tThis AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. \n\tFor the reasons discussed above, I certify that this AD: \n\t(1) Is not a ''significant regulatory action'' under Executive Order 12866, \n\t(2) Is not a ''significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), \n\t(3) Will not affect intrastate aviation in Alaska, and \n\t(4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of theRegulatory Flexibility Act. \n\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.