AD 2014-08-08

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-200, -200C, -300, -400, and -500 series airplanes. This AD was prompted by reports of cracking found in the skin at the lower aft corner of the forward entry doorway on airplanes that do not have an airstair door cutout. This AD requires repetitive inspections for cracking in the lower corners of the forward entry doorway on airplanes that do not have an airstair door cutout, and repair if necessary. We are issuing this AD to detect and correct cracking in the lower corners of the forward entry doorway, which could lead to crack progression and consequent rapid decompression of the airplane.

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\n((Page 23908)) \n\n\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\n2014-08-08 The Boeing Company: Amendment 39-17832; Docket No. FAA- 2013-0837; Directorate Identifier 2013-NM-112-AD. \n\n(a) Effective Date \n\n\n\tThis AD is effective June 3, 2014. \n\n(b) Affected ADs \n\n\n\tFor The Boeing Company Model 737-300, -400, and -500 series airplanes: Certain requirements of AD 2008-09-13, Amendment 39-15494 (73 FR 24164, May 2, 2008), may be affected by certain requirements of this AD. \n\n(c) Applicability \n\n\n\t(1) This AD applies to The Boeing Company Model 737-200, -200C, -300, -400, and -500 series airplanes, certificated in any category, without an airstair door cutout, as identified in Boeing Alert Service Bulletin 737-53A1329, dated June 4, 2013. \n\t(2) Installation of Supplemental Type Certificate (STC) ST01219SE (http://rgl.faa.gov/Regulatory--and--Guidance--Library/ rgstc.nsf/0/be866b732f6cf31086257b9700692796/$FILE/ST01219SE.pdf) 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 section 39.17 of the Federal Aviation Regulations (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 reports of cracking found in the skin at the lower aft corner of the forward entry doorway on airplanes that do not have an airstair door cutout. We are issuing this AD to detect and correct cracking in the lower corners of the forward entry doorway, which could lead to crack progression and consequent rapid decompression of the airplane. \n\n(f) Compliance \n\n\n\tComply with this AD within the compliance times specified, unless already done. \n\n(g) Repetitive Inspections \n\n\n\tExcept as provided by paragraph (i)(1) of this AD, at the applicable times specified in paragraph 1.E., ''Compliance,'' of Boeing Alert Service Bulletin 737-53A1329, dated June 4, 2013, do the actions specified in paragraph (g)(1) or (g)(2) of this AD, as applicable. \n\t(1) For Group 1 airplanes, as identified in Boeing Alert Service Bulletin 737-53A1329, dated June 4, 2013: Except as provided by paragraph (i)(2) of this AD, inspect the lower corners of the forward entry doorway for cracking, using a method approved in accordance with the procedures specified in paragraph (j) of this AD. \n\t(2) For Group 2 and Group 3 airplanes, as identified in Boeing Alert Service Bulletin 737-53A1329, dated June 4, 2013: At the forward entry doorway lower forward and aft corners, as applicable, do an internal detailed inspection of the skin assembly and bear strap, an internal high frequency eddy current (HFEC) inspection of the bear strap, and external detailed and HFEC inspections of the skin assembly for cracking, in accordance with Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737- 53A1329, dated June 4, 2013. If no cracking is found during any inspection required by this paragraph: Except as provided by paragraph (i)(1) of this AD, repeat the applicable inspections at the applicable time specified in paragraph 1.E., ''Compliance,'' of Boeing Alert Service Bulletin 737-53A1329, dated June 4, 2013. \n\n(h) Repair \n\n\n\t(1) If any cracking is found during any inspection required by paragraph (g) of this AD: For Group 3 airplanes with cracking at the aft lower corner of the forward entry doorway, before further flight, repair in accordance withPart 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1329, dated June 4, 2013. Accomplishment of this repair terminates the initial and repetitive inspections required by this AD in the area common to the repair for Group 3 airplanes only. For all other cracking found, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (j) of this AD. \n\t(2) Installation of a repair approved in accordance with paragraph (j) of this AD terminates the repetitive inspections required by this AD for the repaired area only. \n\n(i) Exceptions to Service Information Specifications \n\n\n\t(1) Where Boeing Alert Service Bulletin 737-53A1329, dated June 4, 2013, specifies a compliance time ''after the original issue date of this service bulletin,'' this AD requires compliance within the specified compliance time after the effective date of this AD. \n\t(2) Although Boeing Alert Service Bulletin 737-53A1329, dated June 4, 2013, specifies contacting Boeing for information on certain inspections and repairs, this AD requires that those actions be done by 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, Seattle Aircraft Certification Office (ACO), 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 ACO, send it to the attention of the person identified in paragraph (k) of this AD. Information may be emailed to: 9-ANM-Seattle-ACO-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 holdingdistrict office. \n\t(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD if it is approved by The Boeing Commercial Airplanes Organization Designation Authorization that has been authorized by the Manager, Seattle ACO to make those findings. For a repair method to be approved, the repair 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 Alan Pohl, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6450; fax: 425-917-6590; email: alan.pohl@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 Service Bulletin 737-53A1329, dated June 4, 2013. \n\t(ii) Reserved. \n\t(3) For The Boeing Company service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, WA 98124- 2207; telephone 206-544-5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. \n\t(4) You may view this service information at FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425-227-1221. \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 737-200, -200C, -300, -400, and -500 series airplanes. The NPRM published in the Federal Register on October 2, 2013 (78 FR 60807). The NPRM was prompted by reports of cracking found in the skin at the lower aft corner of the forward entry doorway on airplanes that do not have an airstair door cutout. The NPRM proposed to require repetitive inspections for cracking in the lower corners of the forward entry doorway on airplanes that do not have an airstair door cutout, and repair if necessary. We are issuing this AD to detect and correct cracking in the lower corners of the forward entry doorway, which could lead to crack progression and consequent rapid decompression of the airplane. \n\nComments \n\n\n\tWe gave the public the opportunity to participate in developing this AD. The following presentsthe comments received on the proposal (78 FR 60807, October 2, 2013) and the FAA's response to each comment. \n\nSupport for the Proposed Requirements \n\n\n\tBoeing stated that it concurs with the proposed requirements. \n\nStatement Regarding Effect of Winglets on Accomplishment of AD Requirements \n\n\n\tAviation Partners Boeing stated that the installation of winglets per APB Supplemental Type Certificate (STC) ST01219SE (http:// rgl.faa.gov/Regulatory--and--Guidance--Library/rgstc.nsf/0/ be866b732f6cf31086257b9700692796/$FILE/ST01219SE.pdf) does not affect the accomplishment of the manufacturer's service instructions. \n\tWe agree. We have redesignated paragraph (c) of the NPRM (78 FR 60807, October 2, 2013) as paragraph (c)(1) and added paragraph (c)(2) to this final rule to state that installation of APB STC ST01219SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/ be866b732f6cf31086257b9700692796/$FILE/ST01219SE.pdf) does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which APB STC ST01219SE is installed, a ''change in product'' alternative method of compliance (AMOC) approval request is not necessary to comply with the requirements of section 39.17 of the Federal Aviation Regulations (14 CFR 39.17). \n\nRequest To Allow Credit for Previously Accomplished Repairs \n\n\n\tAlaska Airlines (ASA) requested that we revise the NPRM (78 FR 60807, October 2, 2013) to allow credit for previously accomplished repairs. ASA stated that it has already installed repairs in the specified area using FAA- and Boeing-approved data on some of its airplanes. ASA did not provide details for any specific repair. \n\tWe do not agree to allow credit for unspecified repairs. ASA did not provide criteria for evaluating existing repairs or for demonstrating how such repairs would comply with the requirements of this AD. However, once we issue this AD, any person may request approval of an existing repair as an AMOC under the provisions of paragraph (j) of this AD. We have not changed this final rule in this regard. \n\nRequest To Allow Certain Terminating Repairs for Certain Airplanes \n\n\n\tSouthwest Airlines (SWA) requested that certain structural repairs specified in Part 2 of the Work Instructions of Boeing Alert Service Bulletin 737-53A1329, dated June 4, 2013, terminate both the initial and repetitive inspections required by paragraph (g) of the NPRM (78 FR 60807, October 2, 2013). SWA pointed out that Boeing \n\n((Page 23907)) \n\nAlert Service Bulletin 737-53A1329, dated June 4, 2013, states that certain repairs provided in Part 2 of the Work Instructions terminate both the initial and the repetitive inspections specified in that service bulletin for Group 3 airplanes. \n\tWe agree that the structural repairs specified in Part 2 of the Work Instructions of Boeing Alert Service Bulletin 737-53A1329, dated June 4, 2013, terminate both the initial and repetitive inspections required for Group 3 airplanes identified in that service bulletin. We have revised paragraph (h) of this final rule to specify that both the initial and repetitive inspections are terminated by the specified repairs for Group 3 airplanes. \n\nRequest To Consider Certain STC Modifications as an AMOC With This AD \n\n\n\tASA requested that modifications per STC ST03387AT (http:// rgl.faa.gov/Regulatory--and--Guidance--Library/rgstc.nsf/0/ bd126e373ba4c5da86257a79006f31bf/$FILE/ST03387AT.pdf) and STC SA2969SO (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/ 2a10f5d4090a534686257a79006f0f97/$FILE/SA2969SO.pdf) be considered as an AMOC for the requirements of this AD. ASA noted that it has passenger/cargo configured airplanes that have been modified per these STCs. \n\tWe disagree with the commenter's request. ASA did not demonstrate how these modifications would address the identified unsafe condition. We also need to clarify the AMOC process. AMOCs provide an alternative method of compliance to themethods required to be used in the associated AD. An AMOC is issued only after an AD has been issued and only after data are provided to show that the proposed solution is complete and addresses the unsafe condition. However, once we issue this AD, any person may request approval of an AMOC under the provisions of paragraph (j) of this AD. \n\nRequest To Delegate Repair Approval Authority to the Manufacturer \n\n\n\tSWA requested that AMOC authority be granted to the manufacturer for existing repairs approved previously using FAA Form 8100-9, ''Statement of Compliance with Airworthiness Standards.'' SWA provided no justification for this request. \n\tWe do not agree that a change to this final rule is necessary in this regard. Paragraph (j)(3) of this AD already delegates the authority to approve an AMOC for any repair required by this AD to the Boeing Commercial Airplanes Organization Designation Authorization, as long as the repair meets the certification basis of the airplane and theapproval specifically refers to this AD. We have made no change to this final rule in this regard. \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 AD 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 (78 FR 60807, October 2, 2013) for correcting the unsafe condition; and \n\tDo not add any additional burden upon the public than was already proposed in the NPRM (78 FR 60807, October 2, 2013). \n\nCosts of Compliance \n\n\n\tWe estimate that this AD affects 376 airplanes of U.S. registry. \n\tWe estimate the following costs to comply with this AD: \n\n\n\tEstimated Costs ---------------------------------------------------------------------------------------------------------------- \n\tParts Cost on U.S. \n\tActionLabor cost cost Cost per product operators ---------------------------------------------------------------------------------------------------------------- Inspection of the lower corners of 5 work-hours x $85 $0 $425, per inspection $159,800, per \n\tthe forward entry doorway (Groups per hour = $425, per cycle. inspection cycle. \n\t2 and 3 airplanes) \1\. inspection cycle. ---------------------------------------------------------------------------------------------------------------- \1\ We have received no definitive data that would enable us to provide cost estimates for the inspection on \n\tGroup 1 airplanes. \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. SubtitleI, 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\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 the Regulatory Flexibility Act. \n\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.