AD 2012-23-08

We are superseding an existing airworthiness directive (AD) for certain The Boeing Company Model 737-600, -700, -700C, -800, and - 900 series airplanes. That AD currently requires replacing the drain tube assemblies and support clamps on the aft fairing of the engine struts. This new AD requires replacing the drain tube assembly of the left and right engine strut aft fairings with a new one, which includes an integral support clamp made of nickel alloy 625. This AD also adds airplanes to the applicability. This AD was prompted by a report of a broken drain tube assembly on the left engine strut at the clamp support location under the aft fairing compartment, inside the heat shield cavity of the aft fairing. There have also been reports of tube wear at this clamp location on additional airplanes. We are issuing this AD to prevent failure of the drain tube assemblies and clamps on the aft fairings of the engine struts. Such failure could allow leaked flammable fluids in the drain systems to discharge onto the heat shields of the aft fairings of the engine struts, which could result in an undetected and uncontrollable fire.

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\nSec. 39.13 (Amended) \n\n0 2. The FAA amends Sec. 39.13 by removing airworthiness directive (AD) 2008-08-24, Amendment 39-15478 (73 FR 21242, April 21, 2008), and adding the following new AD: \n\n2012-23-08 The Boeing Company: Amendment 39-17264; Docket No. FAA- 2012-0591; Directorate Identifier 2012-NM-015-AD. \n\n(a) Effective Date \n\n\n\tThis airworthiness directive (AD) is effective December 31, 2012. \n\n(b) Affected ADs \n\n\n\tThis AD supersedes AD 2008-08-24, Amendment 39-15478 (73 FR 21242, April 21, 2008). \n\n(c) Applicability \n\n\n\t(1) This AD applies to The Boeing Company Model 737-600, -700, - 700C, -800, -900, and -900ER series airplanes, certificated in any category, as identified in Boeing Special Attention Service Bulletin 737-54-1043, Revision 2, dated November 4, 2011. \n\t(2) Supplemental Type Certificate (STC) ST00830SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/408E012E008616A7862578880060456C?OpenDocument&Highlight=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. For all other AMOC requests, the operator must request approval for an AMOC in accordance with the procedures specified in paragraph (h) of this AD. \n\n(d) Subject \n\n\n\tJoint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 54, Nacelles/pylons. \n\n(e) Unsafe Condition \n\n\n\tThis AD was prompted by a report of a broken drain tube assembly on the aft fairing of the left engine strut at the clamp support location under the aft fairing compartment, inside the heat shield cavity of the aft fairing. There have also been reports of tube wear at the clamp location on additional airplanes. We are issuing this AD to prevent failure of the drain tube assemblies and clamps on the aft fairings of the engine struts. Such failure could allow leaked flammable fluids in the drain systems to discharge onto the heat shields of the aft fairings of the engine struts, which could result in an undetected and uncontrollable fire. \n\n(f) Compliance \n\n\n\tComply with this AD within the compliance times specified, unless already done. \n\n(g) Replacement \n\n\n\tWithin 60 months after the effective date of this AD, replace the drain tube assemblies and support clamps on the aft fairing of the struts of engines 1 and 2 with new drain tube assemblies and clamps, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-54-1043, Revision 2, dated November 4, 2011. \n\n((Page 70360)) \n\n(h) 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 the Related Information section 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 holding district office. \n\t(3) AMOCs approved previously in accordance with AD 2008-08-24, Amendment 39-15478 (73 FR 21242, April 21, 2008), are not approved as AMOCs with thisAD. \n\n(i) Related Information \n\n\n\tFor more information about this AD, contact Ansel James, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6497; fax: 425-917-6590; email: ansel.james@faa.gov. \n\n(j) 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 Special Attention Service Bulletin 737-54-1043, Revision 2, dated November 4, 2011. \n\t(ii) Reserved. \n\t(3) For 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 \n\tDirectorate, 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 to supersede AD 2008-08-24, Amendment 39-15478 (73 FR 21242, April 21, 2008). That AD applies to the specified products. The NPRM published in the Federal Register on June 12, 2012 (77 FR 34879). That NPRM proposed to require replacing the drain tube assembly of the left and right engine strut aft fairings with a new one which includes an integral support clamp made of nickel alloy 625. That NPRM also proposed to add airplanes to the applicability. \n\nComments \n\n\n\tWe gave the public the opportunity to participate in developing this AD. The following presents the comments received on the proposal (77 FR 34879, June 12, 2012) and the FAA's response to each comment. \n\nSupport for the NPRM (77 FR 34879, June 12, 2012) \n\n\n\tUnited Airlines supports the 60-month compliance time specified in the NPRM (77 FR 34879, June 12, 2012). \n\nClarification of Effect of Winglet Installation \n\n\n\tAviation Partners Boeing stated that accomplishing the supplemental type certificate (STC) ST00830SE does not affect the actions specified in the NPRM (77 FR 34879, June 12, 2012). \n\tWe concur. We have added new paragraph (c)(2) to this AD, which states that STC ST00830SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/408E012E008616A7862578880060456C?OpenDocument&Highlight=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 section 39.17 of the Federal Aviation Regulations. For all other AMOC requests, the operator must request approval for an AMOC in accordance with the procedures specified in paragraph (h) of this AD. \n\nRequest To Extend Compliance Time \n\n\n\tAmerican Airlines (AAL) requested that thecompliance time specified in paragraph (g) of the NPRM (77 FR 34879, June 12, 2012) be extended from 60 to 72 months. AAL stated that the routine maintenance schedule does not allow for accomplishment of the replacements during the proposed compliance time. AAL stated that the compliance time could be extended for all airplanes without jeopardizing aviation safety. \n\tWe disagree with the request to change the compliance time. In developing an appropriate compliance time for this AD, we considered not only the safety implications, but the manufacturer's recommendations, the availability of required parts, and the practical aspect of accomplishing the actions within an interval of time that corresponds to typical scheduled maintenance for affected operators. Under the provisions of paragraph (h) of the final rule, however, we may consider requests for adjustments to the compliance time if data are submitted to substantiate that such adjustments would provide an acceptable level of safety. No change has been made to this AD in this regard. \n\nRequest To Revise Paragraph (f) of the NPRM (77 FR 34879, June 12, 2012) To Include Terminating Action \n\n\n\tAAL requested that we revise paragraph (f) of the NPRM (77 FR 34879, June 12, 2012) to state that accomplishment of Boeing Special Attention Service Bulletin 737-54-1043, Revision 2, dated November 4, 2011, constitutes a terminating action for the specified unsafe condition and that no further action is required. \n\tWe disagree with the request to revise paragraph (f) of the NPRM (77 FR 34879, June 12, 2012). The action required by paragraph (g) of this AD, which is specified in the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-54-1043, Revision 2, dated November 4, 2011, is the only action required by this AD. If operators have previously accomplished the actions specified in Boeing Special Attention Service Bulletin 737-54-1043, Revision 2, dated November 4, 2011, they are in compliance with the AD, as specified in paragraph (f) of this AD. No change has been made to this AD in this regard. \n\nRequest To Clarify Conflicting AMOC Statements \n\n\n\tAlaska Airlines (ASA) requested clarification regarding conflicting AMOC statements. ASA stated that paragraph (h)(3) of the NPRM (77 FR 34879, June 12, 2012) does not allow AMOCs approved for AD 2008-08-24, Amendment 39-15478 (73 FR 21242, April 21, 2008), to be used for the actions proposed in the NPRM. However, ASA pointed out that Boeing Special Attention Service Bulletin 737-54-1043, Revision 2, dated November 4, 2011, states that it is an approved AMOC for paragraphs (f) and (h) of AD 2008-08-24. ASA also requested credit for actions done previously using Boeing Special Attention Service Bulletin 737-54-1043, Revision 2, dated November 4, 2011. \n\tWe agree to clarify. Paragraph 1.F., ''Approval,'' of Boeing Special Attention Service Bulletin 737-54-1043, Revision 2, dated November 4, 2011, states that the actions specified in that service bulletin are approved as an AMOC for paragraphs (f) and (h) of AD 2008- 08-24, Amendment 39-15478 (73 FR 21242, April 21, 2008). That AMOC approval allows operators to use Boeing Special Attention Service Bulletin 737-54-1043, Revision 2, dated November 4, 2011, to comply with AD 2008-08-24. However, on the effective date of this AD, AD 2008- 08-24 will be superseded (i.e., will no longer exist), and the fact that Boeing Special Attention Service Bulletin 737-54-1043, Revision 2, dated November 4, 2011, refers to AD 2008-08-24 will be moot. This AD requires the accomplishment of the actions of that service bulletin as the primary means of compliance with this AD, and not as an AMOC. \n\tThe intent of paragraph (h)(3) of this AD is to prevent the use of any AMOC for AD 2008-08-24, Amendment 39-15478 (73 FR 21242, April 21, 2008), as an AMOC for this new AD. This new AD requires accomplishment of Boeing Special Attention Service Bulletin 737-54-1043, Revision 2, datedNovember 4, 2011. No credit is given for Boeing Special Attention Service Bulletin 737-54-1043, Revision 1, dated October 19, \n\n((Page 70359)) \n\n2009; or Boeing Special Attention Service Bulletin 737-54-1043, dated May 2, 2007; because additional work is necessary for airplanes on which Boeing Special Attention Service Bulletin 737-54-1043, Revision 1, dated October 19, 2009; or Boeing Special Attention Service Bulletin 737-54-1043, dated May 2, 2007; was accomplished. No change has been made to this AD 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 the 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 (77 FR 34879, June 12, 2012) for correcting the unsafe condition; and \n\tDo not add any additional burden upon the public than was already proposed in the NPRM (77 FR 34879, June 12, 2012). \n\nCosts of Compliance \n\n\n\tWe estimate that this AD affects 1,098 airplanes of U.S. registry. \n\tWe estimate the following costs to comply with this AD: \n\n\n\tEstimated costs ---------------------------------------------------------------------------------------------------------------- \n\tCost per Cost on U.S. \n\tAction Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Replacement........................... 14 work-hours x $85 per $12,326 $13,516 $14,840,568 \n\thour = $1,190. ---------------------------------------------------------------------------------------------------------------- \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, Section106, 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\tWe have determined that this 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.