AD 2017-17-06

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-300, -400, and -500 series airplanes. This AD was prompted by a report of fatigue cracking found in a certain fuselage frame common to the water tank support intercostal clip located between certain stringers. This AD requires inspections for any cracking of a certain fuselage frame, and repair if necessary. 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((Page 39513)) \n\nSec. 39.13 (Amended) \n\n0 2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD): \n\n2017-17-06 The Boeing Company: Amendment 39-18996; Docket No. FAA- 2017-0131; Product Identifier 2016-NM-186-AD. \n\n(a) Effective Date \n\n\n\tThis AD is effective September 25, 2017. \n\n(b) Affected ADs \n\n\n\tNone. \n\n(c) Applicability \n\n\n\t(1) This AD applies to The Boeing Company Model 737-300, -400, and -500 series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 737-53A1357, dated August 9, 2016. \n\t(2) Installation of Supplemental Type Certificate (STC) ST01219SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/ rgstc.nsf/0/ebd1cec7b301293e86257cb30045557a/$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 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 of fatigue cracking found in a certain fuselage frame common to the water tank support intercostal clip located between certain stringers. We are issuing this AD to detect and correct cracking, which could grow in size and result in a severed frame. Multiple adjacent severed frames would result in reduced structural integrity 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) InspectionBefore the accumulation of 34,000 total flight cycles or within 6,000 flight cycles after the effective date of this AD, whichever occurs later, do a high frequency eddy current (HFEC) inspection for any cracking in the fuselage frame at station (STA) 947.5 common to the water tank support intercostal clip located between stringers S- 24R and S-25R, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1357, dated August 9, 2016. \n\t(1) If no cracking is found, repeat the inspection thereafter at intervals not to exceed 12,000 flight cycles. \n\t(2) If any cracking is found: Before further flight, repair in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1357, dated August 9, 2016. \n\n(h) Terminating Action \n\n\n\tAccomplishing the repair in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1357, dated August 9, 2016, terminates the inspection requirements of paragraph (g) of this AD. \n\n(i) 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 (j) 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\t(4) For service information that contains steps that are labeled as Required for Compliance (RC), the provisions of paragraphs (i)(4)(i) and (i)(4)(ii) of this AD apply. \n\t(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. \n\t(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 ofan 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. \n\n(j) Related Information \n\n\n\tFor more information about this AD, contact Galib Abumeri, Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627- 5324; fax: 562-627-5210; email: galib.abumeri@faa.gov. \n\n(k) 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 737-53A1357, dated August 9, 2016. \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, 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 737-300, -400, and -500 series airplanes. The NPRM published in the Federal Register on March 23, 2017 (82 FR 14835). The NPRM was prompted by a report of fatigue cracking found in a certain fuselage frame common to the water tank support intercostal clip located between certain stringers. The NPRM proposed to require inspections for any cracking of a certain fuselage frame, and repair if necessary. We are issuing this AD to detect and correct fatigue cracking that could grow in size and result in a severed frame. Multiple adjacent severed frames would result in reduced structural integrity of the airplane. \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 NPRM and the FAA's \n\n((Page 39512)) \n\nresponse to each comment. Boeing supported the NPRM. \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 concur with the commenter. We have redesignated paragraph (c) of the proposed AD as paragraph (c)(1) 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\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 change 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 correcting the 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 Service Bulletin 737-53A1357, dated August 9, 2016. The service information describes procedures for inspections for any cracking of a certain fuselage frame, and repair if necessary. This service information is reasonably available because the interested parties have 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 140 airplanes of U.S. registry. We estimate the following costs to comply with this AD: \n\n\n\tEstimated Costs -------------------------------------------------------------------------------------------------------------------------------------------------------- \n\tAction Labor cost Parts cost Cost per product Cost on U.S. operators -------------------------------------------------------------------------------------------------------------------------------------------------------- Inspection........................ 2 work-hours x $85 per $0 $170 per inspection $23,800 per inspection cycle. \n\thour = $170 per. cycle. \n\tinspection cycle.......... -------------------------------------------------------------------------------------------------------------------------------------------------------- \n\n\n\tWe estimate the following costs to do any necessary repairs that would be required based on the results of the inspection. We have no way of determining the number of aircraft that might needthis repair: \n\n\n\tOn-Condition Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost per \n\tAction Labor cost Parts cost product ---------------------------------------------------------------------------------------------------------------- Repair..................................... 18 work-hours x $85 per hour = $100 $1,630 \n\t$1,530. ---------------------------------------------------------------------------------------------------------------- \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, but during this transition period, the Executive Director has delegated the authority to issue ADs applicable to transport category airplanes 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 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.