AD 2013-23-16

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 757 airplanes. This AD was prompted by a report of a broken forward support fitting at the inboard track of the inboard flap. This AD requires repetitive inspections of the forward support fitting assemblies of the inboard track of the left and right inboard flaps for cracking, and corrective actions if necessary. We are issuing this AD to detect and correct cracking of the forward support fitting assembly, which could result in loss of inboard flap control and subsequent loss of airplane control.

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\n2013-23-16 The Boeing Company: Amendment 39-17671; Docket No. FAA- 2013-0334; Directorate Identifier 2013-NM-027-AD. \n\n(a) Effective Date \n\n\n\tThis AD is effective December 30, 2013. \n\n(b) Affected ADs \n\n\n\tNone. \n\n(c) Applicability \n\n\n\tThis AD applies to all The Boeing Company Model 757-200, -200PF, -200CB, and -300 series airplanes, certificated in any category. \n\n(d) Subject \n\n\n\tJoint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 5753, Trailing edge flaps. \n\n(e) Unsafe Condition \n\n\n\tThis AD was prompted by a report of a broken forward support fitting at the inboard track of the inboard flap. We are issuing this AD to detect and correct cracking of the forward support fitting assembly, which could result in loss of inboard flap control and subsequent loss of airplane control. \n\n(f) Compliance \n\n\n\tComply with this AD within the compliance times specified, unless already done. \n\n(g) Inspection and Corrective Action \n\n\n\tExcept as provided by paragraph (h) of this AD, at the applicable time specified in paragraph 1.E., ''Compliance,'' of Boeing Special Attention Service Bulletin 757-57-0071, dated September 12, 2012: Do a high frequency eddy current (HFEC) inspection for cracking in the forward support fitting assemblies of the inboard track of the left and right inboard flaps, and do all applicable corrective actions, in accordance with paragraph 3.B.2. of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-57-0071, dated September 12, 2012.Do all applicable corrective actions before further flight. Thereafter, repeat the inspections at intervals not to exceed 6,000 flight cycles, except as required by paragraphs (g)(1) and (g)(2) of this AD. \n\t(1) For Group 1 airplanes, as identified in Boeing Special Attention Service Bulletin 757-57-0071, dated September 12, 2012, on which any forward support fitting assembly is replaced: Do the next inspection before 15,000 flight cycles have accumulated on that assembly. \n\t(2) For Group 2 airplanes, as identified in Boeing Special Attention Service Bulletin 757-57-0071, dated September 12, 2012, on which any forward support fitting assembly is replaced: Do the next inspection before 18,000 flight cycles have accumulated on that assembly. \n\n(h) Exceptions to the Service Information \n\n\n\t(1) Where Boeing Special Attention Service Bulletin 757-57-0071, dated September 12, 2012, specifies compliance times ''after the original issue date of this service bulletin,'' this AD requirescompliance within the specified compliance times ''after the effective date of this AD.'' \n\t(2) Paragraphs 3.B.1. and 3.B.3. of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-57- 0071, dated September 12, 2012, are not required by this AD. \n\n(i) 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 (j) 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) 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 (ODA) 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(j) Related Information \n\n\n\tFor more information about this AD, contact Nancy Marsh, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: (425) 917-6440; fax: (425) 917-6590; email: nancy.marsh@faa.gov. \n\n((Page 70214)) \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 Special Attention Service Bulletin 757-57-0071, dated September 12, 2012. \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 Directorate, 1601 Lind Ave 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 the specified products. The NPRM published in the Federal Register on April 22, 2013 (78 FR 23694). The NPRM proposed to require repetitive inspections of the forward support fitting assemblies of the inboard track of the left and right inboard flaps for cracking, and corrective actions if necessary. \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 (78 FR 23964, April 22, 2013) and the FAA's response to each comment. \n\nSupportive Comment \n\n\n\tBoeing stated that it concurs with the NPRM (78 FR 23964, April 22, 2013). \n\nRequest To Provide Justification for AD Action \n\n\n\tFedEx requested further data and justification for this AD action. FedEx stated that it expected a single data point (i.e., the one failure of a forwardsupport fitting assembly) would represent an anomaly. FedEx asked if a root cause analysis was done to determine whether the single failure was an anomaly induced during manufacture or operator maintenance before proceeding with service information and NPRM development. \n\tWe find that clarification is necessary. Boeing Special Attention Service Bulletin 757-57-0071, dated September 12, 2012, states that the cracking occurred at a compound radius in the part. This design detail, which occurs on each part having the part number identified in that service bulletin, has been identified as an area of high stress concentration and a likely location for fatigue cracking to initiate at a relatively low number of flight cycles. The airplane event, as detailed in that service bulletin, occurred at 22,328 flight cycles and both components of the forward support fitting assembly were found to be completely cracked through. Therefore, the occurrence of cracking in this part at this location is likely to occur on other airplanes, and cannot be considered an anomaly. Since these cracked fittings result in an unsafe condition and we determined that this unsafe condition is likely to exist or develop in other products of the same type design, we determined that this AD rulemaking is necessary. We have not changed this final rule in this regard. \n\nRequest for Procedures To Apply a Chemical Conversion Coating \n\n\n\tAmerican Airlines (AAL) recommended that a step be added between steps 10 and 11 in sheet 3 of 6 of the Forward Support Fitting Assembly Replacement figures of Boeing Special Attention Service Bulletin 757- 57-0071, dated September 12, 2012. The additional step would specify applying a chemical conversion coating after match drilling holes as part of the fitting assembly replacement process. AAL noted that in the Material Information of Boeing Special Attention Service Bulletin 757- 57-0071, dated September 12, 2012, chemical conversion coating is identified in the parts lists, but the Accomplishment Instructions section of that service bulletin omits the coating. \n\tWe agree that Boeing Special Attention Service Bulletin 757-57- 0071, dated September 12, 2012, does not specify applying a chemical conversion coating after match drilling holes. Boeing specified that the installation of the fasteners with sealant, as specified in the instructions in the service information, provides corrosion protection at the fastener locations and that application of the chemical conversion coating is not required. Once we issue this AD, any person may request approval of an alternative method of compliance (AMOC) to apply alternative corrosion protection coatings under the provisions of paragraph (i) of this final rule. We have not changed this final rule in this regard. \n\nRequest To Delay AD To Address Parts Availability \n\n\n\tAAL requested that the FAA ensure ample parts availability before releasing the AD. AAL stated that there is a lead time of 160 days forthe fitting assembly and suggested that the NPRM (78 FR 23964, April 22, 2013) be revised to allow for manufacture of parts and provide material specifications and part dimensions. FedEx stated that about seven fitting assemblies are due to be in stock in July 2013. \n\tWe disagree to revise or delay this final rule. In developing this final rule, we coordinated with the manufacturer an appropriate compliance time to address the unsafe condition in a timely manner and take parts availability into consideration. We have not changed 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 as proposed except for minor editorial changes. We have determined that these minor changes: \n\tAre consistent with the intent that was proposed in the NPRM (78 FR 23964, April 22, 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 23964, April 22, 2013). \n\nCosts of Compliance \n\n\n\tWe estimate that this AD affects 690 airplanes of U.S. registry. \n\tWe estimate the following costs to comply with this AD: \n\n\n\tEstimated Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost on U.S. \n\tAction Labor cost Parts cost Cost per product operators ---------------------------------------------------------------------------------------------------------------- High-frequency eddy current 11 work-hours x None.............. $935, per $645,150, per \n\tinspection. $85 per hour = inspection cycle. inspection cycle. \n\t$935, per \n\tinspection cycle. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tWe estimate the following costs to do any necessary replacements that would be required based on the results of the inspection. We have no way of determining the number of aircraft that might need this replacement: \n\n((Page 70213)) \n\n\n\n\n\n\n\tOn-Condition Costs ---------------------------------------------------------------------------------------------------------------- \n\tAction Labor cost Parts cost Cost per product ---------------------------------------------------------------------------------------------------------------- Replacement............................ 7 work-hours x $85 per $10,000 $10,595, per assembly. \n\thour = $595, per assembly. ---------------------------------------------------------------------------------------------------------------- \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 theauthority 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.