AD 2016-22-18

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model MD-90-30 airplanes. This AD requires a detailed inspection of the forward and aft surfaces on the left and right sides at the cant station 1520 bulkhead for any crack in the upper cap and (cap) doubler, webs and doublers, stiffeners, and the lower tee cap between longerons 3 through 11, and repairs if necessary. This AD was prompted by a report of cracking in various structures in the fuselage cant station 1520 bulkhead. We are issuing this AD to detect and correct cracking in the bulkhead, which could result in reduced structural integrity of the airplane.

Final rule; request for comments.

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\n2016-22-18 The Boeing Company: Amendment 39-18707; Docket No. FAA- 2016-9306; Directorate Identifier 2016-NM-169-AD. \n\n(a) Effective Date \n\n\n\tThis AD is effective November 21, 2016. \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 MD-90-30 airplanes, certificated in any category. \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 cracking in various structures in the fuselage cant station1520 bulkhead. We are issuing this AD to detect and correct cracking in the bulkhead, which could 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) Detailed Inspection of the Cant Station 1520 Bulkhead \n\n\n\tAt the applicable time specified in paragraph 1.E., ''Compliance,'' of Boeing Alert Service Bulletin MD90-53A037, dated September 19, 2016, except as required by paragraph (j) of this AD: On the left and right sides at the cant station 1520 bulkhead, do a detailed inspection of the forward and aft surfaces, for any crack in the upper cap and (cap) doubler, webs and doublers, stiffeners, and the lower tee cap between longerons 3 through 11, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-53A037, dated September 19, 2016. \n\n(h) Repair of Cracks in the Bulkhead Web or Doubler \n\n\n\tIf any crack is found in the bulkhead webor doubler, do the repair in accordance with Boeing Alert Service Bulletin MD90-53A037, dated September 19, 2016. Do all repairs before further flight. \n\n(i) Repair of Non-Web or Non-Doubler Cracks in the Bulkhead \n\n\n\tIf any non-web or non-doubler crack is found in the bulkhead, repair before further flight using a method approved in accordance with the procedures specified in paragraph (l) of this AD. \n\n(j) Service Information Exception \n\n\n\tWhere paragraph 1.E., ''Compliance,'' of Boeing Alert Service Bulletin MD90-53A037, dated September 19, 2016, 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\n(k) Special Flight Permit \n\n\n\tSpecial flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the airplane canbe repaired, but if any crack is found as identified in Boeing Alert Service Bulletin MD90-53A037, dated September 19, 2016, concurrence by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, is required before issuance of the special flight permit. \n\n(l) Alternative Methods of Compliance (AMOCs) \n\n\n\t(1) The Manager, Los Angeles 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 (m) 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, 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) Except as required by paragraph (j) of this AD: For service information that contains steps that are labeled as Required for Compliance (RC), the provisions of paragraphs (l)(4)(i) and (l)(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 of an 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(m) Related Information \n\n\n\tFor more information about this AD, contact George Garrido, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office (ACO), 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5232; fax: 562-627-5210; email: george.garrido@faa.gov. \n\n(n) 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 mustuse 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 MD90-53A037, dated September 19, 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 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. \n\n\n\n((Page 76851))

Discussion \n\n\n\tWe have received a report indicating an operator found cracking of various structures in the fuselage cant station 1520 bulkhead on a Model MD-90-30 airplane. The cracks were in the upper left area of the bulkhead, between longerons 5 and 10, in the web, lower tee cap, and the upper cap and (cap) doubler. The affected airplane had accumulated 52,993 total flight hours and 28,718 total flight cycles. Boeing analysis determined that the operational and limit loads cannot duplicate this condition, and the root cause is suspected to be the result of a high load event based on service experience. Cracking of the bulkhead, if not detected and corrected, could result in the inability of the structure to sustain limit loads, and consequent reduced structural integrity of the airplane. We are issuing this AD to correct the unsafe condition on these products. \n\nRelated Service Information Under 1 CFR Part 51 \n\n\n\tWe reviewed Boeing Alert Service Bulletin MD90-53A037, dated September 19, 2016. The service information describes procedures for a detailed inspection of the forward and aft surfaces on the left and right sides at cant station 1520 bulkhead for any crack in the upper cap and (cap) doubler, webs and doublers, stiffeners, and the lower tee cap between longerons 3 through 11, and repairs. 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\nFAA's Determination \n\n\n\tWe are issuing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. \n\nAD Requirements \n\n\n\tThis AD requires accomplishing the actions specified in the service information described previously, except as discussed under ''Differences Between this Proposed AD and the Service Information.'' For information on the procedures and compliance times, see this service information at http://www.regulations.gov by searching for and locating Docket No. FAA-2016-9306. \n\nDifferences Between This Proposed AD and the Service Information \n\n\n\tBoeing Alert Service Bulletin MD90-53A037, dated September 19, 2016, specifies to contact the manufacturer for certain instructions, but this AD would require accomplishment of repair methods, modification deviations, and alteration deviations in one of the following ways: \n\tIn accordance with a method that we approve; or \n\tUsing data that meet the certification basis of the airplane, and that have been approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) whom we have authorized to make those findings. \n\nFAA's Justification and Determination of the Effective Date \n\n\n\tAn unsafe condition exists that requires the immediate adoption of this AD. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule because undetected cracking of the bulkhead may result in the inability of the structure to sustain limit loads, and consequent reduced structural integrity of the airplane. Therefore, we find that notice and opportunity for prior public comment are impracticable and that good cause exists for making this amendment effective in less than 30 days. \n\nComments Invited \n\n\n\tThis AD is a final rule that involves requirements affecting flight safety and was not preceded by notice and an opportunity for public comment. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include the docket number FAA-2016-9306 and Directorate Identifier 2016-NM-169-AD at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments. \n\tWe will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD. \n\nCosts of Compliance \n\n\n\tWe estimate that this AD affects 71 airplanes of U.S. registry. We 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 ---------------------------------------------------------------------------------------------------------------- Detailed inspection............ 2 work-hours x $85 per hour $0 $170 $12,070 \n\t= $170. ---------------------------------------------------------------------------------------------------------------- \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\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 \n\n((Page 76850)) \n\ndistribution 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.