AD 2010-23-10

We are superseding an existing airworthiness directive (AD) for the products listed above. That AD currently requires repetitive high frequency eddy current inspections to detect cracking in the vertical radius (also known as the "vertical leg'') of the upper cap of the center wing rear spar, and repair if necessary. This new AD expands the area to be inspected by including inspections to detect cracking of the horizontal flange of the upper cap of the left and right center wing rear spar, and repair if necessary. This new AD also adds certain airplanes to the applicability. This AD was prompted by reports of cracking in the vertical radius of the upper cap of the center wing rear spar, and the horizontal flange on the inboard side of the of the rear spar upper cap, which resulted from stress corrosion. We are issuing this AD to detect and correct cracking in the vertical leg or the horizontal flange of the upper cap of the left or right center wing rear spar, which could cause a possible fuel leak, damage to the wing skin, and structural failure of the upper cap, and result in reduced structural integrity of the airplane.

Final rule.

2010-23-10 McDonnell Douglas Corporation: Amendment 39-16499; Docket No. FAA-2010-0705; Directorate Identifier 2009-NM-206-AD. \n\nEffective Date \n\n\t(a) This airworthiness directive (AD) is effective December 14, 2010. \n\nAffected ADs \n\n\t(b) This AD supersedes AD 2004-23-11, Amendment 39-13866. \n\nApplicability \n\n\t(c) This AD applies to McDonnell Douglas Corporation Model DC-9- 14, DC-9-15, DC-9-15F, DC-9-21, DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-33F, DC-9-34, DC-9-34F, DC-9-32F (C-9A, C-9B), DC-9- 41, and DC-9-51 airplanes; certificated in any category; as identified in Boeing Service Bulletin DC9-57-223, Revision 1, dated August 13, 2009. \n\nSubject \n\n\t(d) Air Transport Association (ATA) of America Code 57: Wings. \n\nUnsafe Condition \n\n\t(e) This AD results from reports of cracking in the vertical radius (also known as the "vertical leg'') of the upper cap of the center wing rear spar, and the horizontal flange on the inboard side of the rear spar upper cap, which resulted from stress corrosion. The Federal Aviation Administration is issuing this AD to detect and correct cracking in the vertical leg or the horizontal flange of the upper cap of the left or right center wing rear spar, which could cause a possible fuel leak, damage to the wing skin, and structural failure of the upper cap, and result in reduced structural integrity of the airplane. \n\nCompliance \n\n\t(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. \n\nRestatement of Requirements of AD 2004-23-11, With Revised Service Information \n\nInspection \n\n\t(g) For all airplanes except Model DC-9-15F airplanes, at the later of the times specified in paragraphs (g)(1) and (g)(2) of this AD: Do a high frequency eddy current inspection to detect cracks in the vertical radius of the upper cap of the center wing rear spar, in accordance with the Accomplishment Instructions ofBoeing Service Bulletin DC9-57-223, dated July 21, 2003; or Revision 1, dated August 13, 2009. After the effective date of this AD, only Revision 1 may be used. \n\n\t(1) Before the accumulation of 25,000 total flight cycles. \n\n\t(2) Within 15,000 flight cycles or 5 years after December 20, 2004 (the effective date of AD 2004-23-11), whichever occurs first. \n\nCorrective Action \n\n\t(h)(1) If no crack is found during any inspection required by paragraph (g) of this AD, then repeat the inspection thereafter at intervals not to exceed 15,000 flight cycles or 5 years, whichever occurs first, until the initial inspection required by paragraph (i) of this AD is done. \n\n\t(2) If any crack is found during the inspection required by paragraph (g) of this AD, before further flight, repair per a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA. For a repair method to be approved by the Manager, Los Angeles ACO, as required by this paragraph, the Manager's approval letter must specifically refer to this AD. \n\nNew Requirements of This AD \n\nInspection \n\n\t(i) At the later of the times specified in paragraphs (i)(1) and (i)(2) of this AD: Do a high frequency eddy current inspection to detect cracking in the vertical leg (also known as the "vertical radius'') and horizontal flange of the left and right rear spar upper cap, inboard and outboard sides, at the bulkhead at wing station Xcw=58.500, in accordance with the Accomplishment Instructions of Boeing Service Bulletin DC9-57-223, Revision 1, dated August 13, 2009. If no cracking is found, repeat the inspection thereafter at intervals not to exceed 15,000 flight cycles or 5 years, whichever occurs first. Accomplishment of the initial inspection required by paragraph (i) of this AD terminates the requirements of paragraphs (g) and (h)(1) of this AD. \n\n\t(1) Before the accumulation of 25,000 total flight cycles. \n\n\t(2) Within 15,000 flight cycles or 5 years after accomplishing the mostrecent high frequency eddy current inspection required by paragraph (g) of this AD, whichever occurs first. \n\nCorrective Action \n\n\t(j) If any cracking is found during any inspection required by paragraph (i) of this AD, before further flight, repair the cracking using a method approved in accordance with the procedures specified in paragraph (k) of this AD. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(k)(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. Send information to ATTN: Wahib Mina, Aerospace Engineer, Airframe Branch, ANM-120L, Los Angeles ACO, FAA, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5324; fax (562) 627-5210. \n\n\t(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically refer to this AD. \n\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, Los Angeles 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\t(4) AMOCs approved previously in accordance with AD 2004-23-11, Amendment 39-13866, are approved as AMOCs for the corresponding provisions of paragraph (h)(2) of this AD. \n\nMaterial Incorporated by Reference \n\n\t(l) You must use Boeing Service Bulletin DC9-57-223, Revision 1, dated August 13, 2009, to do the actions required by this AD, unless the AD specifies otherwise. \n\n\t(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51. \n\n\t(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, 3855 Lakewood Boulevard, MC D800-0019, Long Beach, California 90846- 0001; telephone 206-544-5000, extension 2; fax 206-766-5683; e-mail dse.boecom@boeing.com; Internet https://www.myboeingfleet.com. \n\n\t(3) You may review copies of the service information at the FAA, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221. \n\n\t(4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at an NARA facility, call 202-741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ ibr_locations.html.

Discussion \n\n\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede airworthiness directive (AD) 2004-23-11, Amendment 39-13866 (69 FR 65522, November 15, 2004). That AD applies to the specified products. The NPRM was published in the Federal Register on August 5, 2010 (75 FR 47242). That NPRM proposed to continue to require repetitive high frequency eddy current inspections to detect cracks in the vertical radius (also known as the "vertical leg'') of the upper cap of the center wing rear spar, and repair if necessary. That NPRM also proposed to expand the area to be inspected by including inspections to detect cracking of the horizontal flange of the upper cap of the left and right center wing rear spar, and repair if necessary. In addition, that NPRM proposed to add certain airplanes to the applicability. \n\nComments \n\n\tWe gave the public the opportunity to participate in developing this AD. We received no commentson the NPRM or on the determination of the cost to the public. \n\nConclusion \n\n\tWe reviewed the relevant data and determined that air safety and the public interest require adopting the AD as proposed, except for minor editorial changes. We have determined that these minor changes: \n\n\tAre consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and \n\n\tDo not add any additional burden upon the public than was already proposed in the NPRM. \n\n\nCosts of Compliance \n\n\tThere are approximately 510 airplanes of the affected design in the worldwide fleet. We estimate that 322 airplanes of U.S. registry will be affected by this AD. The following table provides the estimated costs for U.S. operators to comply with this AD. \n\n\tEstimated Costs\n\n\nAction\nWork hours\nAverage labor rate per hour\nParts\nCost per airplane\nNumber of U.S.-registered airplanes\nFleet cost\nInspection\n3\n$85\n$0\n$255 per inspection cycle\n322\n$82,110 per inspectioncycle\n\nAuthority for This Rulemaking \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\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\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\n\tFor the reasons discussed above, I certify that this AD: \n\n\t(1) Is not a "significant regulatory action'' under Executive Order 12866, \n\n\t(2) Is not a "significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), \n\n\t(3) Will not affect intrastate aviation in Alaska, and \n\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\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\nAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART39--AIRWORTHINESS DIRECTIVES \n\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\nSec. 39.13 (Amended) \n\n2. The FAA amends Sec. 39.13 by removing airworthiness directive (AD) 2004-23-11, Amendment 39-13866 (69 FR 65522, November 15, 2004), and adding the following new AD: