AD 2011-06-12 ACTIVE

We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires repetitive inspections for cracking of the left and right upper center skin panels of the horizontal stabilizer, and corrective action if necessary. This AD was prompted by a report of a crack found in the upper skin panel at the aft inboard corner of a right horizontal stabilizer. We are issuing this AD to detect and correct cracks in the upper center skin panels of the horizontal stabilizer. Uncorrected cracks might ultimately lead to the loss of overall structural integrity of the horizontal stabilizer.

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\n((Page 15802)) \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\n2011-06-12 The Boeing Company: Amendment 39-16637; Docket No. FAA- 2010-1202; Directorate Identifier 2010-NM-167-AD. \n\nEffective Date \n\n\n\t(a) This AD is effective April 26, 2011. \n\nAffected ADs \n\n\n\t(b) None. \n\nApplicability \n\n\n\t(c) This AD applies to all The Boeing Company Model MD-90-30 airplanes, certificated in any category. \n\nSubject \n\n\n\t(d) Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 55, Stabilizers. \n\nUnsafe Condition \n\n\n\t(e) This AD was prompted by a report of a crack found in the upper center skin panel at the aft inboard corner of a right horizontal stabilizer. We are issuing this AD to detect and correct cracks in the upper center skin panel of the horizontal stabilizer. Uncorrected cracks might ultimately lead to the loss of overall structural integrity of the horizontal stabilizer. \n\nCompliance \n\n\n\t(f) Comply with this AD within the compliance times specified, unless already done. \n\nInspections \n\n\n\t(g) Before the accumulation of 20,000 total flight cycles, or within 3,778 flight cycles after the effective date of this AD, whichever occurs later, do eddy current inspections to detect cracking of the left and right upper center skin panels of the horizontal stabilizer, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-55A015, dated July 16, 2010. \n\t(1) If no crack is found during any inspection required by paragraph (g) of this AD, repeat the applicable inspections thereafter at the applicabletimes specified in paragraph 1.E., "Compliance,'' of Boeing Alert Service Bulletin MD90-55A015, dated July 16, 2010. \n\t(2) If any crack is found during any inspection required by paragraph (g) of this AD, before further flight, replace the skin panel with a serviceable skin panel, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90- 55A015, dated July 16, 2010. Within 20,000 flight cycles after the replacement, do eddy current inspections as required by paragraph (g) of this AD. \n\nAlternative Methods of Compliance (AMOCs) \n\n\n\t(h)(1) The Manager, Los Angeles 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. \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, 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 14 CFR 25.571, Amendment 45, and the approval must specifically refer to this AD. \n\nRelated Information \n\n\n\t(i) For more information about this AD, contact Roger Durbin, Aerospace Engineer, Los Angeles ACO, Airframe Branch, ANM-120L, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627- 5233; fax: 562-627-5210; e-mail: Roger.Durbin@faa.gov. \n\nMaterial Incorporated by Reference \n\n\n\t(j) You must use Boeing Alert Service Bulletin MD90-55A015, dated July 16, 2010, to do the actions required by this AD, unless the AD specifies otherwise. \n\t(1) The Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin MD90- 55A015, dated July 16, 2010, under 5 U.S.C. 552(a) and 1 CFR part 51. \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; phone: 206-544-5000, extension 2; fax: 206-766-5683; e-mail: dse.boecom@boeing.com; Internet: https://www.myboeingfleet.com. \n\t(3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221. \n\t(4) You may also review copiesof 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\n\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to the specified products. That NPRM published in the Federal Register on December 23, 2010 (75 FR 80742). That NPRM proposed to require repetitive inspections for cracking of the left and right upper center skin panels of the horizontal stabilizer, and corrective action if necessary. \n\nComments \n\n\n\tWe gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM or on the determination of the cost to the public. \n\nExplanation of Change to Applicability \n\n\n\tWe have revised the applicability of the existing AD to identify model designations as published in the most recent type certificate data sheet for the affected models. \n\nConclusion \n\n\n\tWe reviewed the relevant data, and determined that air safety and the public interest require adopting the AD with the change described previously. 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 the AD. \n\nCosts of Compliance \n\n\n\tWe estimate that this AD affects 19 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 ---------------------------------------------------------------------------------------------------------------- Inspection....................... 4 work-hours x $85 $0 $340 perinspection $6,460 per \n\tper hour = $340 per cycle. inspection 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 need these repairs. \n\n\n\tOn-Condition Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost per \n\tAction Labor cost Parts cost product ---------------------------------------------------------------------------------------------------------------- Skin panel replacement........................ 648 work-hours x $85 per hour = $55,608 $110,688 \n\t$55,080. ---------------------------------------------------------------------------------------------------------------- \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 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.

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; phone: 206-544-5000, extension 2; fax: 206-766-5683; e-mail: dse.boecom@boeing.com; Internet: https://www.myboeingfleet.com. You \n\n((Page 15801)) \n\nmay review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221. \n\nExamining the AD Docket \n\n\n\tYou may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The address for the Docket Office (phone: 800-647-5527) is Document Management Facility, U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.

Roger Durbin, Aerospace Engineer, Los Angeles ACO, Airframe Branch, ANM-120L, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5233; fax: 562-627-5210; e- mail: Roger.Durbin@faa.gov.