AD 2010-05-04

We are adopting a new airworthiness directive (AD) for all Model MD-90-30 airplanes. This AD requires repetitive inspections for cracking of the overwing frames at stations 883, 902, 924, 943, and 962, left and right sides, and corrective actions if necessary. This AD results from reports of cracked overwing frames. We are issuing this AD to detect and correct such cracking, which could sever the frame, increase the loading of adjacent frames, and result in damage to adjacent structure and loss of overall structural integrity of the airplane.

Final rule.

2010-05-04 McDonnell Douglas Corporation: Amendment 39-16213. Docket No. FAA-2009-0783; Directorate Identifier 2009-NM-081-AD. \n\nEffective Date \n\n\t(a) This airworthiness directive (AD) is effective April 1, 2010. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to all McDonnell Douglas Corporation Model MD-90-30 airplanes, certificated in any category. \n\nSubject \n\n\t(d) Air Transport Association (ATA) of America Code 53: Fuselage. \n\nUnsafe Condition \n\n\t(e) This AD results from reports of cracked overwing frames. We are issuing this AD to detect and correct such cracking, which could sever the frame, increase the loading of adjacent frames, and result in damage to adjacent structure and loss of overall 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\nInspections \n\n\t(g) Before the accumulation of 20,000 total flight cycles, or within 60 months after the effective date of this AD, whichever occurs later: Do general visual and high frequency eddy current inspections for cracking of the overwing frames, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-53A031, dated April 10, 2009. Do the applicable corrective actions before further flight, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-53A031, dated April 10, 2009. Repeat the inspections thereafter at the applicable time specified in paragraph 1.E., "Compliance,'' of Boeing Alert Service Bulletin MD90-53A031, dated April 10, 2009. \n\nAlternative Methods of Compliance (AMOCs) \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. Send information to ATTN: Roger Durbin, Aerospace Engineer, Airframe Branch,ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5233; fax (562) 627-5210. \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 reference this AD. \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\nMaterial Incorporated by Reference \n\n\t(i) You must use Boeing Alert Service Bulletin MD90-53A031, dated April 10, 2009, 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 this service information 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; telephone 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 or 425-227-1152. \n\t(4) You may alsoreview 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 NARA, 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 include an airworthiness directive (AD) that would apply to all Model MD-90-30 airplanes. That NPRM was published in the Federal Register on September 4, 2009 (74 FR 45785). That NPRM proposed to require repetitive inspections for cracking of the overwing frames at stations 883, 902, 924, 943, and 962, left and right sides, and corrective actions if necessary. \n\nComments \n\n\tWe gave the public the opportunity to participate in developing this AD. We considered the comments received from the sole commenter. \n\nRequest To Revise Wording in the Summary Section and Unsafe Condition Paragraph of the NPRM \n\n\tThe Boeing Company requests that we revise the wording of the precipitating event in the Summary section and Unsafe Condition paragraph of the NPRM to clarify that the reported cracking was found on Model MD-80 airplanes, and that frames of the same design areinstalled on Model MD-90 airplanes. The commenter explains that the proposed revision will be in line with the first paragraph of the "Discussion'' section of the NPRM. The commenter asserts that otherwise, the Summary section and paragraph (e) of the NPRM read that "Model MD-90 overwing frames have cracked,'' which is not the case. \n\tWe agree that clarification might be necessary. While the commenter's proposed revision is more precise with respect to the history of the service difficulties, the Summary section of ADs is designed to provide only a brief description of the action being proposed. Likewise, the Unsafe Condition paragraph in the regulatory text of an AD is meant to be only a brief statement. Detailed background information is provided in the Discussion section of a proposed AD. We addressed the issues raised by the commenter in the Discussion section of the NPRM. That section is not restated in this final rule. We have not changed the AD in this regard. \n\nRequest To Revise Wording in the Discussion Section of the NPRM \n\n\tThe Boeing Company requests that we revise the first sentence of the second paragraph of the "Discussion'' section of the NPRM to read, "The cracked overwing frames on McDonnell Douglas Model MD-90-30 airplanes have the same design as those installed on Model MD-80 series airplanes.'' The commenter explains that the proposed revision sounds more logical than how it reads in the NPRM and that the issue is the Model MD-90 frames cracking, not the Model MD-80 frames. \n\tWe agree that clarification is needed. The proposed revision would indicate that we have reports of cracks on Model MD-90-30 airplanes, which is not the case. As stated in the NPRM, the reports we received were of cracked frames on Model MD-80 airplanes. This AD is being issued because Model MD-90-30 airplanes have frames with the same design, and therefore, are also susceptible to the unsafe condition addressed by this AD. Regardless, the Discussion section of the NPRM is not restated in this final rule. No change to the AD is necessary in this regard. \n\nExplanation of Name Change Made to This AD \n\n\tWe have revised this AD to identify the legal name of the manufacturer as published in the most recent type certificate data sheet for the affected airplane models. \n\nExplanation of Delegation Authorization Change Made to This AD \n\n\tBoeing Commercial Airplanes has received an Organization Designation Authorization (ODA), which replaces their previous designation as a Delegation Option Authorization (DOA) holder. We have revised paragraph (h)(3) of this AD to delegate the authority to approve an alternative method of compliance for any repair required by this AD to the Boeing Commercial Airplanes ODA. \n\nConclusion \n\n\tWe reviewed the relevant data, considered the comment received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We also determined that these changes will notincrease the economic burden on any operator or increase the scope of the AD. \n\nExplanation of Change to Costs of Compliance \n\n\tSince issuance of the NPRM, we have increased the labor rate used in the Costs of Compliance from $80 per work-hour to $85 per work-hour. The Costs of Compliance information, below, reflects this increase in the specified hourly labor rate. \n\nCosts of Compliance \n\n\tWe estimate that this AD affects 16 airplanes of U.S. registry. We also estimate that it takes about 10 work-hours per product to comply with this AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $13,600, or $850 per product. \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 ofthe 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\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 "significantregulatory 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), and \n\t(3) 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\tYou can find our regulatory evaluation and the estimated costs of compliance in the AD Docket. \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\nPART 39--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 adding the following new AD: