AD 2009-07-04

The FAA is adopting a new airworthiness directive (AD) for certain McDonnell Douglas Model MD-90-30 airplanes. This AD requires modifying the auxiliary hydraulic power system (including doing all applicable related investigative and corrective actions). This AD results from fuel system reviews conducted by the manufacturer, as well as reports of shorted wires in the right wheel well and evidence of arcing on the power cables of the auxiliary hydraulic pump. We are issuing this AD to prevent shorted wires or electrical arcing at the auxiliary hydraulic pump, which could result in a fire in the wheel well; and to reduce the potential of an ignition source adjacent to the fuel tanks, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.

Final rule.

2009-07-04 McDonnell Douglas: Amendment 39-15863. Docket No. FAA- 2007-0074; Directorate Identifier 2007-NM-151-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective May 5, 2009. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to McDonnell Douglas Model MD-90-30 airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin MD90-29A021, Revision 1, dated August 29, 2008. \n\nUnsafe Condition \n\n\t(d) This AD results from fuel system reviews conducted by the manufacturer, as well as reports of shorted wires in the right wheel well and evidence of arcing on the power cables of the auxiliary hydraulic pump. We are issuing this AD to prevent shorted wires or electrical arcing at the auxiliary hydraulic pump, which could result in a fire in the wheel well. We are also issuing this AD to reduce the potential of an ignition source adjacent to the fuel tanks, which, in combination with flammable fuel vapors, could result in a fuel tankexplosion and consequent loss of the airplane. \n\nCompliance \n\n\t(e) 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\nModification \n\n\t(f) Within 18 months after the effective date of this AD, modify the auxiliary hydraulic power system and do all applicable related investigative and corrective actions by accomplishing all applicable actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-29A021, Revision 1, dated August 29, 2008. Do all applicable related investigative and corrective actions before further flight. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(g)(1) The Manager, Los Angeles Aircraft Certification Office, FAA, ATTN: Ken Sujishi, Aerospace Engineer, Cabin Safety/Mechanical and Environmental Systems Branch, ANM-150L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5353; fax (562) 627-5210; has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. \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 appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO. \n\nMaterial Incorporated by Reference \n\n\t(h) You must use Boeing Alert Service Bulletin MD90-29A021, Revision 1, dated August 29, 2008, 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 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 NARA, call 202-741-6030, or go to: http:// www.archives.gov/federal_register/code_of_federal_regulations/ ibr_locations.html.

Discussion \n\n\tThe FAA issued a supplemental notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to certain McDonnell Douglas Model MD-90-30 airplanes. That supplemental NPRM was published in the Federal Register on December 19, 2008 (73 FR 77555). That supplemental NPRM proposed to require modifying the auxiliary hydraulic system (including doing all applicable related investigative and corrective actions). \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. No comments have been received on the supplemental NPRM or on the determination of the cost to the public. \n\nConclusion \n\n\tWe have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed in the supplemental NPRM. \n\nCosts of Compliance \n\n\tThere are about 110 airplanes of the affected design in the worldwide fleet. This AD affects about 16 airplanes of U.S. registry. The actions take between 3 and 7 work-hours per airplane, depending on the configuration, at an average labor rate of $80 per work-hour. Required parts cost up to $5,343 per airplane. Based on these figures, the estimated cost of the AD for U.S. operators is up to $94,448, or $5,903 per airplane. \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\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\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); 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\tWe prepared aregulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation. \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 Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):