AD 2003-04-10

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model MD-90-30 airplanes, that requires a one-time general visual inspection to find wire chafing damage and to determine adequate clearance between the disconnect panel structure and the wires above the aft left lavatory; and corrective actions, if necessary. This action is necessary to prevent damage to certain wires due to contact between the wires and the adjacent structure, which could result in electrical arcing and consequent smoke and fire in the cabin. This action is intended to address the identified unsafe condition.

Final rule.

2003-04-10 McDonnell Douglas: Amendment 39-13058. Docket 2001-NM-389-AD. \n\n\tApplicability: Model MD-90-30 airplanes, as listed in Boeing Alert Service Bulletin MD90-24A074, Revision 01, dated August 8, 2001; certificated in any category. \n\n\tNote 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent damage to certain wires due to contact between the wires and the adjacent structure, which could result in electrical arcing and consequent smoke and fire in the cabin, accomplish the following: \n\nOne-Time Inspection/Corrective Actions \n\n\t(a) Within 12 months after the effective date of this AD: Do a one-time general visual inspection to find wire chafing damage and to determine adequate clearance between the disconnect panel structure and the wires above the aft left lavatory, per the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-24A074, Revision 01, excluding Appendix and Evaluation Form, dated August 8, 2001. If no damage is found and the clearance is adequate, no further action is required by this AD. \n\n\tNote 2: For the purposes of this AD, a general visual inspection is defined as: "A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked." \n\n\t(1) If no damage is found, but the clearance is inadequate: Before further flight, secure the wires using tie-wraps to obtain 0.50-inch minimum clearance per the service bulletin. \n\n\t(2) If damage and/or inadequate clearance is found: Before further flight, repair or replace damaged wires with new wires and/or secure the wires using tie-wraps to obtain 0.50-inch minimum clearance, as applicable, per the service bulletin. \n\n\t(b) Accomplishment of the one-time inspection and corrective actions before the effective date of this AD per Boeing Alert Service Bulletin MD90-24A074, dated May 14, 2001, is considered acceptable for compliance with paragraph (a) of this AD. \n\nAlternative Methods of Compliance \n\n\t(c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO. \n\n\tNote 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. \n\nSpecial Flight Permits \n\n\t(d) Special 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 requirements of this AD can be accomplished. \n\nIncorporation by Reference \n\n\t(e) Unless otherwise specified in this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin MD90-24A074, Revision 01, excluding Appendix and Evaluation Form, dated August 8, 2001. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024). Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; at the FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC. \n\nEffective Date \n\n\t(f) This amendment becomes effective on April 4, 2003.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model MD-90-30 airplanes was published in the Federal Register on August 30, 2002 (67 FR 55735). That action proposed to require a one-time general visual inspection to find wire chafing damage and to determine adequate clearance between the disconnect panel structure and the wires above the aft left lavatory; and corrective actions, if necessary. \n\nComments \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. \n\nRequest for Withdrawal of Proposed AD \n\n\tOne commenter disagrees with the need for an AD to require accomplishment of Boeing Alert Service Bulletin MD90-24A074, Revision 01, dated August 8, 2001. The commenter notes that the incident that prompted the proposed AD occurred on a McDonnell Douglas Model MD-88 airplane, not an MD-90-30 airplane. The commenter notes that the affected wire bundle on the incident airplane chafed on a disconnect bracket on an extruded angle. The commenter states that, after considering the design of the disconnect panel on Model MD-90-30 airplanes, it is confident that no wire chafing will be found on Model MD-90-30 airplanes. The commenter points out that the design of the subject disconnect bracket on the Model MD-90-30 airplane is significantly different, especially in length, from that on the Model MD-88 airplane. The bracket on the Model MD-90-30 airplane does not extend to the area where the wire bundle chafing occurred on the Model MD-88 airplane. The commenter requests that the proposed AD, if issued, include information about inspection findings on Model MD-90-30 airplanes. \n\n\tThe FAA infers that the commenter is requesting that we withdraw the proposed AD. We do not agree. The airplane manufacturer has reviewed the installation drawings and has confirmed that the same disconnect bracket (i.e., same part number) is installed in the same location on both Model MD-88 and Model MD-90-30 airplanes. Therefore, Model MD-90-30 airplanes may be subject to the same unsafe condition revealed on the Model MD-88 airplanes, even though no wire chafing damage has been found to date on Model MD-90-30 airplanes. No change to the final rule is necessary in this regard. \n\nRequest To Extend Compliance Time \n\n\tThe same commenter requests that, if we deem it necessary to issue an AD, we extend the compliance time from 4 months after the effective date of the AD, as proposed, to 12 months after the effective date of the AD. Aside from its comments regarding the appropriateness of the AD, discussed previously, the commenter provides no further justification for its request. \n\n\tWe concur that the compliance time of this AD may be extended. We have determined that a compliance time of 12 months will ensure that the identified unsafe condition is addressed in a timely manner, while allowing the majority of affected operators to complete the required actions during a scheduled maintenance visit. We have revised paragraph (a) of the final rule accordingly. \n\nExplanation of Editorial Change \n\n\tIn the NPRM, we stated that the proposed actions were to be accomplished "per the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-24A074, Revision 01, including Appendix A, dated August 8, 2001." However, the service bulletin's appendix contains a form for reporting inspection findings. This AD does not include such a requirement. Therefore, we have changed the service bulletin citation throughout this final rule to exclude the appendix of the service bulletin. \n\n\tAlso, we have changed the service bulletin citation throughout this final rule to exclude the Evaluation Form. The form is intended to be completed by operators and submitted to the airplane manufacturer to provide inputon the quality of the service bulletin; however, this AD does not include such a requirement. \n\n\tAlso, the Cost Impact section of the NPRM did not include information about warranty remedies that may be available. We have revised the Cost Impact section of this final rule to refer to warranty remedies. \n\nConclusion \n\n\tAfter careful review of the available data, including the comments noted above, we have determined that air safety and the public interest require the adoption of the rule with the changes previously described. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCost Impact \n\n\tThere are approximately 113 Model MD-90-30 airplanes of the affected design in the worldwide fleet. We estimate that 21 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of inspection required by this AD on U.S. operators is estimated to be $1,260, or $60 per airplane. \n\n\tThe cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions. Manufacturer warranty remedies may be available for labor costs associated with this AD. As a result, the costs attributable to this AD may be less than stated above. \n\nRegulatory Impact \n\n\tThe regulations adopted herein will not have a substantial direct effecton 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132. \n\n\tFor the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES. \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\n\tAccordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: \n\nPART 39-AIRWORTHINESS DIRECTIVES \n\n\t1. 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\n\t2. Section 39.13 is amended by adding the following new airworthiness directive: