AD 2001-24-16

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series airplanes and C-9 airplanes. This AD requires an inspection to detect chafing or damage at the conduit and support bracket interface in the forward electrical power center (EPC); and repair or replacement of wires with new wires, if necessary. For certain airplanes, this AD also requires installation of grommets on the conduits of the forward EPC. These actions are necessary to prevent chafing of electrical cables in the forward EPC and a possible short within a conduit, which could result in smoke and fire in the cockpit. These actions are intended to address the identified unsafe condition.

Final rule.

2001-24-16 McDonnell Douglas: Amendment 39-12533. Docket 99-NM-294-AD. \n\n\tApplicability: Model DC-9-10, -20, -30, -40, and -50 series airplanes and C-9 airplanes, as listed in McDonnell Douglas Alert Service Bulletin DC9-24A115, Revision 01, dated April 24, 2000; 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 (b) 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 chafing of the electrical cables in the forward electrical power center (EPC) and a possible short within a conduit, which could result in smoke and fire in the cockpit, accomplish the following: \n\nInspection; Corrective Action, if Necessary; and Installation of Grommets, if Applicable \n\n\t(a) Within 1 year after the effective date of this AD, do the actions specified in paragraphs (a)(1) and (a)(2) of this AD, as applicable, per McDonnell Douglas Alert Service Bulletin DC9-24A115, Revision 01, dated April 24, 2000.\n \n\t(1) For Groups 1 and 2 airplanes identified in the service bulletin: Do a general visual inspection to detect chafing or damage at the conduit and support bracket interface in the forward EPC. If any chafing or damage is detected, before further flight, repair or replace wires with new wires, per the service bulletin. \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 under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, 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(2) For Group 1 airplanes identified in the service bulletin: Install grommets on the conduits of the forward EPC. \n\nAlternative Methods of Compliance \n\n\t(b) 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(c) 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(d) The actions shall be done in accordance with McDonnell Douglas Alert Service Bulletin DC9-24A115, Revision 01, dated April 24, 2000. 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(e) This amendment becomes effective on January 16, 2002.

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 DC-9-10, -20, -30, -40, and -50 series airplanes and C-9 (military) airplanes was published in the Federal Register on July 23, 2001 (66 FR 38176). That action proposed to require an inspection to detect chafing or damage at the conduit and support bracket interface in the forward electrical power center (EPC); and repair or replacement of wires with new wires, if necessary. For certain airplanes, that action also proposed to require installation of grommets on the conduits of the forward EPC. \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 single comment received. \n\nRequest To Withdraw the Proposed AD \n\n\tThe Air Transport Association (ATA) of America, on behalf of its members, recommends that the FAA withdraw the proposed AD. The ATA notes that its members generally do not agree that the proposed AD is needed. One ATA member observes (in a member comment attached to the ATA's comment) that it has accomplished the work described in the referenced service bulletin and found that the metal edge of the conduit is smooth and does not pose a potential chafing hazard on its airplanes. The member states that the only incident of chafing occurred during a maintenance check, not in the course of normal fleet operations. \n\n\tThe FAA does not concur with the request to withdraw the proposed rule. Though the commenter asserts that this AD is unnecessary because there have been no incidents during normal fleet operation, we find that the potential for such chafing exists, as shown by the report of a chafed electrical cable in the forward EPC which we described in the proposed AD. Such chafing may occur during maintenance or operations. This AD addresses that potential unsafe condition. No change to the final rule is necessary. \n\nConclusion \n\n\tAfter careful review of the available data, including the comment noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed. \n\nCost Impact \n\n\tThere are approximately 403 Model DC-9-10, -20, -30, -40, and -50 series airplanes and C-9 airplanes of the affected design in the worldwide fleet. The FAA estimates that 380 airplanes of U.S. registry will be affected by this AD.\n\n\tFor all airplanes, it will take approximately 1 work hour per airplane to accomplish the required inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of this inspection on U.S. operators is estimated to be $22,800, or $60 per airplane.\n \n\tFor airplanes subject to the modification requirement of this AD, it will take approximately 1 work hour per airplane to accomplish the modification, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of this modification is estimated to be $60 per airplane. \n\n\tThe cost impact figures discussed above are 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. \n\nRegulatory Impact \n\n\tThe regulations adopted herein 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. 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. \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 theFederal 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: