AD 99-09-02

This amendment adopts a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model MD-11 series airplanes. This action requires relocating the support bracket and rerouting the electrical wiring in the aft storage compartment drop ceiling structure. This amendment is prompted by an incident in which a burning odor was detected, and the rear galley power repeatedly tripped off line during flight of an in-service airplane, due to the sense wiring of the galley load control unit (GLCU) chafing against the support bracket. The actions specified in this AD are intended to prevent chafing of the sense wire of the GLCU due to the location of the support bracket of the aft drop ceiling, which could result in electrical arcing, smoke, and possible fire in the aft drop ceiling area of the passenger compartments.

Final rule; request for comments.

99-09-02 MCDONNELL DOUGLAS: Amendment 39-11134. Docket 99-NM-43-AD. \n\n\tApplicability: Model MD-11 series airplanes, manufacturer's fuselage numbers 0577, 0579, 0581, 0582, 0584, and 0586; certificated in any category. \n\n\tNOTE 1: This AD is applicable only to convertible freighters. \n\n\tNOTE 2: 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 specificproposed actions to address it. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent chafing of the sense wire of the galley load control unit (GLCU) due to the location of the support bracket of the aft drop ceiling, which could result in electrical arcing, smoke, and possible fire in the aft drop ceiling area of the passenger compartments, accomplish the following: \n\nModification \n\t(a)\tWithin 60 days after the effective date of this AD, relocate the support bracket and reroute the electrical wiring in the aft storage compartment drop ceiling structure, in accordance with McDonnell Douglas Alert Service Bulletin MD11-33A061, dated December 21, 1998. \n\nAlternative Methods of Compliance \n\t(b)\tAn 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, Transport Airplane Directorate. 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\t(c)\tSpecial 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\t(d)\tThe actions shall be done in accordance with McDonnell Douglas Alert Service Bulletin MD11-33A061, dated December 21, 1998. 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: Technical Publications Business Administration, Dept. C1-L51 (2-60). Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, 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\n\t(e)\tThis amendment becomes effective on May 7, 1999.

As part of its practice of re-examining all aspects of the service experience of a particular aircraft whenever an accident occurs, the FAA has become aware of an incident in which a burning odor was detected, and the rear galley power repeatedly tripped off line. This incident occurred on a McDonnell Douglas Model MD-11 series airplane during flight. \n\n\tInvestigation revealed that the sense wiring of the galley load control unit (GLCU) located in the aft drop ceiling of the passenger compartments chafed against the light ballast; consequently, the wiring shorted. The cause of such chafing has been attributed to the location of the support bracket of the aft drop ceiling. (This incident is not considered to be related to an accident that occurred off the coast of Nova Scotia involving a McDonnell Douglas Model MD-11 series airplane. The cause of that accident is still under investigation.) \n\n\tThe location of the support bracket of the aft drop ceiling could cause chafing of the sense wire of the GLCU, which could result in electrical arcing, smoke, and possible fire in the aft drop ceiling area of the passenger compartments. \n\nOther Related Rulemaking \n\n\tThe FAA, in conjunction with Boeing and operators of Model MD-11 series airplanes, is continuing to review all aspects of the service history of those airplanes to identify potential unsafe conditions and to take appropriate corrective actions. This airworthiness directive (AD) is one of a series of actions identified during that process. The process is continuing and the FAA may consider additional rulemaking actions as further results of the review become available. \n\nExplanation of Relevant Service Information \n\n\tThe FAA has reviewed and approved McDonnell Douglas Alert Service Bulletin MD11-33A061, December 21, 1998, which describes procedures for relocating the support bracket and rerouting the electrical wiring in the aft storage compartment drop ceiling structure.Accomplishment of the actions specified in the alert service bulletin is intended to adequately address the identified unsafe condition. \n\nExplanation of the Requirements of the Rule \n\n\tSince an unsafe condition has been identified that is likely to exist or develop on other McDonnell Douglas Model MD-11 series airplanes of the same type design, this AD is being issued to prevent chafing of the sense wire of the GLCU due to the location of the support bracket of the aft drop ceiling, which could result in electrical arcing, smoke, and possible fire in the aft drop ceiling area of the passenger compartments. This AD requires relocating the support bracket and rerouting the electrical wiring in the aft storage compartment drop ceiling structure. The actions are required to be accomplished in accordance with the alert service bulletin described previously. \n\nDifferences Between the AD and the Referenced Alert Service Bulletin \n\n\tOperators should note that, although the alert service bulletin recommends accomplishing the relocation and reroute within 6 months (after the release of the service bulletin), the FAA has determined that an interval of 6 months would not address the identified unsafe condition in a timely manner. In developing an appropriate compliance time for this AD, the FAA considered not only the manufacturer's recommendation, but the degree of urgency associated with addressing the subject unsafe condition, the average utilization of the affected fleet, and the time necessary to perform the relocation and reroute (two work hours). In light of all of these factors, the FAA finds a 60-day compliance time for initiating the required actions to be warranted, in that it represents an appropriate interval of time allowable for affected airplanes to continue to operate without compromising safety. \n\nDetermination of Rule's Effective Date \n\n\tSince a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. \n\nComments Invited \n\n\tAlthough this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed. \n\n\tComments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. \n\n\tCommenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 99-NM-43-AD." The postcard will be date stamped and returned to the commenter. \n\nRegulatory Impact \n\n\tThe regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of powerand responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. \n\n\tThe FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." \n\nList of Subjectsin 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \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: \nAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 (Amended) \n\t2. Section 39.13 is amended by adding the following new airworthiness directive: