AD 95-09-10 SUPERSEDED

This amendment adopts a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-9-80 series airplanes and Model MD-88 airplanes. This action requires an inspection to detect chafing of or damage to the wire bundle in the overhead switch panel of the cockpit, application of spiral wrap to the wire bundle, and corrective actions, if necessary. This amendment is prompted by reports of chafed and shorted wires that resulted in smoke emanating from the overhead switch panel of the cockpit. The actions specified in this AD are intended to prevent the potential for fire and uncontrolled smoke throughout the cockpit as a result of chafing and shorting in the electrical wire bundles.

Final rule; request for comments.

95-09-10 MCDONNELL DOUGLAS: Amendment 39-9213. Docket 95-NM-68-AD.\n\n\tApplicability: Model DC-9-80 series airplanes and Model MD-88 airplanes; as listed in McDonnell Douglas DC-9 Alert Service Bulletin DC9-24A157, dated April 11, 1995; 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 use the authority provided in paragraph (b) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configurationon the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD.\n\n\tCompliance: Required as indicated, unless accomplished previously.\n\n\tTo prevent the potential for fire and uncontrolled smoke throughout the cockpit, accomplish the following:\n\n\t(a)\tWithin 90 days after the effective date of this AD, perform a visual inspection to detect chafing of or damage to the wire bundle in the overhead switch panel of the cockpit, in accordance with McDonnell Douglas Alert Service Bulletin DC9-24A157, dated April 11, 1995.\n\n\t\t(1)\tIf no chafing or damage is detected, prior to further flight, apply spiral wrap to the wire bundle in accordance the alert service bulletin.\n\n\t\t(2)\tIf the wire insulation is chafed, prior to further flight, repair it and then apply spiral wrap to the wire bundle, in accordance with the alert service bulletin.\n\n\t\t(3)\tIf the wire conductor is damaged, prior to further flight, splice the wires and then apply spiral wrap to the wire bundle, in accordance with the alert service bulletin.\n\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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO.\n\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\n\t(d)\tThe inspection, application of spiral wrap, repair, and splicing shall be done in accordance with McDonnell Douglas Alert Service Bulletin DC9-24A157, dated April 11, 1995. 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 McDonnell Douglas Corporation, P.O. Box 1771, Long Beach, California 90801-1771, Attention: Business Unit Manager, Technical Administrative Support, Dept. L51, M.C. 2-98. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles ACO, Transport Airplane Directorate, 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(h)\tThis amendment becomes effective on May 19, 1995.

Recently, the FAA has received reports of smoke emanating from the overhead switch panel of the cockpit of Model DC-9-80 series airplanes and Model MD-88 airplanes. Investigation revealed that the cause of the smoke may be attributed to chafing of a wire bundle in the overhead switch panel of the cockpit. This chafed wire bundle made contact with the electrical connector of the cabin temperature indicator, which resulted in a short circuit. This condition, if not corrected, could result in the potential for fire and uncontrolled smoke throughout the cockpit.\n\n\tThe FAA has reviewed and approved McDonnell Douglas DC-9 Alert Service Bulletin DC9-24A157, dated April 11, 1995, which describes procedures for a one-time visual inspection to detect chafing of the wire bundle in the overhead switch panel of the cockpit, application of spiral wrap, repair of chafed wire insulation, and splicing of damaged wires. The effectivity listing of this service bulletin includes certain Model DC-9, DC-9-80, and C-9 (military) series airplanes, and Model MD-88 airplanes. This service bulletin recommends a compliance time of 6 months.\n\n\tSince an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design, this AD is being issued to prevent the potential for fire and uncontrolled smoke throughout the cockpit. This AD requires a one-time visual inspection to detect chafing of or damage to the wire bundle in the overhead switch panel of the cockpit, application of spiral wrap to the wire bundle, repair of chafed wire insulation, and splicing of damaged wires. The actions are required to be accomplished in accordance with the service bulletin described previously.\n\n\tOperators should note that, although the service bulletin recommends that the inspection be performed within 6 months, this AD requires that it be performed within 90 days. In light of the consequences of fire or smoke in the cockpit,the FAA finds that the 90-day compliance time is appropriate to ensure the safety of this group of airplanes.\n\n\tThis AD does not apply to Model DC-9 and C-9 (military) series airplanes because the wires/wire bundles on these airplanes are manufactured of a stronger material than those on Model DC-9-80 series airplanes and Model MD-88 airplanes, and are therefore less susceptible to the subject damage. Additionally, this AD does not apply to Model MD-90-30 series airplanes. Since these airplanes are relatively new, the FAA does not anticipate that the wire bundles on these airplanes would be chafed as severely as those on the Model DC-9 series airplanes, which have been in service for a much longer period of time. Further, the reported incidents of smoke in the cockpit occurred only on Model DC-9-80 series airplanes and Model MD-88 airplanes. Therefore, the FAA is considering further rulemaking action to revise this AD to require modification of the wire bundles on Model DC-9-80series airplanes and Model MD-88 airplanes. However, the proposed compliance time for the modification is sufficiently long so that notice and time for public comment would not be impracticable.\n\n\tThis is considered to be interim action. The manufacturer has advised that it currently is developing a modification that will positively address the unsafe condition addressed by this AD. Once this modification is developed, approved, and available, the FAA may consider additional rulemaking.\n\n\tAs a result of recent communications with the Air Transport Association (ATA) of America, the FAA has learned that, in general, some operators may misunderstand the legal effect of AD's on airplanes that are identified in the applicability provision of the AD, but that have been altered or repaired in the area addressed by the AD. The FAA points out that all airplanes identified in the applicability provision of an AD are legally subject to the AD. If an airplane has been altered or repairedin the affected area in such a way as to affect compliance with the AD, the owner or operator is required to obtain FAA approval for an alternative method of compliance with the AD, in accordance with the paragraph of each AD that provides for such approvals. A note has been included in this rule to clarify this long-standing requirement.\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\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 identifythe 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 commentssubmitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 95-NM-68-AD." The postcard will be date stamped and returned to the commenter.\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 power and 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 underDOT 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 Subjects in 14 CFR Part 39\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\t1.\tThe authority citation for part 39 continues to read as follows:\nAuthority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.\n\n§ 39.13 - (Amended)\n\t2.\tSection 39.13 is amended byadding the following new airworthiness directive:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 95-NM-68-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.\n\n\tThe service information referenced in this AD may be obtained from McDonnell Douglas Corporation, P.O. Box 1771, Long Beach, California 90801-1771, Attention: Business Unit Manager, Technical Administrative Support, Dept. L51, M.C. 2-98. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft Certification Office, Transport Airplane Directorate, 3960 Paramount Boulevard, Lakewood, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

J. Kirk Baker, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (310) 627-5345; fax (310) 627-5210.