Background \n\n\tIn July 1996, a Boeing Model 747 series airplane was involved in an accident. As part of re-examining all \naspects of the service experience of the airplane involved in the accident, the FAA participated in design review and testing to determine possible sources of ignition in center fuel tanks. As part of the review, we examined fuel system wiring with regard to the possible effects that wire degradation may have on arc propagation. \n\n\tIn 1997 in a parallel preceding, at the recommendation of the White House Commission on Aviation Safety and Security, the FAA expanded its Aging Transport Program to include non-structural systems and assembled a team for evaluating these systems. This team performed visual inspections of certain transport category airplanes for which 20 years or more had passed since date of manufacture. In addition, the team gathered information from interviews with FAA Principal Maintenance Inspectors and meetings with representatives of airplane manufacturers. This evaluation revealed that the length of time in service is not the only cause of wire degradation; inadequate maintenance, contamination, improper repair, and mechanical damage are all contributing factors. From the compilation of this comprehensive information, we developed the Aging Transport Non-Structural Systems Plan to increase airplane safety by increasing knowledge of how non-structural systems degrade and how causes of degradation can be reduced. \n\n\tIn 1998, an accident occurred off the coast of Nova Scotia involving a McDonnell Douglas Model MD-11 series airplane. Investigation indicates that a fire broke out in the cockpit and first class overhead area. Although the ignition source of the fire has not been determined, the FAA, in conjunction with Boeing and operators of Model MD-11, DC-8, DC-9, DC-10, and DC-9-80 series airplanes, is reviewing all aspects of the service history of those airplanes to identify potential unsafeconditions associated with wire degradation due to various contributing factors (e.g., inadequate maintenance, contamination, improper repair, and mechanical damage) and to take appropriate corrective actions. We have issued a series of airworthiness directives (AD) that address unsafe conditions identified during that process. This process is continuing and we may consider additional rulemaking actions as further results of the review become available. The cause of the Nova Scotia MD-11 accident has not yet been determined.\n\n\tIn 1999, the FAA Administrator established a formal advisory committee to facilitate the implementation of the Aging Transport Non-Structural Systems Plan. This committee, the Aging Transport Systems Rulemaking Advisory Committee (ATSRAC), is made up of representatives of airplane manufacturers, operators, user groups, aerospace and industry associations, and government agencies. As part of its mandate, ATSRAC will recommend rulemaking to increase transport category airplane safety in cases where solutions to safety problems connected to aging systems have been found and must be applied. Detailed analyses of certain transport category airplanes that have been removed from service, studies of service bulletins pertaining to certain wiring systems, and reviews of previously issued ADs requiring repetitive inspections of certain wiring systems, have resulted in valuable information on the cause and prevention of wire degradation due to various contributing factors (e.g., inadequate maintenance, contamination, improper repair, and mechanical damage). \n\n\tIn summary, as a result of the investigations described above, the FAA has determined that corrective action may be necessary to minimize the potential hazards associated with wire degradation and related causal factors (e.g., inadequate maintenance, contamination, improper repair, and mechanical damage). \n\nIdentification of Unsafe Condition \n\n\tThe FAA has received the results of an investigation that indicate the existing 10-amp circuit breaker in the navigation transfer circuit on certain McDonnell Douglas Model DC-9-10 and -30 series airplanes will not adequately protect the 24-gage wire during an overload condition. This condition, if not corrected, could result in damage to wires or equipment and consequent smoke/fire in the cockpit from the heat generated in the wires during an overload condition. \n\nOther Related Rulemaking \n\n\tThis proposed AD is one of a series of actions identified as part of the ATSRAC program initiative to maintain continued operational safety of aging non-structural systems in transport category airplanes. The program 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 Boeing Alert Service Bulletin DC9-34A075, Revision 01, dated April 30, 2001. The service bulletin describes proceduresfor replacement of a certain circuit breaker in the navigation transfer circuit located on the overhead circuit breaker panel with a certain new circuit breaker; and installation of a new nameplate. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. \n\nExplanation of Requirements of the Rule \n\n\tSince an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design that may be registered in the United States at some time in the future, this AD is being issued to prevent damage to wires or equipment and consequent smoke/fire in the cockpit from the heat generated in the wires during an overload condition. This AD requires procedures for replacement of a certain circuit breaker in the navigation transfer circuit located on the overhead circuit breaker panel with a certain new circuit breaker; and installation of a new nameplate. The actions are required to be accomplished in accordance with the service bulletin described previously. \n\nCost Impact \n\n\tNone of the Model DC-9-10 and -30 series airplanes affected by this action are on the U.S. Register. All airplanes included in the applicability of this rule currently are operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, the FAA considers that this rule is necessary to ensure that the unsafe condition is addressed in the event that any of these subject airplanes are imported and placed on the U.S. Register in the future. \n\n\tShould an affected airplane be imported and placed on the U.S. Register in the future, it would require approximately 1 work hour to accomplish the required actions, at an average labor rate of $60 per work hour. Required parts would cost $114 per airplane. Based on these figures, the cost impact of this AD would be $174 per airplane. \n\nDetermination of Rule's Effective Date \n\n\tSince this AD action does not affect any airplane that is currently on the U.S. register, it has no adverse economic impact and imposes no additional burden on any person. Therefore, prior notice and public procedures hereon are unnecessary and the amendment may be made effective in less than 30 days after publication in the Federal Register. \n\nComments Invited \n\n\tAlthough this action is in the form of a final rule and was not preceded by notice and 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\tSubmit comments using the following format: \n\nOrganize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues. \n\nFor each issue, state what specific change to the AD is being requested. \n\nInclude justification (e.g., reasons or data) for each request. \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 FAAto 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 2001-NM-102-AD." The postcard will be date stamped and returned to the commenter. \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. \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: