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 Model DC-9-80 series airplanes and Model MD-88 airplanes was published in the Federal Register on September 14, 1994 (59 FR 47103). That action proposed to require a visual inspection to detect damage, burn marks, or black or brown discoloration at certain electrical plugs and receptacles of the sidewall lighting in the passenger cabin, and correction of discrepancies. It also proposed to require the eventual modification of the electrical connectors of the sidewall lighting, which, when accomplished, would terminate the inspection requirement. \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\n\tOne commenter supports the proposed rule. \n\n\tOne commenter requests that, prior to issuing afinal rule, the FAA investigate the possibility of problems (i.e., overheated connectors, smoke in the cabin, etc.) resurfacing at another connector location. The commenter bases this request upon service history following accomplishment of the requirements of AD 91-10-08, amendment 39-6990 (55 FR 51427, December 14, 1990). AD 91-10-08 requires modification of the sidewall lighting system on these same airplanes to preclude overheated connectors, smoke in the cabin, etc., which is similar to the modification described in the proposal (reference McDonnell Douglas MD-80 Service Bulletin 33-99, dated May 24, 1994). This commenter points out that, since accomplishing the modification required by AD 91-10-08, the same problems (i.e., overheated connectors, smoke in the cabin, etc.) have resurfaced at the sidewall lighting connectors located "downstream" at the bag bins. Therefore, the commenter assumes these problems will resurface either at the new disconnects being installed in accordance with the proposal, or at the cabin lighting ballast connectors. \n\n\tThe FAA has re-evaluated the modification required by this AD, and reviewed other relevant data currently available. The FAA finds no basis to support the commenter's suggestion that this problem could resurface at another connection location in the airplane. However, the FAA may consider further rulemaking action if service history indicates that the modification required by this AD produces questionable results. \n\n\tAnother commenter requests that the proposed modification be revised to retrofit a 115 volt electronic ballast system, instead of removing the existing 230 volt system and installing separate wire splice-connectors or hard splice at the 230 VAC (400 Hz) power wires. The commenter considers this suggested method to be superior to the proposed modification for addressing failures of the electrical connectors in the sidewall fluorescent lighting. The commenter states that failures in this systemwere fixed previously in a similar manner (reference AD 91-10-08), but at a different location. The commenter suggests that failures in this system could occur again, but in another location. The commenter states that the root cause of this problem is the high energy level required by the current magnetic ballasts for the sidewall lights. \n\n\tThe FAA does not concur that the rule should be revised to include this suggested action since sufficient data were not provided. As indicated previously, the FAA finds no basis at this time to support any suggestion that this problem could resurface at another connection location in the airplane, or that the proposed modification is inappropriate. However, the FAA also recognizes that alternative methods of compliance with the intent of this rule may also exist; a provision for the approval of such methods is contained in paragraph (c) of the final rule. \n\n\tOne commenter requests that the proposal be revised to require improvement of the existing connector, rather than the proposed action that would break out the 230 volt wire from the bundle and make a second connection to alleviate the problem in the existing connector. Again, the FAA does not concur with this suggestion since sufficient justification and service data was not presented. The FAA has determined that the existing current technology adequately addresses the identified unsafe condition by minimizing the possibility of failure of the electrical connectors. However, under provisions of paragraph (c) of the final rule, operators may apply for the approval of an alternative method of compliance, such as use of a different connector, if sufficient data are presented to the FAA that would justify such approval. \n\n\tTwo commenters request that the applicability of the proposal be limited. One of these commenters requests that the applicability be limited to ". . . Model MD-88 airplanes equipped with magnetic ballasts." This commenter suggests that McDonnellDouglas MD-80 Service Bulletin 33-99, dated May 24, 1994, referenced in the proposal as the appropriate source of service information, is not the optimal solution to the sidewall connector problem. This commenter, in conjunction with McDonnell Douglas and Page Aerospace, has successfully completed testing of the Page electronic ballast, which has been approved as an equivalent level of safety to the modification described in Service Bulletin 33-99. The other commenter requests that the applicability of the proposal be limited to ". . . Model MD-88 airplanes equipped with inter-bin electrical connectors described (or similar to those described) in McDonnell Douglas MD-80 Service Bulletin 33-99, dated May 24, 1994." This commenter suggests that the effectivity listing of Service Bulletin 33-99 does not accurately reflect the fleet configuration. \n\n\tThe FAA does not concur with these commenters' request to limit the applicability of the proposal. The FAA does not consider it appropriate to include various provisions in an AD applicable to a single operator's unique configuration of an affected airplane. Paragraph (c) of this AD provides for the approval of an alternative method of compliance to address these types of unique configurations. \n\n\tTwo commenters question the FAA's cost and work hour estimate in the preamble of the proposal. One commenter has determined that it would take approximately 100 work hours per airplane to accomplish the proposed requirements. This commenter also states that McDonnell Douglas is not supplying required parts at no cost to the operators, as stated in the proposal, but is charging $1,870 per kit. Another commenter suggests that 75 work hours per airplane would be more appropriate than the 50 work hours stated in the proposal. After considering the data presented by these commenters, the FAA finds it necessary to revise its previous estimates. The FAA concurs that 75 work hours is closer to the actual number of labor hours necessary for accomplishing the required actions. The FAA also has verified with the manufacturer that the required parts will cost operators $1,870 per kit. In light of this, the economic impact information, below, has been revised to indicate the higher number of work hours and the price of required parts. \n\n\tAdditionally, the FAA has recently reviewed the figures it has used over the past several years in calculating the economic impact of AD activity. In order to account for various inflationary costs in the airline industry, the FAA has determined that it is necessary to increase the labor rate used in these calculations from $55 per work hour to $60 per work hour. The economic impact information, below, has been revised to reflect this increase in the specified hourly labor rate. \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 repaired in 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 added to this final rule to clarify this long-standing requirement. \n\n\tAfter careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the change previously described. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD. \n\n\tThere are approximately 907 McDonnell Douglas Model DC-9-80 series airplanes and Model MD-88 airplanes of the affected design in the worldwide fleet. The FAA estimates that 490 airplanes of U.S. registry will be affected by this AD, that it will take approximately 75 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $1,870 per airplane. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $3,121,300, or $6,370 per airplane. \n\n\tThe total 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. \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 onthe 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\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.\tThe authority citation for part 39 continues to read as follows: \n\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\n\t2.\tSection 39.13 is amended by adding the following new airworthiness directive: