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 Boeing Model 777-200 series airplanes was published in the Federal Register on September 2, 1997 (62 FR 46221). That action proposed to require modifying the sliding surface of the door 1 left and door 1 right evacuation slide/rafts. \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 comments received. One commenter supports the proposed AD and two commenters oppose it.\n \nRequest that the AD Not Be Issued \n\n\tThe Air Transport Association (ATA) of America states that one operator has already accomplished the modification according to the manufacturer's service bulletin. That operator opposes the proposed rule and states that all 16 of its Model 777 series airplanes have been modified in accordance with the referenced service bulletins (Boeing Service Bulletin 777-25A0035 and Air Cruisers Company Service Bulletin S.B 777-107-25-02), that no other Model 777 operators are affected by these service bulletins, and that the proposed AD will not have a positive impact on safety. For these reasons, the operator does not consider that it is necessary for the FAA to issue the proposed AD. \n\n\tAnother commenter, the manufacturer, states that the proposed AD is not warranted. That commenter advises that it is committed to ensuring the safety of Model 777 series airplanes and has worked aggressively with the affected operators to accomplish the door 1 slide/raft modifications at the earliest possible date. In a letter dated October 15, 1997, the commenter states that 107 slide/rafts out of 113 were modified, only 6 remain unmodified, and none of the unmodified slide/rafts are owned by a U.S. operator. However, in a letter dated October 23, 1997, the commenter states that 104 slide/rafts have been modified and only 9 slide/rafts remain unmodified. Upon inquiry about the correct number of slide/rafts, the FAA was informed by the commenter that the correct numbers were cited in the October 15 letter. That commenter also states that it will continue its efforts to modify the remaining slide/rafts as soon as possible.\n \n\tThe FAA does not concur that issuance of the rule is unnecessary or that it would not have a positive impact on safety, even though the FAA has received information indicating that most of the modifications required by the AD have been accomplished. In accordance with various bilateral airworthiness agreements with countries around the world, the FAA is obligated to advise foreign airworthiness authorities of unsafe conditions identified in products manufactured in the United States. The issuance of AD's is the means by which the FAA satisfies this obligation, and therefore, the issuance of this AD is both warranted and necessary. \n\nFurtherEvaluation of the Slide/Raft Design Recommended \n\n\tThe Air Line Pilots Association supports the proposed AD. However, this commenter questions whether the proposed solution for applying a dry lubricant to the top of the sliding area has been thoroughly evaluated to ensure that it is usable in all possible conditions that would be encountered during the life of the slide. The commenter also questions how the evacuation problem was discovered, since it was not immediately evident in the evacuation demonstration. In addition, the commenter contends that certain evacuation conditions could result in unsafe slide performance (e.g., when the slide is wet with rain). The commenter recommends further evaluation of the slide/raft evacuation scenario. \n\n\tAfter careful consideration of the questions and recommendations presented by the commenter, the FAA does not concur that additional evaluation is required to correct the identified unsafe condition. During evacuation tests of the slide/raft, evacuees wore clothing of several types of fabric. Testing also included various sliding surface treatments, lubricant applications, evacuee jumping styles, sliding angles (sill height), and wet and dry sliding surface conditions. After careful analysis of these test results, the FAA has determined that further evaluation is not necessary. In addition, the FAA has determined that the application of the dry lubricant, as specified in the AD, is adequate to ensure an appropriate level of safety during an evacuation. The FAA has made no change to the final rule. \n\nConclusion \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 as proposed.\n\n Cost Impact \n\n\tThere are approximately 43 Boeing Model 777-200 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 16 airplanes of U.S. registry will be affected by this AD,that it will take approximately 4 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will be provided by the manufacturer at no cost to the operators. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $3,840, or $240 per airplane. \n\n\tThe 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\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 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 AviationRegulations (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: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 (Amended) \n\t2. Section 39.13 is amended by adding the following new airworthiness directive: