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 737-600, -700, and -800 series airplanes was published in the Federal Register on July 14, 1999 (64 FR 37918). That action proposed to require installation of a drain at each of the number 2 window frame assemblies in the airplane. \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. \n\n\tOne commenter has no objection to the proposed rule, and one commenter states that the rule does not affect it. \n\nRequest to Reduce Compliance Time \n\n\tOne commenter supports the proposed rule, but requests that the compliance time be reduced to 12 months from 18 months. The commenter also requests that the maximum time from publication of the final rule in the Federal Register until the effective date of the rule be no more than 30 days. The commenter states that based upon the proposed compliance times, adding in the administrative procedures time to publish the final rule and a possible "delayed" effective date, the affected airplanes may go through two more cold weather seasons before an operator must correct this unsafe condition. The FAA does not concur with the commenter's request to reduce the compliance time of the AD, or accelerate the effective date to no more than 30 days after publication in the Federal Register. Reduction of the compliance time from 18 to 12 months would necessitate reopening the comment period, resulting in further delay of the AD. In developing the compliance time for this AD action, the FAA considered not only the safety implications of the unsafe condition addressed, but the average utilization rate of the affected fleet, the practical aspects of an orderly modification of the fleet during regular maintenance periods, theavailability of parts, and the time necessary for the rulemaking process. The proposed compliance time of 18 months after the effective date of the AD was determined to be appropriate. \n\n\tAlso, the effective date for an AD action is not arbitrarily assigned, as the commenter implies. The Administrative Procedure Act (APA) requires that Federal agencies provide at least 30 days after publication of a final rule in the Federal Register before making it effective, unless "good cause" can be found not to do so. Under the APA, the basis for this finding is similar to the basis for a finding of good cause to dispense with notice and comment procedures in issuing rules. In the case of certain AD's, the nature of the action may be of such urgency that for the FAA to take any additional time to provide notice and opportunity for prior public comment would be impracticable; in those cases, the FAA finds good cause for making the rule effective in less than 30 days. In the case of this AD action, the FAA does not consider that the addressed unsafe condition is of such a critical nature that time could not be afforded for notice and the opportunity for the public to comment on the rule. It follows then, that there is no basis for finding good cause for making this rule effective in less than 30 days. For final rules following notice, the FAA usually assigns an effective date of 30 days after publication. No change to the final rule is necessary.\n\n Request to Increase the Cost Estimate \n\n\tOne commenter requests that the number of work hours in the cost estimate be increased to 5 work hours from 3 work hours. The commenter states that Boeing Service Bulletin 737-56-1011, dated November 19, 1998, states that 5 hours are required per airplane to perform the installation, and the rulemaking cost impact analysis should be consistent with the work hours quoted in the service bulletin. The FAA does not concur with the commenter's request. The cost impact information, below, describes only the "direct" costs of the specific actions required by this AD. The number of work hours necessary to accomplish the required actions, specified as 3 in the cost impact information below, was provided to the FAA by the manufacturer based on the best data available to date. This number represents the time necessary to perform only the actions actually required by this AD. The FAA recognizes that, in accomplishing the requirements of any AD, operators may incur "incidental" costs in addition to the "direct" costs. The cost analysis in AD rulemaking actions, however, typically does not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions. Because incidental costs may vary significantly from operator to operator, they are almost impossible to calculate. No change to the final rule is necessary. \nConclusion \n\n\tAfter careful review of the available data, including thecomments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed. \n\nCost Impact \n\n\tThere are approximately 144 airplanes of the affected design in the worldwide fleet. The FAA estimates that 57 airplanes of U.S. registry will be affected by this AD, that it will take approximately 3 work hours per airplane to accomplish the required installation, and that the average labor rate is $60 per work hour. Required parts will cost approximately $536 per airplane. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $40,812, or $716 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 theStates, 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 ofSubjects 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\n PART 39 - AIRWORTHINESS DIRECTIVES \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: