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 737-100 and -200 series airplanes was published in the Federal Register on August 28, 1996 (61 FR 44230). That action proposed to require replacing the aileron (lateral) control transfer mechanism with a new modified mechanism, or reworking the existing mechanism. \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\nSupport for the Proposal \n\n\tTwo commenters support the proposed rule.\n\n Request for Risk Benefit Analysis \n\n\tOne commenter believes that the FAA should perform a risk benefit analysis before proceeding with the proposed AD. This commenter does not disagree with the requirements of the proposal; however, the commenter suggests that the proposed compliance time of 18 months could overburden competent machine facilities and lead to undesirable workmanship, which would subject the airlines and the flying public to unnecessary risk. \n\n\tThe FAA does not concur with the commenter's request. The commenter did not submit analyses or data to substantiate its claim that competent machine facilities would be overburdened by the requirements of this AD. The FAA has considered the costs of complying with this AD, and does not consider those costs to be excessive to correct the unsafe condition. \n\nRequest to Revise Statement of Findings of Critical Design Review Team \n\n\tOne commenter requests the second paragraph of the Discussion section that appeared in the preamble to the proposed rule be revised to accurately reflect the findings of the Critical Design Review (CDR) team. The commenter asks that the FAA delete the one sentence in that paragraph, which read: "The recommendations of the team include various changes to the design of the flightcontrol systems of these airplanes, as well as correction of certain design deficiencies." The commenter suggests that the following sentences should be added: "The team did not find any design issues that could lead to a definite cause of the accidents that gave rise to this effort. The recommendations of the team include various changes to the design of the flight control systems of these airplanes, as well as incorporation of certain design improvements in order to enhance its already acceptable level of safety." \n\n\tThe FAA does not find that a revision to this final rule in the manner suggested by the commenter is necessary, since the Discussion section of a proposed rule does not reappear in a final rule. The FAA acknowledges that the CDR team did not find any design issue that could lead to a definite cause of the accidents that gave rise to this effort. However, as a result of having conducted the CDR of the flight control systems on Boeing Model 737 series airplanes, the team indicated that there are a number of recommendations that should be addressed by the FAA as may be appropriate to any particular (or all) model(s) of the Model 737. \n\nRequest to Revise Service Bulletin Citation \n\n\tOne commenter requests that the FAA change the service bulletin citation from "Boeing Service Bulletin 27-1033" to "Boeing Service Bulletin 737-27-1033." The commenter considers this to be clearer. \n\n\tThe FAA acknowledges that some clarification is necessary. The title that actually appears on the service bulletin document itself is "Boeing Service Bulletin 27-1033;" therefore, the FAA disagrees with the commenter's specific suggestion. However, to avoid any confusion on the part of operators, the FAA has revised the final rule to refer to the service bulletin as "Boeing 737 Service Bulletin 27-1033." \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 with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCost Impact \n\n\tThere are approximately 236 Model 737-100 and -200 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 157 airplanes of U.S. registry will be affected by this AD. \n\n\tFor operators that elect to accomplish the replacement, it will take approximately 20 work hours per airplane to accomplish it, at an average labor rate of $60 per work hour. Required parts will cost approximately $15,343 per airplane. Based on these figures, the cost impact of the replacement on U.S. operators is estimated to be $16,543 per airplane. \n\n\tFor operators that elect to accomplish the rework by using new components, it will take approximately 40 work hours to accomplish it, at an average labor rate of $60 per work hour. Required parts will costapproximately $6,500. Based on these figures, the cost impact of the rework (by using new components) on U.S. operators is estimated to be $8,900 per airplane. \n\n\tFor operators that elect to accomplish the rework by machine shop rework of the components, it will take approximately 70 work hours to accomplish it, at an average labor rate of $60 per work hour. Required parts will cost approximately $1,450. Based on these figures, the cost impact of the rework (by machine shop rework of the components) on U.S. operators is estimated to be $5,650 per airplane. \n\n\tThe cost impact figures discussed above are 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, oron 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\n List 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: 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: