Discussion \n\n\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Boeing Model 737-600, -700, -700C, -800 and -900 series airplanes. That NPRM was published in the Federal Register on June 6, 2007 (72 FR 31202). That NPRM proposed to require inspecting ground blocks GD261 and GD264 for corrosion, measuring the electrical bond resistance between the ground blocks and the airplane structure, separating the ground wires for the fuel boost pump circuit between ground blocks GD261 and GD264, and doing corrective actions if necessary. \n\nComments \n\n\tWe gave the public the opportunity to participate in developing this AD. We have considered the comments received. \n\nSupport for the NPRM \n\n\tAirTran Airways supports the NPRM. \n\nRequest to Incorporate Revised Service Bulletin \n\n\tThe NPRM referred to Boeing Special Attention Service Bulletin 737- 28-1257, dated February 26, 2007, as the appropriate source of service information for the proposed requirements. Boeing requests that we revise the NPRM to refer to Revision 1 of the service bulletin, which Boeing issued after we issued the NPRM. \n\n\tWe have reviewed the revised service bulletin. In Revision 1, dated November 28, 2007, Boeing removed certain annunciator checks, updated temperature control operational test instructions, and removed certain wire separation requirements. Revision 1 provides no substantive changes or additional work. We agree to revise the final rule to require Revision 1, and to provide credit for the original version. \n\nConclusion \n\n\tWe reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We also determined that these changes will not increase the economic burden on any operator or increase the scope of the AD. \n\nCosts of ComplianceThere are about 1,871 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this AD. \n\n\t\t\t\tEstimated Costs \n\n\nWork hours\nAverage labor rate per hour\nParts\nCost per airplane\nNumber of U.S.- registered airplanes\nFleet cost\n1\n$80\nNone\n$80\n702\n$56,160\n\nAuthority for This Rulemaking \n\n\tTitle 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. "Subtitle VII: Aviation Programs" describes in more detail the scope of the Agency's authority. \n\n\tWe are issuing this rulemaking under the authority described in "Subtitle VII, Part A, Subpart III, Section 44701: General requirements." Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. \n\nRegulatory Findings \n\n\tThis AD will not have federalism implications under Executive Order 13132. This AD 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. \n\n\tFor the reasons discussed above, I certify that this AD: \n\n\t(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 \n\n\t(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. \n\n\tYou can find our regulatory evaluation and the estimated costs of compliance in the AD Docket. \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\nAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. 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\n2. The FAA amends Sec. 39.13 by adding the following new AD: