The FAA proposed to amend 14 CFR part 39 with an AD for certain Boeing Model 767-200, -300, and -300F series airplanes. That action, published in the Federal Register on January 5, 2005 (70 FR 727), proposed to require installing a new, improved foam seal around certain ducts in the forward cargo compartment. \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. We have considered the comments that have been submitted on the proposed AD. Two commenters concur with the proposed AD. \n\nRequest To Change Costs of Compliance Section \n\n\tOne commenter estimates that the proposed modification of the foam seals requires approximately 3.5 work hours per airplane, at a cost of $22,220 for its fleet. The commenter notes that it has accomplished the modification on all of its fleet. A second commenter estimates that the required work hours for the proposed AD would be 4.5 work hours per airplane, as specified in the referenced service information, at an estimated cost of $292.50 per airplane. \n\n\tWe infer that the commenters are asking that the work hour estimate specified in the "Costs of Compliance" section be increased. We do not agree. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. This AD requires installing a new, improved foam seal around certain ducts in the forward cargo compartment. We recognize that in accomplishing the requirements of any AD, operators may incur incidental costs in addition to the direct costs. However, the cost analysis in AD rulemaking actions 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. We have made no change to the AD in thisregard. \n\nConclusion \n\n\tWe have carefully reviewed the available data, including the comments that have been submitted, and determined that air safety and the public interest require adopting the AD as proposed. \n\nCosts of Compliance \n\n\tThere are about 468 airplanes of the affected design in the worldwide fleet. This AD affects about 342 airplanes of U.S. registry. \n\n\tFor Group 1 and 2 airplanes: The foam seal installation around the cooling air supply and exhaust ducts takes about 2 work hours per airplane, at an average labor rate of $65 per work hour. The cost of parts is minimal. Based on these figures, the estimated cost of the installation is $130 per airplane. \n\n\tFor Group 2 airplanes: The foam seal installation around the avionics cooling and refrigeration unit duct takes about 2 work hours per airplane, at an average labor rate of $65 per work hour. The cost of parts is minimal. Based on these figures, the estimated cost of the installation is $130 per airplane.Authority 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\tWe have determined that this AD will not have federalism implications under Executive Order 13132. This ADwill 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; \n\n\t(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\tWe prepared a regulatory evaluation of the estimated costs to comply with this AD. See the ADDRESSES section for a location to examine the regulatory evaluation. \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 airworthiness directive (AD):