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 757-200, -200CB, and -300 series airplanes. That NPRM was published in the Federal Register on August 16, 2007 (72 FR 45961). That NPRM proposed to require repetitive inspections for cracks of the intercostal tee clips and attachment fasteners at the number 3 and number 4 doorstops of the passenger door cutouts, or repetitive inspections for cracks of the intercostal tee clips; and related investigative/corrective actions if necessary. That NPRM also provides an optional terminating action for the repetitive inspections. \n\nComments \n\n\tWe gave the public the opportunity to participate in developing this AD. We considered the comments received. \n\nSupport for the NPRM \n\n\tContinental Airlines (CAL) supports the NPRM and notes that it has an on-going customized passenger door maintenance program already in place to inspect the subject area on its airplanes at 4C and 8C heavy checks. CAL adds that it has found no cracks on its airplanes, but intends to incorporate the terminating action provided in the NPRM at the next 4C or 8C opportunity. \n\nRequest To Include Access and Close-up Costs \n\n\tBoeing asks that the costs to gain and close access for the proposed detailed inspection be included to better reflect the cost difference between the two inspection options provided in the NPRM (detailed versus borescope). Boeing estimates 9.5 work hours to gain access by removing existing galleys, and Boeing estimates another 10 work hours to replace the galleys after inspection to close access. Boeing states that this adds a total of 19.5 hours of work at a cost of $1,560 per airplane based on an average labor rate of $80 per work hour. This adds up to an additional cost to the fleet of $505,440 over the $51,840 cost that is shown. This access cost is not incurred if thealternative borescope inspection method is used; however, if repairs are to be performed, either to address cracking or to terminate inspections, the access and close-out costs would be incurred in addition to parts costs in order to perform the required part replacements. Boeing adds that this would affect the supplementary information in the estimated Costs of Compliance paragraph. \n\n\tWe acknowledge Boeing's concerns. However, because operators are given the option of doing the detailed inspection or the detailed inspection with a borescope (which takes longer), the cost depends on which inspection is done. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, or the costs of "on-condition'' actions such as repairs (that is, actions needed to correct an unsafe condition). We have made no change to the AD in this regard. \n\nClarification of Summary Language \n\n\tWe revised the Summary section of this final rule to specify the repetitive inspection methods. \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 as proposed. \n\nDifference Between the Proposed AD and Service Information \n\n\tThe service bulletin specifies to contact the manufacturer for instructions on how to repair certain conditions, but this AD requires repairing those conditions in one of the following ways: \n\n\tUsing a method that we approve; or Using data that meet the certification basis of the airplane, and that have been approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization whom we have authorized to make those findings. \n\nCosts of Compliance \n\n\tThere are about 912 airplanes of the affected design in the worldwide fleet. This AD affects about 324 airplanes of U.S. registry. \n\n\tThe detailed inspection, if accomplished, takes about 2 work hours per airplane, at an average work rate of $80 per work hour. Based on these figures, the estimated cost of the detailed inspections required by this AD is $51,840, or $160 per airplane, per inspection cycle. \n\n\tThe borescope inspection, if accomplished, takes about 3 work hours per airplane, at an average work rate of $80 per work hour. Based on these figures, the estimated cost of the borescope inspections required by this AD is $77,760, or $240 per airplane, per inspection cycle. \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, \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\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\n 2. The FAA amends Sec. 39.13 by adding the following new AD: