The FAA proposed to amend 14 CFR part 39 with an AD for certain Boeing Model 777-200 and -300 series airplanes. That action, published in the Federal Register on February 15, 2005 (70 FR 7681), proposed to require inspecting the valve control and indication wire bundles of the fuel system of the wing rear spar for discrepancies, and corrective action if necessary. \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. \n\nSupport for Proposed AD \n\n\tOne commenter, the airplane manufacturer, concurs with the content of the proposed AD. Another commenter states that it has done the inspection specified in the service information referenced in the proposed AD on all of its Model 777-200 series airplanes. \n\nRequest for Clarification of Inconsistencies in Referenced Service Information \n\n\tOne commenter concurs with the intent of the proposed AD, but points out some inconsistencies found in the Accomplishment Instructions of the referenced service bulletin. The commenter states that the service bulletin specifies leaving the wire bundle intact, according to the original factory installation, if the inspection does not reveal any wire chafing; however, the service bulletin also specifies modifying the wire bundle routing by installing additional new hardware, such as spacers, if any chafing is found. \n\n\tThe commenter also states that the intent of the proposed AD is to make sure that there is no wire chafing against the structure. The commenter believes that there will potentially be two different aircraft configurations if the modification is required. The commenter states that the configuration with no spacers may cause the wire bundle to rub against the structure in the future. The commenter adds that, without spacers installed, there is no way to positively prove in the future that the proposed AD was complied with in the past. The commenter prefers to modify the wire bundle routing (adding new spacers) even if there is currently no chafing found, in order to keep common configuration within the fleet and prevent potential problems in the future. \n\n\tWe infer that the commenter is asking for clarification about its perceived inconsistencies in the referenced service bulletin. We agree. The service bulletin describes procedures for inspecting the wire bundles in the wing rear spar for three discrepancies (i.e., wire chafing, wire damage, and any missing spacer at each of the five clamping points). The commenter believes there are only two discrepancies (i.e., wire chafing and wire damage). As a result, the commenter's statement that the wire bundle is left intact if the inspection does not reveal any wire chafing is incorrect. There are two conditions that need to be met for the wire bundle to be "left intact." The service bulletin specifies "if no wire bundle damage or chafing is found" and "if the wire bundle routing is in compliance, no more action is required." Wire bundle routing compliance is defined in the service bulletin as "at least one spacer is found installed at each of the five clamping points." In addition, the service bulletin specifies "if no chafing or damage is found" and "if the wire bundle routing is not in compliance, make a modification to the wire bundle routing." The modification involves installing a spacer, screw, clip nut, and clamp, as applicable, at any clamping point with no spacer. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition of this AD (i.e., wire chafing and damage). \n\n\tIn addition, we do not agree with the commenter's statement there is no way to positively prove in the future that the AD was complied with in the past. Compliance with an AD is documented in the permanent records of the affected airplanes and can be audited by a principal maintenance inspector. Therefore, we have made no change to the AD in these regards. \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 403 airplanes of the affected design in the worldwide fleet. This AD will affect about 129 airplanes of U.S. registry. The inspection will take about 1 work hour per airplane, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the inspection for U.S. operators is $8,385, or $65 per airplane. \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 theauthority 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 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\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 airworthinessdirective (AD):