Examining the Docket \n\n\tYou may examine the airworthiness directive (AD) docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif Building at the street address stated in the ADDRESSES section. \n\nDiscussion \n\n\tThe FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to certain Boeing Model 777 airplanes. That NPRM was published in the Federal Register on March 21, 2006 (71 FR 14126). That NPRM proposed to require a one-time inspection of the first bonding jumper aft of the bulkhead fitting to detect damage or failure and to determine the mechanical integrity of its electrical bonding path, and repair if necessary; measuring the bonding resistance between the fitting for thefuel feed tube and the front spar in the left and right main fuel tanks, and repairing the bonding if necessary; and applying additional sealant to completely cover the bulkhead fittings inside the fuel tanks. \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. We have considered the comments received. \n\nSupport for the NPRM \n\n\tBoeing concurs with the NPRM. \n\nRequest To Revise the Service Bulletin \n\n\tJapan Airlines (JAL) suggests that Boeing should revise Boeing Special Attention Service Bulletin 777-28-0044, Revision 1, dated December 20, 2005, to incorporate the repair instructions for the bonding path rather than having them separate from the service bulletin. (This service bulletin was referenced as the appropriate source of service information for accomplishing the actions in the NPRM.) JAL states that it would be simpler if the AD referred to the service bulletin for the whole work instructions, including all repair procedures. \n\n\tWe partially agree. We agree with JAL that having all repair procedures in one place can be simpler for operators. We do not agree that Boeing should revise its service bulletin for this reason, nor can we request a manufacturer to revise a service bulletin to make addressing an unsafe condition more convenient. Waiting to include a revised service bulletin in this action would delay addressing an unsafe condition. In addition, manufacturers' service information often refers to procedures in various maintenance manuals for a number of reasons (e.g., to keep procedures in the service bulletin from becoming too cumbersome, or because the procedure is an industry best practice). In this case, the referenced service bulletin refers to Chapter 28-00- 00 of the Boeing 777 Aircraft Maintenance Manual (AMM) for doing the general visual inspection of the first bonding jumper aft of the bulkhead fitting to detect damage or failure and to determine the mechanical integrity of its electrical bonding path. We assume some of JAL's issue stems from the statement in paragraph (f)(1) of the NPRM that these conditions must be repaired according to a method we approve, and that Chapter 28-00-00 of the Boeing 777 AMM is one approved method. We included that statement in paragraph (f)(1) because although the service bulletin implies repair for the bonding path in accordance with the AMM chapter, the statement in the service bulletin is not explicit and could be confusing. We have not changed the final rule in this regard. \n\nRequest To Revise Cost Estimate \n\n\tAir Transport Association (ATA), on behalf of American Airlines, requests that we revise the cost estimate. American Airlines quotes an "AD memo" that reads "FAA estimates that 46 airplanes of U.S. registry would be affected by this rulemaking." American Airlines points out that it has 45 affected airplanes, and that there are three other U.S. operators that also have affected airplanes. American Airlines also doesnot concur with the statement in the NPRM that the cost of the proposed actions would be $640 per airplane for eight hours of work. Although American Airlines understands that the FAA does not consider access time when calculating the cost to comply with an AD, American Airlines believes it is important to note that this inspection and sealant application requires complete draining and venting of the fuel tanks, which alone could take eight hours. In total, American Airlines estimates the inspection and sealant application will require approximately 48 work hours per airplane at a cost of $202,586. \n\n\tWe partially agree with the commenters. We agree that there are more than 45 airplanes of U.S. registry affected by the actions in the NPRM. We are not familiar with an "AD memo," which could have been a summary of the NPRM initiated by another source. The number of affected airplanes listed in the NPRM is 131 rather than 45. We have revised the "Costs of Compliance" paragraph to reflect this information. \n\n\tWe do not agree with revising the number of work hours in the cost estimate. As American Airlines points out, we do not consider access time when calculating the cost of an AD. The cost information below describes only the direct costs of the specific actions required by this AD. Based on the best data available, the manufacturer provided the number of work hours (8) necessary to do the required actions. This number represents the time necessary to perform only the actions actually required by this AD. We recognize that, in doing the actions required by an AD, operators may incur incidental costs in addition to the direct costs. The cost analysis in AD rulemaking actions excludes the costs of the time required to gain access and close up, as American points out, but it also excludes other incidental costs such as the time necessary for planning, or time for other administrative actions. All of these costs may vary significantly among operators and are almost impossible to calculate. We have not changed the final rule in this regard. \n\nExplanation of Change in Applicability \n\n\tWe have revised the applicability of this final rule to match the most current type certificate data sheet for the affected airplanes. \n\nConclusion \n\n\tWe have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the change described previously. We have determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCosts of Compliance \n\n\tThere are about 497 airplanes of the affected design in the worldwide fleet. This AD affects about 131 airplanes of U.S. registry. The actions take about 8 work hours per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the AD for U.S. operators is $83,840, or $640 per airplane. \n\nAuthority for This RulemakingTitle 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 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 and placed it in the AD docket. 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 theauthority 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 Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):