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 McDonnell Douglas Model 717-200 airplanes. That NPRM was published in the Federal Register on March 28, 2006 (71 FR 15351). That NPRM proposed to require replacing the lightning critical clamp bases of the fuel tank vent system with improved clamp bases; and checking the electrical bond of the modified self-bonding mounting clamps. \n\nActions Since NPRM Was Issued \n\n\tSince we issued the NPRM, Boeing has released Service Bulletin 717- 28-0004, Revision 3, dated June 21, 2006. In the NPRM, we referenced Revision 2 of the service bulletin, dated March 11, 2005, as the appropriate source of service information. The procedures in Revision 3 are essentially the same as those in Revision 2. Revision 3 also provides detailed instructions for checking the electrical bond of the modified self-bonding mounting clamps and accomplishing corrective actions if necessary. If the electrical conductivity of the surface is greater than 2.5 milliohms, the corrective actions include surface prepping and applying a chemical conversion coat to the surface of the structural bracket and vent pipe. (The NPRM proposed to repair the electrical bond of the mounting clamp according to a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, if any electrical bond fails the check. The NPRM specified that Chapter 28-00-00 of the Boeing 717 Aircraft Maintenance Manual and Chapter20- 50-01 of the Boeing 717 Standard Wiring Practices Manual (SWPM) are one approved method.) \n\tWe have revised paragraph (f) of this AD to reference Revision 3 as the appropriate source of service information for replacing the lightning critical clamp bases of the fuel tank vent system with improved clamp bases; and checking the electrical bond of the modified self-bonding mounting clamps. We have also revised paragraph (f) to allow operators to either repair any electrical bond in accordance with Revision 3 of the service bulletin, or according to a method approved by the Manager, Los Angeles ACO. In addition, we have added a new paragraph (g) to this AD, giving credit for actions done before the effective date of this AD in accordance with Revision 2. We have also revised the applicability of paragraph (c) of this AD to reference Revision 3. Revision 2 and Revision 3 both apply to Model 717-200 airplanes having fuselage numbers 5002 through 5121 inclusive; therefore, the applicability of this AD has not changed. \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. We have considered the comment received. \n\nSupport for the NPRM \n\n\tBoeing and AirTran Airways support the NPRM. \n\nRequest for Clarification \n\n\tAirTran Airways states that Boeing Service Bulletin 717-28-0004 refers to Chapter 20-50-01 of the Boeing DC, MD, and 717 SWPM, Class"L," for instructions on accomplishing a check of the electrical bonds. AirTran Airways points out that Class"L" is not identified in Chapter 20-50-01 of the SWPM; instead, that chapter provides the maximum direct current (DC) resistance and path for lightning protection. Therefore, AirTran requests clarification of Class"L." \n\tAs stated previously, since the NPRM was issued, Boeing has issued Revision 3 of the service bulletin and that revision is cited in this final rule. Revision 3 deletes the reference to Class"L." \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 changes described previously. We have determined that these changes 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 120 airplanes of the affected design in the worldwide fleet. This AD affects about 92 airplanes of U.S. registry. The required actions take about 16 work hours per airplane, at an average labor rate of $80 per work hour. Required parts cost about $239 per airplane. Based on these figures, the estimated cost of the AD for U.S. operators is $139,748, or $1,519 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 theAgency's authority. \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\tFor the reasons discussed above, I certify that this AD: \n\t(1) Is not a "significant regulatory action" under Executive Order 12866; \n\t(2) Is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and \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\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 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 Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):