A proposal to amend 14 CFR part 39 to include an AD for the specified model helicopters was published in the Federal Register on February 10, 2004 (69 FR 6214). That action proposed to require inspecting the vertical fin skin paneling to determine if it was manufactured with the correct wall thickness. \n\n\tThe Luftfahrt-Bundesamt (LBA), the airworthiness authority for the Federal Republic of Germany, notified the FAA that an unsafe condition may exist on ECD Model MBB-BK117 helicopters, Model A-1 up to B-2, serial number (S/N) all, and Model C-1, S/N 7500 up to 7545. The LBA advises that during tail boom production, metal sheeting of 0.6-millimeter (mm) thickness was found instead of the specified 0.8-mm thickness for the skin paneling of several tail booms. \n\n\tECD has issued Alert Service Bulletin No. ASB-MBB-BK117-30-109, Revision 1, dated July 3, 2003, which specifies measuring the wall thickness of the skin paneling of the vertical fin to determine thethickness. The LBA classified this service bulletin as mandatory and issued AD No. 2003-219, dated August 21, 2003, to ensure the continued airworthiness of these helicopters in the Federal Republic of Germany. \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposal or the FAA's determination of the cost to the public. The FAA has determined that air safety and the public interest require the adoption of the rule as proposed. \n\n\tThe FAA estimates that this AD will affect 132 helicopters of U.S. registry. The required actions will take about 1 hour per helicopter to do at an average labor rate of $65 per work hour. Based on these figures, we estimate the total cost impact of the AD on U.S. operators to be $8580 assuming no vertical fins will need to be replaced. \n\n\tThe regulations adopted herein will not have a substantial direct effect on the States, on the relationship between the nationalGovernment and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132. \n\n\tFor the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (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. A final evaluation has been prepared for this action and is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Safety. \n\nAdoption of the Amendment \n\n\tAccordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: \n\nPART 39-AIRWORTHINESS DIRECTIVES \n\n\t1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 (Amended) \n\n\t2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: