This amendment adopts a new AD for the specified BHT model helicopters with an installed T/R blade, part number 212-010-750 (all dash numbers), all serial numbers except those with a prefix of ''A'' and the number 17061 or larger. This action requires a one-time inspection of the T/R blade for corrosion or pitting after sanding the paint from the spar area between blade stations 22.5 and 40.0, and repairing or replacing the T/R blade if corrosion, pitting, or damage is discovered. This amendment is prompted by a report from the manufacturer that T/R blades with certain serial numbers may have manufacturing anomalies in the spar area as a result of the chemical milling process. The anomalies may be identified as pits or corrosion on the spar. This corrosion or pitting condition in the forward spar of a T/R blade, if not corrected, could lead to a crack in the T/R blade, loss of the T/R blade, and subsequent loss of control of the helicopter. \n\tWe have reviewed the following BHT Alert Service Bulletins, all Revision A, and all dated December 8, 2009, which specify a one-time inspection of the T/R blades for corrosion or pitting, and repairing or replacing the T/R blade if corrosion, pitting, or other damage is discovered: \n\tAlert Service Bulletin (ASB) No. 205-09-102, for Model 205A and 205A-1 helicopters; \n\tASB No. 205B-09-54, for Model 205B helicopters; \n\tASB No. 212-09-134, for Model 212 helicopters; \n\tASB No. 412CF-09-38, for Model 412CF helicopters; and \n\tASB No. 412-09-136, for Model 412 and 412EP helicopters. \n\tThis unsafe condition is likely to exist or develop on other helicopters of these same type designs. Therefore, this AD is being issued to require inspecting the T/R blades to detect corrosion or pitting in the forward spar area that could result in a crack, loss of a T/R blade, and subsequent loss of control of the helicopter. Accomplish the actions by following specified portions of the ASBs described previously. \n\tThe short compliance time involved is required because the previously described critical unsafe condition can adversely affect the structural integrity and controllability of the helicopter. Therefore, inspecting the T/R blade for corrosion or pitting is required within 25 hours time-in-service (TIS) or 30 days, whichever occurs first. This is a very short compliance time, and this AD must be issued immediately. \n\tSince a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. \n\tWe estimate that this AD will affect 263 helicopters. Removing, inspecting, refinishing, and re-installing the T/R blade will take about 10 work hours at an average labor rate of $85 per work hour and an approximate labor cost of $850 per helicopter. Replacing the T/R blade with an airworthy blade will take about 6 workhours at an average labor rate of $85 per work hour for an approximate labor cost of $510 per helicopter. Required parts will cost about $17,495 for each T/R blade assembly. Based on these figures, we estimate the total cost impact of the AD on U.S. operators to be $277,565, assuming all affected helicopters are inspected and three T/R blades are replaced. \n\nComments Invited \n\n\n\tThis AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an \n\n((Page 35335)) \n\nopportunity for public comment; however, we invite you to submit any written data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include ''Docket No. FAA-2011- 0561; Directorate Identifier 2011-SW-001-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD. We will consider all comments received by the closing date and may amend the AD in light of those comments. \n\tWe will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search function of our docket Web site, you can find and read the comments to any of our dockets, including the name of the individual who sent the comment. You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78). \n\nRegulatory Findings \n\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 the regulation:1. Is not a ''significant regulatory action'' under Executive Order 12866; \n\t2. Is not a ''significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and \n\t3. 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 an economic evaluation of the estimated costs to comply with this AD. See the AD docket to examine the economic evaluation. \n\nAuthority for This Rulemaking \n\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\tWe are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, ''General requirements.'' Under that section, Congress chargesthe 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\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.