This amendment adopts a new AD for the specified Sikorsky model helicopters. This amendment is prompted by the discovery that a certain part-numbered RBD manufactured by PHC was improperly heat treated resulting in "soft" RBDs that have an increased wear rate compared to those heat treated in accordance with the type design requirement. Further investigation reveals that "soft" RBDs develop cracks more frequently than previously manufactured RBDs. The actions specified in this AD are intended to prevent failure of the RBD, damage to the rotor blades and nearby hydraulic and fuel lines, and subsequent loss of control of the helicopter. \n\n\tThe FAA has reviewed Sikorsky Alert Service Bulletin (ASB) Nos. 76-66-36, dated November 12, 2002, and 76-66-37, dated January 31, 2003. ASB No. 76-66-36 describes a one-time visual inspection of the RBD to determine the manufacturer and to reidentify the RBD if necessary. ASB No. 76-66-36 also specifies an initial and recurring inspection for certain reidentified RBDs. ASB No. 76-66-37 specifies removing certain RBDs from service and provides interim instructions for operating the helicopter until a replacement RBD is installed. \n\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 prevent failure of the RBD, damage to the rotor blades and nearby hydraulic and fuel lines, and subsequent loss of control of the helicopter. This AD requires the following: \n\nBefore further flight, determine the manufacturer of each RBD by examining the part number (P/N) markings. This AD requires no further action if the manufacturer is BF Goodrich or Goodyear. \n\nIf the RBD is manufactured by PHC, reidentify it with a P/N 76363-09103-104 or -105, as applicable, depending on the serial number of the RBD. If you cannot determine the PHC RBD serial number or the manufacturer, reidentify the RBD with P/N 76363-09103-104. \n\nBefore thefirst flight of the next day following any day in which the RBD was used, visually inspect each RBD, P/N 76363-09103-104, for a crack. \n\nIf you find a crack through the entire RBD thickness or two or more surface cracks between adjacent boltholes, replace the RBD with an airworthy RBD before further flight. If you find a surface crack or surface cracks separated by the boltholes, replace the RBD with an airworthy RBD or deactivate it before further flight. \n\nReplace PHC RBD, P/N 76363-09103-104, with an airworthy RBD on or before May 31, 2003, or within 60 days after the effective date of this AD, whichever occurs later. \n\nReplacement RBD, P/N 76363-09103-104, is not airworthy. \n\n\tThe short compliance time involved is required because the previously described critical unsafe condition can adversely affect the controllability of the helicopter. Therefore determining the manufacturer, reidentifying the RBD as specified, inspecting the RBD for a crack, and either replacing the RBD or deactivating it is required before further flight and this AD must be issued immediately. \n\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\n\tThe FAA estimates that 165 helicopters will be affected by this AD, that it will take approximately 2 work hours to determine the manufacturer of the RBD, 1 hour to reidentify the RBD, 2 hours to inspect the RBD, and 6 hours to replace the RBD. The average labor rate is $60 per work hour. Required parts will cost approximately $1,250 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $315,150 per helicopter, assuming all RBDs were manufactured by PHC, are with the affected S/N range, must be remarked, do not have sufficient cracking to warrant immediate replacement, and the rotor brake is not used until the day prior to the day that all RBDs are replaced. \n\nComments Invited \n\n\tAlthough this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed. \n\n\tComments are specifically invitedon the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. \n\n\tCommenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket No. 2003-SW-06-AD." The postcard will be date stamped and returned to the commenter. \n\n\tThe regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132. \n\n\tThe FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption ADDRESSES. \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 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\nSec. 39.13 (Amended) \n\n\t2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: