On August 13, 1998, the FAA issued Priority Letter AD 98-17-15, applicable to Sikorsky Aircraft Corporation Model S-76A, B, and C helicopters, which requires, before further flight, a one-time visual inspection of the swashplate assembly retainer for missing bolts and a one-time inspection of each retainer bolt using a magnet to detect the installation of aluminum retainer bolts. If retainer bolts are missing or aluminum bolts are found, the AD requires that they be replaced with airworthy steel bolts. That action was prompted by reports of the installation of aluminum bolts on swashplate assemblies, part numbers 76104-08000-044, -045, -046, and 76104-08500-041 and -043. This condition, if not corrected, could result in failure of the swashplate assembly, loss of control of the main rotor, and subsequent loss of control of the helicopter.
The FAA has reviewed Sikorsky Aircraft Corporation Service Bulletin 76-65-47, dated July 31, 1998 (SB). The SBdescribes procedures for a one-time visual inspection of the swashplate assembly retainer for missing bolts, an inspection with a magnet to determine whether steel bolts are installed, and replacing missing or aluminum bolts with airworthy steel bolts.
Since the unsafe condition described is likely to exist or develop on other Sikorsky Aircraft Corporation Model S-76A, B, and C helicopters of the same type design, the FAA issued Priority Letter AD 98-17-15 to prevent failure of the swashplate assembly, loss of the main rotor, and subsequent loss of control of the helicopter. The AD requires, before further flight, a one-time visual inspection of the swashplate assembly retainer for missing bolts, an inspection with a magnet to detect aluminum bolts, and replacing missing or aluminum bolts with airworthy steel bolts.
Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual letters issued on August 13, 1998 to all known U.S. owners and operators of Sikorsky Aircraft Corporation Model S-76A, B, and C helicopters. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective to all persons.
The FAA estimates that 157 helicopters of U.S. registry will be affected by this AD, that it will take approximately 3 work hours per helicopter to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $3 per swashplate assembly. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $28,731, assuming one inspection and replacement of all retainer bolts in all the helicopters.
Comments Invited
Although 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.
Comments are specifically invited on 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, both before and after the closing date for comments, 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.
Commenters 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. 98-SW-37-AD." The postcard will be date stamped and returned to the commenter.
The regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
The 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."
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
Adoption of the Amendment
Accordingly, 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:
PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
39.13 [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: