AD 99-19-30

This amendment adopts a new airworthiness directive (AD) applicable to Sikorsky Model S-76A, B, and C helicopters. This action requires, within 50 hours time-in-service (TIS), conducting a visual inspection for disbonding on any attachment angle between the fairing and the pylon. Thereafter, a visual inspection is required at intervals not to exceed 1500 hours TIS. If a bonding failure of one square inch or larger is found on the attachment angle, this AD requires repairing or replacing the attachment angle. This amendment is prompted by incidents, two in flight and eight on the ground, of fairing bonding failures. The actions specified in this AD are intended to prevent a separation of the fairing, damage to the tail rotor blades, and subsequent loss of control of the helicopter.

The FAA has reviewed Sikorsky Alert Service Bulletin 76-55-16, dated May 12, 1999 (ASB), which describes procedures for inspecting for disbonding on the attachment anglebetween the fairing and the pylon and either repairing or replacing, as necessary, the attachment angle. The ASB also describes a recurring 1500-hour TIS inspection.

Since an unsafe condition has been identified that is likely to exist or develop on other Sikorsky Model S-76A, B, and C helicopters of the same type design, this AD is being issued to prevent separation of the fairing, damage to the tail rotor blades, and subsequent loss of control of the helicopter. This AD requires visually inspecting the attachment angle on each fairing for disbonding and repairing or replacing the attachment angle as appropriate. The actions are required to be accomplished in accordance with the ASB described previously. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the structural integrity of the helicopter. Therefore, visually inspecting the attachment angle on each fairing for disbonding and repairing or replacing the attachment angle, as appropriate, within 50 hours TIS, is required and this AD must be issued immediately.

Since 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.

The FAA estimates that 150 helicopters will be affected by this AD, that it will take approximately 4 work hours to accomplish the inspection and 8 work hours to replace the attachment angle. The average labor rate is $60 per work hour. Required parts will cost approximately $880 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $240,000.

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 areinvited 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 thatsummarizes 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. 99-SW-44-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 inaircraft, 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, Incorporation by reference, 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 part39 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: