On April 14, 1999, the FAA issued AD 99-09-06, Amendment 39-11139 (64 FR 19881, April 23, 1999), to require inspecting the bearing for the proper rotational torque, axial play, and any brinelling of the bearing. That action was prompted by service difficulty reports citing the need to prematurely replace bearings due to wear and by two in-flight incidents of increased tail rotor vibration levels due to bearing wear. That condition, if not corrected, could result in seizure of the bearing, loss of tail rotor control, and subsequent loss of control of the helicopter.
Since the issuance of that AD, the FAA has received additional reports of deterioration of the bearing affected by AD 99-09-06 and other bearings not covered by AD 99-09-06. Therefore, this AD expands the applicability to include additional bearing P/N's and to reduce the initial and recurring inspection compliance times.
Eurocopter France has issued Service Bulletin (SB) 05.00.29,Revision 2, applicable to Model AS-350 series helicopters, and SB 05.00.30, Revision 2, applicable to Model AS-355 series helicopters, both dated September 29, 1999. These SB's specify a check of the bearing for rotational torque. The Direction Generale De L'Aviation Civile (DGAC), the airworthiness authority for France, classified these SB's as mandatory and issued AD's 1999-085-076(A)R2 and 1999-084-057(A)R2, both dated October 20, 1999, to ensure the continued airworthiness of these helicopters in France.
Since an unsafe condition has been identified that is likely to exist or develop on other Eurocopter France Model AS-350B, B1, B2, B3, BA, and D, and AS-355E, F, F1, F2, and N helicopters of the same type design, this AD supersedes AD 99-09-06 (64 FR 19881, April 23, 1999). This AD has the same requirements as the current AD. This AD also expands the applicability to include additional P/N's 350A33-2004-00, -01 and -02, and 350A33-2009-00 and - 01, installed, and excludes a bearing which has MOD 076551 incorporated. This AD also revises the initial and recurring inspection compliance times. The actions are required to be accomplished in accordance with the SB's described previously. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the controllability of the helicopter. Therefore, including additional P/N's in the applicability, requiring an initial inspection within 10 hours time-in-service (TIS) to measure the bearing rotational torque, and inspecting the bearing for axial play or brinelling at intervals not to exceed 50 hours TIS or 6 months, whichever occurs first, are 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 507 helicopters will be affected by this AD, that it will take approximately 1 work hour to accomplish the inspection, and 4 work hours to replace a bearing, if required, and that the average labor rate is $60 per work hour. Required parts will cost approximately $60 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $182,520 to inspect all affected helicopters and to replace one bearing in each helicopter in the fleet.
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 underthe 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 onwhich the following statement is made: "Comments to Docket No. 99-SW-41-AD." The postcard will be date stamped and returned to the commenter.
The regulations adopted herein will not impose substantial direct compliance costs on states or local governments or 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 13132, the FAA has not consulted with States or local authorities prior to the publication of this rule.
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, 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 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 removing Amendment 39-11139 (64 FR 19881, April 23, 1999), and by adding a new airworthiness directive (AD), Amendment 39-11443, to read as follows: