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Proposed Rule

Airworthiness Directives; Eurocopter France Model AS 365 N3 Helicopters

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Federal Aviation Administration, DOT.


Notice of proposed rulemaking (NPRM).


This document proposes adopting a new airworthiness directive (AD) for the specified Eurocopter France (Eurocopter) model helicopters. This proposal would require installing a tail rotor blade (blade)-to-torsion bar attachment tuning weight assembly on each blade of the Quiet Fenestron tail rotor and replacing each blade attachment bushing. This proposal is prompted by the discovery of tail rotor induced vibrations during flight tests. The actions specified by this proposed AD are intended to prevent vibration in the tail rotor and the pilot's anti-torque pedals, blade pitch control failure, and subsequent loss of control of the helicopter.


Comments must be received on or before January 23, 2004.


Submit comments in triplicate to the Federal Aviation Start Printed Page 65855Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2003-SW-11-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. You may also send comments electronically to the Rules Docket at the following address: Comments may be inspected at the Office of the Regional Counsel between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

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Richard Monschke, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, Fort Worth, Texas 76193-0110, telephone (817) 222-5116, fax (817) 222-5961.

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Comments Invited

Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments will be considered before taking action on the proposed rule. The proposals contained in this document may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their mailed comments submitted in response to this proposal must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. 2003-SW-11-AD.” The postcard will be date stamped and returned to the commenter.


The Direction Generale De L'Aviation Civile (DGAC), the airworthiness authority for France, notified the FAA that an unsafe condition may exist on Eurocopter Model AS 365 N3 helicopters. The DGAC advises of a report of the discovery of an increased level of vibration felt by the crew in the pedal units.

Eurocopter has issued Alert Service Bulletin (ASB) No. 64.00.23, dated October 30, 2002, which specifies installing a tuning weight assembly, part number (P/N) 365A33-3546-00, on each blade of the Quiet Fenestron tail rotor. Compliance with this ASB requires prior compliance with Eurocopter Service Bulletin 64.00.21, dated November 8, 2000 (modification 0761B23, 0765B35, and 0764B39, 40, 41), which specifies installing a Quiet Fenestron tail rotor, and with Eurocopter Service Bulletin 65.00.14, dated January 7, 2002 (modification 0765B41), which specifies installing a reinforced control shaft on the tail rotor hub control shaft assembly. The DGAC classified these service bulletins as mandatory and issued AD No. 2002-622(A), dated December 11, 2002, to ensure the continued airworthiness of these helicopters in France.

This helicopter model is manufactured in France and is type certificated for operation in the United States under the provisions of 14 CFR 21.29 and the applicable bilateral agreement. Pursuant to the applicable bilateral agreement, the DGAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DGAC, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

This previously described unsafe condition is likely to exist or develop on other helicopters of the same type design registered in the United States. Therefore, the proposed AD would require removing each tail rotor attachment bushing, P/N 365A33-3530-20, and then installing a blade-to-torsion bar attachment tuning weight assembly, P/N 365A33-3546-00, on each blade of the Quiet Fenestron tail rotor at the same time. Mixing the existing blade attachment bushings, P/N 365A33-3530-20, and the new tuning weight assembly, P/N 365A33-3546-00, on the same tail rotor hub would be prohibited. The actions would be required to be accomplished in accordance with the service bulletin described previously.

On July 10, 2002, the FAA issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's AD system. The regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. Because we have now included this material in part 39, we no longer need to include it in each individual AD.

The FAA estimates that this proposed AD would affect 6 helicopters of U.S. registry and the proposed actions would take approximately 8 work hours per helicopter to accomplish at an average labor rate of $65 per work hour. Required parts would cost approximately $3,290, and attaching hardware would cost $40. Based on these figures, we estimate the total cost impact of the proposed AD on U.S. operators to be $3,850 per helicopter, or $23,100 for the entire fleet.

The regulations proposed herein would 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 proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

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List of Subjects in 14 CFR Part 39

  • Air transportation
  • Aircraft
  • Aviation safety
  • Safety
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The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

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1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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2. Section 39.13 is amended by adding a new airworthiness directive to read as follows:

Eurocopter France: Docket No. 2003-SW-11-AD.

Applicability: Model AS 365 N3 helicopters, with a Quiet Fenestron tail rotor (tail rotor gearbox, part number (P/N) 365A33-6005-06, and tail rotor hub, P/N Start Printed Page 65856365A33-3500-02), tail rotor hub attachment bushings, part number (P/N) 365A33-3530-20, and a reinforced control shaft, P/N 365A33-6214-20, on the tail rotor hub control shaft assembly, installed, certificated in any category.

Compliance: Within 3 months, unless accomplished previously.

To prevent vibration in the tail rotor attachments and the pilot's anti-torque pedals, blade pitch control failure, and subsequent loss of control of the helicopter, accomplish the following:

(a) Install a tail rotor blade (blade)-to-torsion bar attachment tuning weight assembly, P/N 365A33-3546-00, on each blade of the Quiet Fenestron tail rotor in accordance with paragraph 2, Accomplishment Instructions, of Eurocopter France Alert Service Bulletin 64.00.23, dated October 30, 2002. Replace each of the 10 blade attachment bushings, P/N 365A33-3530-20, at the same time. Do not mix the existing blade attachment bushings, P/N 365A33-3530-20, and the new tuning weight assemblies, P/N 365A33-3546-00, on the same tail rotor hub.

(b) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Safety Management Group, Rotorcraft Directortate, FAA, for information about previously approved alternative methods of compliance.


The subject of this AD is addressed in Direction Generale De L'Aviation Civile (France) AD 2002-622(A), dated December 11, 2002.

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Issued in Fort Worth, Texas, on November 17, 2003.

Mark R. Schilling,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

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[FR Doc. 03-29221 Filed 11-21-03; 8:45 am]