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Proposed Rule

Airworthiness Directives; Eurocopter France Model AS350B, B1, B2, B3, BA, and D 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 model Eurocopter France (ECF) helicopters. This proposal would require replacing the main gearbox (MGB) opening neoprene Start Printed Page 19760cowling seals (seals) with airworthy glass/silicone seals. This proposal is prompted by the discovery that neoprene seals currently installed on the MGB opening cowlings do not provide the fire protection required by the airworthiness standards. The actions specified by this proposed AD are intended to require installation of fire-resistant seals to prevent a fire in the engine compartment from reaching the MGB compartment that contains parts that are not fire resistant and subsequent loss of control of the helicopter.


Comments must be received on or before June 23, 2003.


Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2003-SW-02-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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Ed Cuevas, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Regulations Group, Fort Worth, Texas 76193-0111, telephone (817) 222-5355, 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-02-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 the specified ECF Model helicopters delivered before July 1, 2002. The DGAC advises that neoprene seals bonded to the MGB mobile cowlings have low fire resistance, which does not meet the certification criteria. In the event of an uncontrolled fire in the engine compartment, the fire could spread to the MGB compartment.

ECF has issued Alert Service Bulletin No. 53.00.31, dated July 11, 2002 (ASB), which specifies replacing the MGB neoprene seals with glass/silicone seals that have increased fire-resistance. The DGAC classified this ASB as mandatory and issued AD 2002-537-094(A), dated October 30, 2002, to ensure the continued airworthiness of these helicopters in France.

These helicopter models are manufactured in France and 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 these type designs that are certificated for operation in the United States.

This unsafe condition is likely to exist or develop on other helicopters of the same type designs registered in the United States. Therefore, the proposed AD would require, within 200 hours time-in-service, replacing the neoprene seals with glass/silicone seals, which is terminating action for the requirements of this AD. The actions would be required to be accomplished in accordance with the ASB described previously.

The FAA estimates that this AD would affect 583 helicopters of U.S. registry, that it would take approximately 2 work hours per helicopter to install the seals, and that the average labor rate is $60 per work hour. Required parts would cost approximately $98. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $127,094.

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-02-AD.

Applicability: Model AS350B, B1, B2, B3, BA, and D helicopters, certificated in any category.

Note 1:

This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. Start Printed Page 19761The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required within 200 hours time-in-service, unless accomplished previously.

To prevent a fire in the engine compartment from reaching the main gearbox (MGB) compartment that contains parts that are not fire resistant and subsequent loss of control of the helicopter, accomplish the following:

(a) Replace the MGB opening neoprene cowling seals with glass/silicone seals in accordance with the Accomplishment Instructions, paragraph 2.B., of Eurocopter Alert Service Bulletin No. 53.00.31, dated July 11, 2002.

(b) Replacing the MGB opening neoprene cowling seals with glass/silicone seals is terminating action for the requirements of this AD.

(c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Regulations Group, Rotorcraft Directorate, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Regulations Group.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group.

(d) Special flight permits may be issued in accordance with 14 CFR 21.197 and 21.199 to operate the helicopter to a location where the requirements of this AD can be accomplished.

Note 3:

The subject of this AD is addressed in Direction Generale De L'Aviation Civile (France), AD 2002-537-094(A), dated October 30, 2002.

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Issued in Fort Worth, Texas, on April 15, 2003.

David A. Downey,

Manager, Rotorcraft Directorate, Aircraft Certification Service.

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[FR Doc. 03-9863 Filed 4-21-03; 8:45 am]