[Federal Register Volume 66, Number 173 (Thursday, September 6, 2001)]
[Proposed Rules]
[Pages 46562-46563]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-22313]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 66, No. 173 / Thursday, September 6, 2001 / 
Proposed Rules  

[[Page 46562]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NE-06-AD]
RIN 2120-AA64


Airworthiness Directives; Turbomeca S.A. Arriel-1D, -1D1, -1S, -
1S1, -2S1 and -2B Series Turboshaft Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The Federal Aviation Administration (FAA) proposes to adopt a 
new airworthiness directive (AD) that is applicable to Turbomeca S.A. 
Arriel-1D, -1D1, -1S, -1S1, -2S1 and -2B series turboshaft engines. 
This proposal would require the insertion of a sleeve in the attachment 
boss of the compressor bleed valve. This proposal is prompted by 
several cases of contained centrifugal compressor impeller blade 
ruptures that have occurred in service. The actions specified by the 
proposed AD are intended to prevent acoustic excitation of the 
centrifugal compressor impeller blades resulting in contained 
compressor impeller blade ruptures and power loss that could lead to an 
uncommanded in-flight shutdown.

DATES: Comments must be received by November 5, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 2001-NE-06-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may also be sent 
via the Internet using the following address: [email protected]. 
Comments sent via the Internet must contain the docket number in the 
subject line. Comments may be inspected at this location between 8 a.m. 
and 4:30 p.m., Monday through Friday, except Federal holidays. The 
service information referenced in the proposed rule may be obtained 
from Turbomeca S.A, Turbomeca S.A., 64511 Bordes Cedex, France; 
telephone 33 05 59 64 40 00, fax 33 05 59 64 60 80.

FOR FURTHER INFORMATION CONTACT: Glorianne Niebuhr, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7132; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

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, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action 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 comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NE-06-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRM's

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, New England Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 2001-NE-06-AD, 12 New England Executive 
Park, Burlington, MA 01803-5299.

Discussion

    The Direction Generale de L'Aviation Civile (DGAC), which is the 
airworthiness authority for France, recently notified the FAA that an 
unsafe condition may exist on Turbomeca S.A. Arriel-1D, -1D1, -1S, -
1S1, -2S1 and -2B series turboshaft engines. The DGAC advises that 
several cases of contained centrifugal compressor impeller blade 
ruptures caused by acoustic excitation of the blades have occurred in 
service. This excitation may lead to initiation of cracks on the blades 
resulting in contained compressor impeller blade ruptures and power 
loss that could lead to an uncommanded inflight shutdown. To reduce the 
level of acoustic vibration of the compressor blades, a coupling effect 
must be removed. This is accomplished by distributing the symmetry by 
insertion of a metal sleeve. The actions specified by the proposed AD 
are intended to prevent acoustic excitation of the centrifugal 
compressor impeller blades resulting in contained compressor impeller 
blade ruptures and power loss that could lead to an uncommanded in-
flight shutdown.

Manufacturer's Service Information

    Turbomeca S.A. has issued Service Bulletin (SB) No. 292 72 2054, 
dated September 20, 1999, and SB No. 292 72 0261, dated September 20, 
1999, that provide instructions for the removal of the compresser bleed 
valve, installation of the sleeve, and reinstallation of the compresser 
bleed valve. The DGAC classified these SB's as mandatory and issued 
AD's No. 1999-391(A) and 1999-392(A), dated October 6, 1999, in order 
to ensure the airworthiness of these Turbomeca S.A. engines in France.

Bilateral Agreement Information

    This engine model is manufactured in France and is the type 
certificated for operation in the United States under the provisions of 
Section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. Pursuant to this 
bilateral airworthiness 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

[[Page 46563]]

type design that are certificated for operation in the United States.

Proposed Requirements of This AD

    Since an unsafe condition has been identified that is likely to 
exist or develop on other Turbomeca S.A. Arriel-1D, -1D1, -1S, -1S1, -
2S1 and -2B series turboshaft engines of the same type design that are 
used on rotocraft registered in the United States, the proposed AD 
would require insertion of a sleeve in the attachment boss of the 
compresser bleed valve. The actions would be required to be 
accomplished in accordance with the SB's described previously.

Economic Impact

    There are approximately 1,406 engines of the affected design in the 
worldwide fleet. The FAA estimates that 476 engines installed on 
aircraft of U.S. registry would be affected by this proposed AD. The 
FAA also estimates that it would take approximately 0.5 work hours per 
engine to accomplish the proposed actions, and that the average labor 
rate is $60 per work hour. Required parts would cost approximately $430 
per engine. Based on these figures, the total cost impact of the 
proposed AD on U.S. operators is estimated to be $218,960.

Regulatory Impact

    This proposed rule does not have federalism implications, as 
defined in Executive Order 13132, because it 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. 
Accordingly, the FAA has not consulted with state authorities prior to 
publication of this proposed rule.
    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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

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:

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.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Turbomeca S.A.: Docket No. 2001-NE-06-AD.

Applicability

    This airworthiness directive (AD) is applicable to Turbomeca 
S.A. Arriel-1D, -1D1, -1S, -1S1, -2S1 and -2B series turboshaft 
engines. These engines are installed on, but not limited to, 
Eurocopter France AS350B1, AS350B2, AS350B3; Astar 350D, Fennic 
AD550U2 and Sikorsky S-76A and S-76C series helicopters.

    Note 1: This AD applies to each engine identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For engines 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 (b) of 
this AD. The 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

    Compliance with this AD is required within 30 days after the 
effective date of this AD, unless already done. To prevent acoustic 
excitation of the centrifugal compressor impeller blades resulting 
in contained blade ruptures and power loss that could lead to an 
uncommanded in-flight shutdown, do the following:
    (a) Remove the compressor bleed valve, install the sleeve at the 
bottom of the boss attachment and install the valve as follows:
    (1) For Arriel 2S1 and -2B engines in accordance with Paragraph 
2.B. and 2.C. of Turbomeca S.A. Service Bulletin (SB) No. 292 72 
2054, dated September 20, 1999.
    (2) For Arriel 1D, -1D1, -1S, and -1S1 engines in accordance 
with Paragraph 2.B. and 2.C. of Turbomeca S.A. SB No. 292 72 0261, 
dated September 20, 1999.

Alternative Methods of Compliance

    (b) 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, Engine Certification Office (ECO). 
Operators shall submit their request through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, ECO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the ECO.

Special Flight Permits

    (c) Special flight permits may be issued in accordance with 
Secs. 21.197 and 21.199 of the Federal Aviation Regulations (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 (DGAC) Airworthiness Directives No. 
1999-391(A) and 1999-392 (A), dated October 6, 1999.


    Issued in Burlington, Massachusetts, on August 28, 2001.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 01-22313 Filed 9-5-01; 8:45 am]
BILLING CODE 4910-13-U