
[Federal Register Volume 76, Number 34 (Friday, February 18, 2011)]
[Proposed Rules]
[Pages 9515-9517]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-3684]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0115; Directorate Identifier 2010-NE-40-AD]
RIN 2120-AA64


Airworthiness Directives; Turbomeca S.A. ARRIEL 2B and 2B1 
Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for the 
products listed above. This proposed AD results from mandatory 
continuing airworthiness information (MCAI) issued by an aviation 
authority of another country to identify and correct an unsafe 
condition on an aviation product. The MCAI describes the unsafe 
condition as:

    Several cases of Gas Generator (GG) Turbine Blade rupture 
occurred in service on ARRIEL 2 twin engine applications and 
recently one on a single engine helicopter. For the case occurring 
in flight on a single engine helicopter (ARRIEL 2B1 engine), the 
pilot performed an emergency autorotation, landing the helicopter 
without further incident.

We are proposing this AD to prevent rupture of a GG turbine blade, 
which could result in an uncommanded in-flight shutdown and an 
emergency autorotation landing or accident.

DATES: We must receive comments on this proposed AD by April 4, 2011.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 1200 New Jersey Avenue, SE., West Building Ground 
Floor, Room W12-140, Washington, DC 20590-0001.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
     Fax: (202) 493-2251.
    Contact Turbomeca S.A., 40220 Tarnos, France; e-mail: noria-dallas@turbomeca.com; telephone 33 05 59 74 40 00, fax 33 05 59 74 45 
15, or go to: http://www.turbomeca-support.com for the service 
information identified in this proposed AD.

[[Page 9516]]

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Operations office (phone (800) 647-5527) is the 
same as the Mail address provided in the ADDRESSES section. Comments 
will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: James Gray, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803-5299; e-mail: 
james.e.gray@faa.gov; telephone (781) 238-7742; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2011-0115; 
Directorate Identifier 2010-NE-40-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD based on those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact 
with FAA personnel concerning this proposed AD. Using the search 
function of the Web site, anyone can find and read the comments in any 
of our dockets, including, if provided, the name of the individual who 
sent the comment (or signed the comment on behalf of an association, 
business, labor union, etc.). You may review the DOT's complete Privacy 
Act Statement in the Federal Register published on April 11, 2000 (65 
FR 19477-78).

Discussion

    The European Aviation Safety Agency (EASA), which is the Technical 
Agent for the Member States of the European Community, has issued EASA 
Airworthiness Directive 2010-0198, dated October 1, 2010 (referred to 
after this as ``the MCAI''), to correct an unsafe condition for the 
specified products. The MCAI states:

    Several cases of Gas Generator (GG) Turbine Blade rupture 
occurred in service on ARRIEL 2 twin engine applications and 
recently one on a single engine helicopter. For the case occurring 
in flight on a single engine helicopter (ARRIEL 2B1 engine), the 
pilot performed an emergency autorotation, landing the helicopter 
without further incident.
    The design of ARRIEL 2 engines (containment shield around the GG 
turbine) allows debris from a blade or the disc inter-blade area to 
be contained in the event of rupture. However, the rupture of a GG 
Turbine Blade may lead to an uncommanded In Flight Shut-Down which, 
on a single-engine helicopter, could ultimately lead to an emergency 
autorotation landing.
    The most probable root cause of the ruptures is an excitation of 
one of the vibration modes of the GG Turbine Blade in conjunction 
with several secondary contributing factors which are deemed 
sufficient to reduce the stress margin of the blade to a level 
consistent with the rate of occurrences of ruptures encountered.
    Turbomeca has released TU166 modification which consists of 
inserting Blade dampers between the GG Turbine Disc and the GG 
Turbine Blade platform. Introduction of these dampers minimizes the 
effects of HP blade vibratory excitation and increases the blade 
tolerance for this type of stress.

You may obtain further information by examining the MCAI in the AD 
docket.

Relevant Service Information

    Turbomeca S.A. has issued Mandatory Service Bulletin A292 72 3166, 
Version B, dated September 20, 2010. The actions described in this 
service information are intended to correct the unsafe condition 
identified in the MCAI.

FAA's Determination and Requirements of This Proposed AD

    This product has been approved by the aviation authority of France, 
and is approved for operation in the United States. Pursuant to our 
bilateral agreement with France, they have notified us of the unsafe 
condition described in the MCAI and service information referenced 
above. We are proposing this AD because we evaluated all information 
provided by EASA and determined the unsafe condition exists and is 
likely to exist or develop on other products of the same type design.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD 
would affect about 537 products of U.S. registry. We also estimate that 
it would take about 60 work-hours per product to comply with this 
proposed AD. The average labor rate is $85 per work-hour. Required 
parts would cost about $3,900 per product. Based on these figures, we 
estimate the cost of the proposed AD on U.S. operators to be 
$4,833,000.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify 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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

[[Page 9517]]

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. The FAA amends Sec.  39.13 by adding the following new AD:

Turbomeca S.A.: Docket No. FAA-2011-0115; Directorate Identifier 
2010-NE-40-AD.

Comments Due Date

    (a) We must receive comments by April 4, 2011.

Affected Airworthiness Directives (ADs)

    (b) None.

Applicability

    (c) This AD applies to Turbomeca S.A. ARRIEL 2B and 2B1 
turboshaft engines not modified by TU166 modification. These engines 
are installed on, but not limited to, Eurocopter AS 350 B3 and EC 
130 B4 helicopters.

Reason

    (d) This AD results from:
    Several cases of Gas Generator (GG) Turbine Blade rupture 
occurred in service on ARRIEL 2 twin engine applications and 
recently one on a single engine helicopter. For the case occurring 
in flight on a single engine helicopter (ARRIEL 2B1 engine), the 
pilot performed an emergency autorotation, landing the helicopter 
without further incident.
    We are issuing this AD to prevent rupture of a GG turbine blade, 
which could result in an uncommanded in-flight shutdown and an 
emergency autorotation landing or accident.

Actions and Compliance

    (e) Unless already done, do the following actions.
    (1) Accomplish TU166 modification in accordance with the 
instructions specified within Turbomeca Mandatory Service Bulletin 
(MSB) A292 72 3166 Version B, dated September 20, 2010, when the GG 
Turbine is replaced or when the engine or Module M03 is going 
through overhaul or repair, or within 1,300 cycles-in-service after 
the effective date of this AD, whichever occurs first.
    (2) Accomplishment, before the effective date of this AD, of 
TU166 modification in accordance with the instructions of Turbomeca 
MSB A292 72 3166 Version A, dated August 17, 2010, satisfies the 
requirement of paragraph (e)(1) of this AD.

FAA AD Differences

    (f) This AD differs from the Mandatory Continuing Airworthiness 
Information (MCAI) and or service information by the following:
    (1) European Aviation Safety Agency (EASA) AD No. 2010-0198, 
dated October 1, 2010, applies to the ARRIEL 2B1A engine. This AD 
does not apply to that model because it has no U.S. type 
certificate.
    (2) EASA AD No. 2010-198 has a compliance date of ``but no later 
than 25 months after the effective date of this AD. This AD has a 
compliance time of ``1,300 cycles-in-service,'' based on average 
fleet usage data supplied by Turbomeca.

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:

Alternative Methods of Compliance (AMOCs)

    (h) The Manager, Engine Certification Office, FAA, has the 
authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19.

Related Information

    (i) Refer to MCAI EASA Airworthiness Directive 2010-0198, dated 
October 1, 2010, and Turbomeca S.A. Mandatory Service Bulletins A292 
72 3166, Version A, dated August 17, 2010, and A292 72 3166 Version 
B, dated September 20, 2010, for related information. Contact 
Turbomeca S.A., 40220 Tarnos, France; e-mail: noria-dallas@turbomeca.com; telephone 33 05 59 74 40 00, fax 33 05 59 74 
45 15, or go to: http://www.turbomeca-support.com, for a copy of 
this service information.
    (j) Contact James Gray, Aerospace Engineer, Engine Certification 
Office, FAA, Engine & Propeller Directorate, 12 New England 
Executive Park, Burlington, MA 01803-5299; e-mail: 
james.e.gray@faa.gov; telephone (781) 238-7742; fax (781) 238-7199, 
for more information about this AD.


    Issued in Burlington, Massachusetts, on February 14, 2011.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2011-3684 Filed 2-17-11; 8:45 am]
BILLING CODE 4910-13-P


