[Federal Register Volume 72, Number 166 (Tuesday, August 28, 2007)]
[Proposed Rules]
[Pages 49236-49238]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-17003]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28053; Directorate Identifier 2007-NE-18-AD]
RIN 2120-AA64


Airworthiness Directives; Turbomeca Arrius 2F 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) provided by the aviation 
authority of France to identify and correct an unsafe condition on 
Turbomeca Arrius 2F turboshaft engines. The MCAI states the following:

    This AD is issued following a case of non-commanded in-flight 
engine shutdown which occurred on an Arrius 2F turboshaft engine, 
following the seizing of the gas generator. The result may be an 
emergency autorotation landing, or, at worst, an accident.
    Investigations of this event have revealed that the seizing of 
the gas generator was caused by the fracture of the separator cage 
of the gas generator front bearing, due to high-cycle fatigue cracks 
initiated in the lubrication slots of the separator cage.

    We are proposing this AD to prevent uncommanded shutdown of the 
engine, which could lead to an accident.

DATES: We must receive comments on this proposed AD by September 27, 
2007.

ADDRESSES: You may send comments by any of the following methods:
     DOT Docket Web Site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     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.
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the instructions for submitting comments.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov; or in person at the Docket Management Facility 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 Office (telephone (800) 647-5527) is in the ADDRESSES section. 
Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Christopher Spinney, Aerospace 
Engineer, Engine Certification Office, FAA, Engine and Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803; e-
mail: [email protected]; telephone (781) 238-7175, fax (781) 
238-7199.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about

[[Page 49237]]

this proposed AD. Send your comments to an address listed under the 
ADDRESSES section. Include ``Docket No. FAA-2007-28053; Directorate 
Identifier 2007-NE-18-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://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    The European Aviation Safety Agency (EASA), which is the Technical 
Agent for the Member States of the European Community, has issued AD 
2007-0057, dated March 1, 2007, to correct an unsafe condition for the 
specified products. The EASA AD states:

    This AD is issued following a case of non-commanded in-flight 
engine shutdown which occurred on an Arrius 2F turboshaft engine, 
following the seizing of the gas generator. The result may be an 
emergency autorotation landing, or, at worst, an accident.
    Investigations of this event have revealed that the seizing of 
the gas generator was caused by the fracture of the separator cage 
of the gas generator front bearing, due to high-cycle fatigue cracks 
initiated in the lubrication slots of the separator cage.
    Modification Tf 12 introduces a new gas generator front bearing 
without lubrication slots on the separator cage.

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

Relevant Service Information

    Turbomeca has issued Mandatory Service Bulletin No. 319 72 4012, 
Update No. 1, dated September 19, 2006. The actions described in this 
service information are intended to correct the unsafe condition 
identified in the EASA AD.

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 EASA AD 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. 
This proposed AD would require replacing the engine module 02 with a 
module that incorporates Turbomeca Modification Tf 12A. That 
replacement must occur at the next engine shop visit after the 
effective date of the proposed AD, but no later than April 30, 2008. 
Modification Tf 12A installs into the engine module 02, a new gas 
generator front bearing without lubrication slots on the separator 
cage.

Costs of Compliance

    We estimate that this proposed AD would affect 61 engines installed 
on aircraft of U.S. registry. We also estimate that it would take about 
10 work-hours per engine to perform the proposed actions, and that the 
average labor rate is $80 per work-hour. Required parts would cost 
about $111,440 per engine. Based on these figures, we estimate the 
total cost of the proposed AD to U.S. operators to be $6,846,640. Our 
cost estimate is exclusive of possible warranty coverage.

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, 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:

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: Docket No. FAA-2007-28053; Directorate Identifier 2007-
NE-18-AD.

Comments Due Date

    (a) We must receive comments by September 27, 2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Turbomeca Arrius 2F turboshaft engines 
that have not incorporated Turbomeca Modification Tf 12A. These 
engines are installed on, but not limited to, Eurocopter EC120B 
helicopters.

Reason

    (d) European Aviation Safety Agency (EASA) AD No. 2007-0057, 
dated March 1, 2007, states:

    This AD is issued following a case of non-commanded in-flight 
engine shutdown which occurred on an Arrius 2F turboshaft engine, 
following the seizing of the gas generator. The result may be an 
emergency autorotation landing, or, at worst, an accident.
    Investigations of this event have revealed that the seizing of 
the gas generator was caused by the fracture of the separator cage 
of the gas generator front bearing, due to high-cycle fatigue cracks 
initiated in the lubrication slots of the separator cage.
    Modification Tf12 introduces a new gas generator front bearing 
without lubrication slots on the separator cage.

Actions and Compliance

    (e) Unless already done, do the following actions.

[[Page 49238]]

    (1) At the next engine shop visit after the effective date of 
this AD, but no later than April 30, 2008, replace the engine module 
02 with a module that incorporates Turbomeca Modification Tf 12A. 
Turbomeca Modification Tf 12A installs into the engine module 02 a 
new gas generator front bearing without lubrication slots on the 
separator cage.
    (2) Use the Instructions to be Incorporated section of Turbomeca 
Mandatory Service Bulletin No. 319 72 4012, Update No. 1, dated 
September 19, 2006, to do the actions in paragraph (e)(1) of this 
AD.

Other FAA AD Provisions

    (f) Alternative Methods of Compliance (AMOCs): 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

    (g) Refer to EASA AD 2007-0057, dated March 1, 2007, for related 
information.
    (h) Contact Christopher Spinney, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
[email protected]; telephone (781) 238-7175, fax (781) 
238-7199, for more information about this AD.

    Issued in Burlington, Massachusetts, on August 22, 2007.
Mark A. Rumizen,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E7-17003 Filed 8-27-07; 8:45 am]
BILLING CODE 4910-13-P