
[Federal Register: December 9, 2008 (Volume 73, Number 237)]
[Proposed Rules]               
[Page 74661-74663]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09de08-16]                         

=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28077; Directorate Identifier 2007-NE-20-AD]
RIN 2120-AA64

 
Airworthiness Directives; Turbomeca S.A. Arriel 2B, 2B1, and 2B1A 
Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

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 an 
aviation product. The MCAI states the following:

    Several cases of Gas Generator Turbine (HP Turbine) blade 
rearward displacement have been detected during borescope inspection 
or in repair centre following engine disassembly. Two of them 
resulted in blade rubs between the rear face of the fir-tree roots 
and the rear bearing support cover. High HP blade rearward 
displacement can potentially result in blade release due to fatigue 
of the blade, which would cause an uncommanded in-flight engine 
shutdown.

We are proposing this AD to prevent an uncommanded in-flight engine 
shutdown which could result in an emergency autorotation landing or, at 
worst, an accident.

DATES: We must receive comments on this proposed AD by January 8, 2009.

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.

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 (telephone (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: Christopher Spinney, Aerospace 
Engineer, Engine Certification Office, FAA, Engine & Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803; e-
mail: christopher.spinney@faa.gov; 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 this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2007-
28077; Directorate Identifier 2007-NE-27-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 2007-0109, dated April 19, 2007 (referred to 
after this as ``the MCAI''), to correct an unsafe condition for the 
specified products. The EASA AD states:

    Several cases of Gas Generator Turbine (HP Turbine) blade 
rearward displacement have been detected during borescope inspection 
or in repair centre following engine disassembly. Two of them 
resulted in blade rubs between the rear face of the fir-tree roots 
and the rear bearing support cover.
    High HP blade rearward displacement can potentially result in 
blade release due to fatigue of the blade, which would cause an 
uncommanded in-flight engine shutdown.
    The evaluation of this condition has prompted to require a 
periodic borescope inspection in order to detect HP blade rearward 
displacement. Additionally, in case displacement is found above the 
specified limit, removal of Module 03 is required.

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

Relevant Service Information

    Turbomeca S.A. has issued Mandatory Service Bulletin No. 292 72

[[Page 74662]]

2825, Original Issue, dated April 5, 2007. 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 inspecting for HP blade rearward 
displacement.

Costs of Compliance

    We estimate that this proposed AD would affect about 248 engines on 
helicopters of U.S. registry. We also estimate that it would take about 
2 work-hours per engine to perform the proposed actions and that the 
average labor rate is $80 per work-hour. Based on these figures, we 
estimate the total cost of the proposed AD to U.S. operators to be 
$39,680. 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, 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:

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-2007-28077; Directorate Identifier 
2007-NE-20-AD.

Comments Due Date

    (a) We must receive comments by January 8, 2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Turbomeca S.A. Arriel 2B, 2B1, and 2B1A 
turboshaft engines. These engines are installed on, but not limited 
to, Eurocopter AS 350 B3 and EC 130 B4 helicopters.

Reason

    (d) Several cases of Gas Generator Turbine (HP Turbine) blade 
rearward displacement have been detected during borescope inspection 
or in repair centre following engine disassembly. Two of them 
resulted in blade rubs between the rear face of the fir-tree roots 
and the rear bearing support cover. High HP blade rearward 
displacement can potentially result in blade release due to fatigue 
of the blade, which would cause an uncommanded in-flight engine 
shutdown.
    We are issuing this AD to prevent an uncommanded in-flight 
engine shutdown which could result in an emergency autorotation 
landing or, at worst, an accident.

Actions and Compliance

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

Initial Inspection

    (1) Perform an initial HP turbine borescope inspection according 
to Turbomeca S.A. Mandatory Service Bulletin (MSB) No. 292 72 2825, 
dated April 5, 2007 as follows:
    (i) For engines with fewer than 500 hours and 450 cycles since 
new or since the last HP turbine borescope inspection, inspect 
before reaching 600 hours or 500 cycles whichever occurs first. 
Replace HP turbine modules with rearward turbine blade displacement 
greater than 0.5 mm.
    (ii) For the remaining engines, inspect within the next 100 
hours. Replace HP turbine modules with rearward turbine blade 
displacement greater than 0.5 mm.

Repetitive Inspections

    (2) Perform repetitive HP turbine borescope inspections 
according to Turbomeca S.A. MSB No. 292 72 2825, dated April 5, 
2007:
    (i) Within 600 hours or 500 cycles from the previous inspection, 
whichever occurs first, if the rearward displacement of the turbine 
blades was less than 0.2 mm. Replace HP turbine modules with 
rearward turbine blade displacement greater than 0.5 mm.
    (ii) Within 100 hours of the previous inspection if the rearward 
displacement of the turbine blades was between 0.2 mm and 0.5 mm. 
Replace HP turbine modules with rearward turbine blade displacement 
greater than 0.5 mm.
    (3) After each inspection, the compliance certificate must be 
sent to Turbomeca S.A. within 7 days, according to Sec.  2.D(1)(c) 
of Turbomeca S.A. MSB No. 292 72 2825, dated April 5, 2007.

FAA AD Differences

    (f) We modified the drawdown times to be more consistent with 
the compliance times.

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:
    (1) 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.
    (2) Reporting Requirements: For any reporting requirement in 
this AD, under the provisions of the Paperwork Reduction Act, the 
Office of Management and Budget (OMB) has approved the information 
collection requirements and has assigned OMB Control Number 2120-
0056.

Related Information

    (h) Refer to EASA Airworthiness Directive 2007-0109, dated April 
19, 2007, and Turbomeca S.A. MSB No. 292 72 2825, dated April 5, 
2007, for related information.
    (i) Contact Christopher Spinney, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA

[[Page 74663]]

01803; e-mail: christopher.spinney@faa.gov; telephone (781) 238-
7175; fax (781) 238-7199, for more information about this AD.

    Issued in Burlington, Massachusetts, on December 2, 2008.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E8-29102 Filed 12-8-08; 8:45 am]

BILLING CODE 4910-13-P
