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

[Federal Register Volume 76, Number 131 (Friday, July 8, 2011)]
[Rules and Regulations]
[Pages 40222-40223]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-16955]


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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; 
Amendment 39-16728; AD 2011-13-05]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the 
products listed above. This 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 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.

DATES: This AD becomes effective August 12, 2011. The Director of the 
Federal Register approved the incorporation by reference of a certain 
publication listed in this AD as of August 12, 2011.

ADDRESSES: The Docket Operations office is located at Docket Management 
Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, 
SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-
0001.

FOR FURTHER INFORMATION CONTACT: Rose Len, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: [email protected]; 
phone: (781) 238-7772; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM was published in the Federal Register on February 18, 2011 
(76 FR 9515). That NPRM proposed 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.
    Turbom[eacute]ca has released TU166 modification which consists 
in 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.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We received no comments on the NPRM.

Conclusion

    We reviewed the available data and determined that air safety and 
the public interest require adopting the AD as proposed.

Costs of Compliance

    Based on the service information, we estimate that this 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 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 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 AD will not have federalism implications 
under Executive Order 13132. This AD will 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 AD:
    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

[[Page 40223]]

under the criteria of the Regulatory Flexibility Act.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket.

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 AD, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Operations office (phone: (800) 647-5527) is provided in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2011-13-05 Turbomeca S.A.: Amendment 39-16728. Docket No. FAA-2011-
0115; Directorate Identifier 2010-NE-40-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective August 
12, 2011.

Affected 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 Turbom[eacute]ca 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 
Turbom[eacute]ca 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, for related information.
    (j) Contact Rose Len, Aerospace Engineer, Engine Certification 
Office, FAA, Engine & Propeller Directorate, 12 New England 
Executive Park, Burlington, MA 01803; e-mail: [email protected]; 
phone: (781) 238-7772; fax (781) 238-7199, for more information 
about this AD.

Material Incorporated by Reference

    (k) You must use Turbomeca S.A. Mandatory Service Bulletin A292 
72 3166 Version B, dated September 20, 2010, to do the actions 
required by this AD, unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Turbomeca S.A., 40220 Tarnos, France; e-mail: [email protected]; telephone 33 05 59 74 40 00, fax 33 05 59 74 
45 15, or go to: http://www.turbomeca-support.com.
    (3) You may review copies at the FAA, New England Region, 12 New 
England Executive Park, Burlington, MA; or at the National Archives 
and Records Administration (NARA). For information on the 
availability of this material at NARA, call (202) 741-6030, or go 
to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Burlington, Massachusetts, on June 14, 2011.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2011-16955 Filed 7-7-11; 8:45 am]
BILLING CODE 4910-13-P

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