AD 2011-13-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Aviat | Various | Airworthiness Directives; Turbomeca S.A. ARRIEL 2B and 2B1 Turboshaft Engines |
| engine | Turbomeca | S | Airworthiness Directives; Turbomeca S.A. ARRIEL 2B and 2B1 Turboshaft Engines |
Unsafe Condition
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. Rupture of a GG turbine blade could result in an uncommanded in-flight shutdown and an emergency autorotation landing or accident.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Accomplish TU166 modification in accordance with Turbomeca Mandatory Service Bulletin (MSB) A292 72 3166 Version B, dated September 20, 2010, when the GG Turbine is replaced, during engine or Module M03 overhaul or repair, or within 1,300 cycles-in-service after the effective date of this AD, whichever occurs first.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 1,300 cycles-in-service after the effective date of this AD.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Turbomeca S.A. ARRIEL 2B and 2B1 turboshaft engines not modified by TU166 modification, installed on, but not limited to, Eurocopter AS 350 B3 and EC 130 B4 helicopters.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
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:
Document Text
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[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 [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[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: <a href="/cdn-cgi/l/email-protection#ddafb2aeb8f3b1b8b39dbbbcbcf3bab2ab"><span class="__cf_email__" data-cfemail="7b0914081e55171e153b1d1a1a551c140d">[email protected]</span></a>;
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 <a href="http://www.regulations.gov">http://www.regulations.gov</a>; 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: <a href="/cdn-cgi/l/email-protection#c1b3aeb2a4efada4af81a7a0a0efa6aeb7"><span class="__cf_email__" data-cfemail="0d7f627e68236168634d6b6c6c236a627b">[email protected]</span></a>;
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: <a href="/cdn-cgi/l/email-protection#fe90918c979fd39a9f92929f8dbe8a8b8c9c91939b9d9fd09d9193"><span class="__cf_email__" data-cfemail="274948554e460a43464b4b46546753525545484a4244460944484a">[email protected]</span></a>; telephone 33 05 59 74 40 00, fax 33 05 59 74
45 15, or go to: <a href="http://www.turbomeca-support.com">http://www.turbomeca-support.com</a>.
(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: <a href="http://www.archives.gov/federal-register/cfr/ibr-locations.html">http://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.
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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Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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