Airworthiness Directives; Turbomeca Arriel 1 Series Turboshaft Engines

[Federal Register Volume 76, Number 239 (Tuesday, December 13, 2011)]
[Rules and Regulations]
[Pages 77378-77380]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-31797]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0710; Directorate Identifier 2010-NE-26-AD; 
Amendment 39-16892; AD 2011-26-02]
RIN 2120-AA64


Airworthiness Directives; Turbomeca Arriel 1 Series Turboshaft 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are revising an existing airworthiness directive (AD) for 
the products listed above. This AD was prompted by Turbomeca restoring 
all or part of the life limits of the affected discs, and European 
Aviation Safety Agency's (EASA) issuance of AD 2010-0101R2, dated March 
24, 2011, to do the same. Turbomeca has introduced a reinforced eddy-
current inspection (ECI) which, combined with a revised analysis, 
allows the life limit of the affected discs to be extended. We are 
issuing this revision to prevent failure of the gas generator (GG) 
second stage turbine disc which could result in the release of high 
energy debris and damage to the helicopter.

DATES: This AD is effective January 17, 2012.

ADDRESSES: For service information identified in this AD, contact 
Turbomeca, 40220 Tarnos, France; phone: 33 05 59 74 40 00; fax: 33 05 
59 74 45 15; email: [email protected]. You may review copies 
of the referenced service information at the FAA, Engine & Propeller 
Directorate, 12 New England Executive Park, Burlington, MA. For 
information on the availability of this material at the FAA, call (781) 
238-7125.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.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 AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (phone: (800) 647-5527) is Document Management Facility, 
U.S. Department of Transportation, Docket Operations, M-30, West 
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Frederick Zink, Aerospace Engineer, 
Engine Certification Office, FAA, 12 New England Executive Park, 
Burlington, MA; phone: (781) 238-7779; fax: (781) 238-7199; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to revise AD 2010-19-06, amendment 39-16434 (75 FR 57371, 
September 21, 2010). That AD applies to the specified products. The 
NPRM published in the Federal Register on July 19, 2011 (76 FR 42610). 
That NPRM proposed to require removing GG second stage turbine discs, 
P/N 0 292 25 040 0, that do not have the ``CFR'' marking, from service 
before exceeding 4,000 cycles-in-service (CIS) since-new. That NPRM 
also proposed to require removing GG second stage turbine discs, P/N 0 
292 25 040 0, that have the ``CFR'' marking, from service before 
exceeding 6,500 CIS since-new.
    That NPRM was prompted by Turbomeca restoring all or part of the 
life limits of the affected discs, per

[[Page 77379]]

EASA's issuance of AD 2010-0101R2, dated March 24, 2011, to do the 
same. Turbomeca's reinforced ECI provides a lower (improved) detection 
threshold for metallurgical non-conformities. This reinforced ECI, 
combined with a revised analysis, allows the life limit of the post-
TU347 GG second stage turbine discs identified as ``CFR'' to be 
extended to 6,500 CIS since-new. Further, as a result of this testing 
and analysis, the non-CFR 2nd stage turbine discs pre-TU347 inspection 
disc life has been extended to 4,000 CIS since-new. This new AD still 
prevents disc failure but also extends the life limits of the affected 
discs. We are issuing this revision to prevent failure of the GG second 
stage turbine disc which could result in the release of high energy 
debris and damage to the helicopter.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We received no comments on the NPRM (76 FR 42610, July 19, 
2011) or on the determination of the cost to the public.

Conclusion

    We reviewed the relevant data and determined that air safety and 
the public interest require adopting the AD as proposed except for 
minor clarifications. We have determined that these minor changes:
    <bullet> Are consistent with the intent that was proposed in the 
NPRM (76 FR 42610, July 19, 2011) for correcting the unsafe condition; 
and
    <bullet> Do not add any additional burden upon the public than was 
already proposed in the NPRM (76 FR 42610, July 19, 2011).

Costs of Compliance

    We estimate that this AD will affect 203 Turbomeca Arriel 1 series 
turboshaft engines on helicopters of U.S. registry. We estimate that no 
additional labor costs will be incurred to return part of the life 
limit of the discs that do not have the ``CFR'' marking to the original 
published life limit. Based on these figures, we estimate the total 
cost of this AD to U.S. operators to be $0.

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 have 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 that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

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 removing airworthiness directive (AD) 
2010-19-06, Amendment 39-16434 (75 FR 57371, September 21, 2010), and 
adding the following new AD:

2011-26-02 Turbomeca: Amendment 39-16892; Docket No. FAA-2010-0710; 
Directorate Identifier 2010-NE-26-AD.

(a) Effective Date

    This airworthiness directive (AD) is effective January 17, 2012.

(b) Affected ADs

    This AD revises AD 2010-19-06, Amendment 39-16434.

(c) Applicability

    This AD applies to Turbomeca Arriel 1A, 1A1, 1B, 1C, 1C1, 1C2, 
1D, 1D1, and 1S1 turboshaft engines that have incorporated 
Modification TU347.

(d) Unsafe Condition

    This AD was prompted by Turbomeca restoring all or part of the 
life limits of the affected discs. We are issuing this AD to prevent 
failure of the gas generator (GG) second stage turbine disc which 
could result in the release of high energy debris and damage to the 
helicopter.

(e) Compliance

    (1) Comply with this AD within the compliance times specified, 
unless already done.
    (2) Remove from service the GG second stage turbine discs, part 
number (P/N) 0 292 25 040 0, that do not have the ``CFR'' marking 
before exceeding 4,000 cycles-in-service (CIS) since-new.
    (3) Remove from service gas generator second stage turbine 
discs, P/N 0 292 25 040 0, that have the ``CFR'' marking before 
exceeding 6,500 CIS since-new.

(f) Gas Generator Second Stage Turbine Installation Prohibition

    (1) After the effective date of this AD, do not install into any 
engine gas generator second stage turbine discs, P/N 0 292 25 040 0, 
that do not have the ``CFR'' marking and have 4,000 or more CIS 
since-new.
    (2) After the effective date of this AD, do not install into any 
engine gas generator second stage turbine discs, P/N 0 292 25 040 0, 
that have the ``CFR'' marking and have 6,500 or more CIS since-new.

(g) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, FAA, may approve AMOCs 
for this AD. Use the procedures found in 14 CFR 39.19 to make your 
request.

(h) Related Information

    (1) Refer to Turbomeca Alert Mandatory Service Bulletin No. A292 
72 0831, Version C, for related information. Contact Turbomeca, 
40220 Tarnos, France; phone: 33 05 59 74 40 00; fax: 33 05 59 74 45 
15; or email: [email protected] for a copy of this service 
information.
    (2) You may review copies of the referenced service information 
at the FAA, Engine & Propeller Directorate, 12 New England Executive 
Park, Burlington, MA. For information on the availability of this 
material at the FAA, call (781) 238-7125.
    (3) For more information about this AD, contact Frederick Zink, 
Aerospace Engineer, Engine Certification Office, FAA, 12 New England 
Executive Park, Burlington, MA 01803; phone: (781) 238-7779; fax: 
(781) 238-7199; email: [email protected].

(i) Material Incorporated by Reference

    None.


[[Page 77380]]


    Issued in Burlington, MA, on December 5, 2011.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-31797 Filed 12-12-11; 8:45 am]
BILLING CODE 4910-13-P

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