Airworthiness Directives; Turbomeca Astazou XIV B and XIV H Turboshaft Engines

[Federal Register Volume 75, Number 104 (Tuesday, June 1, 2010)]
[Rules and Regulations]
[Pages 30270-30272]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-12539]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0219; Directorate Identifier 2010-NE-14-AD; 
Amendment 39-16315; AD 2010-11-10]
RIN 2120-AA64


Airworthiness Directives; Turbomeca Astazou XIV B and XIV H 
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:

    Investigation of an uncommanded in-flight shutdown (IFSD) 
revealed that a third stage turbine wheel rupture was not contained 
by the turbine casings. The released portion consisted of a turbine 
blade together with the rim piece immediately below the blade. The 
rim piece was bounded by two adjacent axial slots and a fatigue 
crack that had developed between the holes in which the slots 
terminate. The slots and holes, which are closed by riveted plugs, 
were introduced by modification AB 173 in order to improve the 
vibration characteristics of the turbine wheel. Modification AB 208 
brings an improvement to modification AB 173 by changing only the 
riveting detail. SN 283 72 0805 provides instructions for re-boring 
the holes at overhaul or repair in order to improve their surface 
condition. A manufacturing process modification has been introduced 
to improve the surface condition of these holes in third stage 
turbine wheels. Wheels subject to the improved manufacturing process 
have S/Ns outside the range specified in Table 1. Although there is 
only one known event, and although it resulted only in an 
uncommanded IFSD, with no damage to the aircraft, the possibility 
exists that additional events may occur, potentially involving 
damage to the aircraft.

We are issuing this AD to prevent uncontained failures of the third 
stage turbine wheel, which could result in damage to the helicopter.

DATES: This AD becomes effective July 6, 2010. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in this AD as of July 6, 2010.

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: Kevin Dickert, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; e-mail: 
[email protected]; telephone (781) 238-7117, 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 March 30, 2010 (75 
FR 15627). That NPRM proposed to correct an unsafe condition for the 
specified products. The MCAI states that:

    Investigation of an uncommanded IFSD revealed that a third stage 
turbine wheel rupture was not contained by the turbine casings. The 
released portion consisted of a turbine blade together with the rim 
piece immediately below the blade. The rim piece was bounded by two 
adjacent axial slots and a fatigue crack that had developed between 
the holes in which the slots terminate. The slots and holes, which 
are closed by riveted plugs, were introduced by modification AB 173 
in order to improve the vibration characteristics of the turbine 
wheel. Modification AB 208 brings an improvement to modification AB 
173 by changing only the riveting detail. SB 283 72 0805 provides 
instructions for re-boring the holes at overhaul or repair in order 
to improve their surface condition. A manufacturing process 
modification has been introduced to improve the surface condition of 
these holes in third stage turbine wheels. Wheels subject to the 
improved manufacturing process have S/Ns outside the range specified 
in Table 1. Although there is only one known event, and although it 
resulted only in an uncommanded IFSD, with no damage to the 
aircraft, the possibility exists that additional events may occur, 
potentially involving damage to the aircraft.
    To address the unsafe condition, EASA issued AD 2009-0136, 
mandating inspection of certain third stage turbine wheels and 
removal of any damaged wheel. The wheels to be inspected were those 
whose cycles since new (CSN) would exceed 2,000 by February 1, 2011. 
Following additional research by Turbomeca on crack initiation and 
growth, this AD mandates inspections based on new criteria and 
removal of any damaged wheel.

Comments

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

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 will 
affect about three Astazou engines installed on products of U.S. 
registry. We also estimate that it will take about 5 work-hours per 
engine to comply with this AD. The average labor rate is $85 per work-
hour. We anticipate no parts to be required. Based on these figures, we 
estimate the cost of the AD on U.S. operators to be $1,275.

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.

[[Page 30271]]

    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 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

0
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:

2010-11-10 Turbomeca: Amendment 39-16315. Docket No. FAA-2010-0219; 
Directorate Identifier 2010-NE-14-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective July 6, 
2010.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Turbomeca Astazou XIV B and XIV H 
turboshaft engines with the following part number (P/N) third stage 
turbine wheels that incorporate modification AB 173 (Turbomeca 
Service Bulletin (SB) No. 283 72 0091) or modification AB 208 
(Turbomeca SB No. 283 72 0117), but that do not incorporate 
Turbomeca SB No. 283 72 805:
    (1) Third stage turbine wheels P/N 0265257000, all serial 
numbers (S/Ns);
    (2) Third stage turbine wheels P/N 0265257020, all S/Ns;
    (3) Third stage turbine wheels P/N 0265257060, all S/Ns;
    (4) Third stage turbine wheels P/N 0265257050, of the S/Ns 
listed in Appendix 1 of Turbomeca Mandatory Service Bulletin (MSB) 
No. 283 72 0804, Version C, dated October 23, 2009.
    (5) These engines are installed on, but not limited to, single-
engine Aerospatiale AS319B ``Alouette III'' and AS342J ``Gazelle'' 
helicopters.

Reason

    (d) European Aviation Safety Agency (EASA) AD No. 2010-0004, 
dated January 5, 2010, states:

    Investigation of an uncommanded in-flight shutdown (IFSD) 
revealed that a third stage turbine wheel rupture was not contained 
by the turbine casings. The released portion consisted of a turbine 
blade together with the rim piece immediately below the blade. The 
rim piece was bounded by two adjacent axial slots and a fatigue 
crack that had developed between the holes in which the slots 
terminate. The slots and holes, which are closed by riveted plugs, 
were introduced by modification AB 173 in order to improve the 
vibration characteristics of the turbine wheel. Modification AB 208 
brings an improvement to modification AB 173 by changing only the 
riveting detail. SN 283 72 0805 provides instructions for re-boring 
the holes at overhaul or repair in order to improve their surface 
condition. A manufacturing process modification has been introduced 
to improve the surface condition of these holes in third stage 
turbine wheels. Wheels subject to the improved manufacturing process 
have S/Ns outside the range specified in Table 1. Although there is 
only one known event, and although it resulted only in an 
uncommanded IFSD, with no damage to the aircraft, the possibility 
exists that additional events may occur, potentially involving 
damage to the aircraft.
    To address the unsafe condition, EASA issued AD 2009-0136, 
mandating inspection of certain third stage turbine wheels and 
removal of any damaged wheel. The wheels to be inspected were those 
whose cycles since new (CSN) would exceed 2,000 by February 1, 2011. 
Following additional research by Turbomeca on crack initiation and 
growth, this AD mandates inspections based on new criteria and 
removal of any damaged wheel.

    We are issuing this AD to prevent uncontained failures of the 
third stage turbine wheel, which could result in damage to the 
helicopter.

Actions and Compliance

    (e) Unless already done, do the following actions.
    (1) For any affected third stage turbine wheel that on the 
effective date of this AD has accumulated fewer than 500 cycles-
since-last-overhaul or repair, or since-new if the engine has never 
been overhauled or repaired:
    (i) Within 300 additional cycles, perform a dye penetrant 
inspection on the rear face of the third stage turbine wheel.
    (ii) Use Section 2, Instructions to Be Incorporated, of 
Turbomeca MSB No. 283 72 0804, Version C, dated October 23, 2009, to 
do the inspection.
    (iii) Perform a second dye penetrant inspection when the engine 
has accumulated between 450 and 550 cycles from the first 
inspection.
    (2) For any affected third stage turbine wheel that on the 
effective date of this AD, has accumulated 500 or more but fewer 
than 700 cycles-since-last-overhaul or repair, or since-new if the 
engine has never been overhauled or repaired:
    (i) Within 200 additional cycles, perform a dye penetrant 
inspection on the rear face of the third stage turbine wheel.
    (ii) Use Section 2, Instructions to Be Incorporated, of 
Turbomeca MSB No. 283 72 0804, Version C, dated October 23, 2009, to 
do the inspection.
    (3) For any affected third stage turbine wheel that on the 
effective date of this AD, has accumulated 700 or more but fewer 
than 1,200 cycles-since-last-overhaul or repair, or since-new if the 
engine has never been overhauled or repaired:
    (i) Within 150 additional cycles, perform a dye penetrant 
inspection on the rear face of the third stage turbine wheel.
    (ii) Use Section 2, Instructions to Be Incorporated, of 
Turbomeca MSB No. 283 72 0804, Version C, dated October 23, 2009, to 
do the inspection.
    (4) If any crack indication is found, then before further 
flight, remove the third stage turbine wheel from service.
    (5) For any affected third stage turbine wheel that on the 
effective date of this AD has accumulated 1,200 or more cycles-
since-last-overhaul or repair, or since-new if the engine has never 
been overhauled or repaired, no action is required.

[[Page 30272]]

FAA AD Differences

    (f) This AD differs from the Mandatory Continuing Airworthiness 
Information (MCAI) and or service information as follows:
    (1) EASA AD 2010-0004, dated January 5, 2010, requires removing 
the engine from service before further flight if a third stage 
turbine wheel is found cracked.
    (2) This AD requires removing the third stage turbine wheel from 
service before further flight if a third stage turbine wheel is 
found cracked.

Alternative Methods of Compliance

    (g) 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

    (h) Refer to MCAI EASA AD 2010-0004, dated January 5, 2010, for 
related information.
    (i) Contact Kevin Dickert, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
[email protected]; telephone (781) 238-7117, fax (781) 238-7199, 
for more information about this AD.

Material Incorporated by Reference

    (j) You must use Turbomeca Mandatory Service Bulletin No. 283 72 
0804, Version C, dated October 23, 2009, 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, 40220 Tarnos, France; telephone (33) 05 59 74 40 00, fax 
(33) 05 59 74 45 15.
    (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 May 19, 2010.
Tracy Murphy,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2010-12539 Filed 5-28-10; 8:45 am]
BILLING CODE 4910-13-P

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