
[Federal Register Volume 76, Number 169 (Wednesday, August 31, 2011)]
[Proposed Rules]
[Pages 54143-54145]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-22246]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0904; Directorate Identifier 2010-NE-33-AD]
RIN 2120-AA64


Airworthiness Directives; Turbomeca Arriel 1B Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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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) 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:

    During quality inspections in repair centre some 2nd stage 
Nozzle Guide Vanes (NGVs) to be installed on Pre TU 148 standard 
Arriel 1B were found not conforming to the definition. The affected 
parts had been repaired and were found drilled on the rear flange 
instead of the front flange. This configuration corresponds to 2nd 
stage Turbine NGVs to be installed on post-TU 148 standard Arriel 1B 
engines. This non compliance may only be found on post-TU 76 
standard 2nd stage Turbine NGVs (i.e., with flexible hub).
    This non compliance would increase hot gas ingestion and 
generate an increase of temperature in the Gas Generator (GG) 
turbine rotor, potentially resulting in turbine damage and an 
uncommanded in-flight shutdown.

We are proposing this AD to prevent over-temperature damage of the gas 
generator turbine, which could result in an uncommanded in-flight 
engine shutdown, and a subsequent forced autorotation landing or 
accident.

DATES: We must receive comments on this proposed AD by October 17, 
2011.

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.
    Contact Turbomeca, 40220 Tarnos, France; phone: 33 05 59 74 40 00, 
fax: 33 05 59 74 45 15, for the service information identified in this 
proposed AD.

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 (phone: 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: Rose Len, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; phone: 781-238-7772; fax: 
781-238-7199; e-mail: rose.len@faa.gov.

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-2010-0904; 
Directorate Identifier 2010-NE-33-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

[[Page 54144]]

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 
AD 2010-0273R1, dated February 16, 2011 (referred to after this as 
``the MCAI''), to correct an unsafe condition for the specified 
products. The MCAI states:

    During quality inspections in repair centre some 2nd stage 
Nozzle Guide Vanes (NGVs) to be installed on Pre TU 148 standard 
Arriel 1B were found not conforming to the definition. The affected 
parts had been repaired and were found drilled on the rear flange 
instead of the front flange. This configuration corresponds to 2nd 
stage Turbine NGVs to be installed on post-TU 148 standard Arriel 1B 
engines. This non compliance may only be found on post-TU 76 
standard 2nd stage Turbine NGVs (i.e., with flexible hub).
    This non compliance would increase hot gas ingestion and 
generate an increase of temperature in the Gas Generator (GG) 
turbine rotor, potentially resulting in turbine damage and an 
uncommanded in-flight shutdown.

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

Relevant Service Information

    Turbomeca has issued Mandatory Service Bulletin (MSB) No. A292 72 
0829, Version B, dated December 13, 2010. The actions described in this 
service information are intended to correct the unsafe condition 
identified in the MCAI.

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 MCAI 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 daily checks for evidence of turbine 
damage, and removal of the engine from service before further flight if 
turbine damage is found. This proposed AD would also require inspecting 
the configuration of the holes in the repaired 2nd stage turbine NGV. 
If the holes are non-conforming, then before further flight this 
proposed AD would require replacing the 2nd stage turbine NGV, 1st 
stage turbine disc, and 2nd stage turbine disc, with discs eligible for 
installation.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD 
would affect about 20 Turbomeca Arriel 1B turboshaft engines installed 
on helicopters of U.S. registry. We also estimate that it would take 
about 40 work-hours per engine to inspect a repaired 2nd stage turbine 
NGV for the non-conforming hole configuration. We also estimate that it 
would take about 60 work-hours to replace the NGV, the 1st stage 
turbine disc, and the 2nd stage turbine disc, and that one engine would 
require these replacements. The average labor rate is $85 per work-
hour. Required parts would cost about $19,889 per engine. Based on 
these figures, we estimate the cost of the proposed AD on U.S. 
operators to be $92,989. 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, 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: Docket No. FAA-2010-0904; Directorate Identifier 2010-NE-
33-AD.

Comments Due Date

    (a) We must receive comments by October 17, 2011.

Affected Airworthiness Directives (ADs)

    (b) None.

Applicability

    (c) This AD applies to Turbomeca Arriel 1B turboshaft engines 
with M03 modules modified by TU 76 or TU 202, and not modified by TU 
148, and if fitted with a repaired 2nd stage turbine nozzle guide 
vane. The M03 module contains the 2nd stage turbine NGV, 1st stage 
turbine disc, and 2nd stage turbine disc. Guidance on determining if 
an engine has an unrepaired 2nd stage turbine nozzle guide vane 
installed can be found in paragraph 1.C. of Turbomeca Mandatory 
Service Bulletin (MSB) No. A292 72 0829, Version B, dated December 
13, 2010.

Reason

    (d) During quality inspections in repair centre some 2nd stage 
Nozzle Guide Vanes (NGVs) to be installed on Pre TU 148 standard 
Arriel 1B were found not conforming to the definition. The affected 
parts had been repaired and were found drilled on the rear flange 
instead of the front flange. This configuration corresponds to 2nd 
stage Turbine NGVs to be installed on post-TU 148 standard Arriel 1B 
engines. This non compliance may only be found on post-TU

[[Page 54145]]

76 standard 2nd stage Turbine NGVs (i.e., with flexible hub).
    This non compliance would increase hot gas ingestion and 
generate an increase of temperature in the Gas Generator (GG) 
turbine rotor, potentially resulting in turbine damage and an 
uncommanded in-flight shutdown. On a single-engine helicopter, this 
could ultimately lead to an emergency autorotation landing.
    We are issuing this AD to prevent over-temperature damage of the 
gas generator turbine, which could result in an uncommanded in-
flight engine shutdown, and a subsequent forced autorotation landing 
or accident.

Compliance

    (e) Comply with this AD within the compliance times specified, 
unless already done.

Daily Checks

    (f) Starting from the effective date of this AD, perform a daily 
check (after last flight of the day) for:
    (1) Normal rundown time of the gas generator rotor; and
    (2) The free rotation of the gas generator rotor; and
    (3) No grinding noise during the rundown check, and during the 
free rotation check of the gas generator rotor.
    (g) Guidance on performing the daily checks can be found in the 
Maintenance Manual, task 71-02-09-760-801 and task 05-20-01-200-801.
    (h) If the engine fails any of these daily checks, remove the 
engine from service before further flight.

Inspection of Repaired 2nd Stage Turbine NGVs

    (i) Inspect the 2nd stage turbine NGV for a non-conforming hole 
configuration, at the compliance times in Table 1 of this AD. 
Guidance on 2nd stage turbine NGV non-conforming hole configuration 
can be found in Turbomeca MSB No. A292 72 0829, Version B, dated 
December 13, 2010.


                                      Table 1--Inspection Compliance Times
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    If accumulated Gas Generator (GG) Cycles-in-Service (CIS) on the
                     effective date of this AD are:                                   Then inspect:
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(1) Fewer than 1,200 CIS on both the 1st and 2nd stage turbines........  Before exceeding 1,500 GG CIS.
(2) 1,200 or more but fewer than 1,800 CIS on either the 1st or 2nd      Before exceeding 300 GG CIS after the
 stage turbines.                                                          effective date of this AD but not to
                                                                          exceed 2,000 CIS on either the 1st or
                                                                          2nd stage turbines.
(3) 1,800 or more but fewer than 2,400 CIS on either the 1st or 2nd      Before exceeding 200 GG CIS after the
 stage turbine.                                                           effective date of this AD but not to
                                                                          exceed 2,500 CIS on either the 1st or
                                                                          2nd stage turbines.
(4) Greater than 2,400 CIS on either the 1st or 2nd stage turbine......  Before exceeding 100 GG CIS after the
                                                                          effective date of this AD but not to
                                                                          exceed 3,000 CIS on either the 1st or
                                                                          2nd stage turbine.
----------------------------------------------------------------------------------------------------------------

     (j) If the configuration of the holes in the repaired 2nd stage 
turbine NGV are conforming, then no further action is required.
    (k) If the configuration of the holes in the repaired 2nd stage 
turbine NGV are non-conforming, then before further flight:
    (1) Replace the 2nd stage turbine NGV with a 2nd stage turbine 
NGV eligible for installation; and
    (2) Replace the 1st stage turbine disc and 2nd stage turbine 
disc with discs eligible for installation.

Terminating Action

    (l) Complying with paragraph (i) and either paragraph (j) or 
paragraphs (k)(1) through (k)(2) of this AD, or replacing the M03 
module with an M03 module that is eligible for installation, is 
terminating action for the requirements of this AD.

Installation Prohibition

    (m) Do not reinstall the 1st stage turbine disc and the 2nd 
stage turbine disc removed in paragraph (k)(2) of this AD into any 
engine.
    (n) After the effective date of this AD, do not install an M03 
module that has incorporated TU 202 but not incorporated TU 148, 
unless the module is in compliance with the requirements of this AD.
    (o) After the effective date of this AD, do not install an M03 
module that has incorporated TU 76 but not incorporated TU 148, 
unless the module is in compliance with the requirements of this AD.

FAA AD Differences

    (p) This AD differs from the Mandatory Continuing Airworthiness 
Information (MCAI) and/or service information as follows:
    (1) This AD does not require sending data to Turbomeca to 
confirm whether Turbomeca MSB No. A292 72 0829, Version B, dated 
December 13, 2010, is applicable to the operator's engine; the MCAI 
does.
    (2) This AD does not incorporate by reference (IBR) Turbomeca 
MSB No. A292 72 0829, Version B, dated December 13, 2010; the MCAI 
does.
    (3) This AD requires replacing non-conforming 2nd stage turbine 
NGVs and 1st stage and 2nd stage turbine discs that were operated 
with non-conforming 2nd stage turbine NGVs but does not require 
replacing affected M03 modules. The MCAI requires replacing affected 
M03 modules with M03 modules eligible for installation.

Definition

    (q) For the purpose of this AD, a conforming repaired 2nd stage 
turbine NGV is one with cooling holes in the forward inner flange, 
and with no cooling holes in the rear flange.

Alternative Methods of Compliance (AMOCs)

    (r) 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

    (s) Refer to European Aviation Safety Agency AD 2010-0273R1, 
dated February 16, 2011, and Turbomeca MSB No. A292 72 0829, Version 
B, dated December 13, 2010, for related information. Contact 
Turbomeca, 40220 Tarnos, France; telephone 33 05 59 74 40 00, fax 33 
05 59 74 45 15, for a copy of this service information.
    (t) Contact Rose Len, Aerospace Engineer, Engine Certification 
Office, FAA, Engine & Propeller Directorate, 12 New England 
Executive Park, Burlington, MA 01803; e-mail: rose.len@faa.gov; 
phone: 781-238-7772; fax: 781-238-7199, for more information about 
this AD.

    Issued in Burlington, Massachusetts, on August 23, 2011.
Thomas A. Boudreau,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2011-22246 Filed 8-30-11; 8:45 am]
BILLING CODE 4910-13-P


