Document ID: FAA-2010-0904-0003
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Turbomeca Turboshaft Engines
Posted Date: 2011-12-23T05:00Z

[Federal Register Volume 76, Number 247 (Friday, December 23, 2011)]
[Rules and Regulations]
[Pages 80228-80230]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-32890]

[[Page 80228]]

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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; 
Amendment 39-16902; AD 2011-27-01]
RIN 2120-AA64

Airworthiness Directives; Turbomeca 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 
Turbomeca Arriel 1B turboshaft engines. This AD results from mandatory 
continuing airworthiness information (MCAI) originated 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 an increase in hot gas ingestion and an increase of 
temperature in the gas generator (GG) turbine rotor, potentially 
resulting in turbine damage and an uncommanded in-flight shutdown. We 
are issuing this AD to prevent over-temperature damage of the GG 
turbine, which could result in an uncommanded in-flight engine 
shutdown, and a subsequent forced autorotation landing or accident.

DATES: This AD becomes effective January 27, 2012.

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; phone: (781) 238-7772; 
fax: (781) 238-7199; email: rose.len@faa.gov.

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 August 31, 2011 (76 
FR 54143). That NPRM proposed 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.

    The corrective action includes daily checks for evidence of turbine 
damage, and removal of the engine from service before further flight if 
turbine damage is found. The corrective action also includes inspecting 
the configuration of the holes in the repaired 2nd stage turbine NGV. 
If the holes are non-conforming, then before further flight replacement 
of the 2nd stage turbine NGV, 1st stage turbine disc, and 2nd stage 
turbine disc, with discs eligible for installation, is required. You 
may obtain further information by examining the MCAI in the AD docket.

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 affects 
about 20 Turbomeca Arriel 1B turboshaft engines installed on 
helicopters of U.S. registry. We estimate that it will 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 will 
take about 60 work-hours to replace the NGV, the 1st stage turbine 
disc, and the 2nd stage turbine disc, and that one engine will require 
these replacements. The average labor rate is $85 per work-hour. 
Required parts cost about $19,889 per engine. Based on these figures, 
we estimate the cost of the 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 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.

[[Page 80229]]

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:

2011-27-01 Turbomeca: Amendment 39-16902; Docket No. FAA-2010-0904; 
Directorate Identifier 2010-NE-33-AD.

(a) Effective Date

    This airworthiness directive (AD) becomes effective January 27, 
2012.

(b) Affected ADs

    None.

(c) Applicability

    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 
(NGV). 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 NGV installed can be 
found in paragraph 1.C. of Turbomeca Mandatory Service Bulletin 
(MSB) No. A292 72 0829, Version B, dated December 13, 2010.

(d) Reason

    This AD was prompted by an increase in hot gas ingestion and an 
increase of temperature in the gas generator (GG) turbine rotor, 
potentially resulting in turbine damage and an uncommanded in-flight 
shutdown. We are issuing this AD to prevent over-temperature damage 
of the GG turbine, which could result in an uncommanded in-flight 
engine shutdown, and a subsequent forced autorotation landing or 
accident.

(e) Compliance

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

(f) Daily Checks

    (1) Starting from the effective date of this AD, perform a daily 
check (after last flight of the day) for:
    (i) Normal rundown time of the GG rotor; and
    (ii) The free rotation of the GG rotor; and
    (iii) No grinding noise during the rundown check, and during the 
free rotation check of the GG rotor.
    (2) 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.
    (3) If the engine fails any of these daily checks, remove the 
engine from service before further flight.

(g) Inspection of Repaired 2nd Stage Turbine NGVs

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

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

(h) Terminating Action

    Complying with paragraph (g)(1) and either paragraph (g)(2) or 
paragraphs (g)(3)(i) through (g)(3)(ii) 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.

(i) Installation Prohibition

    (1) Do not reinstall the 1st stage turbine disc and the 2nd 
stage turbine disc removed in paragraph (g)(3)(ii) of this AD into 
any engine.
    (2) 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.
    (3) 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.

(j) FAA AD Differences

    (1) This AD differs from the Mandatory Continuing Airworthiness 
Information (MCAI) and/or service information as follows:
    (i) 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.
    (ii) This AD does not incorporate by reference (IBR) Turbomeca 
MSB No. A292 72 0829, Version B, dated December 13, 2010; the MCAI 
does.
    (iii) 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.

(k) Definition

    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.

(l) Alternative Methods of Compliance (AMOCs)

    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.

(m) Related Information

    (1) 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; phone: 33 05 59 74 40 00; fax: 33 
05 59 74 45 15; for a copy of this service information.
    (2) 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; email: rose.len@faa.gov, for more information about 
this AD.

[[Page 80230]]

(n) Material Incorporated by Reference

    None.

    Issued in Burlington, Massachusetts, on December 16, 2011.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-32890 Filed 12-22-11; 8:45 am]
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