Document ID: FAA-2012-0520-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Turbomeca S.A. Turboshaft Engines
Posted Date: 2012-07-25T04:00Z

[Federal Register Volume 77, Number 143 (Wednesday, July 25, 2012)]
[Proposed Rules]
[Pages 43550-43552]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-18155]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0520; Directorate Identifier 2002-NE-43-AD]
RIN 2120-AA64

Airworthiness Directives; Turbomeca S.A. Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede an existing airworthiness directive 
(AD) that applies to all Turbomeca S.A. Arriel 1A, 1A1, 1A2, 1B, 1C, 
1C1, 1C2, 1D, 1D1, 1E, 1E2, 1K, 1K1, 1S, and 1S1 turboshaft engines. 
The existing AD currently requires initial and repetitive visual 
inspections for erosion caused by dust ingestion and, if necessary, 
cleaning of the gas generator (module M03). Since we issued that AD, 
in-service experience has shown that dust inside the gas generator 
hollow shaft may be found when the axial compressor wheel has less 
erosion than initially assessed. This proposed AD would require 
determining the engine history, a one-time visual inspection of the 
axial compressor for erosion, initial and repetitive cleaning of the 
gas generator hollow shaft, and replacement of the rear bearing if the 
amount of dust collected during cleaning exceeds 8 grams. This proposed 
AD also includes an optional terminating action. We are proposing this 
AD to prevent an unbalance of the gas generator rotating assembly, 
which may lead to gas generator rear bearing failure, and uncommanded 
engine shutdown.

DATES: We must receive comments on this proposed AD by September 24, 
2012.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this AD, contact Turbomeca 
S.A., 40220 Tarnos, France; phone: 33 05 59 74 40 00; fax: 33 05 59 74 
45 15. 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 proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (phone: 800-647-5527) is 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; email: 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-2012-0520; 
Directorate Identifier 2002-NE-43-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

[[Page 43551]]

closing date and may amend this proposed AD because of 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 we 
receive about this proposed AD.

Discussion

    On June 13, 2003, we issued AD 2003-12-14, Amendment 39-13199 (68 
FR 36900, June 20, 2003), for all Turbomeca S.A. Arriel 1A, 1A1, 1A2, 
1B, 1C, 1C1, 1C2, 1D, 1D1, 1E, 1E2, 1K, 1K1, 1S, and 1S1 turboshaft 
engines. That AD requires initial and repetitive visual inspections for 
ingestive erosion and, if necessary, cleaning of the module M03. That 
AD resulted from reports from the manufacturer of an unbalance due to 
accumulation of dust in the gas generator hollow shaft. We issued that 
AD to prevent an unbalance of the gas generator rotating assembly, 
which may lead to deterioration of the gas generator rear bearing and 
uncommanded engine shutdown.

Actions Since Existing AD Was Issued

    Since we issued AD 2003-12-14, Amendment 39-13199 (68 FR 36900, 
June 20, 2003), in-service experience has shown that dust inside the 
gas generator hollow shaft may be found when the axial compressor wheel 
has less erosion than initially assessed. Also, since we issued that 
AD, Turbomeca S.A. has developed an improvement of the gas generator 
hollow shaft (Modification TU360), which makes the engine less 
susceptible to dust ingestion. This proposed AD would have optional 
terminating action to the inspections and cleaning, by the 
incorporation of Modification TU360. Also, since we issued AD 2003-12-
14, the European Aviation Safety Agency (EASA) issued AD 2012-0071, 
dated April 26, 2012, to address the conditions and improvements just 
described in the European Community. This proposed AD would remove 
Turbomeca S.A. Arriel 1E and 1K turboshaft engines from the 
applicability section of the AD. The 1E engine is no longer in service. 
The 1K engine is not an FAA validated engine and was incorrectly 
included in AD 2003-12-14.

Relevant Service Information

    We reviewed Turbomeca S.A. Alert Mandatory Service Bulletin (MSB) 
No. A292 72 0230, Version C, dated February 29, 2012. The Alert MSB 
describes procedures for the determination of the engine history, a 
one-time visual inspection of the axial compressor for erosion, to 
define the initial cleaning of the gas generator hollow shaft, and the 
interval for repetitive cleaning of the shaft. The referenced service 
bulletin also describes the criteria for replacement of the rear 
bearing if dust is found.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This proposed AD would require the following:
     Determining the engine history; and
     Performing a one-time visual inspection of the axial 
compressor for erosion, and initial and repetitive cleaning of the gas 
generator hollow shaft; and
     Replacing the gas generator rear bearing before further 
flight if the dust collected during any cleaning inside the gas 
generator hollow shaft exceeds 8 grams; and
     If there are any changes in accordance with paragraph 
1.A.(1)(a)1.3 of Turbomeca S.A. Alert MSB No. A292 72 0230, Version C, 
dated February 29, 2012, within 50 engine hours time-in-service after 
such a change, accomplish the actions required by this AD; and
     After the effective date of the AD, do not install a 
module M03 on an engine unless it is in compliance with the 
requirements in this proposed AD.

Costs of Compliance

    We estimate that this proposed AD would affect about 1,421 engines 
installed on helicopters of U.S. registry. We also estimate that it 
would take about 24 work-hours per engine to inspect and clean the gas 
generator module. The average labor rate is $85 per work-hour. A 
replacement gas generator rear bearing would cost about $4,128 per 
engine and take about 8 work-hours to replace. Based on these figures, 
we estimate the cost of the proposed AD on U.S. operators to be 
$2,898,840.

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 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 that the 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),
    (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.

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 removing airworthiness directive 
(AD) 2003-12-14, Amendment 39-13199 (68 FR 36900, June 20, 2003), and 
adding the following new AD:

Turbomeca S.A.: Docket No. FAA-2012-0520; Directorate Identifier 
2002-NE-43-AD.

[[Page 43552]]

(a) Comments Due Date

    The FAA must receive comments on this AD action by September 24, 
2012.

(b) Affected ADs

    This AD supersedes AD 2003-12-14, Amendment 39-13199 (68 FR 
36900, June 20, 2003).

(c) Applicability

    This AD applies to all Turbomeca S.A. Arriel 1A, 1A1, 1A2, 1B, 
1C, 1C1, 1C2, 1D, 1D1, 1E2, 1K1, 1S, and 1S1 turboshaft engines that 
have not incorporated Turbomeca S.A. Modification TU360.

(d) Unsafe Condition

    This AD was prompted by in-service experience showing that dust 
inside the gas generator hollow shaft may be found when the axial 
compressor wheel has less erosion than initially assessed. We are 
issuing this AD to prevent an unbalance of the gas generator 
rotating assembly, which may lead to deterioration of the gas 
generator rear bearing and uncommanded engine shutdown.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.
    (1) Within 50 engine hours after the effective date of this AD, 
determine the engine history and perform the maintenance actions at 
the specified schedules. Use paragraphs 1.A. and 2.A. through 2.C. 
of Turbomeca S.A. Alert Mandatory Service Bulletin (MSB) No. A292 72 
0230 Version C, dated February 29, 2012 to perform the maintenance 
actions and to establish the cleaning schedule.
    (2) If during any of the cleanings, the dust weight collected 
inside the gas generator hollow shaft is more than 8 grams, replace 
the gas generator rear bearing before further flight.
    (3) After the effective date of this AD, if there are any 
changes in accordance with paragraph 1.A.(1)(a)1.3 of Turbomeca S.A. 
Alert MSB No. A292 72 0230, Version C, dated February 29, 2012, 
within 50 engine hours time-in-service after such a change, 
accomplish the actions as specified in paragraph (e)(1) and (e)(2) 
in this AD.
    (4) After the effective date of this AD, do not install any gas 
generator (module M03) on an engine unless it is in compliance with 
this AD.
    (5) After the effective date of this AD, do not install any gas 
generator rear bearing that has operated on an engine with a hollow 
shaft that has been found to have a dust weight more than 8 grams.

(f) Optional Terminating Action

    As optional terminating action to the repetitive actions in this 
AD, modify the engine by incorporating Turbomeca S.A. Modification 
TU360.

(g) Alternative Methods of Compliance (AMOCs)

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

(h) Related Information

    (1) For more information about this AD, 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.
    (2) Refer to European Aviation Safety Agency AD 2012-0071, dated 
April 26, 2012, and Turbomeca S.A. Alert MSB No. A292 72 0230, 
Version C, dated February 29, 2012, for related information.
    (3) For service information identified in this AD, contact 
Turbomeca S.A., 40220 Tarnos, France; phone: 33 05 59 74 40 00; fax: 
33 05 59 74 45 15. 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.

    Issued in Burlington, Massachusetts, on July 20, 2012.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-18155 Filed 7-24-12; 8:45 am]
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