[Federal Register Volume 76, Number 215 (Monday, November 7, 2011)]
[Proposed Rules]
[Pages 68661-68663]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-28677]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0889; Directorate Identifier 2009-NE-35-AD]
RIN 2120-AA64


Airworthiness Directives; Turbomeca S.A. Arriel 2B and 2B1 
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 2B and 2B1 turboshaft 
engines. The existing AD currently requires checking the transmissible 
torque between the low-pressure (LP) pump impeller and the high-
pressure (HP) pump shaft on HP/LP pump hydro-mechanical metering units 
(HMUs) that do not incorporate Modification TU 147. Since we issued 
that AD, EASA issued a new AD. This proposed AD would require 
inspection and possible replacement of the HMU. We are proposing this 
AD to prevent reduced engine power or, at worst, an uncommanded in-
flight shutdown (IFSD), which can result in a forced autorotation 
landing or accident.

DATES: We must receive comments on this proposed AD by January 6, 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, 
40220 Tarnos, France; phone: 33-05-59-74-

[[Page 68662]]

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 01803. 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: James Rosa, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; phone: (781) 238-7152; 
fax: (781) 238-7199; email: [email protected].

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-2009-0889; 
Directorate Identifier 2009-NE-35-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 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 January 21, 2010, we issued AD 2010-03-06, Amendment 39-16189 
(75 FR 5689, February 4, 2010), for all Turbomeca Arriel 2B and 2B1 
turboshaft engines. That AD requires checking the transmissible torque 
between the LP pump impeller and the HP pump shaft on HMUs that do not 
incorporate Turbomeca Modification TU 147. That AD also requires 
replacing the HMU, if it fails that check, with an HMU that has not 
incorporated Modification TU 147 but passes the check, or with an HMU 
that incorporates Modification TU 147. That AD resulted from several 
events of uncoupling of the LP fuel pump impeller and the HP fuel pump 
shaft on Arriel 2 engines which do not incorporate modification TU 147. 
The uncoupling of the LP fuel pump impeller and the HP fuel pump shaft 
may lead to reduced engine power or, at worst, an uncommanded IFSD, 
which can result in a forced autorotation landing or accident.

Actions Since Existing AD Was Issued

    Since we issued AD 2010-03-06 (75 FR 5689, February 4, 2010), three 
additional cases of uncoupling of the LP fuel pump impeller and the HP 
fuel pump shaft have been encountered. However, these failures were in 
HMUs that were modified to post-TU 147 configuration HMUs, and the 
investigation indicates that these HMUs that fail the transmissible 
torque check must also be replaced.

Relevant Service Information

    We reviewed Turbomeca Alert Mandatory Service Bulletin (MSB) No. 
A292 73 2830, Version B, dated July 10, 2009, and Alert MSB No. A292 73 
2836, Version A, dated August 17, 2010. The Alert MSBs describe 
procedures for inspecting and replacing the HMU.

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 checking of the transmissible 
torque between the LP pump impeller and the HP pump shaft on HMUs. This 
proposed AD would also require replacing the HMU if it fails the 
transmissible torque check, with an HMU that is eligible for 
installation.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD 
would affect about 540 engines installed on helicopters of U.S. 
registry. We also estimate that it would take about 2.5 work-hours per 
engine to comply with this proposed AD. The average labor rate is $85 
per work-hour. Replacement HMUs would cost about $12,000 per engine. 
Based on these figures, if all of the HMUs were to fail the check, we 
estimate the cost of the proposed AD on U.S. operators to be 
$6,594,750.

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.

[[Page 68663]]

Sec.  39.13  [Amended]

    2. The FAA amends Sec.  39.13 by removing airworthiness directive 
(AD) 2010-03-06, Amendment 39-16189 (75 FR 5689, February 4, 2010), and 
adding the following new AD:

Turbomeca S.A.: Docket No. FAA-2009-0889; Directorate Identifier 
2009-NE-35-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by January 6, 
2012.

(b) Affected ADs

    This AD supersedes AD 2010-03-06, Amendment 39-16189 (75 FR 
5689, February 4, 2010).

(c) Applicability

    This AD applies to all Turbomeca S.A. Arriel 2B and 2B1 
turboshaft engines.

(d) Unsafe Condition

    This AD was prompted by three additional cases of uncoupling of 
the high-pressure/low-pressure (HP/LP) pump hydro-mechanical 
metering unit (HMU) LP fuel pump impeller and the HP fuel pump 
shaft, since AD 2010-03-06 (75 FR 5689, February 4, 2010) was 
issued. However, these failures were in HMUs that were modified to 
post-TU 147 configuration HMUs. The investigation indicates that 
these HMUs may also need to be replaced. We are issuing this AD to 
prevent reduced engine power or, at worst, an uncommanded in-flight 
shutdown, which can result in a forced autorotation landing or 
accident.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.
    (1) Check the transmissible torque between the LP fuel pump 
impeller and the HP fuel pump shaft as follows:
    (i) For HMUs that do not incorporate Modification TU 147, check 
the torque before accumulating 500 engine flight hours (EFH) since 
March 11, 2010 (the effective date of AD 2010-03-06 (75 FR 5689, 
February 4, 2010)). Use Paragraph 2 of Turbomeca Alert Mandatory 
Service Bulletin (MSB) No. A292 73 2830, Version B, dated July 10, 
2009, to do the check.
    (ii) For HMUs that incorporate Modification TU 147 and which 
Modification TU 147 was applied on or before March 31, 2010, and the 
HMUs are not listed in Figures 2 or 3 of Turbomeca Alert MSB No. 
A292 73 2836, Version A, dated August 17, 2010, check the torque 
within 750 EFH from the effective date of this AD, but no later than 
14 months after the effective date of this AD. Use Paragraph 2 of 
Turbomeca Alert MSB No. A292 73 2836, Version A, dated August 17, 
2010, to do the check.
    (2) If the HMU does not pass the torque check, then replace the 
HMU with an HMU that is eligible for installation.

(f) HMU Reinstallation

    Do not install any HMU removed from service by this AD until it 
has been checked in accordance with Paragraph 2 of Turbomeca Alert 
MSB No. A292 73 2836, Version A, dated August 17, 2010, or checked 
in accordance with Paragraph 2 of Turbomeca Alert MSB No. A292 73 
2830, Version B, dated July 10, 2009, and found eligible for 
installation.

(g) 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.

(h) Related Information

    (1) For more information about this AD, contact James Rosa, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, MA 
01803; phone: (781) 238-7152; fax: (781) 238-7199; email: 
[email protected].
    (2) 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 01803. For information on the 
availability of this material at the FAA, call (781) 238-7125.

    Issued in Burlington, Massachusetts, on October 28, 2011.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-28677 Filed 11-4-11; 8:45 am]
BILLING CODE 4910-13-P