DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0889; Product Identifier 2009-NE-35-AD; Amendment
39-19305; AD 2018-12-01]
RIN 2120-AA64

Airworthiness Directives; Safran Helicopter Engines, S.A.,
Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are superseding Airworthiness Directive (AD) 2012-03-11 for
all Safran Helicopter Engines, S.A., Arriel 2B and 2B1 turboshaft
engines. AD 2012-03-11 required checking the transmissible torque
between the low-pressure (LP) pump impeller and the high-pressure (HP)
pump shaft on the HP/LP pump and metering valve assembly, hereafter
referred to as the hydro-mechanical metering unit (HMU). Since we
issued AD 2012-03-11, the manufacturer determined that incorporating
Modification TU 178 is a more effective method to reduce the risk of
uncoupling between the LP fuel pump impeller and the HP fuel pump shaft
than the prior Modification TU 147. This AD requires inspection and
possible replacement of the HMU. This AD was prompted by three cases of
uncoupling of the HMU LP fuel pump impeller and the HP fuel pump shaft
since AD 2012-03-11 was issued. We are issuing this AD to address the
unsafe condition on these products.

DATES: This AD is effective September 12, 2018.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of March 11,
2010 (75 FR 5689, February 4, 2010).
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of March 20,
2012 (77 FR 8092, February 14, 2012).

ADDRESSES: For service information identified in this final rule,
contact Safran Helicopter Engines, S.A., 40220 Tarnos, France; phone:
(33) 05 59 74 40 00; fax: (33) 05 59 74 45 15. You may view this
service information at the FAA, Engine and Propeller Standards Branch,
1200 District Avenue, Burlington, MA 01803. For information on the
availability of this material at the FAA, call 781-238-7759. It is also
available on the internet at http://www.regulations.gov by searching
for and locating Docket No. FAA-2009-0889.

Examining the AD Docket

You may examine the AD docket on the internet at http://www.regulations.
gov by searching for and locating Docket No. FAA-2009-
0889; or in person at Docket Operations between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays. The AD docket contains
this final rule, the mandatory continuing airworthiness information,
regulatory evaluation, any comments received, and other information.
The address for Docket Operations (phone: 800-647-5527) is Document
Operations, U.S. Department of Transportation, Docket Operations, M-30,
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE,
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: John Frost, Aerospace Engineer, ECO
Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781-
238-7756; fax: 781-238-7199; email: john.frost@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 to supersede AD 2012-03-11, Amendment 39-16953 (77 FR 8092,
February 14, 2012), (``AD 2012-03-11''). AD 2012-03-11 applied to all
Safran Helicopter Engines, S.A., Arriel 2B and 2B1 turboshaft engines.
The NPRM published in the Federal Register on October 6, 2017 (82 FR
46727). The NPRM was prompted by instances of uncoupling between the LP
fuel pump impeller and the HP fuel pump shaft. The NPRM proposed to
require inspection and, depending on the results of the inspection,
possible replacement of the HMU. The NPRM also proposed to require
replacement of pre-Modification TU 178 HMUs with an HMU incorporating
Modification TU 178 within 2,200 engine flight hours or 72 months,
whichever occurs first, after the effective date of this AD. We are
issuing this AD to address the unsafe condition on these products.

Comments

We gave the public the opportunity to participate in developing
this AD. The following presents the comments received on the NPRM and
the FAA's response to the comment.

Request To Clarify Reason for AD

An individual commenter questioned how the new modification in this
AD is better and different from the actions required by the previous AD
2012-03-11.
AD 2012-03-11 required a check of the transmissible torque between
the LP fuel pump impeller and the HP fuel pump shaft and replacement of
the HMU if it does not pass the torque check. Since we issued AD 2012-
03-11, Safran Service Bulletin (SB) 292 73 2178, Version A, dated April
1, 2015 introduced Modification TU 178. This AD accepts Modification TU
178 as a more robust drive link between the LP fuel pump impeller and
the HP fuel pump shaft that ensures the LP impeller pump is driven even
if the link with the drive shaft loosens. This AD requires installation
of a Modification TU 178 HMU for any HMU that fails the torque sensor
check and as a mandatory terminating action for the inspections
required by this AD, as well as purging the fleet of the pre- and post-
TU 147 configuration parts. We did not change this AD.

Clarification to Service Information for Torque Check

We updated paragraphs (g)(1)(i) and (ii) of this AD to clarify that
only paragraph 2.A, rather than paragraph 2, in Turbomeca Alert
Mandatory SB (MSB) A292 73 2830, Version B, dated July 10, 2009, and
Turbomeca Alert MSB A292 73 2836, Version A, dated August 17, 2010, is
used to perform the torque check.

Conclusion

We reviewed the relevant data, considered the comment received, and
determined that air safety and the public interest require adopting
this AD as proposed except for minor editorial changes. We have
determined that these minor changes:
Are consistent with the intent that was proposed in the
NPRM for addressing the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

We reviewed Turbomeca, S.A., Alert MSB A292 73 2830, Version B,
dated July 10, 2009, and Alert MSB A292 73 2836, Version A, dated
August 17, 2010. Turbomeca Alert MSB A292 73 2830, Version B, describes
procedures for inspecting pre-Modification TU 147 HMUs. Turbomeca Alert
MSB A292 73 2836, Version A, dated August 17, 2010, describes
procedures for inspecting HMUs that have incorporated Modification TU
147. This service information is reasonably available because the
interested parties have access to it through their normal course of
business or by the means identified in the ADDRESSES section.

Other Related Service Information

We reviewed Safran Helicopter Engines MSB 292 73 2178, Version B,
dated March 23, 2017. Safran Helicopter Engines MSB 292 73 2178,
Version B, describes HMU improvements that includes a reinforced drive
link between the LP impeller and HP fuel pump shaft (Modification TU
178). Safran Helicopter Engines has also issued MSB A292 73 2830,
Version C; and A292 73 2836, Version B, both dated April 5, 2017, which
exempt HMUs incorporating Modification TU 178 from the inspections
previously recommended by Safran Helicopter Engines.

Costs of Compliance

We estimate that this AD affects 417 engines installed on
helicopters of U.S. registry.
We estimate the following costs to comply with this AD:

Estimated Costs

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.
This AD is issued in accordance with authority delegated by the
Executive Director, Aircraft Certification Service, as authorized by
FAA Order 8000.51C. In accordance with that order, issuance of ADs is
normally a function of the Compliance and Airworthiness Division, but
during this transition period, the Executive Director has delegated the
authority to issue ADs applicable to engines, propellers, and
associated appliances to the Manager, Engine and Propeller Standards
Branch, Policy and Innovation Division.

Regulatory Findings

We have 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 that this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Is not a ``significant rule'' under 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.

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

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)
2012-03-11, Amendment 39-16953 (77 FR 8092, February 14, 2012), and
adding the following new AD: