AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

SUMMARY: We are adopting a new airworthiness directive (AD) for
Turbomeca S.A. Arriel 2C1, 2C2, and 2S2 turboshaft engines. This AD
requires replacement of affected digital engine control units (DECUs).
This AD was prompted by a report of a helicopter experiencing a DECU
malfunction during flight. We are issuing this AD to prevent loss of
automatic control on one or both engines installed on the same
helicopter, which could result in an uncommanded in-flight engine
shutdown, forced autorotation landing, or accident.

DATES: This AD becomes effective July 26, 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 February 21, 2012
(77 FR 9874). That NPRM proposed to correct an unsafe condition for the
specified products. European Aviation Safety Agency AD 2011-0249
states:

An incident has been reported of a helicopter which experienced
a Digital Engine Control Unit (DECU) malfunction in flight from one
of its Arriel 2C1 engines. The indicating system of the helicopter
displayed a ``FADEC FAIL'' message, with a concurrent loss of
automatic control of the engine. The mission was aborted and the
helicopter returned to its base without any further incident.
The subsequent technical investigations carried out by Turbomeca
revealed that a Digital Engine Control Unit (DECU) assembly non-
conformity was at the origin of this event. Further investigations
performed with the supplier of the DECU led to the conclusion that
only a limited number of DECU are potentially affected by the non-
conformity.

Comments

We gave the public the opportunity to participate in developing
this AD. We received no comments on the NPRM (77 FR 9874, February 21,
2012).

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 will
affect about two engines installed on helicopters of U.S. registry. We
also estimate that it will take about one work-hour per engine to
comply with this AD. The average labor rate is $85 per work-hour.
Required parts will cost about $12,551 per engine. Based on these
figures, we estimate the cost of the AD on U.S. operators to be
$25,272. 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.

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 adding the following new AD: