DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0100; Project Identifier MCAI-2020-00309-E;
Amendment 39-21613; AD 2021-13-08]
Airworthiness Directives; Safran Helicopter Engines, S.A. (Type
Certificate Previously Held by Turbomeca, S.A.) Turboshaft Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
Safran Helicopter Engines, S.A. Arriel 2C and Arriel 2S1 model
turboshaft engines. This AD was prompted by reports of error messages
on the full authority digital engine control (FADEC) B digital engine
control unit (DECU), caused by blistering of the varnish on the DECU
circuit board. This AD requires the replacement of certain FADEC B
DECUs. The FAA is issuing this AD to address the unsafe condition on
DATES: This AD is effective August 19, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of August 19,
ADDRESSES: For service information identified in this final rule,
contact Safran Helicopter Engines, S.A., Avenue du 1er Mai, 40220
Tarnos, France; phone: +33 (0) 5 59 74 40 00. You may view this service
information at the FAA, Airworthiness Products Section, Operational
Safety 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 at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-0100.
Examining the AD Docket
You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-0100; 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 (MCAI), any comments
received, and other information. The address for Docket Operations is
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: Wego Wang, Aviation Safety Engineer,
ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone:
(781) 238-7134; fax: (781) 238-7199; email: email@example.com.
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to all Safran Helicopter
Engines, S.A. Arriel 2C and Arriel 2S1 model turboshaft engines. The
NPRM published in the Federal Register on February 26, 2021 (86 FR
11662). The NPRM was prompted by reports of error messages on the FADEC
B DECU, caused by blistering of the varnish on the DECU circuit board.
In the NPRM, the FAA proposed to require the replacement of certain
FADEC B DECUs. The FAA is issuing this AD to address the unsafe
condition on these products.
The European Union Aviation Safety Agency (EASA), which is the
Technical Agent for the Member States of the European Community, has
issued EASA AD 2020-0046, dated March 4, 2020 (referred to after this
as ``the MCAI''), to address the unsafe condition on these products.
The MCAI states:
Occurrences have been reported of FADEC B DECU error messages,
which were found to be caused by blistering of the varnish on the
DECU circuit board. Subsequent investigation determined that the use
of a non-compliant primer is related to the blistering effect which,
in wet conditions, can cause malfunction of the stepper motor.
This condition, if not corrected, could lead to loss of
automatic control on both engines concurrently, possibly resulting
in reduced control of the helicopter.
To address this potentially unsafe condition, SAFRAN issued the
MSB, as defined in this [EASA] AD, to provide instructions for
identification and replacement of affected parts. For the reason
described above, this [EASA] AD requires replacement of affected
parts with serviceable parts. This [EASA] AD also prohibits (re-
installation of affected parts.
You may obtain further information by examining the MCAI in the AD
docket on at https://www.regulations.gov by searching for and locating
Docket No. FAA-2021-0100.
Discussion of Final Airworthiness Directive
The FAA received no comments on the NPRM or on the determination of
The FAA reviewed the relevant data and determined that air safety
requires adopting this AD as proposed. Accordingly, the FAA is issuing
this AD to address the unsafe condition on these products. This AD is
adopted as proposed in the NPRM.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Safran Helicopter Engines Note Technique AA187866,
Version A, dated 18 Octobre 2019 [October 18, 2019]. This service
information identifies the serial numbers (S/Ns) of certain FADEC B
DECUs installed on Arriel 2C and Arriel 2S1 model turboshaft engines.
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 ADDRESSES.
Other Related Service Information
The FAA reviewed Safran Helicopter Engines Mandatory Service
Bulletin (MSB) No. 292 73 2872, Version A, dated October 17, 2019. This
MSB describes procedures for identifying the S/Ns of certain FADEC B
DECUs and replacing certain FADEC B DECUs on Arriel 2C and Arriel 2S1
model turboshaft engines.
Costs of Compliance
The FAA estimates that this AD affects 148 engines installed on
helicopters of U.S. registry.
The FAA estimates the following costs to comply with this AD:
|Replace the FADEC B DECU
||1 work-hour x $85 per hour =
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.
The FAA is 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 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
(2) Will not affect intrastate aviation in Alaska, 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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
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 airworthiness