DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0137; Project Identifier MCAI-2020-00269-E;
Amendment 39-21688; AD 2021-17-05]
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 superseding Airworthiness Directive (AD) 2014-04-06
for all Safran Helicopter Engines,
S.A. (Safran Helicopter Engines) Arrius 2B1, 2B1A, 2B2, and 2K1 model
turboshaft engines. AD 2014-04-06 required initial and repetitive
inspections of the hydro-mechanical metering unit (HMU) high-pressure
pump drive gear shaft splines, cleaning and inspections of the sleeve
assembly splines, and replacement of the sleeve assembly on the
affected high-pressure pump drive gear shaft or replacement of the HMU
if the HMU fails inspection. This AD was prompted by in-flight
shutdowns caused by interrupted fuel supply at the HMU. This AD
requires revised inspections and continues to require cleaning of the
sleeve assembly splines, and replacement of the sleeve assembly on the
affected high-pressure pump drive gear shaft or replacement of the HMU
if the HMU fails an inspection. The FAA is issuing this AD to address
the unsafe condition on these products.
DATES: This AD is effective October 12, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of October 12,
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 45 11. 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-2021-0137.
Examining the AD Docket
You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-0137; 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: firstname.lastname@example.org.
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2014-04-06, Amendment 39-17764 (79 FR 9990,
February 24, 2014), (AD 2014-04-06). AD 2014-04-06 applied to all
Turbomeca S.A. Arrius 2B1, 2B1A, 2B2, and 2K1 model turboshaft engines.
The NPRM published in the Federal Register on March 12, 2021 (86 FR
14017). The NPRM was prompted by in-flight shutdowns caused by
interrupted fuel supply at the HMU. Since the FAA issued AD 2014-04-06,
the manufacturer has published new service information that revises the
inspections for certain HMUs, reduces compliance times for initial
inspections, and allows application of non-cumulative tolerance of 10%
of operating hours to be applied to the timing of the repetitive
inspection of HMUs installed on certain engines. In the NPRM, the FAA
proposed to continue to require cleaning of the sleeve assembly splines
and replacing the HMU or the sleeve assembly on the affected high-
pressure pump drive gear shaft if the HMU fails inspection. In the
NPRM, the FAA also proposed to require initial and repetitive
inspections of the HMU high-pressure pump drive gear shaft splines. The
FAA is issuing this AD to address the unsafe condition on these
The European Union Aviation Safety Agency (EASA), which is the
Technical Agent for the Member States of the European Community, has
issued EASA AD 2020-0033, dated February 25, 2020 (referred to after
this as ``the MCAI''), to address the unsafe condition on these
products. The MCAI states:
A number of in-flight shut-down (IFSD) occurrences have been
reported for ARRIUS 2 engines. The results of the technical
investigations concluded that these events were caused by
deterioration of the splines on the high pressure (HP)/low pressure
(LP) pump assembly drive shaft of the HMU, which eventually
interrupted the fuel supply to the engine.
This condition, if not detected and corrected, could lead to
further cases of engine IFSD, possibly resulting in forced landing
with consequent damage to the helicopter and injury to occupants.
To address these occurrences, Turbom[eacute]ca published MSB 319
73 2825 (up to version G) to provide instructions for inspection of
the HMU and sleeve assembly. Consequently, EASA issued AD 2013-0082
to require repetitive inspections of the drive gear shaft splines of
the HP pump, and, depending on findings, accomplishment of
applicable corrective action(s).
Since that [EASA] AD was issued, SAFRAN published the MSB to
provide specific inspection instructions for HMU installed on a
helicopter after 31 January 2013, to reduce the compliance time for
the initial inspection of Group 1 engines that were not previously
inspected in accordance with version G or later of the MSB, and to
provide some operational margin before the first inspection in all
For the reason described above, this [EASA] AD retains the
requirements of AD 2013-0082, which is superseded, and requires
accomplishment of the actions in accordance with the instructions of
the MSB, as defined in this [EASA] AD.
You may obtain further information by examining the MCAI in the AD
docket at https://www.regulations.gov by searching for and locating
Docket No. FAA-2021-0137.
This product has been approved by EASA and is approved for
operation in the United States. Pursuant to the FAA's bilateral
agreement with the European Community, EASA has notified the agency of
the unsafe condition described in the MCAI and service information. The
FAA is issuing this final rule because the agency evaluated all the
relevant information provided by EASA and determined the unsafe
condition described previously is likely to exist or develop in other
products of the same type design.
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 adoption of the 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 Mandatory Service
Bulletin (MSB) No. 319 73 2825, Version J, dated March 15, 2019. This
MSB specifies procedures for inspecting the HMU high-pressure pump
drive gear shaft splines and cleaning and inspecting the sleeve
assembly splines. 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.
Per Safran Helicopter Engines standing practice at the time MSB 319
73 2825, Version J, was issued, MSB 319 73 2825, Version J, is undated.
The issue date for MSB 319 73 2825, Version J, appears on the Safran Helicopter
Engines Arrius 2 B1 Service Bulletin Index, No. X 319 L5 980 2, dated
December 11, 2020.
Costs of Compliance
The FAA estimates that this AD affects 194 engines installed on
helicopters of U.S. registry.
The FAA estimates the following costs to comply with this AD:
|Visual inspection of drive gear
shaft splines; cleaning and inspection of sleeve assembly splines.
||2 work-hours x $85 per hour
The FAA estimates the following costs
to do any necessary
replacements that would be required based on the results of the
inspection. The agency has no way of determining the number of aircraft
that might need these replacements:
|Replace sleeve assembly on high-pressure
pump drive gear shaft
||1 work-hour x $85 per hour =
||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.
The FAA has 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
(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:
a. Removing Airworthiness Directive 2014-04-06, Amendment 39-17764 (79
FR 9990, February 24, 2014); and
b. Adding the following new airworthiness directive: