DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-1720; Project Identifier MCAI-2023-00003-R;
Amendment 39-22598; AD 2023-22-14]
Airworthiness Directives; Airbus Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
Airbus Helicopters Model SA-365C1, SA-365C2, and SA-365N helicopters.
This AD was prompted by reports of damaged control rod dual bearings
(dual bearings) that are installed on the tail rotor gearbox (TGB).
This AD requires repetitively inspecting the TGB magnetic plug for
particles, analyzing any particles collected, taking corrective actions
if necessary, and reporting certain information. Finally, this AD
allows an affected dual bearing to be installed on a helicopter if
certain actions are accomplished, as specified in a European Union
Aviation Safety Agency (EASA) AD, which is incorporated by reference.
The FAA is issuing this AD to address the unsafe condition on these
DATES: This AD is effective December 26, 2023.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of December 26,
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2023-1720; 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, 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.
Material Incorporated by Reference:
For EASA material identified in this final rule, contact
EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221
8999 000; email ADs@easa.europa.eu; internet easa.europa.eu. You may
find the EASA material on the EASA website ad.easa.europa.eu.
You may view this material at the FAA, Office of the
Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-
321, Fort Worth, TX 76177. For information on the availability of this
material at the FAA, call (817) 222-5110. It is also available at
regulations.gov under Docket No. FAA-2023-1720.
Other Related Service Information: For Airbus Helicopters service
information identified in this AD, contact Airbus Helicopters, 2701
North Forum Drive, Grand Prairie, TX 75052; telephone (972) 641-0000 or
(800) 232-0323; fax (972) 641-3775; or at airbus.com/en/products-services/
helicopters/hcare-services/airbusworld. You may also view this
service information at the FAA contact information under Material
Incorporated by Reference above.
FOR FURTHER INFORMATION CONTACT: Kevin Kung, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone
(781) 238-7244; email 9-AVS-AIR-BACO-COS@faa.gov.
EASA, which is the Technical Agent for the Member States of the
European Union, has issued a series of EASA ADs with the most recent
being EASA AD 2023-0001, dated January 4, 2023 (EASA AD 2023-0001), to
correct an unsafe condition on Airbus Helicopters Model SA 365 C1, SA
365 C2, SA 365 C3, and SA 365 N helicopters, all manufacturer serial
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to Airbus Helicopters
Model SA-365C1, SA-365C2, and SA-365N helicopters. The NPRM published
in the Federal Register on September 1, 2023 (88 FR 60402). The NPRM
was prompted by reports of damaged dual bearings that are installed on
the TGB. The NPRM proposed to require repetitively inspecting the TGB
magnetic plug for particles, analyzing any particles collected, taking
corrective actions if necessary, and reporting certain information. The
NPRM also proposed to allow installing an affected dual bearing on a
helicopter if certain actions are accomplished, as specified in EASA AD
The FAA is issuing this AD to inspect for particles in the TGB
magnetic plug. The unsafe condition, if not addressed, could result in
loss of yaw control and subsequent loss of control of the helicopter.
See EASA AD 2023-0001 for additional background information.
Discussion of Final Airworthiness Directive
The FAA received no comments on the NPRM or on the determination of
These helicopters have been approved by EASA and are approved for
operation in the United States. Pursuant to the FAA's bilateral
agreement with the European Union, EASA has notified the FAA about the
unsafe condition described in its AD. 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 helicopters. Except for clarifying the conditions
that could exist after performing a metallurgical analysis in paragraph
(h)(17) of this AD and minor editorial changes, this AD is adopted as
proposed in the NPRM.
Related Service Information Under 1 CFR Part 51
EASA AD 2023-0001 requires continuing close monitoring for certain
helicopters and analyzing any particles collected during required
inspections, repetitively inspecting the magnetic plug of the TGB for
particles, and corrective actions. Corrective actions include replacing
or repairing an affected TGB; sending certain information and affected
parts to the manufacturer; accomplishing a metallurgical analysis; and
replacing an affected dual bearing and other affected parts.
Additionally, EASA AD 2023-0001 requires for certain helicopters
with an affected dual bearing installed, performing a one-time
inspection of the dual bearing.
EASA AD 2023-0001 allows a dual bearing part number (P/N) 360A33-
4052-00 installed on a control rod of a TGB P/N 365A33-4000-00, 365A33-
4000-01, 365A33-4000-02, or 365A33-5000-00 to be installed on an
aircraft, if certain requirements are met.
This material 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
The FAA reviewed Airbus Helicopters Alert Service Bulletin (ASB)
No. AS365-05.00.83 and Airbus Helicopters ASB No. SA365-05.35, both
Revision 0, and both dated February 7, 2022. This service information
specifies procedures to inspect the magnetic plug of the TGB for
particles; analyze and define the particles collected; replace an
affected TGB and an affected dual bearing; perform a metallurgical
analysis; and report certain information to the manufacturer.
The FAA also reviewed Airbus Helicopters ASB No. AS365-65.00.20
Revision 0, dated November 23, 2022. This service information specifies
procedures for a one-time inspection of a certain dual bearing and
replacement of the dual bearing if any particles are found.
Additionally, the FAA reviewed Airbus Standard Practices Manual,
20-08-01-601, Periodical monitoring of lubricating oil checking
elements, dated July 7, 2020. This service information specifies
procedures for analyzing collected particles.
The FAA considers this AD to be an interim action. If final action
is later identified, the FAA might consider further rulemaking then.
Differences Between This AD and the EASA AD
EASA AD 2023-0001 applies to Airbus Helicopters Model SA 365 C3
helicopters, whereas this AD does not because that model is not FAA
This AD clarifies that Model SA-365N helicopters with an affected
dual bearing installed that has an unknown total number of hours time-
in-service accumulated on the dual bearing are subject to certain
requirements in this AD, whereas EASA AD 2023-0001 is unclear about
those parts with an accumulated usage that cannot be determined.
EASA AD 2023-0001 does not clarify what is considered an anomaly
regarding the chip detector and conical housing chip detector; whereas,
for this AD, an anomaly may be indicated by the magnetic component of
the TGB chip detector or the conical housing chip detector not being
magnetized. EASA AD 2023-0001 also does not clarify what is considered
good condition regarding the chip detector or conical housing chip
detector; whereas, for this AD, good condition for the chip detector is
indicated when there are no signs of wear on the locking systems
(including wear on the bayonets and slotted tubes) and good condition
for the conical housing chip detector is when the conical housing chip
detector is magnetized.
Where EASA AD 2023-0001 describes a doubt concerning the physical
characteristics of any collected particles, this AD requires performing
a metallurgical analysis. If there is any doubt remaining after
performing the metallurgical analysis, EASA AD 2023-0001 requires
contacting Airbus, whereas this AD requires removing an affected TGB
from service and replacing it with an airworthy part, or repairing the
TGB in accordance with a method approved by the FAA, EASA, or Airbus
Helicopters' Design Organizational Approval (DOA) if the type, size, or
classification of any collected particle cannot be determined after
performing a metallurgical analysis.
If any particles (including abrasion-type particles) are found on
the magnetic plug during any inspection that are outside the limits,
EASA AD 2023-0001 requires replacing each affected dual bearing with a
serviceable dual bearing, and replacing the TGB, whereas this AD
requires removing each affected dual bearing and replacing with a
serviceable dual bearing, or removing the TGB from service and
replacing it with an airworthy TGB, or repairing the TGB in accordance
with a method approved by the FAA, EASA, or Airbus Helicopters' DOA.
Service information referenced in EASA AD 2023-0001 permits a pilot
to perform a magnetic plug check, whereas this AD does not.
Service information referenced in EASA AD 2023-0001 specifies
sending compliance forms, certain parts, and particles to the
manufacturer, whereas this AD requires reporting certain information
but does not require sending any parts or particles to the
Costs of Compliance
The FAA estimates that this AD affects 1 helicopter of U.S.
Registry. Labor rates are estimated at $85 per work-hour. Based on
these numbers, the FAA estimates the following costs to comply with
Inspecting the magnetic plug of the TGB for particles takes about 1
work-hour for an estimated cost of $85 per inspection and up to $85 for
the U.S. fleet, per inspection cycle.
Inspecting a dual bearing takes about 16 work-hours for an
estimated cost of $1,360 per inspection and up to $1,360 for the U.S.
fleet. If required, replacing a dual bearing takes about 1 additional
work-hour following the inspection and parts cost about $6,678 for an
estimated cost of $6,763 per dual bearing replacement.
If required, analyzing collected particles takes about 1 work-hour
for an estimated cost of $85 per helicopter. If required, a
metallurgical analysis takes about 1 work-hour for an estimated cost of
$85 per instance.
If required, replacing an O-ring takes about 1 work-hour and parts
cost about $100 for an estimated cost of $185 per O-ring.
If required, replacing a TGB takes about 8 work-hours and parts
cost about $155,302 for an estimated cost of $155,982 per replacement.
The FAA has received no definitive data for the repair cost of a
If required, reporting information to the manufacturer takes about
1 work-hour for an estimated cost of $85 per instance.
Paperwork Reduction Act
A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to a penalty for
failure to comply with a collection of information subject to the
requirements of the Paperwork Reduction Act unless that collection of
information displays a currently valid OMB Control Number. The OMB
Control Number for this information collection is 2120-0056. Public
reporting for this collection of information is estimated to take
approximately 1 hour per response, including the time for reviewing
instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the
collection of information. All responses to this collection of
information are mandatory. Send comments regarding this burden estimate
or any other aspect of this collection of information, including
suggestions for reducing this burden to: Information Collection
Clearance Officer, Federal Aviation Administration, 10101 Hillwood
Parkway, Fort Worth, TX 76177-1524.
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 that 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