DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-1720; Project Identifier MCAI-2023-00003-R]
Airworthiness Directives; Airbus Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to adopt a new airworthiness directive
for Airbus Helicopters Model SA-365C1, SA-365C2, and SA-365N
helicopters. This proposed AD was prompted by reports of damaged
control rod dual bearings (dual bearings) that are installed on the
tail rotor gearbox (TGB). This proposed AD would require repetitively
inspecting the TGB magnetic plug for particles, analyzing any particles
collected, taking corrective actions if necessary, and reporting
certain information. Finally, this proposed AD would allow 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 proposed for incorporation by reference. The FAA is
proposing this AD to address the unsafe condition on these products.
DATES: The FAA must receive comments on this proposed AD by October
ADDRESSES: You may send comments, using the procedures found in
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to regulations.gov. Follow
the instructions for submitting comments.
Fax: (202) 493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
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 NPRM, the EASA AD, any comments received, and
other information. The street address for Docket Operations is listed
Material Incorporated by Reference:
For EASA material that is proposed for incorporation by
reference in this NPRM, 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 at ad.easa.europa.eu.
You may view this material at the FAA, Office of the
Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321,
Fort Worth, TX 76177. For information on the availability of this
material at the FAA, call (817) 222-5110. The EASA material is also
available at regulations.gov under Docket No. FAA-2023-1720.
Other Related Service Information: For Airbus Helicopters service
information identified in this NPRM, 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/
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.
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2023-1720; Project Identifier
MCAI-2023-00003-R'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
this proposal because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
regulations.gov, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this NPRM.
Confidential Business Information
CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to 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. Any commentary that the FAA receives that is not
specifically designated as CBI will be placed in the public docket for
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 for Airbus Helicopters Model SA 365 C1, SA
365 C2, SA 365 C3, and SA 365 N helicopters, all manufacturer serial
This proposed AD was prompted by reports of damaged dual bearings
that are installed on the TGB. The FAA is proposing 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.
You may examine EASA AD 2023-0001 in the AD docket at
regulations.gov under Docket No. FAA-2023-1720.
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.
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 is proposing this AD
after determining that the unsafe condition described previously is
likely to exist or develop on other helicopters of the same type
Proposed AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified
in EASA AD 2023-0001, described previously, as incorporated by
reference, except for any differences identified as exceptions in the
regulatory text of this proposed AD and discussed under ``Differences
Between this Proposed AD and the EASA AD.''
Explanation of Required Compliance Information
In the FAA's ongoing efforts to improve the efficiency of the AD
process, the FAA developed a process to use some civil aviation
authority (CAA) ADs as the primary source of information for compliance
with requirements for corresponding FAA ADs. The FAA has been
coordinating this process with manufacturers and CAAs. As a result, the
FAA proposes to incorporate EASA AD 2023-0001 by reference in the FAA
final rule. This proposed AD would, therefore, require compliance with
EASA AD 2023-0001 AD in its entirety through that incorporation, except
for any differences identified as exceptions in the regulatory text of
this proposed AD. Using common terms that are the same
as the heading of a particular section in EASA AD 2023-0001 does not
mean that operators need comply only with that section. For example,
where the AD requirement refers to ``all required actions and
compliance times,'' compliance with this AD requirement is not limited
to the section titled ``Required Action(s) and Compliance Time(s)'' in
EASA AD 2023-0001. Service information referenced in EASA AD 2023-0001
for compliance will be available at regulations.gov under Docket No.
FAA-2023-1720 after the FAA final rule is published.
Differences Between This Proposed AD and the EASA AD
EASA AD 2023-0001 applies to Airbus Helicopters Model SA 365 C3
helicopters, whereas this proposed AD would not because that model is
not FAA type-certificated.
This proposed AD would clarify 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 would be subject
to certain requirements in this proposed AD, whereas EASA AD 2023-0001
is unclear about those parts with an accumulated usage that cannot be
EASA AD 2023-0001 does not clarify what is considered an anomaly
regarding the chip detector and conical housing chip detector; whereas,
for this proposed 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 proposed 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 proposed AD would require 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.
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 proposed
AD would require 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' Design
Service information referenced in EASA AD 20223-0001 permits a
pilot to perform a magnetic plug check, whereas this proposed AD would
Service information referenced in EASA AD 2023-0001 specifies
sending compliance forms, certain parts, and particles to the
manufacturer, whereas this proposed AD would require reporting certain
information but would not require sending any parts or particles to the
The FAA considers this proposed AD would be an interim action. If
final action is later identified, the FAA might consider further
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 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 this proposed AD.
Inspecting the magnetic plug of the TGB for particles would take
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 would take 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 would take about 1
additional work-hour following the inspection and parts would cost
about $6,678 for an estimated cost of $6,763 per dual bearing
If required, analyzing collected particles would take about 1 work-
hour for an estimated cost of $85 per helicopter. If required, a
metallurgical analysis would take about 1 work-hour for an estimated
cost of $85 per instance.
If required, replacing an O-ring would take about 1 work-hour and
parts would cost about $100 for an estimated cost of $185 per O-ring.
If required, replacing a TGB would take about 8 work-hours and
parts would cost about $155,302 for an estimated cost of $155,982 per
The FAA has received no definitive data for the repair cost of a
If required, reporting information to the manufacturer would take
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 current 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.
The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 proposed
(1) Is not a ``significant regulatory action'' under Executive
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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