Rule2026-06621
Airworthiness Directives; Airbus Helicopters
Primary source
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Published
April 6, 2026
Effective
May 11, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Model AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters. This AD was prompted by a report of a structural crack in the vertical attachment spar of the tail fin. This AD requires repetitive inspections of certain vertical upper fin spars and, depending on the results, corrective action. This AD also prohibits installing certain upper fin assemblies. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 91 Issue 65 (Monday, April 6, 2026)</title>
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[Federal Register Volume 91, Number 65 (Monday, April 6, 2026)]
[Rules and Regulations]
[Pages 17135-17137]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-06621]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-5039; Project Identifier MCAI-2024-00426-R;
Amendment 39-23303; AD 2026-07-08]
RIN 2120-AA64
Airworthiness Directives; Airbus Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all
Airbus Helicopters Model AS355E, AS355F, AS355F1, AS355F2, AS355N, and
AS355NP helicopters. This AD was prompted by a report of a structural
crack in the vertical attachment spar of the tail fin. This AD requires
repetitive inspections of certain vertical upper fin spars and,
depending on the results, corrective action. This AD also prohibits
installing certain upper fin assemblies. The FAA is issuing this AD to
address the unsafe condition on these products.
DATES: This AD is effective May 11, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of May 11,
2026.
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-5039; 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.
Material Incorporated by Reference:
<bullet> For European Union Aviation Safety Agency (EASA) material
identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668
Cologne, Germany; phone: +49 221 8999 000; email: <a href="/cdn-cgi/l/email-protection#3e7f7a4d7e5b5f4d5f105b4b4c514e5f105b4b"><span class="__cf_email__" data-cfemail="3071744370555143511e5545425f40511e5545">[email protected]</span></a>;
website: easa.europa.eu. You may find the EASA material on the EASA
website at ad.easa.europa.eu.
<bullet> 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
<a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2025-5039.
FOR FURTHER INFORMATION CONTACT: Yves Petiote, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: (202) 975-4867; email: <a href="/cdn-cgi/l/email-protection#70090615035e001504191f0415301611115e171f06"><span class="__cf_email__" data-cfemail="a6dfd0c3d588d6c3d2cfc9d2c3e6c0c7c788c1c9d0">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice proposed rulemaking (NPRM) to amend 14 CFR
part 39 by adding an AD that would apply to all Airbus Helicopters
Model AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP
helicopters. The NPRM was published in the Federal Register on December
17, 2025 (90 FR 58519). The NPRM was prompted by EASA AD 2023-0154R1,
dated July 19, 2024 (EASA AD 2023-0154R1) (also referred to as the
MCAI), issued by EASA, which is the Technical Agent for the Member
States of the European Union. The MCAI advises of a report of a
structural crack (not a complete failure) in the vertical attachment
spar of the tail fin. The MCAI states that the unsafe condition, if not
addressed, may lead to in-flight separation of the upper part of the
vertical fin, which could result in loss of control of the helicopter.
EASA has issued related EASA AD 2024-0139, dated July 12, 2024
(EASA AD 2024-0139), for these same model helicopters as well as
certain Model AS350B3 helicopters, to address cracking in a different
area of the upper fin spar as well as the fin's front attachment
screws. The FAA issued AD 2025-24-04, Amendment 39-23199 (90 FR 56679,
December 8, 2025) (AD 2025-24-04), to address EASA AD 2024-0139. This
AD includes actions that would be contingent on some of the required
actions in AD 2025-24-04.
In the NPRM, the FAA proposed to require repetitive inspections of
certain vertical upper fin spars and, depending on the results,
corrective action. The FAA also proposed to prohibit installing certain
upper fin assemblies. The FAA is issuing this AD to address the unsafe
condition on these products.
You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-5039.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from four commenters. The commenters were
two anonymous commenters and two individual commenters. The commenters
supported the NPRM without change.
Conclusion
These products have been approved by the civil aviation authority
of another country and are approved for operation in the United States.
Pursuant to the FAA's bilateral agreement with this State of Design
Authority, that authority has notified the FAA of the unsafe condition
described in the MCAI referenced above. The FAA reviewed the relevant
data, considered any comments received, 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. Except for
minor editorial changes, this AD is adopted as proposed in the NPRM.
None of the changes will increase the economic burden on any operator.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed EASA AD 2023-0154R1, which specifies procedures
for removing the tail gear box (TGB) fairing and the rear fairing from
the tail boom, cleaning, and inspecting the right-hand external side
around the two top screws
[[Page 17136]]
of certain upper fin spars for a crack. EASA AD 2023-0154R1 also
specifies procedures for conducting repetitive borescope inspections of
that upper fin spar area for a crack or repeating the initial
inspection as an alternative. Additionally, EASA AD 2023-0154R1
specifies accomplishing the inspections before and after maintenance
flights that exceed the reduced Velocity Never Exceed (V<INF>NE</INF>)
required by EASA AD 2024-0139 and before the next flight following any
other exceedance of the reduced V<INF>NE</INF> required by EASA AD
2024-0139. Depending on the results of an inspection, EASA AD 2023-
0154R1 specifies procedures for marking the two top right-hand screw
ends or replacing the upper fin. EASA AD 2023-0154R1 further specifies
that installing an upper fin assembly part number (P/N) 355A14-0522-
1751 constitutes terminating action for its repetitive inspection
requirements and prohibits installing certain upper fin assemblies on
any helicopter. 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.
Differences Between This AD and the MCAI
Where the MCAI defines an affected part as those listed in any
revision of the manufacturer's service information, this AD defines an
affected part as those listed in specific versions of the
manufacturer's service information and would include upper fin
assemblies for which the P/N cannot be determined.
Costs of Compliance
The FAA estimates that this AD affects 177 helicopters of U.S.
registry. Labor rates are estimated at $85 per hour. Based on these
numbers, the FAA estimates the following costs to comply with this AD.
Initial cleaning and inspection of the vertical fin spar and, if
necessary, application of a paint mark on the top two right-hand screw
ends takes 2.5 work-hours for an estimated cost of $213 per helicopter
and $37,701 for the U.S. fleet.
Repetitive borescope inspection of the upper fin spar takes 0.5
work-hour for an estimated cost of $43 per helicopter and up to $7,611
for the U.S. fleet, per inspection cycle. Alternatively, repeating the
initial inspection takes 2.5 work-hours for an estimated cost of $213
per helicopter and up to $37,701 for the U.S. fleet, per inspection
cycle.
If required, removing the upper fin from service and installing
upper fin assembly P/N 355A14-0522-1751 to modify the upper fin takes
40 work-hours and parts cost $25,360 for an estimated cost of $28,760
per helicopter.
The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some of the costs of this AD
may be covered under warranty, thereby reducing the cost impact on
affected operators.
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.
Regulatory Findings
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
Order 12866,
(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
reference, Safety.
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
0
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]
0
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive:
2026-07-08 Airbus Helicopters: Amendment 39-23303; Docket No. FAA-
2025-5039; Project Identifier MCAI-2024-00426-R.
(a) Effective Date
This airworthiness directive (AD) is effective May 11, 2026.
(b) Affected ADs
This AD affects AD 2025-24-04, Amendment 39-23199 (90 FR 56679,
December 8, 2025) (AD 2025-24-04).
(c) Applicability
This AD applies to Airbus Helicopters Model AS355E, AS355F,
AS355F1, AS355F2, AS355N, and AS355NP helicopters, certificated in
any category.
(d) Subject
Joint Aircraft System Component (JASC) Code 5531, Vertical
Stabilizer, Spar/Rib Structure.
(e) Unsafe Condition
This AD was prompted by a report of a structural crack in the
vertical attachment spar of the tail fin. The FAA is issuing this AD
to address cracking in the upper fin spar. This condition, if not
addressed, could lead to in-flight separation of the upper part of
the vertical fin, which could result in loss of control of the
helicopter.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Requirements
Except as specified in paragraphs (h) and (i) of this AD: Comply
with all required actions and compliance times specified in, and in
accordance with, European Union Aviation Safety Agency (EASA) AD
2023-0154R1, dated July 19, 2024 (EASA AD 2023-0154R1).
(h) Exceptions to EASA AD 2023-0154R1
(1) Where EASA AD 2023-0154R1 defines an ``affected part,'' this
AD requires replacing that text with ``an upper fin assembly having
a part number (P/N) identified in the Applicability, Accomplishment
Procedure, of Airbus Helicopters Emergency Alert Service Bulletin
EASB AS355-05-00-0001, Issue 001, dated July 25, 2023, or Issue 002,
dated July 9, 2024, or an upper fin assembly having a P/N that
cannot be determined''.
Note 1 to paragraph (h)(1): MOD 0720098 involves installing a
new upper fin that has a reinforced fin spar (P/N 355A14-0522-1751)
that is not affected by this AD. Airbus
[[Page 17137]]
Helicopters Alert Service Bulletin No. AS355-55.00.18, Revision 1,
dated June 6, 2024, contains information regarding MOD 0720098.
(2) Where EASA AD 2023-0154R1 refers to August 3, 2023 (the
effective date of EASA AD 2023-0154, dated July 27, 2023), this AD
requires using the effective date of this AD.
(3) Where EASA AD 2023-0154R1 requires compliance in terms of
flight hours, this AD requires using hours time-in-service.
(4) Where paragraph (3) of EASA AD 2023-0154R1 specifies
``following the Rotorcraft Flight Manual (RFM) amendment as required
by paragraph (1) or (2) of EASA AD 2024-0139, as applicable, it is
allowed to exceed the temporary reduced Vne during a maintenance
flight'', this AD requires replacing that text with ``following the
Rotorcraft Flight Manual (RFM) amendment required by AD 2025-24-04,
it is allowed to exceed the temporary reduced Velocity Never Exceed
(V<INF>NE</INF>) during a flight to perform an operational check as
specified in 14 CFR 91.407''.
(5) Where paragraphs (3.1), (3.2), and (3.3) of EASA AD 2023-
0154R1 specify ``maintenance flight'', this AD requires replacing
that text with ``flight to perform an operational check as specified
in 14 CFR 91.407''.
(6) Where paragraph (4) of EASA AD 2023-0154R1 specifies ``if,
following the RFM amendment as required by paragraph (1) or (2) of
EASA AD 2024-0139, as applicable, the temporary reduced Vne is
exceeded on a helicopter'', this AD requires replacing that text
with ``if, following the RFM amendment required by AD 2025-24-04,
the temporary reduced V<INF>NE</INF> is exceeded on a helicopter''.
(7) Where Note 1 of EASA AD 2023-0154R1 specifies ``It is
allowed to temporarily remove the RFM amendment and the placard, as
required by paragraph (1) or (2) of EASA AD 2024-0139, as
applicable, to allow maintenance flight(s) during which the
temporarily reduced Vne may be exceeded'', this AD requires
replacing that text with ``It is allowed to temporarily remove the
RFM amendment and the placard required by AD 2025-24-04 to allow
flight(s) to perform an operational check as specified in 14 CFR
91.407, during which the temporarily reduced V<INF>NE</INF> may be
exceeded''.
Note 2 to paragraph (h)(7): Refer to AD 2025-24-04 for
requirements pertaining to exceeding V<INF>NE</INF> 110 kts. Airbus
Helicopters Emergency Alert Service Bulletin EASB AS355-05-00-0001,
Issue 002, dated July 9, 2024, also contains information regarding
exceeding V<INF>NE</INF> 110 kts.
(8) Instead of complying with paragraph (6) of EASA AD 2023-
0154R1, if there is a crack as a result of the inspections required
by paragraphs (1) through (4) of EASA AD 2023-0154R1, this AD
requires, before further flight, removing the upper fin from service
and installing upper fin assembly P/N 355A14-0522-1751 in accordance
with paragraph (7) and Note 2 of EASA AD 2023-0154R1.
(9) Where Note 2 of EASA AD 2023-0154R1 specifies ``paragraph
(12) of EASA AD 2024-0139'', this AD requires replacing that text
with ``AD 2025-24-04''.
(10) This AD does not adopt the ``Remarks'' section of EASA AD
2023-0154R1.
(i) No Reporting Requirement
Although the material referenced in EASA AD 2023-0154R1
specifies to submit certain information to the manufacturer, this AD
does not include that requirement.
(j) Special Flight Permits
Special flight permits are prohibited.
(k) Alternative Methods of Compliance (AMOCs)
(1) The Manager, International Validation Branch, FAA, has the
authority to approve AMOCs for this AD, if requested using the
procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19,
send your request to your principal inspector or local Flight
Standards District Office, as appropriate. If sending information
directly to the manager of the International Validation Branch, send
it to the attention of the person identified in paragraph (l)(1) of
this AD and email to: <a href="/cdn-cgi/l/email-protection#6a2b2725292a0c0b0b440d051c"><span class="__cf_email__" data-cfemail="387975777b785e5959165f574e">[email protected]</span></a>.
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the local flight standards district office/certificate holding
district office.
(l) Related Information
(1) For more information about this AD, contact Yves Petiote,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: (202) 975-4867; email:
<a href="/cdn-cgi/l/email-protection#730a0516005d0316071a1c0716331512125d141c05"><span class="__cf_email__" data-cfemail="40393625336e302534292f3425002621216e272f36">[email protected]</span></a>.
(2) Airbus Helicopters material identified in this AD that is
not incorporated by reference is available at Airbus Helicopters,
2701 North Forum Drive, Grand Prairie, TX 75052; phone: (972) 641-
0000 or (800) 232-0323; fax: (972) 641-3775; website <a href="http://airbus.com/en/products-services/helicopters/hcare-services/airbusworld">airbus.com/en/products-services/helicopters/hcare-services/airbusworld</a>.
(m) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference of the material listed in this paragraph
under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this material as applicable to do the actions
required by this AD, unless this AD specifies otherwise.
(i) European Union Aviation Safety Agency (EASA) AD 2023-0154R1,
dated July 19, 2024.
(ii) [Reserved]
(3) For EASA material identified in this AD, contact EASA,
Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999
000; email: <a href="/cdn-cgi/l/email-protection#f0b1b483b095918391de9585829f8091de9585"><span class="__cf_email__" data-cfemail="cf8e8bbc8faaaebcaee1aababda0bfaee1aaba">[email protected]</span></a>; website: easa.europa.eu. You may
find the EASA material on the EASA website at ad.easa.europa.eu.
(4) 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.
(5) You may view this material at the National Archives and
Records Administration (NARA). For information on the availability
of this material at NARA, visit <a href="http://www.archives.gov/federal-register/cfr/ibr-locations">www.archives.gov/federal-register/cfr/ibr-locations</a> or email <a href="/cdn-cgi/l/email-protection#c8aebae6a1a6bbb8adabbca1a7a688a6a9baa9e6afa7be"><span class="__cf_email__" data-cfemail="1b7d69357275686b7e786f7274755b757a697a357c746d">[email protected]</span></a>.
Issued on March 31, 2026.
Christopher R. Parker,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-06621 Filed 4-3-26; 8:45 am]
BILLING CODE 4910-13-P
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