Rule2026-07168
Airworthiness Directives; Airbus Helicopters
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
April 14, 2026
Effective
April 29, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for certain Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, and AS350D helicopters. This AD was prompted by a report of a gap between the bolted assemblies under the attachment fittings of the main gearbox (MGB) suspension bars. This AD requires replacing any affected front and rear attachment fittings, screws, nuts and washers of the MGB suspension bars, and prohibits installing any affected parts unless they are new (never previously installed) parts. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
<html>
<head>
<title>Federal Register, Volume 91 Issue 71 (Tuesday, April 14, 2026)</title>
</head>
<body><pre>
[Federal Register Volume 91, Number 71 (Tuesday, April 14, 2026)]
[Rules and Regulations]
[Pages 19073-19076]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-07168]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-3479; Project Identifier MCAI-2026-00085-R;
Amendment 39-23308; AD 2026-07-12]
RIN 2120-AA64
Airworthiness Directives; Airbus Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
-----------------------------------------------------------------------
SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2,
AS350B3, and AS350D helicopters. This AD was prompted by a report of a
gap between the bolted assemblies under the attachment fittings of the
main gearbox (MGB) suspension bars. This AD requires replacing any
affected front and rear attachment fittings, screws, nuts and washers
of the MGB suspension bars, and prohibits installing any affected parts
unless they are new (never previously installed) parts. The FAA is
issuing this AD to address the unsafe condition on these products.
DATES: This AD is effective April 29, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of April 29,
2026.
The FAA must receive comments on this AD by May 29, 2026.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
<bullet> Federal eRulemaking Portal: Go to <a href="http://regulations.gov">regulations.gov</a>. Follow
the instructions for submitting comments.
<bullet> Fax: (202) 493-2251.
<bullet> 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.
<bullet> 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 <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-3479; 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
street address for Docket Operations is listed above.
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#26676255664347554708435354495647084353"><span class="__cf_email__" data-cfemail="c68782b586a3a7b5a7e8a3b3b4a9b6a7e8a3b3">[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-2026-3479.
FOR FURTHER INFORMATION CONTACT: Matthew Bloomer, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: (847) 294-7524; email: <a href="/cdn-cgi/l/email-protection#dfb2beababb7baa8f1b8f1bdb3b0b0b2baad9fb9bebef1b8b0a9"><span class="__cf_email__" data-cfemail="036e6277776b66742d642d616f6c6c6e6671436562622d646c75">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written data, views, or arguments
about this final rule. Send your comments using a method listed under
ADDRESSES. Include ``Docket No. FAA-2026-3479; Project Identifier MCAI-
2026-00085-R'' at the beginning of your comments. The most helpful
comments reference a specific portion of the final rule, 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 final rule 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
<a href="http://regulations.gov">regulations.gov</a>, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this final rule.
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 AD contain commercial
or financial information that is customarily treated as private,
[[Page 19074]]
that you actually treat as private, and that is relevant or responsive
to this AD, 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 AD. Submissions containing CBI should be sent to Matthew
Bloomer, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590. Any commentary that the FAA receives which is not
specifically designated as CBI will be placed in the public docket for
this rulemaking.
Background
EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2026-0021, dated January 29, 2026
(EASA AD 2026-0021) (also referred to as the MCAI), to correct an
unsafe condition on Airbus Helicopters Model AS 350 B, AS 350 BA, AS
350 BB, AS 350 B1, AS 350 B2, AS 350 B3, and AS 350 D helicopters, all
serial numbers, delivered before January 1, 2026 (date of EASA Form 52,
or equivalent statement of conformity). The MCAI states there was a
report of occurrences of a gap between bolted assemblies under the
attachment fittings of the MGB suspension bars. The MCAI also states
that after investigations it was determined that this unsafe condition
could impact the safe life limit of the MGB fittings and bolts. This
condition, if not addressed, could lead to structural failure of the
MGB attachment screws, which could result in detachment of the MGB
suspension bars with consequent loss of control of the helicopter.
You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-3479.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed EASA AD 2026-0021, which specifies procedures for
certain helicopters, performing a torque check of the nuts of each MGB
attachment fitting. EASA AD 2026-0021 also specifies procedures for
certain helicopters, performing a sealing compound check in the
inspection areas as defined in EASA AD 2026-0021 and, depending on the
inspection results, performing a torque check of the nuts of the MGB
attachment fitting, measuring the flatness of the MGB deck, measuring
the plays of the assembly between the reinforcement plate and shim,
measuring the cumulative thickness of the assembly between the
reinforcement plate and shim, and reporting results to Airbus
Helicopters.
Additionally, EASA AD 2026-0021 specifies procedures for replacing
the front and rear attachment fittings, screws, nuts and washers of the
MGB suspension bars with new (never previously installed) parts. EASA
AD 2026-0021 also prohibits installing any affected front and rear
attachment fittings, screws, nuts and washers on any helicopter unless
they are new (never previously installed) parts.
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.
FAA's Determination
These products have been approved by the civil aviation authority
(CAA) 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 is issuing
this AD after determining that the unsafe condition described
previously is likely to exist or develop on other products of the same
type design.
AD Requirements
This AD requires accomplishing the actions specified in EASA AD
2026-0021, described previously, as incorporated by reference, except
for any differences identified as exceptions in the regulatory text of
this AD. See ``Differences Between this AD and the MCAI'' for a
discussion of the general differences included in this AD.
Differences Between This AD and the MCAI
The MCAI applies to Airbus Helicopters Model AS350BB helicopters,
whereas this AD does not because that model does not have an FAA type
certificate. The MCAI requires replacing affected parts after having
accomplished certain inspections as defined in EASA AD 2026-0021,
whereas this AD requires those actions before exceeding certain
compliance times as specified in Table 1 of EASA AD 2026-0021.
The MCAI requires performing a torque check and performing a
sealing compound check in certain inspection areas as defined in EASA
AD 2026-0021 and, depending on the inspection results, performing
corrective actions, whereas this AD does not require those actions and
only requires replacing the affected parts before exceeding certain
compliance times as defined in EASA AD 2026-0021.
The MCAI also requires reporting results to Airbus Helicopters,
whereas this AD does not require reporting.
Interim Action
The FAA considers that this AD is an interim action. If final
action is later identified, the FAA might consider additional
rulemaking.
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 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, EASA AD 2026-0021 is incorporated
by reference in this AD. This AD requires compliance with EASA AD 2026-
0021 in its entirety through that incorporation, except for any
differences identified as exceptions in the regulatory text of this AD.
Using common terms that are the same as the heading of a particular
section in EASA AD 2026-0021 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 2026-0021. Material required by
EASA AD 2026-0021 for compliance will be available at <a href="http://regulations.gov">regulations.gov</a>
under Docket No. FAA-2026-3479 after this AD is published.
Justification for Immediate Adoption and Determination of the Effective
Date
Section 553(b) of the Administrative Procedure Act (APA) (5 U.S.C.
551 et seq.) authorizes agencies to dispense with notice and comment
procedures for rules when the agency, for ``good cause,'' finds that
those procedures are ``impracticable, unnecessary, or contrary to the
public interest.'' Under this section, an agency, upon finding good
cause, may issue a final rule without providing notice and seeking
comment prior to issuance. Further, section 553(d) of the APA
authorizes agencies to make rules effective in less than thirty days,
upon a finding of good cause.
An unsafe condition exists that requires the immediate adoption of
this AD without providing an opportunity for public comments prior to
adoption. The FAA has found that the risk to the flying public
justifies forgoing notice
[[Page 19075]]
and comment prior to adoption of this rule because the occurrence of a
gap between bolted assemblies under the attachment fittings of the MGB
suspension bars has an impact on the safe life limit of fittings and
bolts, which are critical parts to the helicopter. This unsafe
condition poses a significant risk of structural failure to the
attachment screws, as failure of these parts could occur earlier than
previously expected, which could lead to detachment of the MGB
suspension bars. Further, the compliance requirement for replacing any
affected parts is within 10 hours time-in-service (TIS) after the
effective date of this AD, for all helicopters that have accumulated
35,950 hours TIS or more. There are currently helicopters on the U.S.
registry that are approaching or exceeding the 35,950 hours TIS
threshold. Consequently, these helicopters are subject to the 10-hour
compliance timeframe, which is shorter than the time necessary for the
public to comment and for publication of the final rule. Accordingly,
notice and opportunity for prior public comment are impracticable
pursuant to 5 U.S.C. 553(b).
In addition, the FAA finds that good cause exists pursuant to 5
U.S.C. 553(d) for making this amendment effective in less than 30 days,
for the same reasons the FAA found good cause to forgo notice and
comment.
Regulatory Flexibility Act
The requirements of the Regulatory Flexibility Act (RFA) do not
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt
a rule without prior notice and comment. Because the FAA has determined
that it has good cause to adopt this rule without prior notice and
comment, RFA analysis is not required.
Costs of Compliance
The FAA estimates that this AD affects 903 helicopters of U.S.
registry.
The FAA estimates the following costs to comply with this AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
----------------------------------------------------------------------------------------------------------------
Replace front and rear attachment 8 work-hour x $85 per $13,800 $14,480 $13,075,440
fittings. hour = $680 *.
----------------------------------------------------------------------------------------------------------------
* The labor cost is for two front and two rear attachment fitting replacements.
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, and
(2) Will not affect intrastate aviation in Alaska.
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:
2026-07-12 Airbus Helicopters: Amendment 39-23308; Docket No. FAA-
2026-3479; Project Identifier MCAI-2026-00085-R.
(a) Effective Date
This airworthiness directive (AD) is effective April 29, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all Airbus Helicopters Model AS350B, AS350BA,
AS350B1, AS350B2, AS350B3, and AS350D helicopters, certificated in
any category, that were delivered before January 1, 2026.
Note 1 to paragraph (c): Helicopters with AS350B3e designation
are Model AS350B3 helicopters.
(d) Subject
Joint Aircraft System Component (JASC) Code 6330, Main rotor
transmission mount.
(e) Unsafe Condition
This AD was prompted by a report of a gap between the bolted
assemblies under the attachment fittings of the main gearbox (MGB)
suspension bars. The FAA is issuing this AD to prevent structural
failure of the MGB attachment screws. The unsafe condition, if not
addressed, could result in detachment of the MGB suspension bars
with consequent loss of control of the helicopter.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
Except as specified in paragraph (h) of this AD: Comply with all
required actions and compliance times specified in, and in
accordance with European Union Aviation Safety Agency (EASA) AD
2026-0021, dated January 29, 2026 (EASA AD 2026-0021).
(h) Exceptions to EASA AD 2026-0021
(1) Where EASA AD 2026-0021 refers to its effective date, this
AD requires using the effective date of this AD.
(2) Where EASA AD 2026-0021 requires compliance in terms of
flight hours, this AD requires using hours time-in-service.
(3) Where EASA AD 2026-0021 defines ``affected part'', this AD
requires replacing that definition with ``Front and rear attachment
fittings, screws, nuts and washers of the MGB suspension bars,
having a part number as defined in Airbus Helicopters Emergency
Alert Service Bulletin (EASB)
[[Page 19076]]
AS350-63-31-0001 Issue 002, dated January 22, 2026 (EASB AS350-63-
31-0001, Issue 002). The part number is identified as ``Reference''
in EASB AS350-63-31-0001, Issue 002, as applicable to the part''.
(4) This AD does not adopt paragraphs (1), (2), (3), (4), (6),
and (7) of EASA AD 2026-0021.
(5) Where paragraph (5) of EASA AD 2026-0021 specifies ``before
next flight after having accomplished the actions as required by
paragraph (1), (3), or (4) of this AD, as applicable,'', this AD
requires replacing that text with ``Within the compliance time as
specified in Table 1 of EASA AD 2026-0021, as applicable, after the
effective date of this AD''.
(6) Where the material referenced in EASA AD 2026-0021 specifies
``discard'', this AD requires replacing that text with ``remove from
service''.
(7) This AD does not adopt the ``Remarks'' section of EASA AD
2026-0021.
(i) 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 (j) of
this AD and email to <a href="/cdn-cgi/l/email-protection#f5b4b8bab6b5939494db929a83"><span class="__cf_email__" data-cfemail="f2b3bfbdb1b2949393dc959d84">[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.
(j) Additional Information
For more information about this AD, contact Matthew Bloomer,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: (847) 294-7524; email:
<a href="/cdn-cgi/l/email-protection#98f5f9ececf0fdefb6ffb6faf4f7f7f5fdead8fef9f9b6fff7ee"><span class="__cf_email__" data-cfemail="eb868a9f9f838e9cc58cc589878484868e99ab8d8a8ac58c849d">[email protected]</span></a>.
(k) 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 the AD specifies otherwise.
(i) European Union Aviation Safety Agency (EASA) AD 2026-0021,
dated January 29, 2026.
(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#abeaefd8ebcecad8ca85ceded9c4dbca85cede"><span class="__cf_email__" data-cfemail="e4a5a097a481859785ca8191968b9485ca8191">[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#375145195e5944475254435e5859775956455619505841"><span class="__cf_email__" data-cfemail="caacb8e4a3a4b9baafa9bea3a5a48aa4abb8abe4ada5bc">[email protected]</span></a>.
Issued on April 6, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-07168 Filed 4-13-26; 8:45 am]
BILLING CODE 4910-13-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js" defer></script></body>
</html>Indexed from Federal Register on April 14, 2026.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.