Rule2026-04614
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
March 10, 2026
Effective
March 25, 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 broken hose of the draining system in the rear cargo compartment due to hot air leakage from an engine combustion chamber drain valve failure. This AD requires for certain helicopters operational inspections (checks) of each engine drain valve, inspection of each affected rear cargo compartment hose (hose), installation and repetitive inspections of thermal papers, and depending on the results of those inspections, corrective actions. This AD also requires for certain helicopters, inspection of the rear cargo compartment hoses in conjunction with the initial operational inspections (checks) and, depending on the results of the inspections, performing corrective actions. Additionally, this AD prohibits installing an affected hose on any helicopter unless certain requirements are met. 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 46 (Tuesday, March 10, 2026)</title>
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[Federal Register Volume 91, Number 46 (Tuesday, March 10, 2026)]
[Rules and Regulations]
[Pages 11446-11449]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-04614]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-2290; Project Identifier MCAI-2025-01833-R;
Amendment 39-23282; AD 2026-05-09]
RIN 2120-AA64
Airworthiness Directives; Airbus Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
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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 broken hose
of the draining system in the rear cargo compartment due to hot air
leakage from an engine combustion chamber drain valve failure. This AD
requires for certain helicopters operational inspections (checks) of
each engine drain valve, inspection of each affected rear cargo
compartment hose (hose), installation and repetitive inspections of
thermal papers, and depending on the results of those inspections,
corrective actions. This AD also requires for certain helicopters,
inspection of the rear cargo compartment hoses in conjunction with the
initial operational inspections (checks) and, depending on the results
of the inspections, performing corrective actions. Additionally, this
AD prohibits installing an affected hose on any helicopter unless
certain requirements are met. The FAA is issuing this AD to address the
unsafe condition on these products.
DATES: This AD is effective March 25, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of March 25,
2026.
The FAA must receive comments on this AD by April 24, 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-2026-2290; 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#3372774073565240521d5646415c43521d5646"><span class="__cf_email__" data-cfemail="b3f2f7c0f3d6d2c0d29dd6c6c1dcc3d29dd6c6">[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,
[[Page 11447]]
call (817) 222-5110. It is also available at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-2290.
FOR FURTHER INFORMATION CONTACT: Evan Weaver, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316)
944-8910; email: <a href="/cdn-cgi/l/email-protection#2d485b4c43035d035a484c5b485f6d4b4c4c034a425b"><span class="__cf_email__" data-cfemail="d6b3a0b7b8f8a6f8a1b3b7a0b3a496b0b7b7f8b1b9a0">[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-2026-2290; Project Identifier MCAI-
2025-01833-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, 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 Evan
Weaver, 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 2025-0287, dated December 17, 2025
(EASA AD 2025-0287) (also referred to as the MCAI), to correct an
unsafe condition on all Airbus Helicopters Model AS 355 E, AS 355 F, AS
355 F1, AS 355 F2, AS 355 N, and AS 355 NP helicopters. The MCAI states
that there was a report where the hose of the draining system was found
broken in the rear cargo compartment, and the engine combustion chamber
drain valve was blocked in the open position. This resulted in an
emergency landing due to a smoke event in the cabin. The MCAI further
states subsequent investigation revealed that the hose cannot withstand
high temperature, in cases of hot air leakage, due to failure of the
engine drain valve.
The FAA is issuing this AD to prevent failure of the rear cargo
compartment hoses. The unsafe condition, if not addressed, could result
in an uncontrolled fire in the cargo compartment, reduced control of
the helicopter, and possible 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-2026-2290.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed EASA AD 2025-0287, which specifies procedures for
certain helicopters for performing operational inspections (checks) of
each engine drain valve, inspection of each affected hose (right-side
and left-side), part number (P/N) 350A21010123 (manufacturer P/N
350A21-0101-23), installation of thermal paper on each drain pipe, and
for certain helicopters repetitive operational inspections (checks) of
each engine drain valve, and inspection of each affected hose in
conjunction with the initial operational inspection (check). Depending
on the results of these inspections, EASA AD 2025-0287 specifies
procedures for corrective actions, which include installation of
silicone tape on the hose, replacement of an affected hose, replacement
of the drain pipe, visual inspection of the thermal paper, repetitive
operational inspections (checks), and replacement of the thermal paper.
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
2025-0287, 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.
The owner/operator (pilot) holding at least a private pilot
certificate may perform a visual check of both sides of the thermal
paper and must enter compliance with this requirement into the
helicopter maintenance records in accordance with 14 CFR 43.9(a) and 14
CFR 91.417(a)(2)(v). The record must be maintained as required by 14
CFR 91.417, 121.380, or 135.439. The pilot may perform these actions
because they only involve a visual check of the thermal paper and no
maintenance or material is required to perform this check. This action
could be performed equally well by a pilot or mechanic.
Differences Between This AD the MCAI and the Material Referenced
Where the MCAI and the material referenced in EASA AD 2025-0287
specify to perform operational checks or to perform certain checks,
this AD refers to this as inspections, except the visual check of the
thermal paper.
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,
EASA AD 2025-0287 is incorporated by reference in this AD. This AD
requires compliance with EASA AD 2025-0287 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 2025-0287 does not mean
that operators need comply only with that
[[Page 11448]]
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 2025-0287. Material required by EASA AD 2025-0287
for compliance will be available at <a href="http://regulations.gov">regulations.gov</a> under Docket No.
FAA-2026-2290 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 occurrence that prompted the MCAI resulted in an
emergency landing due to a smoke event in the cabin. The FAA has found
that the risk to the flying public justifies forgoing notice and
comment prior to adoption of this rule because failure of the rear
cargo compartment hose due to high temperature from hot air leakage
increases the risk of undetected and uncontrolled fire, which could
result in loss of the helicopter.
Additionally, the compliance times for the operational checks, hose
inspection, and installation of thermal paper based on usage would
average to about four months. This compliance time 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 and contrary to the public interest 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 36 helicopters of U.S.
registry.
The FAA estimates the following costs to comply with this AD:
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Inspect engine drain valve, hoses, and 2 work-hours x $85 per $20 $190 $6,840
install thermal paper on drain pipe hour = $170.
(Model AS355N and AS355NP
helicopters).
Replace thermal paper (Model AS355N 1 work-hour x $85 per 38 123 4,428
and AS355NP helicopters). hour = $85.
Inspect thermal paper (Model AS355N 1 work-hour x $85 per 0 85 3,060
and AS355NP helicopters). hour = $85.
Install silicone tape (Model AS355N 1 work-hour x $85 per 17 102 3,672
and AS355NP helicopters). hour = $85.
Inspect engine drain valve and hoses 1 work-hour x $85 per 0 85 3,060
(Model AS355E, AS355F, AS355F1, and hour = $85.
AS355F2 helicopters).
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The FAA estimates the following costs to do any repairs or
replacements that would be required based on the results of the
inspection. The agency has no way of determining the number of
helicopters that might need these repairs or replacements:
On-Condition Costs
----------------------------------------------------------------------------------------------------------------
Cost per
Action Labor cost Parts cost product
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Inspect engine drain valve, replace hose, and 3 work-hours x $85 per hour = $647 $902
install silicone tape and thermal paper $255.
(Model AS355N and AS355NP helicopters).
Replace hose, and install silicone tape (Model 2 work-hours x $85 per hour = 609 779
AS355N and AS355NP helicopters). $170.
Replace hose, install silicone tape, and 3 work-hours x $85 per hour = 1,065 1,320
replace drain pipe (Model AS355E, AS355F, $255.
AS355F1, and AS355F2 helicopters).
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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
[[Page 11449]]
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:
2026-05-09 Airbus Helicopters: Amendment 39-23282; Docket No. FAA-
2026-2290; Project Identifier MCAI-2025-01833-R.
(a) Effective Date
This airworthiness directive (AD) is effective March 25, 2026
(b) Affected ADs
None.
(c) Applicability
This AD applies to all Airbus Helicopters Model AS355E, AS355F,
AS355F1, AS355F2, AS355N, and AS355NP helicopters, certificated in
any category.
(d) Subject
Joint Aircraft System Component (JASC) Code 7170, Powerplant/
Engine Drains.
(e) Unsafe Condition
This AD was prompted by a report of a broken hose of the
draining system in the rear cargo compartment due to hot air leakage
from an engine combustion chamber drain valve failure. The FAA is
issuing this AD to prevent failure of the rear cargo compartment
hoses. The unsafe condition, if not addressed, could result in an
uncontrolled fire in the cargo compartment, reduced control of the
helicopter, and possible loss of control of the helicopter.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Requirements
(1) 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 AD
2025-0287, dated December 17, 2025 (EASA AD 2025-0287).
(2) The owner/operator (pilot) holding at least a private pilot
certificate may perform a visual check of both sides of the thermal
paper and must enter compliance with this requirement into the
helicopter maintenance records in accordance with 14 CFR 43.9(a) and
14 CFR 91.417(a)(2)(v). The record must be maintained as required by
14 CFR 91.417, 121.380, or 135.439.
(h) Exceptions to EASA AD 2025-0287
(1) Where EASA AD 2025-0287 refers to its effective date, this
AD requires using the effective date of this AD.
(2) Where EASA AD 2025-0287 specifies compliance in terms of
flight hours, this AD requires using hours time-in-service.
(3) Where paragraph (6) of EASA AD 2025-0287 specifies
``accomplish a visual inspection of those thermal papers in
accordance with the instructions of the ASB'', this AD requires
replacing that text with ``accomplish a visual check of those
thermal papers for any colored boxes, and if one or more boxes are
found colored, before further flight, a licensed mechanic authorized
under 14 CFR part 43 must perform the corrective actions specified
in paragraph (7) of EASA AD 2025-0287''.
(4) Where the material referenced in EASA AD 2025-0287 specifies
discarding parts, this AD requires removing those parts from
service.
(5) Where the material referenced in EASA AD 2025-0287 specifies
``check'' this AD requires replacing that text with ``inspect'',
except for the visual check (inspection) of the thermal papers,
after the last flight of each day.
(6) Where the material referenced in EASA AD 2025-0287 specifies
``new'', this AD requires replacing that text with ``new (never
previously installed)''.
(7) This AD does not adopt ``Note 1'' or the ``Remarks'' section
of EASA AD 2025-0287.
(i) No Reporting Requirement
Although the material referenced in EASA AD 2025-0287 specifies
to submit certain information to the manufacturer, this AD does not
require that action.
(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) of
this AD and email to <a href="/cdn-cgi/l/email-protection#a1e0eceee2e1c7c0c08fc6ced7"><span class="__cf_email__" data-cfemail="6b2a2624282b0d0a0a450c041d">[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) Additional Information
For more information about this AD, contact Evan Weaver,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: (316) 944-8910; email:
<a href="/cdn-cgi/l/email-protection#c7a2b1a6a9e9b7e9b0a2a6b1a2b587a1a6a6e9a0a8b1"><span class="__cf_email__" data-cfemail="77120116195907590012160112053711161659101801">[email protected]</span></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 the AD specifies otherwise.
(i) European Union Aviation Safety Agency (EASA) AD 2025-0287,
dated December 17, 2025.
(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#87c6c3f4c7e2e6f4e6a9e2f2f5e8f7e6a9e2f2"><span class="__cf_email__" data-cfemail="7e3f3a0d3e1b1f0d1f501b0b0c110e1f501b0b">[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 Pkwy., 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#6503174b0c0b16150006110c0a0b250b0417044b020a13"><span class="__cf_email__" data-cfemail="a6c0d488cfc8d5d6c3c5d2cfc9c8e6c8c7d4c788c1c9d0">[email protected]</span></a>.
Issued on March 2, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-04614 Filed 3-9-26; 8:45 am]
BILLING CODE 4910-13-P
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