Rule2025-22623
Airworthiness Directives; Bell Textron Canada Limited 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
December 12, 2025
Effective
January 16, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited (Bell) Model 427 helicopters. This AD was prompted by a report of a cracked transmission oil check valve (check valve). This AD requires inspecting and measuring certain check valves and, depending on the results, repetitively inspecting and removing the check valve from service if it has leaks or is cracked. This AD also prohibits installing the affected check valves on any helicopter. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
<html>
<head>
<title>Federal Register, Volume 90 Issue 237 (Friday, December 12, 2025)</title>
</head>
<body><pre>
[Federal Register Volume 90, Number 237 (Friday, December 12, 2025)]
[Rules and Regulations]
[Pages 57678-57680]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-22623]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-1727; Project Identifier MCAI-2024-00750-R;
Amendment 39-23209; AD 2025-25-01]
RIN 2120-AA64
Airworthiness Directives; Bell Textron Canada Limited Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Bell Textron Canada Limited (Bell) Model 427 helicopters. This
AD was prompted by a report of a cracked transmission oil check valve
(check valve). This AD requires inspecting and measuring certain check
valves and, depending on the results, repetitively inspecting and
removing the check valve from service if it has leaks or is cracked.
This AD also prohibits installing the affected check valves on any
helicopter. The FAA is issuing this AD to address the unsafe condition
on these products.
DATES: This AD is effective January 16, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of January 16,
2026.
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-1727; 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 Transport Canada material identified in this AD,
contact Transport Canada, Transport Canada National Aircraft
Certification, 159 Cleopatra Drive, Nepean, Ontario, K1A 0N5, Canada;
phone: (888) 663-3639; email: <a href="/cdn-cgi/l/email-protection#abffe885eac2d9dcc4d9dfc3c2c5ced8d8efc2d9cec8dfc2ddced886e8c4c5d8c2ccc5ced8cfcec5caddc2cccac9c2c7c2dfce85ffe8ebdfc885ccc885c8ca"><span class="__cf_email__" data-cfemail="b8ecfb96f9d1cacfd7caccd0d1d6ddcbcbfcd1cadddbccd1ceddcb95fbd7d6cbd1dfd6ddcbdcddd6d9ced1dfd9dad1d4d1ccdd96ecfbf8ccdb96dfdb96dbd9">[email protected]</span></a>; website: tc.canada.ca/en/aviation.
You may find the Transport Canada material on the Transport Canada
website at tc.canada.ca/en/aviation.
[[Page 57679]]
<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-2025-1727.
FOR FURTHER INFORMATION CONTACT: Michael Yeshiambel, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: (316) 946-4133; email: <a href="/cdn-cgi/l/email-protection#0964606a61686c65276427706c7a616068646b6c65496f6868276e667f"><span class="__cf_email__" data-cfemail="e5888c868d848089cb88cb9c80968d8c8488878089a5838484cb828a93">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to Bell Model 427
helicopters, serial numbers 56001 through 56084 inclusive, 58001, and
58002. The NPRM was published in the Federal Register on August 5, 2025
(90 FR 37432). The NPRM was prompted by Transport Canada AD CF-2024-42
dated December 13, 2024 (Transport Canada AD CF-2024-42) (also referred
to as the MCAI), issued by Transport Canada, which is the aviation
authority for Canada. The MCAI states that there has been a report of a
cracked check valve, part number (P/N) 209-062-520-001, manufactured in
2009 by Circor Aerospace (Circle Seal), and that the crack was caused
by applying an incorrect torque value to the threaded fitting at the
inlet end of the check valve during assembly.
Additionally, the MCAI states that this condition may be indicated
by an enlarged outside diameter measurement at the inlet end of the
check valve housing where the threaded fitting is installed or by the
presence of a leak, and that this check valve is used in the
transmission lubrication system of the helicopter.
In the NPRM, the FAA proposed to require inspecting and measuring
certain check valves and, depending on the results, repetitively
inspecting and removing the check valve from service if it has leaks or
is cracked. In the NPRM, the FAA also proposed to prohibit installing
the affected check valves on any helicopter. The FAA is issuing this AD
to detect and address cracked or leaking check valves. The unsafe
condition, if not addressed, could result in the degradation or loss of
lubrication to the transmission, failure of the transmission, and
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-2025-1727.
Comments
The FAA received no comments on the NPRM or on the determination of
the costs.
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 Transport Canada AD CF-2024-42, which specifies
procedures for measuring the outside diameter of the affected part
housing at the center and at the inlet end where the threaded fitting
is installed. If the dimension measured at the inlet end is not greater
than 0.003 inch (0.0762 mm) compared to the measurement at the center,
Transport Canada AD CF-2024-42 specifies no further action, and if the
dimension is greater than 0.003 inch (0.0762 mm) compared to the
measurement at the center, Transport Canada AD CF-2024-42 specifies a
repetitive visual inspection of the check valve for general condition
and oil leaks and the inlet end for cracks. If a crack or leak is
found, Transport Canada AD CF-2024-42 specifies replacing the valve
with a new valve, which constitutes a terminating action for the
repetitive inspections. Finally, Transport Canada AD CF-2024-42
prohibits installing the affected check valve 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
The MCAI uses the term new, whereas this AD uses the term new (zero
hours time-in-service).
Costs of Compliance
The FAA estimates that this AD affects 14 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
----------------------------------------------------------------------------------------------------------------
Perform measurements.................. 0.50 work-hour x $85 per hour $85 $127.50 $1,785
= $42.50.
----------------------------------------------------------------------------------------------------------------
The FAA estimates the following costs to do any additional
inspections or replacements that would be required based on the results
of the measurement. The agency has no data to determine the number of
helicopters that might need these additional actions:
On-Condition Costs
------------------------------------------------------------------------
Cost per
Action Labor cost Parts cost product
------------------------------------------------------------------------
Perform repetitive 1 work-hour x $0 $85
inspections. $85 per hour =
$85.
Replace the check valve...... 1 work-hour x 796 881
$85 per hour =
$85.
------------------------------------------------------------------------
[[Page 57680]]
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:
2025-25-01 Bell Textron Canada Limited Helicopters: Amendment 39-
23209; Docket No. FAA-2025-1727; Project Identifier MCAI-2024-00750-
R.
(a) Effective Date
This airworthiness directive (AD) is effective January 16, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to Bell Textron Canada Limited Model 427
helicopters, serial numbers 56001 through 56084 inclusive, 58001,
and 58002, certificated in any category.
(d) Subject
Joint Aircraft System Component (JASC) Code: 6300, Main Rotor
Drive System.
(e) Unsafe Condition
This AD was prompted by a report of a cracked transmission oil
check valve (check valve). The FAA is issuing this AD to detect and
address cracked or leaking check valves. The unsafe condition, if
not addressed, could result in the degradation or loss of
lubrication to the transmission, failure of the transmission, and
consequent 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 paragraph (h) of this AD: Comply with all
required actions and compliance times specified in, and in
accordance with, Transport Canada AD CF-2024-42, dated December 13,
2024 (Transport Canada AD CF-2024-42).
(h) Exceptions to Transport Canada AD CF-2024-42
(1) Where Transport Canada AD CF-2024-42 refers to its effective
date, this AD requires using the effective date of this AD.
(2) Where Transport Canada AD CF-2024-42 refers to air time,
this AD requires using hours time-in-service.
(3) Where Parts I and II of Transport Canada AD CF-2024-42 state
``new,'' this AD requires replacing each instance of that text with
``new (zero hours time-in-service)''.
(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#a8e9e5e7ebe8cec9c986cfc7de"><span class="__cf_email__" data-cfemail="bcfdf1f3fffcdadddd92dbd3ca">[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 Michael Yeshiambel,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: (316) 946-4133; email:
<a href="/cdn-cgi/l/email-protection#e28f8b818a83878ecc8fcc9b87918a8b838f80878ea2848383cc858d94"><span class="__cf_email__" data-cfemail="d8b5b1bbb0b9bdb4f6b5f6a1bdabb0b1b9b5babdb498beb9b9f6bfb7ae">[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) Transport Canada AD CF-2024-42, dated December 13, 2024.
(ii) [Reserved]
(3) For Transport Canada material identified in this AD, contact
Transport Canada, Transport Canada National Aircraft Certification,
159 Cleopatra Drive, Nepean, Ontario, K1A 0N5, Canada; phone: (888)
663-3639; email: <a href="/cdn-cgi/l/email-protection#c09483ee81a9b2b7afb2b4a8a9aea5b3b384a9b2a5a3b4a9b6a5b3ed83afaeb3a9a7aea5b3a4a5aea1b6a9a7a1a2a9aca9b4a5ee948380b4a3eea7a3eea3a1"><span class="__cf_email__" data-cfemail="7c283f523d150e0b130e08141512190f0f38150e191f08150a190f513f13120f151b12190f1819121d0a151b1d1e151015081952283f3c081f521b1f521f1d">[email protected]</span></a>; website: tc.canada.ca/en/
aviation. You may find the Transport Canada material on the
Transport Canada website at tc.canada.ca/en/aviation.
(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#6107134f080f1211040215080e0f210f0013004f060e17"><span class="__cf_email__" data-cfemail="3452461a5d5a47445157405d5b5a745a5546551a535b42">[email protected]</span></a>.
Issued on December 3, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2025-22623 Filed 12-11-25; 8:45 am]
BILLING CODE 4910-13-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on December 12, 2025.
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.