Proposed Rule2026-03549
Airworthiness Directives; Airbus Canada Limited Partnership (Type Certificate Previously Held by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.) Airplanes
Primary source
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Published
February 23, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to supersede Airworthiness Directive (AD) 2025-06-01, which applies to all Airbus Canada Limited Partnership Model BD-500-1A10 and BD-500-1A11 airplanes. AD 2025-06-01 requires revising the existing airplane flight manual (AFM) to incorporate the procedures for the flightcrew to manually isolate the opposite functional engine in the event of an engine bleed duct large leak condition. Since the FAA issued AD 2025-06-01, an electronic engine control (EEC) software update has been developed to address the unsafe condition. This proposed AD would continue to require the actions in AD 2025-06-01 and would require installing a certain EEC software update on both engines. This proposed AD would also remove airplanes from the applicability. The FAA is proposing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 91 Issue 35 (Monday, February 23, 2026)</title>
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[Federal Register Volume 91, Number 35 (Monday, February 23, 2026)]
[Proposed Rules]
[Pages 8390-8393]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-03549]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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Federal Register / Vol. 91, No. 35 / Monday, February 23, 2026 /
Proposed Rules
[[Page 8390]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-1336; Project Identifier MCAI-2025-00254-T]
RIN 2120-AA64
Airworthiness Directives; Airbus Canada Limited Partnership (Type
Certificate Previously Held by C Series Aircraft Limited Partnership
(CSALP); Bombardier, Inc.) Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
2025-06-01, which applies to all Airbus Canada Limited Partnership
Model BD-500-1A10 and BD-500-1A11 airplanes. AD 2025-06-01 requires
revising the existing airplane flight manual (AFM) to incorporate the
procedures for the flightcrew to manually isolate the opposite
functional engine in the event of an engine bleed duct large leak
condition. Since the FAA issued AD 2025-06-01, an electronic engine
control (EEC) software update has been developed to address the unsafe
condition. This proposed AD would continue to require the actions in AD
2025-06-01 and would require installing a certain EEC software update
on both engines. This proposed AD would also remove airplanes from the
applicability. 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 April 9,
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-2026-1336; 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 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 Transport Canada material identified in this proposed
AD, contact Transport Canada, Transport Canada National Aircraft
Certification, 159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada;
telephone 888-663-3639; email <a href="/cdn-cgi/l/email-protection#2276610c634b50554d50564a4b4c475151664b504741564b5447510f614d4c514b454c475146474c43544b4543404b4e4b56470c76616256410c45410c4143"><span class="__cf_email__" data-cfemail="47130469062e35302835332f2e29223434032e352224332e3122346a042829342e2029223423222926312e2026252e2b2e3322691304073324692024692426">[email protected]</span></a>. You may find this material on the
Transport Canada website at tc.canada.ca/en/aviation. It is also
available at <a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2026-1336.
<bullet> You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 2200 South 216th St., Des
Moines, WA. For information on the availability of this material at the
FAA, call 206-231-3195.
FOR FURTHER INFORMATION CONTACT: Erica Bayles, Aviation Safety
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; telephone:
907-271-5844; email: <a href="/cdn-cgi/l/email-protection#89ecfbe0eae8a7eca7ebe8f0e5ecfac9efe8e8a7eee6ff"><span class="__cf_email__" data-cfemail="e08592898381ce85ce8281998c8593a0868181ce878f96">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments using a method listed
under the ADDRESSES section. Include ``Docket No. FAA-2026-1336;
Project Identifier MCAI-2025-00254-T'' 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
<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 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 Erica
Bayles, Aviation Safety Engineer, FAA, 2200 South 216th St., Des
Moines, WA 98198; telephone: 907-271-5844; email:
<a href="/cdn-cgi/l/email-protection#fa9f8893999bd49fd4989b83969f89ba9c9b9bd49d958c"><span class="__cf_email__" data-cfemail="5e3b2c373d3f703b703c3f27323b2d1e383f3f70393128">[email protected]</span></a>. Any commentary that the FAA receives which is
not specifically designated as CBI will be placed in the public docket
for this rulemaking.
Background
The FAA issued AD 2025-06-01, Amendment 39-22989 (90 FR 12457,
March 18, 2025) (AD 2025-06-01), for all Airbus Canada Limited
Partnership Model BD-500-1A10 and BD-500-1A11 airplanes. AD 2025-06-01
was prompted by an MCAI originated by Transport Canada, which is the
aviation authority for Canada. Transport Canada issued AD CF-2024-30,
dated August 27, 2024, to correct an unsafe condition.
AD 2025-06-01 requires revising the existing AFM to incorporate the
procedures for the flightcrew to manually isolate the opposite
functional engine in the event of an engine bleed duct large leak
condition. The FAA issued AD 2025-06-01 to address
[[Page 8391]]
partially impaired software protection logic for potential large leaks
from the engine bleed duct inside the engine core compartments. Under
certain large leak conditions (e.g., a duct burst at a specific portion
of the engine's bleed ducting), Pratt & Whitney's PW1500G engine's
electronic engine control (EEC) would not transmit the necessary
information to the aircraft controller to automatically isolate the
opposite engine from the leak path in the bleed system. The unsafe
condition, if not addressed, could result in dual engine failure.
Actions Since AD 2025-06-01 Was Issued
Since the FAA issued AD 2025-06-01, Transport Canada superseded AD
CF-2024-30 and issued Transport Canada AD CF-2025-12, dated March 4,
2025 (Transport Canada AD CF-2025-12) (also referred to as the MCAI),
to correct an unsafe condition for certain Airbus Canada Limited
Partnership Model BD-500-1A10 and BD-500-1A11 airplanes. The MCAI
states that since Transport Canada AD CF-2024-30 was issued, Pratt &
Whitney developed an EEC software update (version 2.12.1, part number
5324158-15), to address the detection and protection for potential
large leaks. Installation of EEC software version 2.12.1 on both
engines is a terminating action to the AFM revision specified in the
MCAI. The MCAI also removes production airplanes from the applicability
that will have an equivalent modification incorporated before delivery.
The FAA is proposing 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-2026-1336.
Explanation of Retained Requirements
Although this proposed AD does not explicitly restate the
requirements of AD 2025-06-01, this proposed AD would retain all of the
requirements of AD 2025-06-01. Those requirements are referenced in
Transport Canada AD CF-2025-12, which, in turn, is referenced in
paragraph (g) of this proposed AD.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed Transport Canada AD CF-2025-12, which specifies
procedures for revising the ``Non-Normal Procedure'' of the AFM to
incorporate the procedures for the flightcrew to manually isolate the
opposite functional engine in the event of an engine bleed duct large
leak condition, and the installation of a certain EEC software update
on both engines, which terminates the AFM revision. The installation
consists of updating the EEC software to version 2.12.1 by either
replacing or modifying the EEC to include software version 2.12.1. 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.
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
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 NPRM
after determining that the unsafe condition described previously is
likely to exist or develop in other products of the same type design.
Proposed AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified
in Transport Canada AD CF-2025-12 described previously, except for any
differences identified as exceptions in the regulatory text of this
proposed AD.
Compliance With AFM Revisions
Transport Canada AD CF-2025-12 requires operators to ``inform all
flight crews'' of revisions to the AFM, and thereafter to ``operate the
aeroplane accordingly.'' However, this proposed AD would not
specifically require those actions as those actions are already
required by FAA regulations. FAA regulations require operators furnish
to pilots any changes to the AFM (for example, 14 CFR 121.137), and to
ensure the pilots are familiar with the AFM (for example, 14 CFR
91.505). As with any other flightcrew training requirement, training on
the updated AFM content is tracked by the operators and recorded in
each pilot's training record, which is available for the FAA to review.
FAA regulations also require pilots to follow the procedures in the
existing AFM including all updates. Section 91.9 requires that any
person operating a civil aircraft must comply with the operating
limitations specified in the AFM. Therefore, including a requirement in
this proposed AD to operate the airplane according to the revised AFM
would be redundant and unnecessary.
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 Transport Canada AD CF-2025-12 by reference
in the FAA final rule. This proposed AD would, therefore, require
compliance with Transport Canada AD CF-2025-12 in its entirety through
that incorporation, except for any differences identified as exceptions
in the regulatory text of this proposed AD. Material required by
Transport Canada AD CF-2025-12 for compliance will be available at
<a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2026-1336 after the FAA final rule
is published.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 152 airplanes of U.S. registry. The FAA estimates the following
costs to comply with this proposed AD:
Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Retained actions from AD 2025-06-01...... 1 work-hour x $85 per hour $0 $85 $12,920
= $85.
New proposed actions (software upgrade).. 10 work-hours x $85 per 0 850 129,200
hour = $850.
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[[Page 8392]]
Estimated Costs for Optional Actions
----------------------------------------------------------------------------------------------------------------
Action Labor cost Parts cost Cost per product
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Replace EEC.................................. 9 work-hours x $85 per hour = $1,291,050 $1,291,815
$765.
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The FAA has determined that it is not likely that operators would
need to replace the EEC in order to complete the software upgrade;
therefore, the rule is not significant.
The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some or all of the costs of
this proposed 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
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
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(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
reference, Safety.
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
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:
0
a. Removing Airworthiness Directive (AD) 2025-06-01, Amendment 39-22989
(90 FR 12457, March 18, 2025); and
0
b. Adding the following new AD:
Airbus Canada Limited Partnership (Type Certificate Previously Held
by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.):
Docket No. FAA-2026-1336; Project Identifier MCAI-2025-00254-T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by April 9, 2026.
(b) Affected ADs
This AD replaces AD 2025-06-01, Amendment 39-22989 (90 FR 12457,
March 18, 2025) (AD 2025-06-01).
(c) Applicability
This AD applies to Airbus Canada Limited Partnership (Type
Certificate previously held by C Series Aircraft Limited Partnership
(CSALP); Bombardier, Inc.) Model BD-500-1A10 and BD-500-1A11
airplanes, certificated in any category, as identified in Transport
Canada AD CF-2025-12, dated March 4, 2025 (Transport Canada AD CF-
2025-12).
(d) Subject
Air Transport Association (ATA) of America Code 73, Engine fuel
and control.
(e) Unsafe Condition
This AD was prompted by a design review that discovered software
protection logic for potential large leaks from the engine bleed
duct inside the engine core compartments was partially impaired.
Under certain large leak conditions (e.g., a duct burst at a
specific portion of the engine's bleed ducting), Pratt & Whitney's
PW1500G engine's electronic engine control (EEC) would not transmit
the necessary information to the aircraft controller to
automatically isolate the opposite engine from the leak path in the
bleed system. In addition, since AD 2025-06-01 was issued, the FAA
determined the installation of an engine EEC software update must be
done to address the unsafe condition. The FAA is issuing this AD to
address the unsafe condition which, if not addressed, could result
in dual engine failure.
(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-2025-12.
(h) Exceptions to Transport Canada AD CF-2025-12
(1) Where Transport Canada AD CF-2025-12 refers to September 10,
2024 (the effective date of Transport Canada AD CF-2024-30, dated
August 27, 2024), this AD requires using April 22, 2025 (the
effective date of AD 2025-06-01).
(2) Where Transport Canada AD CF-2025-12 refers to its effective
date, this AD requires using the effective date of this AD.
(3) Where paragraph B. of part I of Transport Canada AD CF-2025-
12 specifies to ``inform all flight crews of these changes in the
AFM procedures and thereafter operate the aeroplane accordingly,''
this AD does not require those actions as those actions are already
required by existing FAA operating regulations (see 14 CFR 91.9, 14
CFR 91.505, and 14 CFR 121.137).
(4) Where the material referenced in Transport Canada AD CF-
2025-12 specifies to replace or modify the EEC to update the EEC
software to version 2.12.1, this AD requires modifying the EEC to
update the EEC software to version 2.12.1.
(i) No Reporting Requirement
Although the material referenced in Transport Canada AD CF-2025-
12 specifies to submit certain information to the manufacturer, this
AD does not include that requirement.
(j) Additional AD Provisions
The following provisions also apply to this AD:
(1) Alternative Methods of Compliance (AMOCs): The Manager, AIR-
520, Continued Operational Safety 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
[[Page 8393]]
or responsible Flight Standards Office, as appropriate. If sending
information directly to the manager of the Continued Operational
Safety Branch, send it to the attention of the person identified in
paragraph (k) of this AD and email to: <a href="/cdn-cgi/l/email-protection#1c5d51535f5c7a7d7d327b736a"><span class="__cf_email__" data-cfemail="dc9d91939f9cbabdbdf2bbb3aa">[email protected]</span></a>.
(i) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the responsible Flight Standards Office.
(ii) AMOCs approved previously for AD 2025-06-01 are approved as
AMOCs for the corresponding provisions of Transport Canada AD CF-
2025-12 that are required by paragraph (g) of this AD.
(2) Contacting the Manufacturer: For any requirement in this AD
to obtain instructions from a manufacturer, the instructions must be
accomplished using a method approved by the Manager, AIR-520,
Continued Operational Safety Branch, FAA; or Transport Canada; or
Airbus Canada Limited Partnership's Transport Canada Design Approval
Organization (DAO). If approved by the DAO, the approval must
include the DAO-authorized signature.
(k) Additional Information
For more information about this AD, contact Erica Bayles,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA
98198; telephone: 907-271-5844; email: <a href="/cdn-cgi/l/email-protection#abced9c2c8ca85ce85c9cad2c7ced8ebcdcaca85ccc4dd"><span class="__cf_email__" data-cfemail="1376617a70723d763d71726a7f7660537572723d747c65">[email protected]</span></a>.
(l) 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) Transport Canada AD CF-2025-12, dated March 4, 2025.
(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; telephone 888-
663-3639; email <a href="/cdn-cgi/l/email-protection#2e7a6d006f475c59415c5a4647404b5d5d6a475c4b4d5a47584b5d036d41405d4749404b5d4a4b404f5847494f4c4742475a4b007a6d6e5a4d00494d004d4f"><span class="__cf_email__" data-cfemail="5004137e113922273f222438393e352323143922353324392635237d133f3e2339373e352334353e312639373132393c3924357e04131024337e37337e3331">[email protected]</span></a>. You may find this material on
the Transport Canada website at tc.canada.ca/en/aviation.
(4) You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 2200 South 216th St.,
Des Moines, WA. For information on the availability of this material
at the FAA, call 206-231-3195.
(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#f79185d99e9984879294839e9899b799968596d9909881"><span class="__cf_email__" data-cfemail="fc9a8ed295928f8c999f88959392bc929d8e9dd29b938a">[email protected]</span></a>.
Issued on February 19, 2026.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2026-03549 Filed 2-20-26; 8:45 am]
BILLING CODE 4910-13-P
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