Proposed Rule2026-05699
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
March 24, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for certain Airbus Canada Limited Partnership Model BD-500-1A10 and BD- 500-1A11 airplanes. This proposed AD was prompted by a report of multiple in-service failures of pressure regulating shutoff valves (PRSOVs). This proposed AD would require revising the existing airplane flight manual (AFM) to incorporate procedures for reducing the thrust lever or shutting down the engine when the BLEED LEAK caution message is persistent, prohibit operation in known or forecasted icing conditions under certain minimum equipment list (MEL) provisions where the only operative PRSOV is an affected part, and require replacement of affected PRSOVs with improved PRSOVs. 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 56 (Tuesday, March 24, 2026)</title>
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[Federal Register Volume 91, Number 56 (Tuesday, March 24, 2026)]
[Proposed Rules]
[Pages 13982-13984]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-05699]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-2721; Project Identifier MCAI-2025-00617-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 adopt a new airworthiness directive (AD)
for certain Airbus Canada Limited Partnership Model BD-500-1A10 and BD-
500-1A11 airplanes. This proposed AD was prompted by a report of
multiple in-service failures of pressure regulating shutoff valves
(PRSOVs). This proposed AD would require revising the existing airplane
flight manual (AFM) to incorporate procedures for reducing the thrust
lever or shutting down the engine when the BLEED LEAK caution message
is persistent, prohibit operation in known or forecasted icing
conditions under certain minimum equipment list (MEL) provisions where
the only operative PRSOV is an affected part, and require replacement
of affected PRSOVs with improved PRSOVs. 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 May 8,
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-2026-2721; 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#9aced9b4dbf3e8edf5e8eef2f3f4ffe9e9def3e8fff9eef3ecffe9b7d9f5f4e9f3fdf4ffe9fefff4fbecf3fdfbf8f3f6f3eeffb4ced9daeef9b4fdf9b4f9fb"><span class="__cf_email__" data-cfemail="e8bcabc6a9819a9f879a9c8081868d9b9bac819a8d8b9c819e8d9bc5ab87869b818f868d9b8c8d86899e818f898a8184819c8dc6bcaba89c8bc68f8bc68b89">[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-2026-2721.
<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; phone: 907-
271-5844; email: <a href="/cdn-cgi/l/email-protection#6f0a1d060c0e410a410d0e16030a1c2f090e0e41080019"><span class="__cf_email__" data-cfemail="dbbea9b2b8baf5bef5b9baa2b7bea89bbdbabaf5bcb4ad">[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-2026-2721;
Project Identifier MCAI-2025-00617-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; phone: 907-271-5844; email: <a href="/cdn-cgi/l/email-protection#0366716a60622d662d61627a6f6670436562622d646c75"><span class="__cf_email__" data-cfemail="1075627973713e753e7271697c7563507671713e777f66">[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
Transport Canada, which is the aviation authority for Canada, has
issued Transport Canada AD CF-2025-20, dated April 15, 2025 (Transport
Canada AD CF-2025-20) (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 there have
been multiple in-service failures of PRSOVs. The PRSOVs allow isolation
of the bleed air system in the event of a bleed air leak detection. In
case of failure, the inability to isolate a bleed air source combined
with a bleed air leak on the same engine side could cause damage to
surrounding structures and systems that can prevent continued safe
flight and landing.
The MCAI also states the PRSOV provides bleed air source from the
engines to pneumatic systems. Current master minimum equipment list
(MMEL) items allow airplane dispatch with one inoperative PRSOV. In the
event of dispatching the airplane with one or both engines bleed ON,
the high failure rate of the PRSOV could lead to a total loss of bleed
air systems, thus reducing safety margin and increasing pilots'
workload.
The FAA is proposing this AD to address the high failure rate of
the PRSOVs, which could lead to the inability to isolate a bleed air
leak. The unsafe condition, if not addressed,
[[Page 13983]]
could lead to damage to surrounding structures and systems (i.e., loss
of functionality for assisted engine start capability, cabin
pressurization, fuel tank inerting, and wing anti-ice systems), which
could reduce the safety margin and increase the pilots' workload or
result in loss of continued safe flight and landing.
You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-2721.
Material Incorporated by Reference Under 1 CFR Part 51
Transport Canada AD CF-2025-20 specifies procedures for revising
the existing AFM to incorporate ``L BLEED LEAK (Caution)'' and ``R
BLEED LEAK (Caution)'' procedures instructing pilots to reduce the
thrust lever or shut down the engine when the BLEED LEAK caution
message is persistent; prohibiting operation in known or forecasted
icing conditions under certain MEL provisions where the only operative
(functional) PRSOV is part number (P/N) 70115B010001; and replacing the
right and left engine PRSOV with a re-designed part having P/N
70115C010001, which includes replacing the PRSOV precooler sense hose
assembly, P/N 999D0004-513, with P/N999D0004-515. 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-2025-20 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-2025-20 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-2025-20 by reference
in the FAA final rule. This proposed AD would, therefore, require
compliance with Transport Canada AD CF-2025-20 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-2025-20 for compliance will be available at
<a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2026-2721 after the FAA final rule
is published.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 112 airplanes of U.S. registry. The FAA estimates the following
costs to comply with this proposed AD:
Estimated Costs for Required Actions
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Labor cost Parts cost Cost per product Cost on U.S. operators
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Up to 13 work-hours x $85 per hour = Up to $30,156.......... Up to $31,261.......... Up to $3,501,232.
$1,105.
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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 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.
[[Page 13984]]
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 adding the following new airworthiness
directive:
Airbus Canada Limited Partnership (Type Certificate Previously Held
by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.):
Docket No. FAA-2026-2721; Project Identifier MCAI-2025-00617-T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by May 8, 2026.
(b) Affected ADs
None.
(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-2025-20, dated April 15, 2025 (Transport Canada AD CF-
2025-20).
(d) Subject
Air Transport Association (ATA) of America Code 36, Pneumatic.
(e) Unsafe Condition
This AD was prompted by a report of multiple in-service failures
of pressure regulating shutoff valves (PRSOVs). The FAA is issuing
this AD to address the high failure rate of the PRSOVs, which could
lead to the inability to isolate a bleed air leak. The unsafe
condition, if not addressed, could lead to damage to the surrounding
structures and systems (e.g., loss of functionality for assisted
engine start capability, cabin pressurization, fuel tank inerting,
and wing anti-ice systems), which could reduce the safety margin and
increase the pilots' workload or result in loss of continued safe
flight and landing.
(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-2025-20.
(h) Exception to Transport Canada AD CF-2025-20
(1) Where Transport Canada AD CF-2025-20 refers to its effective
date, this AD requires using the effective date of this AD.
(2) Where Transport Canada AD CF-2025-20 refers to total hours
air time, this AD requires using total flight hours.
(3) Where paragraph B. of Part I of Transport Canada AD CF-2025-
20 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,
91.505, and 121.137).
(i) 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 or responsible Flight Standards Office,
as appropriate. If sending information directly to the manager of
the Operational Safety 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#96d7dbd9d5d6f0f7f7b8f1f9e0"><span class="__cf_email__" data-cfemail="6f2e22202c2f090e0e41080019">[email protected]</span></a>. Before using any approved AMOC, notify your
appropriate principal inspector, or lacking a principal inspector,
the manager of the responsible Flight Standards Office.
(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's Transport Canada Design Approval Organization (DAO).
If approved by the DAO, the approval must include the DAO-authorized
signature.
(3) Required for Compliance (RC): Except as required by
paragraph (i)(2) of this AD, if any material contains procedures or
tests that are identified as RC, those procedures and tests must be
done to comply with this AD; any procedures or tests that are not
identified as RC are recommended. Those procedures and tests that
are not identified as RC may be deviated from using accepted methods
in accordance with the operator's maintenance or inspection program
without obtaining approval of an AMOC, provided the procedures and
tests identified as RC can be done and the airplane can be put back
in an airworthy condition. Any substitutions or changes to
procedures or tests identified as RC require approval of an AMOC.
(j) Additional Information
For more information about this AD, contact Erica Bayles,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA
98198; phone: 907-271-5844; email: <a href="/cdn-cgi/l/email-protection#afcaddc6ccce81ca81cdced6c3cadcefc9cece81c8c0d9"><span class="__cf_email__" data-cfemail="80e5f2e9e3e1aee5aee2e1f9ece5f3c0e6e1e1aee7eff6">[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 this AD specifies otherwise.
(i) Transport Canada AD CF-2025-20, dated April 15, 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#f3a7b0ddb29a81849c81879b9a9d968080b79a819690879a859680deb09c9d809a949d968097969d92859a9492919a9f9a8796dda7b0b38790dd9490dd9092"><span class="__cf_email__" data-cfemail="4b1f08650a22393c24393f2322252e38380f22392e283f223d2e386608242538222c252e382f2e252a3d222c2a292227223f2e651f080b3f28652c2865282a">[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#d9bfabf7b0b7aaa9bcbaadb0b6b799b7b8abb8f7beb6af"><span class="__cf_email__" data-cfemail="c2a4b0ecabacb1b2a7a1b6abadac82aca3b0a3eca5adb4">[email protected]</span></a>.
Issued on March 19, 2026.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2026-05699 Filed 3-23-26; 8:45 am]
BILLING CODE 4910-13-P
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