# [Amended]
**AGENCY:**
Federal Aviation Administration (FAA), DOT.
**ACTION:**
Notice of proposed rulemaking (NPRM).
**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:
• *Federal eRulemaking Portal:* Go to *regulations.gov.* Follow the instructions for submitting comments.
• *Fax:* 202-493-2251.
• *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.
• *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 *regulations.gov* 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:*
• 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 *[email protected]* . You may find this material on the Transport Canada website at *tc.canada.ca/en/aviation.* It is also available at *regulations.gov* under Docket No. FAA-2026-1336.
• 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: *[email protected].*
**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 *regulations.gov,* 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: *[email protected].* 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 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 *regulations.gov* 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 *regulations.gov* 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:
| Action | Labor cost | Parts cost | Cost per | Cost on U.S. |
| --- | --- | --- | --- | --- |
| Retained actions from AD 2025-06-01 | 1 work-hour × $85 per hour = $85 | $0 | $85 | $12,920 |
| New proposed actions (software upgrade) | 10 work-hours × $85 per hour = $850 | 0 | 850 | 129,200 |
| Action | Labor cost | Parts cost | Cost per product |
| --- | --- | --- | --- |
| Replace EEC | 9 work-hours × $85 per hour = $765 | $1,291,050 | $1,291,815 |
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**
1. The authority citation for part 39 continues to read as follows:
**Authority:**
49 U.S.C. 106(g), 40113, 44701.
§ 39.13
2. The FAA amends § 39.13 by:
a. Removing Airworthiness Directive (AD) 2025-06-01, Amendment 39-22989 (90 FR 12457, March 18, 2025); and
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 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: *[email protected].*
(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: *[email protected].*
**(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 *[email protected].* 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 *www.archives.gov/federal-register/cfr/ibr-locations* or email *[email protected].*
Issued on February 19, 2026.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft Certification Service.