[Federal Register Volume 90, Number 176 (Monday, September 15, 2025)]
[Proposed Rules]
[Pages 44356-44359]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-17733]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-2545; Project Identifier MCAI-2024-00657-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).

-----------------------------------------------------------------------

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 reports of certain 
fuel transfer float valves failing in the closed position, preventing 
normal fuel transfer between the center and wing fuel tanks. This 
proposed AD would require replacing the existing fuel transfer float 
valves on airplanes that are approved for extended-range twin-engine 
operation performance standards (ETOPS). 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 October 30, 
2025.

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-2025-2545; 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-2025-2545.
     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: Joseph Catanzaro, Aviation Safety 
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
phone: 516-228-7366; 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-2025-2545; 
Project Identifier MCAI-2024-00657-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

[[Page 44357]]

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 
Joseph Catanzaro, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, 
Suite 410, Westbury, NY 11590; phone: 516-228-7366; 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

    Transport Canada, which is the aviation authority for Canada, has 
issued Transport Canada AD CF-2024-37, dated November 4, 2024 
(Transport Canada AD CF-2024-37) (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 several reports of fuel transfer float 
valves failing in the closed position, preventing normal fuel transfer 
between the center fuel tank and wing fuel tanks. An investigation 
determined that high friction of the fuel transfer float valve carbon 
seal prevents the fuel transfer float valve from opening. Each wing 
tank is equipped with one fuel transfer float valve. If one fuel 
transfer float valve fails closed, the crew is alerted and may manually 
transfer fuel to correct the resulting lateral fuel imbalance. A 
gravity fuel transfer system provides a back-up to the manual transfer. 
If both fuel transfer float valves simultaneously fail in the closed 
position, the crew is alerted, and fuel in the center tank becomes 
unusable as it cannot be transferred to the wing tanks. The crew may 
need to divert to prevent fuel starvation before reaching the 
destination airport. Simultaneous failure of both fuel transfer float 
valves in the closed position is critical for ETOPS missions as fuel 
starvation and engine shutdown may occur before reaching a diversion 
airport.
    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-2025-2545.

Material Incorporated by Reference Under 1 CFR Part 51

    Transport Canada AD CF-2024-37 specifies procedures for replacing 
the existing fuel transfer float valves and O-rings on left- and right-
wing with new fuel transfer float valves and O-rings and performing 
operational tests of the center to wing fuel transfer. Transport Canada 
AD CF-2024-37 also specifies that inserting a copy of Transport Canada 
AD CF-2024-37 into the ETOPS Configuration, Maintenance, and Procedures 
(CMP) or using ETOPS CMP issue 009.00 or later is an acceptable method 
of compliance. 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-2024-37 described previously, except for any 
differences identified as exceptions in the regulatory text of this 
proposed AD.

Compliance With CMP Revisions

    Transport Canada AD CF-2024-37 requires operators to ``operate the 
aeroplane accordingly'' after accomplishing the optional method of 
compliance specified in paragraph B. of Transport Canada AD CF-2024-37. 
However, this proposed AD would not specifically require those actions 
as those actions are already required by FAA regulations. FAA 
regulations (14 CFR 121.374(n)) require airplanes to be operated using 
a system that ensures compliance with the operator's CMP document. 
Therefore, including a requirement in this proposed AD to operate the 
airplane according to the revised CMP 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-2024-37 by reference 
in the FAA final rule. This proposed AD would, therefore, require 
compliance with Transport Canada AD CF-2024-37 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-2024-37 for compliance will be available at 
regulations.gov under Docket No. FAA-2025-2545 after the FAA final rule 
is published.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 35 airplanes of U.S. registry. The FAA estimates the following 
costs to comply with this proposed AD:

                                      Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
             Labor cost               Parts cost     Cost per product             Cost on U.S. operators
----------------------------------------------------------------------------------------------------------------
Up to 16 work-hours x $85 per hour           (*)  Up to $1,360.........  Up to $47,600.
 = $1,360.
----------------------------------------------------------------------------------------------------------------
* The FAA has received no definitive data on which to base the cost estimates for the parts specified in this
  proposed AD.


[[Page 44358]]

    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 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-2025-2545; Project Identifier MCAI-2024-00657-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by October 30, 2025.

(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-2024-37, dated November 4, 2024 (Transport Canada AD 
CF-2024-37).

(d) Subject

    Air Transport Association (ATA) of America Code 28, Fuel.

(e) Unsafe Condition

    This AD was prompted by reports of certain fuel transfer float 
valves failing in the closed position, preventing normal fuel 
transfer between the center and wing fuel tanks. The FAA is issuing 
this AD to address the simultaneous failure of both fuel transfer 
float valves in the closed position during an extended-range twin-
engine operation performance standards (ETOPS) flight. The unsafe 
condition, if not addressed, during an ETOPS flight, could lead to a 
forced diversion or fuel starvation and engine shutdown before 
reaching a diversion airport.

(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-2024-37.

(h) Exception To Transport Canada AD CF-2024-37

    (1) Where Transport Canada AD CF-2024-37 refers to its effective 
date, this AD requires using the effective date of this AD.
    (2) Where Transport Canada AD CF-2024-37 refers to hours air 
time, this AD requires using flight hours.
    (3) Where paragraph B. of Transport Canada AD CF-2024-37 
specifies ``thereafter, operating the aeroplane accordingly,'' this 
AD does not require that action as that action is already required 
by existing FAA operating regulations (see 14 CFR 121.374 (n)).
    (4) Where the material referenced in Transport Canada AD CF-
2024-37 specifies discarding parts, this AD requires removing those 
parts from service.

(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 
AIR-520, Continued Operational Safety Branch, send it to the 
attention of the person identified in paragraph (j) of this AD and 
email to: [email protected]. 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 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 Designee's authorized signature.

(j) Additional Information

    For more information about this AD, contact Joseph Catanzaro, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; phone: 516-228-7366; email: 
[email protected].

(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-2024-37, dated November 4, 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; 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.

[[Page 44359]]

    (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 September 10, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft 
Certification Service.
[FR Doc. 2025-17733 Filed 9-12-25; 8:45 am]
BILLING CODE 4910-13-P