[Federal Register Volume 90, Number 184 (Thursday, September 25, 2025)]
[Proposed Rules]
[Pages 46098-46102]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-18606]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-0199; Project Identifier MCAI-2024-00332-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: Supplemental notice of proposed rulemaking (SNPRM).

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

SUMMARY: The FAA is revising a notice of proposed rulemaking (NPRM) 
that would have applied to certain Airbus Canada Limited Partnership 
Model BD-500-1A10 and BD-500-1A11 airplanes. This action revises the 
NPRM by adding a requirement to re-identify the ceiling panel liners. 
The FAA is proposing this airworthiness directive (AD) to address the 
unsafe condition on these products. Since these actions would impose an 
additional burden over those in the NPRM, the FAA is requesting 
comments on this SNPRM.

DATES: The FAA must receive comments on this SNPRM by November 10, 
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-2025-0199; 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 SNPRM, 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-2025-0199.
     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: Brenda L. Buitrago, Aviation Safety 
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 516-
288-7368; 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-2025-0199; 
Project Identifier MCAI-2024-00332-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 SNPRM.

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 SNPRM 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 SNPRM, it is important that you clearly designate 
the submitted comments as CBI. Please mark each page of your submission

[[Page 46099]]

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 SNPRM. Submissions containing CBI should 
be sent to Brenda L. Buitrago, Aviation Safety Engineer, FAA, 2200 
South 216th St., Des Moines, WA 98198; phone: 516-288-7368; 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 an NPRM to amend 14 CFR part 39 by adding an AD that 
would have applied to certain Airbus Canada Limited Partnership Model 
BD-500-1A10 and BD-500-1A11 airplanes. The NPRM was published in the 
Federal Register on February 13, 2025 (90 FR 9526). The NPRM was 
prompted by AD CF-2024-21, dated June 20, 2024 (Transport Canada AD CF-
2024-21), issued by Transport Canada, which is the aviation authority 
for Canada. Transport Canada AD CF-2024-21 states that environmental 
control system (ECS) ducts, located on forward and aft cargo 
compartment ceiling panels, having part numbers (P/Ns) D761189-105, 
D761189-501, and D762232-509, have been manufactured using material 
APF1180-7781, which replaced discontinued legacy material Solvay 
L591PG-7781. The material change to APF1180-7781 was done without 
changing the ECS duct part number. Subsequent certification testing of 
the ECS ducts made using material APF1180-7781 failed flammability test 
requirements. These noncompliant ECS ducts may have been installed on 
certain affected airplanes during production. Noncompliant ECS ducts 
could result in the inability to contain a fire within the cargo 
compartment, which could result in an uncontrolled fire.
    In the NPRM, the FAA proposed to require inspecting the affected 
ECS ducts and, as applicable, installing a fire-resistant sleeve 
assembly over any non-compliant ECS duct, and prohibit the installation 
of ECS ducts as replacement parts under certain conditions.

Actions Since the NPRM Was Issued

    Since the FAA issued the NPRM, Transport Canada superseded 
Transport Canada AD CF-2024-21 and issued Transport Canada AD CF-2025-
10, dated February 27, 2025 (Transport Canada AD CF-2025-10) (also 
referred to as the MCAI), to correct an unsafe condition for all Airbus 
Canada Limited Partnership Model BD-500-1A10 and BD-500-1A11 airplanes. 
The MCAI states that since Transport Canada AD CF-2024-21 was issued, 
Airbus Canada revised the instructions in their service information to 
include a requirement to identify the ceiling panel liners to ensure 
configuration control.
    The FAA is proposing this AD to address noncompliant ECS ducts that 
could cause an inability to contain a fire within the cargo 
compartment. The unsafe condition, if not addressed, could result in an 
uncontrolled fire.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2025-0199.

Comments

    The FAA received comments from the Air Line Pilots Association, 
International (ALPA) and two individuals who supported the NPRM without 
change.
    The FAA received additional comments from Delta Air Lines (Delta). 
The following presents the comments received on the NPRM and the FAA's 
response to each comment.

Request To Reference Transport Canada AD CF-2025-10

    Delta requested that the proposed AD be updated to incorporate 
Transport Canada AD CF-2025-10, which supersedes Transport Canada AD 
CF-2024-21 and requires additional identification of the ceiling panel 
liners in affected cargo compartments for airplanes that already 
incorporated corrective actions. Delta added that Transport Canada AD 
CF-2025-10 updates the definition of the applicable service information 
to reference revision 3.
    The FAA agrees. As previously stated, the FAA has revised this 
proposed AD to reference Transport Canada AD CF-2025-10.

Request for a 60-Day Grace Period

    Delta requested the inclusion of a 60-day grace period in paragraph 
(h) of the proposed AD. Delta stated the requested 60-day grace period 
is intended to address Delta aircraft that would be approaching/
exceeding the 9,350 total flight hours compliance time when the FAA AD 
is published. Delta stated it owns three aircraft that need to 
accomplish the modification required by the proposed AD, and that 
without a grace period, those aircraft would be grounded. Delta noted 
that it found many issues with the service information that needed to 
be reconciled, and a 60-day grace period would allow adequate time to 
schedule the aircraft into a hanger and to procure parts and materials.
    The FAA agrees with the commenter's request for a grace period, but 
has determined that a 30 day grace period will allow operators adequate 
time to plan and procure parts and materials. The FAA has added 
paragraph (h)(3) of this proposed AD to provide a 30-day grace period.

Request To Address Discrepancies in Service Information

    Delta requested the FAA add exceptions to paragraph (h) of the 
proposed AD to address discrepancies in the related service 
information. Delta stated paragraph (g) of the proposed AD mandates 
accomplishing the instructions of Airbus Canada Limited Partnership 
Service Bulletin BD500-501003 Issue 001, or later revisions, and Safran 
Service Bulletin F493000-50-06, as a corrective action for the related 
unsafe condition. Delta stated that it discovered four discrepancies in 
the instructions of Safran Service Bulletin F493000-50-06 Revision 1, 
dated October 31, 2024. Delta suggested wording to address each of the 
following discrepancies:
    Instructions to drill holes for inserts that are placed before 
instructions to mark and identify locations for those inserts.
    A guidance note that could be moved to a different location to help 
guide maintenance personnel.
    Instructions related to the installation of masking tape and 
inserts that could be done in a different order.
    Missing instructions to drill holes for installing a sleeve 
assembly.
    The FAA partially agrees with the commenter's request. Regarding 
the position of the note, the FAA clarifies that the note is guidance 
material, not mandatory, and may be deviated from, including applying 
that guidance after a different step in the referenced material. 
Therefore, no change to this proposed AD is needed regarding the note. 
For the commenter's other requests, the FAA has added paragraphs (h)(4) 
through (6) of this proposed AD to address the discrepancies.

Request To Confirm Intent To Allow Use of Later Revisions of Service 
Information

    Delta requested the FAA include an acknowledgement in the preamble 
of the proposed AD to state the FAA intends to allow the use of later 
revisions of the service information specified in Transport Canada AD 
CF-2024-21. Delta stated it discovered errors that prompted Airbus to 
initiate two service bulletin revisions and

[[Page 46100]]

operators should use later revisions of the service information to 
comply with the proposed AD.
    The FAA confirms that it intends to allow the use of applicable 
later service bulletins revisions to comply with the requirements of 
this proposed AD. This proposed AD refers to Transport Canada AD CF-
2025-10 as the appropriate source of service information for 
accomplishing the required actions. Transport Canada AD CF-2025-10 
specifies acceptance of the use of later-approved revisions of the 
referenced Airbus Canada Limited Partnership service bulletin for 
compliance. Therefore, applicable later-approved service bulletin 
revisions are acceptable. The FAA has not changed the proposed AD 
regarding this request.

Request To Address Reporting Requirement

    Delta requested a statement be added to paragraph (h) of the 
proposed AD to addresses the reporting requirement in Airbus Canada 
Limited Partnership Service Bulletin BD500-501003 Issue No. 003, dated 
December 18, 2024, or later revisions. Delta noted the service bulletin 
requires the submission of a data sheet to the Airbus customer response 
center for analysis. Delta stated the collection of ECS duct lot 
numbers does not provide public benefit or utility towards creating 
project scope or determining terminating action. Delta requested that 
the FAA revise paragraph (h) of the proposed AD to state that reporting 
is not required.
    The FAA agrees with the commenter's request. The FAA has added 
paragraph (i) of this proposed AD to specify that reporting to the 
manufacturer is not required, and redesignated subsequent paragraphs 
accordingly.

Material Incorporated by Reference Under 1 CFR Part 51

    Transport Canada AD CF-2025-10 specifies procedures for inspecting 
to determine the lot numbers of affected ECS ducts, installing a fire-
resistant sleeve assembly over any non-compliant ECS duct, and 
reidentifying the ceiling panel liners in the cargo compartments. 
Transport Canada AD CF-2025-10 also prohibits the installation of ECS 
ducts as replacement parts under certain conditions. 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 SNPRM 
after determining that the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.
    Certain changes described above expand the scope of the NPRM. As a 
result, it is necessary to reopen the comment period to provide 
additional opportunity for the public to comment on this SNPRM.

Proposed AD Requirements in This SNPRM

    This proposed AD would require accomplishing the actions specified 
in Transport Canada AD CF-2025-10 described previously, except for any 
differences identified as exceptions in the regulatory text of this 
proposed AD.

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-2025-10 by reference 
in the FAA final rule. This proposed AD would, therefore, require 
compliance with Transport Canada AD CF-2025-10 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-2025-10 for compliance will be available at 
regulations.gov under Docket No. FAA-2025-0199 after the FAA final rule 
is published.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 11 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
----------------------------------------------------------------------------------------------------------------
12 work-hours x $85 per hour = $1,020...............           $0              $1,020                   $11,220
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary on-
condition actions that would be required based on the results of any 
required actions. The FAA has no way of determining the number of 
aircraft that might need these on-condition actions:

                 Estimated Costs of On-Condition Actions
------------------------------------------------------------------------
              Labor cost                 Parts cost    Cost per product
------------------------------------------------------------------------
2 work-hours x $85 per hour = $170....       $4,840              $5,010
------------------------------------------------------------------------

    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

[[Page 46101]]

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-2025-0199; Project Identifier MCAI-2024-00332-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by November 10, 2025.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Airbus Canada Limited Partnership Model 
BD-500-1A10 and BD-500-1A11 airplanes, certificated in any category.

(d) Subject

    Air Transport Association (ATA) of America Code 25, Equipment/
furnishings.

(e) Unsafe Condition

    This AD was prompted by certification testing that found that 
environmental control system (ECS) ducts manufactured using material 
APF1180-7781 failed the flammability test requirements established 
for compliance. The FAA is issuing this AD to address noncompliant 
ECS ducts that could cause an inability to contain a fire within the 
cargo compartment. The unsafe condition, if not addressed, could 
result in an uncontrolled fire.

(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-2025-10, dated February 27, 
2025 (Transport Canada AD CF-2025-10).

(h) Exception to Transport Canada AD CF-2025-10

    (1) Where Transport Canada AD CF-2025-10 refers to its effective 
date, this AD requires using the effective date of this AD.
    (2) Where Transport Canada AD CF-2025-10 refers to June 20, 2024 
(the effective date of Transport Canada AD CF-2024-21), this AD 
requires using the effective date of this AD.
    (3) Where the first paragraph under Part 1 of Transport Canada 
AD CF-2025-10 specifies a compliance time for the inspection and 
retrofit, for this AD the compliance time is at the later of the 
times specified in paragraphs (h)(3)(i) or (ii) of this AD:
    (i) Prior to the accumulation of 9,350 total flight hours or 
within 60 months after the effective date of this AD, whichever 
occurs first.
    (ii) Within 30 days after the effective date of this AD.
    (4) Where the Safran material referenced in Transport Canada AD 
CF-2025-10 specifies to drill holes, this AD allows identifying and 
marking the new locations for the inserts prior to drilling the 
holes.
    (5) Where the Safran material referenced in Transport Canada AD 
CF-2025-10 specifies accomplishing step 3.D.(8) after accomplishing 
steps 3.D.(6) and 3.D.(7), this AD allows accomplishing step 3.D.(8) 
concurrently with or after step 3.D.(5).
    (6) Where the Safran material referenced in Transport Canada AD 
CF-2025-10 specifies ``mark the holes position'', for this AD 
replace that text with ``mark the holes position and drill the 
holes''.
    (7) Where the second paragraph under Part II of Transport Canada 
AD CF-2025-10 specifies ``The use of the Accomplishment Instructions 
of Safran Cabin Service Bulletin F493000-50-06 as contained within 
Airbus Canada SB BD500-501003 Issue 001, dated 21 December 2023, or 
Issue 002, dated November 15, 2024, prior to the effective date of 
this AD, also meet the intent of Part II of this AD'', this AD 
requires replacing that text with ``The use of the Accomplishment 
Instructions of Safran Cabin Service Bulletin F493000-50-06 as 
contained within Airbus Canada SB BD500-501003 Issue 001, dated 21 
December 2023, or Issue 002, dated November 15, 2024, prior to the 
effective date of this AD, also meet the intent of Part II of this 
AD, provided the ceiling panel liners in the cargo compartments have 
been re-identified in accordance with the procedure in Section 3 of 
Part B of the Accomplishment Instructions of the ACLP SB.''

(i) No Reporting Requirement

    Although the material referenced in Transport Canada AD CF-2025-
10 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]. 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 Limited Partnership'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 (j)(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.

[[Page 46102]]

(k) Additional Information

    For more information about this AD, contact Brenda L. Buitrago, 
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 
98198; phone: 516-288-7368; 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-2025-10, dated February 27, 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]; website 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 September 23, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft 
Certification Service.
[FR Doc. 2025-18606 Filed 9-24-25; 8:45 am]
BILLING CODE 4910-13-P