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-2026-4649; Project Identifier MCAI-2025-00835-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 Dan Rodina, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3225; email: Dan.Rodina@faa.gov. 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 2025-04-05, Amendment 39-22963 (90 FR 10853, February 28, 2025) (AD 2025-04-05), for all Airbus SAS Model A330-841 and -941 airplanes. AD 2025-04-05 was prompted by an MCAI originated by EASA, which is the Technical Agent for the Member States of the European Union. EASA issued EASA AD 2023-0111R1, dated May 28, 2024 (EASA AD ( printed page 33675) 2023-0111R1), to correct an unsafe condition.

AD 2025-04-05 requires a revision of the existing AFM and removal of the previously required limitations; a revision of the existing MEL; one-time or repetitive seal integrity tests of each EBAS HPV; additional maintenance instructions and corrective actions; and repetitive replacement of affected HPV clips; as applicable. AD2025-04-05 also limits the installation of affected HPV clips. The FAA issued AD 2025-04-05 to address a leaking HPV that may expose the pressure regulating valve (PRV), which is installed downstream from the HPV to high pressure, possibly damaging the PRV itself and preventing its closure. The unsafe condition, if not addressed, could result in high pressure and temperatures in the duct downstream from the PRV, with possible duct burst, damage to several systems, and consequent loss of control of the airplane.

Actions Since AD 2025-04-05 Was Issued

AD 2025-04-05 explains that the FAA considers the requirements “interim action” and was considering further rulemaking. The FAA has now determined that further rulemaking is necessary, and this proposed AD follows from that determination.

Since the FAA issued AD 2025-04-05, EASA superseded EASA AD 2023-0111R1 with EASA AD 2025-0104, dated May 7, 2025, which was revised by EASA AD 2025-0104R1, dated March 19, 2026 (EASA AD 2025-0104R1) (also referred to as the MCAI). The MCAI states, since EASA AD 2023-0111R1 was issued, an improved HPV has been certified (Airbus Modification 210503), which introduces several design improvements and is equipped with HPV clips that do not have to be replaced at predefined intervals; new service information has been issued, which provides instructions to replace the affected HPV with the improved HPV; other service information has been issued, which provides instructions to do additional work on airplanes that have embodied Airbus Service Bulletin A330-36-3055 at the original issue; new master minimum equipment list (MMEL) content has been certified, which introduces additional instructions for airplanes on which BMC SW 4.0 or 4.1 is installed. The MCAI also states that it has been determined that the optional modification to install BMC SW 5.0 must be mandated on airplanes on which BMC SW 4.0 or 4.1 is installed, additional work defined in a later revision of the other service information must be accomplished, and new MMEL content must be implemented for airplanes on which BMC SW 4.0 or 4.1 is installed.

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-2026-4649.

Explanation of Retained Requirements

Although this proposed AD does not explicitly restate the requirements of AD 2025-04-05, this proposed AD would retain certain requirements of AD 2025-04-05. Those requirements are referenced in EASA AD 2025-0104R1, which, in turn, is referenced in paragraph (g) of this proposed AD.

Material Incorporated by Reference Under 1 CFR Part 51

EASA AD 2025-0104R1 specifies procedures for the following retained actions:

• For Group 1 airplanes (equipped with BMC SW 4.0) and Group 2 airplanes (equipped with BMC SW 4.1 standard), a revision of the Limitations section of the existing AFM; and for Groups 1 and 2 and Group 3 (equipped with BMC SW 5.0 or later approved SW standard and an affected HPV) airplanes, removal of the previously required limitations.
• For Groups 1 and 2 airplanes, implementation of the MMEL update that includes new provisions and procedures for Air Conditioning Pack, Engine Bleed Air Supply System, Engine Bleed IP (Intermediate Pressure) Check Valve, and Engine Bleed HP (High Pressure) Valve; and cancellation of the dispatch restrictions.
• For Group 2 airplanes, a seal integrity test of each HPV; for Group 1 airplanes, repetitive seal integrity tests of each HPV; and corrective actions, which include replacement of the HPV, a detailed inspection of the wing bellow on engine 1(2), and replacement of any damaged or deformed wing bellow.

EASA AD 2025-0104R1 describes the following retained maintenance instructions, among other actions, to be accomplished following certain faults or failures, on Groups 1 and 2 airplanes:

• HPV troubleshooting procedure and additional maintenance actions after any Class 1 maintenance message associated with an HPV fault and corrective actions, which includes replacement of the HPV or wing bellow.
• HPV seal integrity test and the additional maintenance actions after any Class 1 or Class 2 maintenance message associated with a PRV fault and corrective actions, which includes replacement of the HPV and PRV, a detailed inspection of the wing bellow on engine 1(2), and replacement of any damaged or deformed wing bellow.
• A visual (borescope) inspection of the EBAS to detect signs of foreign object debris (FOD), including metallic debris in the butterfly valve and dents or damage of the flaps of the intermediate pressure check valve (IPCV), and dents and missing segments in the PRV, the header of the HP/IP duct, y-duct, and pylon ducts after any failure of an HPV clip and/or any of the HPV butterfly sealing rings, and corrective actions, which includes FOD removal and replacement of the IPCV or PRV.
• A seal integrity test of each HPV after any takeoff or go-around accomplished with “packs OFF” or “APU bleed ON” or “engine bleed OFF” and corrective actions, which include replacement of the HPV, a detailed inspection of the wing bellow on engine 1(2), and replacement of any damaged or deformed wing bellow.
• Additional actions to be performed for any Class 1 maintenance message associated with an HPV fault.

EASA AD 2025-0104R1 also specifies the following retained limitations for the installation of affected parts:

• For Groups 1, 2, and 3 airplanes, installation of an affected HPV clip on an affected HPV on an airplane, provided it is a new affected clip (i.e., not previously installed on any HPV) and that following installation, it is replaced according to the referenced service information.
• For Groups 1, 2, and 3 airplanes, installation of an affected HPV on an airplane, provided it is a serviceable HPV and that following installation, the affected HPV clips of that HPV are replaced with new clips according to the referenced service information.

EASA AD 2025-0104R1 also specifies that, for Group 1 airplanes, modification (update to BMC SW 4.1) of the airplane terminates the repetitive seal integrity tests of each HPV.

EASA AD 2025-0104R1 specifies the following new actions:

• For Groups 1 and 2 airplanes, modification (update to BMC SW 5.0) of the airplane, which includes deletion of the operations engineering bulletin (OEB) reminder data from the flight warning computer (FWC) database.
• For Group 3 airplanes, accomplishment of additional work (deletion of the OEB reminder data from the FWC database).
• For Groups 1 and 2 airplanes, implementation of the MMEL update that includes new provisions for Engine Bleed Overpressure Valve. ( printed page 33676)

EASA AD 2025-0104R1 also prohibits the installation of the following affected parts:

• BMC SW 4.0 or BMC SW 4.1 on any Group 3 or Group 4 (embodied with Airbus modifications 210503 and 210504 in production) airplane, and on any Group 1 or 2 airplane after modification (update to BMC SW 5.0) of the airplane.
• An affected HPV on any Group 4 airplane.

EASA AD 2025-0104R1 also specifies that, for Groups 1, 2, and 3 airplanes, modification of both affected HPVs terminates the HPV clip replacement for the airplane, provided no affected HPV is re-installed on that airplane; and if modification of the two affected HPV are accomplished at different times, the HPV clip replacement is only applicable to the affected HPV.

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 retain certain requirements of AD 2025-04-05. This proposed AD would require accomplishing the actions specified in EASA AD 2025-0104R1 described previously, except for any differences identified as exceptions in the regulatory text of this proposed AD.

Compliance With AFM and MEL Revisions

EASA AD 2025-0104R1 requires operators to “inform all flight crews” of revisions to the AFM and MEL, 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. FAA regulations (14 CFR 121.628(a)(2)) require operators to provide pilots with access to all the information contained in the operator's MEL. Further, § 121.628(a)(5) requires airplanes to be operated under all applicable conditions and limitations contained in the operator's MEL. Therefore, including a requirement in this proposed AD to operate the airplane according to the revised AFM and MEL 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 EASA AD 2025-0104R1 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with EASA AD 2025-0104R1 in its entirety through that incorporation, except for any differences identified as exceptions in the regulatory text of this proposed AD. Using common terms that are the same as the heading of a particular section in EASA AD 2025-0104R1 does not mean that operators need to comply only with that section. For example, where the AD requirement refers to “all required actions and compliance times,” compliance with this AD requirement is not limited to the section titled “Required Action(s) and Compliance Time(s)” in EASA AD 2025-0104R1. Material required by EASA AD 2025-0104R1 for compliance will be available at regulations.gov under Docket No. FAA-2026-4649 after the FAA final rule is published.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 22 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:

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:

( printed page 33677)

The FAA has received no definitive data on which to base the cost estimates for the maintenance actions specified in this AD.

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.

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

2. The FAA amends § 39.13 by:

a. Removing Airworthiness Directive (AD) 2025-04-05, Amendment 39-22963 ( 90 FR 10853, February 28, 2025); and

b. Adding the following new AD:

Airbus SAS: Docket No. FAA-2026-4649; Project Identifier MCAI-2025-00835-T.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by July 20, 2026.

(b) Affected ADs

This AD replaces AD 2025-04-05, Amendment 39-22963 (90 FR 10853, February 28, 2025) (AD 2025-04-05).

(c) Applicability

This AD applies to all Airbus SAS Model A330-841 and -941 airplanes, certificated in any category.

(d) Subject

Air Transport Association (ATA) of America Code 36, Pneumatic.

(e) Unsafe Condition

This AD was prompted by reports of leaking bleed system high pressure valves (HPV), likely due to HPV clip failure and sealing ring damage. This AD was also prompted by certification of an improved HPV with unaffected HPV clips and the determination that the bleed monitoring computer (BMC) software must be updated. The FAA is issuing this AD to address a leaking HPV that may expose the pressure regulating valve (PRV), which is installed downstream from the HPV to high pressure, possibly damaging the PRV itself and preventing its closure. The unsafe condition, if not addressed, could result in high pressure and temperatures in the duct downstream from the PRV, with possible duct burst, damage to several systems, and consequent loss of control of the airplane.

(f) Compliance

Comply with this AD within the compliance times specified, unless already done.

(g) Requirements

Except as specified in paragraphs (h) and (i) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, European Union Aviation Safety Agency (EASA) AD 2025-0104R1, dated March 19, 2026 (EASA AD 2025-0104R1).

(h) Exceptions to EASA AD 2025-0104R1

(1) Where EASA AD 2025-0104R1 refers to May 21, 2025 (the effective date of the original issue of EASA AD 2025-0104, dated May 7, 2025), this AD requires using the effective date of this AD.

(2) Where EASA AD 2025-0104R1 refers to May 28, 2024 (the effective date of EASA AD 2023-0111R1, dated May 28, 2024), this AD requires using April 4, 2025 (the effective date of AD 2025-04-05).

(3) Where EASA AD 2025-0104R1 refers to June 2, 2023 (the effective date of the original issue of EASA AD 2023-0111, dated May 26, 2023), this AD requires using April 4, 2025 (the effective date of AD 2025-04-05).

(4) Where paragraph (19) of EASA AD 2025-0104R1 refers to December 8, 2022 (the effective date of EASA AD 2022-0227, dated November 24, 2022), this AD requires using April 4, 2025 (the effective date of AD 2025-04-05).

(5) Where paragraph (21) of EASA AD 2025-0104R1 refers to December 8, 2022 (the effective date of EASA AD 2022-0227, dated November 24, 2022), this AD requires using July 18, 2023 (the effective date of AD 2023-11-08, Amendment 39-22454 (88 FR 38384, June 13, 2023)).

(6) Where EASA AD 2025-0104R1 refers to September 5, 2022 (the effective date of EASA AD 2022-0181, dated August 29, 2022), this AD requires using September 15, 2022 (the effective date of AD 2022-19-05, Amendment 39-22174 (87 FR 54870, September 8, 2022)).

(7) Where EASA AD 2025-0104R1 defines a Serviceable HPV, in part, as “EBAS HPV, eligible for installation in accordance with Airbus instructions”, this AD requires replacing that text with “EBAS HPV eligible for installation”.

(8) Where paragraphs (1), (2), (3), (7), and (29) of EASA AD 2025-0104R1 specify to inform all flightcrews of airplane flight manual (AFM) revisions and dispatch limitations, and thereafter operate the airplane 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 for AFM requirements and 14 CFR 121.628(a)(2) and (5) for minimum equipment list requirements).

(9) Where paragraph (20) of EASA AD 2025-0104R1 specifies “as required by paragraph (17) of the original issue of this AD”, this AD requires replacing that text with “as required by AD 2025-04-05 as ( printed page 33678) specified in paragraph (17) of EASA AD 2023-0111R1”.

(10) Where paragraph (30) of EASA AD 2025-0104R1 specifies “Modification of both EBAS HPV”, this AD requires replacing that text with “Modification of both affected HPVs”.

(11) This AD does not adopt the “Remarks” section of EASA AD 2025-0104R1.

(i) No Reporting Requirement

Although the material referenced in EASA AD 2025-0104R1 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: AMOC@faa.gov.

(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 2025-04-05 are approved as AMOCs for the corresponding provisions of EASA AD 2025-0104R1 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 EASA; or Airbus SAS's EASA Design Organization Approval (DOA). If approved by the DOA, the approval must include the DOA-authorized signature.

(3) Required for Compliance (RC): Except as required by paragraphs (i) and (j)(2) of this AD, if any material referenced in EASA AD 2025-0104R1 contains paragraphs that are labeled as RC, the instructions in RC paragraphs, including subparagraphs under an RC paragraph, must be done to comply with this AD; any paragraphs, including subparagraphs under those paragraphs, that are not identified as RC are recommended. The instructions in paragraphs, including subparagraphs under those paragraphs, 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 instructions identified as RC can be done and the airplane can be put back in an airworthy condition. Any substitutions or changes to instructions identified as RC require approval of an AMOC.

(k) Additional Information

For more information about this AD, contact Dan Rodina, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3225; email: Dan.Rodina@faa.gov.

(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) European Union Aviation Safety Agency (EASA) AD 2025-0104R1, dated March 19, 2026.

(ii) [Reserved]

(3) For EASA material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221 8999 000; email ADs@easa.europa.eu. You may find this material on the EASA website at ad.easa.europa.eu.

(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 fr.inspection@nara.gov.