SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2025-04-05, Amendment 39-22963 (90 FR 10853, February 28, 2025) (AD 2025-04-05). AD 2025-04-05 applied to all Airbus SAS Model A330-841 and -941 airplanes. AD 2025-04-05 required 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. AD 2025-04-05 also limited 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.

The NPRM was published in the Federal Register on June 4, 2026 (91 FR 33674). The NPRM was prompted by EASA AD 2025-0104R1, dated March 19, 2026 (EASA AD 2025-0104R1) (also referred to as the MCAI), issued by EASA, which is the Technical Agent for the Member States of the European Union. The MCAI states 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. 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 master minimum equipment list (MMEL) content must be implemented for airplanes on which BMC SW 4.0 or 4.1 is installed. The MCAI further specifies that modification of both affected HPVs terminates the HPV clip replacement for the airplane, provided no affected HPV is re-installed on that airplane.

In the NPRM, the FAA proposed to continue to require the actions in AD 2025-04-05 except for repetitive replacement of affected HPV clips, as specified in EASA AD 2025-0104R1. The NPRM also proposed to require updating the BMC SW, additional work, and an additional revision of the existing MEL for the engine bleed overpressure valve, as applicable; and to prohibit the installation of certain BMC software; as specified in EASA AD 2025-0104R1. The FAA is issuing 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.

Discussion of Final Airworthiness Directive

Comments

The FAA received a comment from the Air Line Pilots Association, International (ALPA) who supported the NPRM without change.

The FAA received an additional comment from Delta Air Lines (Delta). The following presents the comments received on the NPRM and the FAA's response.

Request To Provide Credit for Replacement of Affected HPVs

Delta requested that the FAA revise the proposed AD to provide credit for replacement of affected EBAS HPVs (part number (P/N) 71070A010001 or P/N 71070A020001) with non-affected EBAS HPVs (P/N 71070A030001), using FAA-approved maintenance data, including the Airbus aircraft maintenance manual (AMM). Delta noted Option 2 of Airbus Service Bulletin A330-36-3057, dated October 28, 2024 (Airbus Service Bulletin A330-36-3057), provides procedures for replacing affected HPVs with non-affected HPVs using Airbus AMM Tasks 36-11-51-000-806 and 36-11-51-400-806, in lieu of modification of the HPVs in Option 1 of that service bulletin as referenced in paragraph (30) of EASA AD 2025-0104R1. Delta stated operators are already conducting unscheduled removal and replacement of HPVs during normal operations, and that allowing credit for replacement of affected HPVs with non-affected HPVs using approved AMM procedures would provide operational flexibility during unscheduled maintenance while achieving the same configuration and ( printed page 65956) maintaining an acceptable level of safety.

The FAA agrees it acceptable to replace the affected HPVs with non-affected HPVs using Option 2 of Airbus Service Bulletin A330-36-3057 in lieu of modifying the affected HPVs using Option 1 of that service bulletin. Accordingly, the FAA has revised the exception in paragraph (h)(10) to specify that the modification or replacement of both affected HPVs in accordance with Airbus Service Bulletin A330-36-3057 constitutes terminating action for the HPV clip replacement. In addition, the FAA has added new paragraph (i) to this AD to provide credit for accomplishing the replacement using AMM Tasks 36-11-51-000-806 and 36-11-51-400-806 before the effective date of this AD. Under the provisions of paragraph (k)(1) of this AD, the FAA will consider requests for alternative methods of compliance, should operators wish to use other maintenance data or the applicable AMM tasks after the effective date of this AD.

Conclusion

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 reviewed the relevant data, considered any comments received, and determined that air safety requires adopting this AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on these products. Except for minor editorial changes, and any other changes described previously, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator.

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.

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 HPVs 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.

Costs of Compliance

The FAA estimates that this AD would affect 22 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: ( printed page 65957)

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:

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

This AD will not have federalism implications under Executive Order 13132. This AD will 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 that this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Will not affect intrastate aviation in Alaska, and

(3) Will 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 Amendment

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