AD 2026-09-15

This AD is effective July 21, 2026.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of July 21, 2026.

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2025-5387; 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 final rule, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.

Material Incorporated by Reference:

• For Airbus Helicopters material identified in this AD, contact Airbus Helicopters, 2701 North Forum Drive, Grand Prairie, TX 75052; phone: (972) 641-0000 or (800) 232-0323; fax: (972) 641-3775; website: airbus.com/en/products-services/helicopters/hcare-services/airbusworld.

• You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 10101 Hillwood Parkway, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110. It is also available at regulations.gov under Docket No. FAA-2025-5387.

Matthew Williams, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316) 946-4134; email: matthew.t.williams@faa.gov.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2023-01-04, Amendment 39-22298 (88 FR 6618, February 1, 2023), (AD 2023-01-04). AD 2023-01-04 applied to Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters. AD 2023-01-04 required, for helicopters with certain part-numbered TRH spider pitch change units installed, inspecting for correct installation of the nut; marking a 2 to 5 mm wide black paint index mark to identify the position of certain parts; and after the initial marking, repetitively inspecting the alignment of the marking; and additional inspections and corrective actions if necessary. Additionally, AD 2023-01-04 prohibited installing an affected part on a helicopter unless certain requirements were met. The FAA issued AD 2023-01-04 to detect improper installation of the nut and improper alignment of a black index marking.

The NPRM was published in the Federal Register on December 17, 2025 (90 FR 58512). The NPRM was prompted by European Union Aviation Safety Agency (EASA) AD 2021-0282R1, Revision 1, dated July 10, 2024 (EASA AD 2021-0282R1) (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 that the manufacturer revised the Airworthiness Limitations Section (ALS), as applicable, which now includes the repetitive black index marking checks (inspections).

In the NPRM, the FAA proposed to require the same actions as AD 2023-01-04, except the NPRM only proposed to require the initial black paint index marking inspection, not the repetitive inspections. The FAA also proposed to prohibit installing an affected part on a helicopter unless certain requirements are met.

You may examine the AD docket at regulations.gov under Docket No. FAA-2025-5387.

The FAA received a comment from an individual commenter. The following presents the comment received on the NPRM and the FAA's response to the comment.

The commenter requested that the FAA add language to paragraph (g)(2) of the proposed AD to clarify whether a 10 hour time-in-service visual inspection of the black paint index mark is required on a pitch change unit that is new or newly overhauled.

The FAA disagrees with the request to update paragraph (g)(2) of this AD but agrees to clarify that the repetitive black paint index mark visual inspections are now integrated into the ALS for affected part numbers 350A33-2030-00, 350A33-2167-00, and 350A33-2167-01, in accordance with the applicable ALS. No changes were made to this AD as a result of this comment.

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 technical corrections in paragraph (h) to accurately reflect the parts installation limitations, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator.

The FAA reviewed Airbus Helicopters Alert Service Bulletin (ASB) No. AS350-05.01.03, and Airbus Helicopters ASB No. AS355-05.00.86, both Revision 1 and dated July 8, 2024, which include Figure 1 that identifies the position of the TRH pitch change unit and of the bearing spacer to be marked with a 2 to 5 mm wide black paint index mark. This material also specifies procedures for inspecting the condition and installation of the nut; and inspecting the application and alignment of the black index mark on the TRH pitch change unit and the bearing spacer.

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.

The MCAI applies to Airbus Helicopters Model AS350BB, whereas this AD does not because that model does not have an FAA type certificate.

The FAA estimates that this AD affects 972 helicopters of U.S. registry.

The FAA estimates the following costs to comply with this AD.

The FAA estimates the following costs to do any repairs/replacements that would be required based on the results of the inspection. The agency has no way of determining the number of helicopters that might need these repairs or replacements:

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.

The FAA has determined that 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.

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

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

2. The FAA amends § 39.13 by:

a. Removing Airworthiness Directive 2023-01-04, Amendment 39-22298 (88 FR 6618, February 1, 2023); and

b. Adding the following new airworthiness directive: