AD 2025-24-01

This AD is effective January 12, 2026.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of January 12, 2026.

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2025-1350; 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 European Union Aviation Safety Agency (EASA) material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: ADs@easa.europa.eu; website: easa.europa.eu.

• You may view this material at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-321, 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-2025-1350.

Adam Hein, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316) 946-4116; email: adam.hein@faa.gov.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all Airbus Helicopters Model EC 155B and EC 155B1 helicopters. The NPRM was published in the Federal Register on July 2, 2025 (90 FR 28913). The NPRM was prompted by AD 2024-0173, dated September 4, 2024 (EASA AD 2024-0173) (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 during tests concerning jettisoning of windows on a Model EC 155 helicopter, it was identified that the required forces to jettison the windows exceed the maximum jettisoning effort requirements. The MCAI also states that Airbus Helicopters developed a modification of the jettisonable windows to address this unsafe condition.

In the NPRM, the FAA proposed to require replacement of the jettisonable windows and seals on the sliding doors and fixed panels on the left-hand and right-hand sides. The FAA also proposed the installation of new labels.

The FAA is issuing this AD to prevent the inability to jettison the window(s) during an emergency. The unsafe condition, if not addressed, could result in a reduced capability to evacuate helicopter occupants during an emergency and consequent injury to helicopter occupants.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2025-1350.

The FAA received comments from two anonymous commenters that were unrelated to the actions proposed in the NPRM or that did not make a request that the FAA can act on. These comments are outside the scope of this AD.

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, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator.

The FAA reviewed EASA AD 2024-0173, which specifies procedures for replacement of the jettisonable windows and seals on the sliding doors and fixed panels on the left-hand and right-hand sides. The MCAI also specifies procedure for installation of new labels on the sliding doors and fixed panels. 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 FAA estimates that this AD affects 16 helicopters of U.S. registry. The FAA estimates the following costs to comply with this AD.

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.

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 adding the following new airworthiness directive: