    [Federal Register Volume 90, Number 84 (Friday, May 2, 2025)]
    [Rules and Regulations]
    [Pages 18774-18776]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 2025-07573]

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    DEPARTMENT OF TRANSPORTATION

    Federal Aviation Administration

    14 CFR Part 39

    [Docket No. FAA-2025-0007; Project Identifier MCAI-2023-00998-R;
    Amendment 39-23021; AD 2025-08-08]
    RIN 2120-AA64

    Airworthiness Directives; Airbus Helicopters

    AGENCY: Federal Aviation Administration (FAA), DOT.

    ACTION: Final rule.

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    SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all
    Airbus Helicopters Model SA341G and SA342J helicopters. This AD was
    prompted by reports of corrosion on the contact surfaces of the tail
    rotor inclined and horizontal drive shaft flanges. This AD requires
    repetitively inspecting the inclined and horizontal drive shaft flanges
    and, depending on the results, replacing the inclined or horizontal
    drive shaft. This AD also prohibits installing certain inclined and
    horizontal drive shafts unless certain requirements are met. These
    actions are specified in a European Union Aviation Safety Agency (EASA)
    AD, which is proposed for incorporation by reference. The FAA is
    issuing this AD to address the unsafe condition on these products.

    DATES: This AD is effective June 6, 2025.
        The Director of the Federal Register approved the incorporation by
    reference of a certain publication listed in this AD as of June 6,
    2025.

    ADDRESSES:
        AD Docket: You may examine the AD docket at regulations.gov under
    Docket No.FAA-2025-0007; 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 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 find
    the EASA material on the EASA website at ad.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-2025-0007.

    FOR FURTHER INFORMATION CONTACT: Evan Weaver, Aviation Safety Engineer,
    FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316)
    946-4152; email: Evan.P.Weaver@faa.gov.

    SUPPLEMENTARY INFORMATION:

    Background

        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 SA341G and SA342J (Gazelle) helicopters. The NPRM published in
    the Federal Register on January 17, 2025 (90 FR 5748). The NPRM was
    prompted by AD 2023-0168, dated August 31, 2023 (EASA AD 2023-0168)
    (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
    there have been several reports of corrosion on the contact surfaces of
    the tail rotor inclined and horizontal drive shaft flanges. More
    detailed non-destructive testing indicated pitting corrosion on the
    mating faces of several flanges and further investigation revealed
    various regions of intergranular failure beneath

    [[Page 18775]]

    the surface of corrosion pits. The unsafe condition, if not addressed,
    could result in the failure of the tail rotor drive and subsequent loss
    of control of the helicopter.
        In the NPRM, the FAA proposed to require repetitively inspecting
    the inclined and horizontal drive shaft flanges and, depending on the
    results, replacing the inclined or horizontal drive shaft. In the NPRM,
    the FAA also proposed to prohibit installing certain inclined and
    horizontal drive shafts unless certain requirements are met. 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-2025-0007.

    Discussion of Final Airworthiness Directive

    Comments

        The FAA received two comments from an anonymous commenter and an
    individual who supported the NPRM without change.

    Conclusion

        These products have been approved by the 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, it has notified the FAA of the unsafe condition described in
    the MCAI referenced above. The FAA reviewed the relevant data,
    considered the comment received, and determined that air safety
    requires adopting the 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.

    Material Incorporated by Reference Under 1 CFR Part 51

        The FAA reviewed EASA AD 2023-0168, which specifies procedures for
    repetitively inspecting the flanges of certain part-numbered inclined
    and horizontal drive shafts for corrosion, and if corrosion is found,
    replacing the affected inclined or horizontal drive shaft. EASA AD
    2023-0168 also prohibits installing an affected inclined or horizontal
    drive shaft on any helicopter unless it is a serviceable part as
    defined within.
        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.

    Differences Between This AD and the MCAI

        The material referenced in the MCAI specifies sending corroded
    parts to Airbus Helicopters, whereas this AD does not require that
    action.

    Costs of Compliance

        The FAA estimates that this AD affects 63 helicopters of U.S.
    registry. Labor rates are estimated at $85 per work-hour. Based on
    these numbers, the FAA estimates the following costs to comply with
    this AD.
        Visually inspecting the inclined and horizontal drive shaft flanges
    takes 4 work-hours for an estimated cost of $340 per helicopter and
    $21,420 for the U.S. fleet, per inspection cycle. If required,
    replacing the inclined or horizontal drive shaft takes 4 work-hours and
    parts will cost $17,900 (inclined drive shaft) or $35,500 (horizontal
    drive shaft), for an estimated cost of $18,240 or $35,840 respectively
    per helicopter.

    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.

    List of Subjects in 14 CFR Part 39

        Air transportation, Aircraft, Aviation safety, Incorporation by
    reference, Safety.

    The Amendment

        Accordingly, under the authority delegated to me by the
    Administrator, the FAA amends 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:

    2025-08-08 Airbus Helicopters: Amendment 39-23021; Docket No. FAA-
    2025-0007; Project Identifier MCAI-2023-00998-R.

    (a) Effective Date

        This airworthiness directive (AD) is effective June 6, 2025.

    (b) Affected ADs

        None.

    (c) Applicability

        This AD applies to Airbus Helicopters Model SA341G and SA342J
    helicopters, certificated in any category.

    (d) Subject

        Joint Aircraft System Component (JASC) Code 6510, Tail Rotor
    Drive Shaft.

    (e) Unsafe Condition

        This AD was prompted by reports of corrosion on the contact
    surfaces of the tail rotor inclined and horizontal drive shaft
    flanges. The FAA is issuing this AD to detect and address corrosion
    on the inclined and horizontal drive shaft flanges. The unsafe
    condition, if not addressed, could result in the failure of the tail
    rotor drive and subsequent loss of control of the helicopter.

    (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 AD 2023-0168,
    dated August 31, 2023 (EASA AD 2023-0168).

    [[Page 18776]]

    (h) Exceptions to EASA AD 2023-0168

        (1) Where EASA AD 2023-0168 requires compliance in terms of
    flight hours, this AD requires using hours time-in-service.
        (2) Where EASA AD 2023-0168 refers to its effective date, this
    AD requires using the effective date of this AD.
        (3) Where the material referenced in paragraph (2) of EASA 2023-
    0168 specifies sending corroded inclined or horizontal drive shaft
    to Airbus Helicopters, this AD does not require that action.
        (4) This AD does not adopt the ``Remarks'' section of EASA AD
    2023-0168.

    (i) No Reporting Requirement

        Although the material referenced in EASA AD 2023-0168 specifies
    to submit certain information to the manufacturer, this AD does not
    require that action.

    (j) Special Flight Permits

        Special flight permits are prohibited.

    (k) Alternative Methods of Compliance (AMOCs)

        (1) The Manager, International Validation 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 local Flight
    Standards District Office, as appropriate. If sending information
    directly to the manager of the International Validation Branch, send
    it to the attention of the person identified in paragraph (l) of
    this AD and email to: AMOC@faa.gov.
        (2) Before using any approved AMOC, notify your appropriate
    principal inspector, or lacking a principal inspector, the manager
    of the local flight standards district office/certificate holding
    district office.

    (l) Additional Information

        For more information about this AD, contact Evan Weaver,
    Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
    Westbury, NY 11590; phone: (316) 946-4152; email:
    Evan.P.Weaver@faa.gov.

    (m) 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 the AD specifies otherwise.
        (i) European Union Aviation Safety Agency (EASA) AD 2023-0168,
    dated August 31, 2023.
        (ii) [Reserved]
        (3) For 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
    find this EASA material on the EASA website at ad.easa.europa.eu.
        (4) 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.
        (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.

        Issued on April 21, 2025.
    Steven W. Thompson,
    Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
    Certification Service.
    [FR Doc. 2025-07573 Filed 5-1-25; 8:45 am]
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