AD 2024-15-08

This AD is effective October 15, 2024.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of October 15, 2024.

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2024-1002; 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-2024-1002.

Other Related Material: For Airbus Helicopters material identified in this AD, contact Airbus Helicopters, 2701 North Forum Drive, Grand Prairie, TX 75052; telephone (972) 641-0000 or (800) 232-0323; fax (972) 641-3775; or at airbus.com/en/products-services/helicopters/hcare-services/airbusworld. You may also view this material at the FAA contact information under Material Incorporated by Reference above.

Dan McCully, Aviation Safety Engineer, FAA, 1600 Stewart Ave., Suite 410, Westbury, NY 11590; phone: (404) 474-5548; email: william.mccully@faa.gov.

EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2022-0246, dated December 12, 2022 (EASA AD 2022-0246), to correct an unsafe condition on all Airbus Helicopters Model AS 350 B, AS 350 BA, AS 350 B1, AS 350 B2, AS 350 BB, AS 350 D, AS 355 E, AS 355 F, AS 355 F1, AS 355 F2, and AS 355 N helicopters.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350D, AS355E, AS355F, AS355F1, AS355F2, and AS355N helicopters. The NPRM published in the Federal Register on April 16, 2024 (89 FR 26794). The NPRM was prompted by reports of debonding on the stainless steel leading edge protection of certain part-numbered MRBs. The NPRM proposed to require repetitively tap inspecting the MRB and, depending on the results, taking corrective action. The NPRM also prohibited installing an affected MRB on any helicopter unless its requirements are met, as specified in EASA AD 2022-0246.

The FAA is issuing this AD to address the debonding of the MRB leading edge protection. The unsafe condition, if not addressed, could result in a significant unbalance of the main rotor, a high level of vibration, failure of the main rotor, failure of the main gearbox, and subsequent loss of control of the helicopter.

The FAA received no comments on the NPRM or on the determination of the costs.

These helicopters have been approved by EASA and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with the European Union, EASA has notified the FAA about the unsafe condition described in its AD. The FAA reviewed the relevant data 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 helicopters. Except for minor editorial changes, this AD is adopted as proposed in the NPRM.

EASA AD 2022-0246 requires repetitively tap inspecting affected MRBs and, depending on findings, either repairing or replacing the MRB. For certain helicopters, EASA AD 2022-0246 prohibits installing an affected MRB unless it is a serviceable part as defined within and is inspected following installation. For other certain helicopters, EASA AD 2022-0246 prohibits installing an affected MRB.

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 also reviewed Airbus Helicopters Alert Service Bulletin No. AS350-05.01.07 and No. AS355-05.00.91, both Revision 0 and dated December 6, 2022. This material describes procedures for tap inspecting the stainless steel leading edge protection of the MRB and, depending on the results, repairing or sending the MRB for repair to Airbus Helicopters. This material also specifies sending certain information to Airbus Helicopters.

EASA AD 2022-0246 applies to Model AS350BB helicopters, whereas this AD does not because that model is not FAA-type certificated.

The FAA estimates that this AD affects 405 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.

Tap inspecting affected MRBs for disbonding takes up to approximately 1 work-hour (up to three MRBs per helicopter) for an estimated cost of up to $85 per helicopter and $34,425 for the U.S. fleet, per inspection cycle. Replacing a blade takes approximately 6 work-hours and parts cost up to approximately $84,000 for an estimated cost of up to $84,510 per MRB. The FAA has no data to determine the cost of or the number of helicopters that might need the MRB repaired.

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: