DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-1002; Project Identifier MCAI-2022-01574-R;
Amendment 39-22799; AD 2024-15-08]
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 AS350B, AS350BA, AS350B1, AS350B2, AS350D,
AS355E, AS355F, AS355F1, AS355F2, and AS355N helicopters. This AD was
prompted by reports of debonding on the leading edge protection of
certain part-numbered main rotor blades (MRBs). This AD requires
repetitively tap inspecting the MRB and, depending on the results,
taking corrective action. This AD also prohibits installing an affected
MRB on any helicopter unless its requirements are met. These actions
are specified in a European Union Aviation Safety Agency (EASA) AD,
which is incorporated by reference. The FAA is issuing this AD to
address the unsafe condition on these products.

DATES: 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.

ADDRESSES:
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.

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

SUPPLEMENTARY INFORMATION:

Background

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.

Discussion of Final Airworthiness Directive

Comments

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

Conclusion

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.

Material Incorporated by Reference Under 1 CFR Part 51

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.

Other Related Material

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.

Differences Between This AD and the EASA AD

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

Costs of Compliance

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.

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

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]

2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive: