DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-2231; Project Identifier MCAI-2022-01623-R;
Amendment 39-22684; AD 2024-04-05]
RIN 2120-AA64

Airworthiness Directives; Leonardo S.p.a. 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
Leonardo S.p.a. Model AB412 and AB412 EP helicopters. This AD was
prompted by reports of cracks in the lateral mounts of the main
transmission support case. This AD requires repetitive visual
inspections and fluorescent penetrant inspections (FPI) and, depending
on the results, corrective action, as 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 April 19, 2024.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of April 19,
2024.

ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2023-2231; 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, 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 that is identified in this final rule,
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 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-2023-2231.
Other Related Service Information: For Bell Helicopter service
information identified in this final rule, contact Bell Textron, Inc.,
P.O. Box 482, Fort Worth, TX 76101; phone 1-450-437-2862 or 1-800-363-
8023; fax 1-450-433-0272; email productsupport@bellflight.com; or at
bellflight.com/support/contact-support. You may also view this service
information at the FAA contact information under Material Incorporated
by Reference above.

FOR FURTHER INFORMATION CONTACT: Sungmo Cho, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (781)
238-7241; email: sungmo.d.cho@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2022-0258, dated December 20, 2022
(EASA AD 2022-0258), to correct an unsafe condition on all Leonardo
S.p.A. Model AB212, AB412, and AB412EP helicopters.
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to all Leonardo S.p.a.
Model AB412 and AB412 EP helicopters. The NPRM published in the Federal
Register on December 6, 2023 (88 FR 84767). The NPRM was prompted by
reports of cracks in the lateral mounts of the main transmission
support case. Such cracking is usually caused by excessive corrosion of
the surface under a washer and originates from a washer attachment
screw threaded hole. Cracking can occur at the upper or lower surfaces
of the lateral mount. The NPRM proposed to require repetitive visual
inspections and FPI and, depending on the results, corrective action,
as specified in EASA AD 2022-0258.
The FAA is issuing this AD to detect and address cracking of the
main transmission support case. The unsafe condition, if not addressed,
could result in the loss of load carrying capabilities of the main
transmission and subsequent loss of control of the helicopter. See EASA
AD 2022-0258 for additional background information.

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 a minor editorial change,
this AD is adopted as proposed in the NPRM. The change will not
increase the economic burden on any operator.

Related Service Information Under 1 CFR Part 51

EASA AD 2022-0258 requires repetitive visual inspections and FPIs
of the main transmission support case and, depending on the findings,
corrective action. Corrective actions include repairing or replacing
the main transmission support case hardware including screws, washers,
or case bushings, repairing the lateral mounts, or replacing the main
transmission support case.
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 Service Information

The FAA also reviewed Bell Helicopter Component Repair and Overhaul
Manual (CR&O) BHT-412-CR&O Chapter 63, paragraphs 63-57 Transmission
Main Support Case-Inspection and 63-58 Transmission Main Support Case-
Repair, Revision 12, dated February 28, 2020. This service information
specifies procedures for inspecting and repairing the main transmission
support case.

Differences Between This AD and the EASA AD

EASA AD 2022-0258 applies to Model AB212 helicopters, whereas this
AD does not because that model is not FAA type-certificated.
The service information referenced in EASA AD 2022-0258 specifies
contacting Product Support Engineering for possible repairs regarding
corrosion or pitting in the case bushings that exceeds allowable
limits, whereas this AD requires repair done in accordance with a
method approved by the FAA, EASA, or Leonardo S.p.a. Helicopters' EASA
Design Organization Approval.
Where EASA AD 2022-0258 requires performing an FPI, this AD
requires that the FPI be performed by a Level II or Level III inspector
certified in the FAA-acceptable standards for nondestructive inspection
personnel.

Costs of Compliance

The FAA estimates that this AD affects 69 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 main transmission support case takes
approximately 2 work-hours for an estimated cost of $170 per helicopter
and $11,730 for the U.S. fleet, per inspection cycle. Performing an FPI
of the main transmission support case takes approximately 2 work-hours
for an estimated cost of $170 per helicopter and $11,730 for the U.S.
fleet, per inspection cycle.
The FAA has no way of determining the costs pertaining to necessary
repairs that are required to be done. Replacing the transmission
support case assembly hardware parts including screws, washers, and
case bushings takes approximately 2 work-hours and parts cost up to
$4,000 per helicopter for an estimated cost of up to $4,170 per
helicopter. Replacing the main transmission support case takes
approximately 47 work-hours and parts cost approximately $120,000 for
an estimated cost of $123,995 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

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

Authority: 49 U.S.C. 106(g), 40113, 44701.

39.13 [Amended]

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