DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-0997; Project Identifier MCAI-2022-01306-R;
Amendment 39-22832; AD 2024-17-07]
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 AB139 and AW139 helicopters. This AD was prompted
by multiple reports of cracks found on tail rotor (TR) damper bracket
assemblies. This AD requires accomplishing repetitive detailed visual
inspections (DVIs) of certain part-numbered TR damper bracket
assemblies for corrosion and cracks and, depending on the results,
taking corrective action. This AD also prohibits installing an affected
TR damper bracket assembly unless it is new. 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 November 12, 2024.

The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of November 12, 2024.

ADDRESSES:

AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2024-0997; 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; internet: 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 Pkwy., Room 6N-321,
Fort Worth, TX 76177. For information on the availability of this
material at the FAA, call (817) 222-5110. The EASA material is also
available at regulations.gov under Docket No. FAA-2024-0997.

Other Related Material: For Leonardo Helicopters material, contact
Leonardo S.p.A., Emanuele Bufano, Head of Airworthiness, Viale G.
Agusta 520, 21017 C. Costa di Samarate (Va) Italy; phone: (+39) 0331-
225074; fax: (+39) 0331-229046; or at
customerportal.leonardocompany.com/en-US/.

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

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to Leonardo S.p.a. Model
AB139 and AW139 helicopters. The NPRM published in the Federal Register
on April 10, 2024 (89 FR 25194). The NPRM was prompted by EASA AD 2022-
0154, dated August 1, 2022 (EASA AD 2022-0154; also referred to as the
MCAI), issued by EASA, which is the Technical Agent for the Member
States of the European Union. EASA AD 2022-0154 stated that during
scheduled inspections, some TR damper bracket assemblies were found cracked and
that subsequent investigation revealed that the cracks originated from
the outer edges of the TR damper bracket lug bores and were due to
stress corrosion. That condition, if not detected and corrected, could
lead to fracture of the affected part (TR damper bracket assembly), TR
blade loss, unbalance or damage to the tail or other parts of the
helicopter, possibly resulting in failure of the TR damper, and
consequent loss of control of the helicopter. Therefore, EASA AD 2022-
0154 required repetitive DVIs of the affected part for cracks and
corrosion, and, depending on findings, replacing the affected part with
a serviceable part.

After EASA AD 2022-0154 was issued, new occurrences were reported
on additional serial-numbered and part-numbered TR damper bracket
assemblies that were not included in the initial batch of affected
parts and it was determined that additional TR damper bracket
assemblies must also be inspected. Consequently, EASA issued EASA AD
2022-0205, dated October 4, 2022 (EASA AD 2022-0205), to retain the
requirements of EASA AD 2022-0154, which is superseded, expand the
definition of "affected part," and require the DVIs for all affected
parts.

In the NPRM, the FAA proposed to require accomplishing repetitive
DVIs of certain part-numbered TR damper bracket assemblies for
corrosion and cracks and, depending on the results, taking corrective
action. In the NPRM, the FAA also proposed to prohibit installing an
affected TR damper bracket assembly unless it is new. The FAA is
issuing this AD to address the unsafe condition on these products.

You may examine EASA AD 2022-0205 in the AD docket at
regulations.gov under Docket No. FAA-2024-0997.

Discussion of Final Airworthiness Directive

Comments

The FAA received a comment from one anonymous commenter. The
commenter supported the NPRM without change.

Conclusion

These products have been approved 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 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.

Related Material Under 1 CFR Part 51

EASA AD 2022-0205 requires repetitive DVIs of the TR damper bracket
assembly for cracks and corrosion. Depending on the results of these
inspections, EASA AD 2022-0205 requires removing any corrosion,
replacing any cracked part or a part which the corrosion cannot be
removed with a serviceable part, and reporting any discrepancies to
Leonardo. EASA AD 2022-0205 allows installing an affected part on any
helicopter, provided it is a serviceable part, which is an affected
part that is new. EASA AD 2022-0205 also allows installing any TR
damper bracket assembly that is not an affected 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 ADDRESSES section.

Other Related Material

The FAA also reviewed Leonardo Helicopters Alert Service Bulletin
No. 139-724, Revision B, dated September 29, 2022. This material
specifies procedures for inspecting and if necessary, replacing certain
part-numbered and serial-numbered TR damper bracket assemblies.

Differences Between This AD and EASA AD 2022-0205

EASA AD 2022-0205 requires reporting certain information to
Leonardo, whereas this AD does not.

Costs of Compliance

The FAA estimates that this AD affects 126 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.

A DVI of the TR damper bracket assembly takes approximately 1 work-
hour for an estimated cost of $85 per helicopter and up to $10,710 for
the U.S. fleet, per inspection cycle.

If required, removing corrosion from the TR damper bracket assembly
takes approximately 1 work-hour for an estimated cost of $85 per
helicopter.

If required, removing a TR damper bracket assembly and replacing it
with a serviceable part takes approximately 8 work-hours and parts cost
approximately $4,540 for an estimated cost of $5,220 per TR damper
bracket assembly.

The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some of the costs of this AD
may be covered under warranty, thereby reducing the cost impact on
affected operators.

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: