DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-0997; Project Identifier MCAI-2022-01306-R]
RIN 2120-AA64

Airworthiness Directives; Leonardo S.p.a. Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for all Leonardo S.p.a. Model AB139 and AW139 helicopters. This
proposed AD was prompted by multiple reports of cracks found on tail
rotor (TR) damper bracket assemblies. This proposed AD would require
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 proposed
AD would also prohibit 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 proposed for
incorporation by reference. The FAA is proposing this AD to address the
unsafe condition on these products.

DATES: The FAA must receive comments on this NPRM by May 28, 2024.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to regulations.gov. Follow
the instructions for submitting comments.
Fax: (202) 493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
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 NPRM, any comments received, and other
information. The street address for Docket Operations is listed above.
Material Incorporated by Reference:
For EASA material, contact EASA, Konrad-Adenauer-Ufer 3,
50668 Cologne, Germany; telephone +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 Service Information: For Leonardo Helicopters service
information, contact Leonardo S.p.A., Emanuele Bufano, Head of
Airworthiness, Viale G. Agusta 520, 21017 C. Costa di Samarate (Va)
Italy; telephone (+39) 0331-225074; fax (+39) 0331-229046; or at
customerportal.leonardocompany.com/en-US/. 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:

Comments Invited

The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2024-0997; Project Identifier
MCAI-2022-01306-R'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing
date and may amend this proposal because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
regulations.gov, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this NPRM.

Confidential Business Information

CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to
Sungmo Cho, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite
410, Westbury, NY 11590; phone: (781) 238-7241; email:
Sungmo.D.Cho@faa.gov. Any commentary that the FAA receives which is not
specifically designated as CBI will be placed in the public docket for
this rulemaking.

Background

EASA, which is the Technical Agent for the Member States of the
European Union, previously issued EASA AD 2022-0154, dated August 1,
2022 (EASA AD 2022-0154) for all serial-numbered Leonardo S.p.A. Model
AB139 and AW139 helicopters. EASA stated in AD 2022-0154 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), 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. See EASA AD 2022-0205 for additional background information.
The FAA is proposing this AD to detect and address corrosion or
cracks on the TR damper bracket assembly. The unsafe condition, if not
addressed, could result in an in-flight TR blade loss, unbalance or
damage to the tail or other parts of the helicopter, and subsequent
loss of control of the helicopter.

Related Service Information 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 Service Information

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

FAA's Determination

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 is proposing this AD
after evaluating all known relevant information and determining that
the unsafe condition described previously is likely to exist or develop
on other helicopters of the same type designs.

Proposed AD Requirements in This NPRM

This proposed AD would require accomplishing the actions specified
in EASA AD 2022-0205, described previously, as incorporated by
reference, except for any differences identified as exceptions in the
regulatory text of this proposed AD and except as discussed under
``Differences Between this Proposed AD and EASA AD 2022-0205.''

Explanation of Required Compliance Information

In the FAA's ongoing efforts to improve the efficiency of the AD
process, the FAA developed a process to use some civil aviation
authority (CAA) ADs as the primary source of information for compliance
with requirements for corresponding FAA ADs. The FAA has been
coordinating this process with manufacturers and CAAs. As a result, the
FAA proposes to incorporate EASA AD 2022-0205 by reference in the FAA
final rule. This proposed AD would, therefore, require compliance with
EASA AD 2022-0205 in its entirety through that incorporation, except
for any differences identified as exceptions in the regulatory text of
this proposed AD. Using common terms that are the same as the heading
of a particular section in EASA AD 2022-0205 does not mean that
operators need comply only with that section. For example, where the AD
requirement refers to ``all required actions and compliance times,''
compliance with this AD requirement is not limited to the section
titled ``Required Action(s) and Compliance Time(s)'' in EASA AD 2022-
0205. Service information referenced in EASA AD 2022-0205 for
compliance will be available at regulations.gov under Docket No. FAA-
2024-0997 after the FAA final rule is published.

Differences Between This Proposed AD and EASA AD 2022-0205

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

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 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 proposed AD.
A DVI of the TR damper bracket assembly would take 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
would take 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 would take approximately 8 work-hours and parts
would 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
proposed 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

The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 this proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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 Proposed Amendment

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