DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0554; Product Identifier 2016-SW-088-AD]
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 Leonardo S.p.a. (Leonardo) Model AB139 and AW139 helicopters. This
proposed AD would require removing certain main gearbox (MGB) input
modules from service. This proposed AD was prompted by the discovery
that a batch of duplex bearings, which are installed on the MGB input
modules, are defective. The actions of this proposed AD are intended to
address an unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by July 23,
2020.

ADDRESSES: You may send comments by any of the following methods:

Federal eRulemaking Docket: Go to https://www.regulations.gov. Follow the
online instructions for sending your comments electronically.

Fax: 202-493-2251.

Mail: Send comments to the U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590-0001.

Hand Delivery: Deliver to the "Mail" address between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Examining the AD Docket

You may examine the AD docket on the internet at https://
www.regulations.gov by searching for and locating Docket No. FAA-2020-
0554; or in person at the Docket Operations Office between 9 a.m. and 5
p.m., Monday through Friday, except Federal holidays. The AD docket
contains this proposed AD, the European Aviation Safety Agency (now
European Union Aviation Safety Agency) (EASA) AD, any comments
received, and other information. The street address for Docket
Operations is listed above. Comments will be available in the AD docket
shortly after receipt.

For service information identified in this proposed rule, contact
Leonardo S.p.a. Helicopters, 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 https://www.leonardocompany.
com/en/home. You may view the referenced service
information at the FAA, Office of the Regional Counsel, Southwest
Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 76177.

FOR FURTHER INFORMATION CONTACT: Rao Edupuganti, Aviation Safety
Engineer, Regulations and Policy Section, Rotorcraft Standards Branch,
FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-
5110; email rao.edupuganti@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to participate in this rulemaking by submitting
written comments, data, or views. The FAA also invites comments
relating to the economic, environmental, energy, or federalism impacts
that might result from adopting the proposals in this document. The
most helpful comments reference a specific portion of the proposal,
explain the reason for any recommended change, and include supporting
data. To ensure the docket does not contain duplicate comments,
commenters should send only one copy of written comments, or if
comments are filed electronically, commenters should submit only one
time.

The FAA will file in the docket all comments received, as well as a
report summarizing each substantive public contact with FAA personnel
concerning this proposed rulemaking. Before acting on this proposal,
the FAA will consider all comments received on or before the closing
date for comments. The FAA will consider comments filed after the
comment period has closed if it is possible to do so without incurring
expense or delay. The FAA may change this proposal in light of the
comments received.

Discussion

EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2016-0255R1, dated January 17, 2017
(EASA AD 2016-0255R1) to correct an unsafe condition for Leonardo
(formerly Finmeccanica S.p.A., AgustaWestland Philadelphia Corporation,
Agusta Aerospace Corporation) Model AB139 and AW139 helicopters with
certain serial-numbered MGB input modules part-number (P/N)
3K6320A00135 or P/N 3K6320A00136 installed. EASA advises that the
supplier of a batch of duplex bearings installed on MGB input modules
reported that the bearings were defective, due to a quality control
issue. This condition, if not detected or corrected, could lead to
damage of the input module duplex ball bearing inner race, possibly
resulting in loss of engine power and reduced control of the
helicopter. Accordingly, EASA AD 2016-0255R1 requires removing the
affected MGB input modules from service.

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 an
unsafe condition is likely to exist or develop on other helicopters of
the same type designs.

Related Service Information

The FAA reviewed Leonardo Helicopters Bollettino Tecnico No. 139-
303, dated September 20, 2016, which specifies replacing certain duplex
bearings on MGB left-hand and right-hand input modules on Model AB139
and AW139 helicopters.

Proposed AD Requirements

This proposed AD would require compliance with certain procedures
described in the manufacturer's service bulletin. For helicopters with
one affected MGB input module installed, this proposed AD would require
the affected MGB input module to be removed from service within 1200
hours time-in-service (TIS). For helicopters with two affected MGB
input modules installed, this proposed AD would require both affected
MGB input modules to be removed from service within 300 hours TIS.

Differences Between This Proposed AD and the EASA AD

The EASA AD requires returning affected parts and sending
information to Leonardo; however, this proposed AD would not.

Costs of Compliance

The FAA estimates that this proposed AD would affect 71 helicopters
of U.S. Registry. The FAA estimates that operators may incur the
following costs in order to comply with this AD. Labor costs are
estimated at $85 per work-hour.

Replacing one input module would require about 60 work-hours for an
estimated cost of $5,100 and parts would cost about $84,847 for an
estimated cost of $89,947 per helicopter.

Replacing two input modules would require about 100 work-hours for
an estimated cost of $8,500 and parts would cost about $169,694 for an
estimated cost of $178,194 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

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, I certify this proposed regulation:

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 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 (AD):