DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0304; Project Identifier 2017-SW-108-AD]
RIN 2120-AA64

Airworthiness Directives; Leonardo S.p.a. (Type Certificates
Previously Held by Agusta S.p.A. and AgustaWestland S.p.A.) Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for Leonardo S.p.a. (Type Certificate previously held by Agusta S.p.A.)
Model AB139 and AW139 helicopters and Leonardo S.p.a. (Type Certificate
previously held by AgustaWestland S.p.A.) Model AW189 helicopters. This
proposed AD was prompted by reports of missing lock wire and loose
fasteners. This proposed AD would require a one-time inspection of the
main rotor (M/R) slip ring and depending on the outcome, removing the
M/R slip ring from service, removing screws and washers from service,
applying torque, installing lock wire, and re-identifying the M/R slip
ring. This proposed AD would also prohibit the installation of certain
M/R slip rings. The FAA is proposing this AD to address the unsafe
condition on these products.

DATES: The FAA must receive comments on this proposed AD by June 3,
2021.

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 https://www.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 between 9 a.m. and
5 p.m., Monday through Friday, except Federal holidays.

For Leonardo Helicopters and Moog service information identified in
this NPRM, 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 this service information
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.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-0304; 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, the European
Aviation Safety Agency (now European Union Aviation Safety Agency)
(EASA) ADs, any comments received, and other information. The street
address for Docket Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Steven Warwick, Aerospace Engineer,
Certification Section, Fort Worth ACO Branch, Compliance &
Airworthiness Division, 10101 Hillwood Pkwy., Fort Worth, TX 76177;
telephone (817) 222-5225; email steven.r.warwick@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-2021-0304; Project Identifier
2017-SW-108-AD" 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
https://www.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
Steven Warwick, Aerospace Engineer, Certification Section, Fort Worth
ACO Branch, Compliance & Airworthiness Division, 10101 Hillwood Pkwy.,
Fort Worth, TX 76177; telephone (817) 222-5225; email
steven.r.warwick@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, has issued EASA AD 2017-0083, dated May 10, 2017 (EASA
AD 2017-0083), to correct an unsafe condition for Leonardo S.p.A.
(formerly Finmeccanica S.p.A, AgustaWestland S.p.A., Agusta S.p.A),
AgustaWestland Philadelphia Corporation (formerly Agusta Aerospace
Corporation) Model AB139 and AW139 helicopters, and EASA AD 2017-0087,
dated May 12, 2017 (EASA AD 2017-0087), to correct the same unsafe
condition for Leonardo S.p.A. Helicopters (formerly Finmeccanica S.p.A,
AgustaWestland S.p.A.) Model AW189 helicopters. EASA advises of reports
of missing lock wire and loose fasteners found during inspections of
the M/R slip ring of Model AW139 helicopters. EASA also advises that
the same part-numbered M/R slip ring may also be installed on Model
AW189 helicopters. Model AB139 helicopters may also be affected by this
unsafe condition due to having the same type design as Model AW139
helicopters. EASA ADs 2017-0083 and 2017-0087 require a one-time visual
inspection of the M/R slip ring fastener installation, and depending on
the outcome, replacing the M/R slip ring, replacing fasteners, applying
torque, installing lock wire, and re-identifying the M/R slip ring.
EASA ADs 2017-0083 and 2017-0087 also prohibit installation of an
affected M/R slip ring. EASA states, this condition, if not detected
and corrected, could lead to failure of the M/R slip ring bearing inner
race, possibly resulting in damage to drive system components and
subsequent reduced control of the helicopter.

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 of the
unsafe condition described in its ADs. 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 products of the
same type designs.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Leonardo Helicopters Alert Service Bulletin (ASB)
No. 139-472, dated May 9, 2017 (ASB 139-472), for Model AB139 and AW139
helicopters, and Leonardo Helicopters ASB No. 189-138, dated May 12,
2017 (ASB 189-138), for Model AW189 helicopters. ASB 139-472 and ASB
189-138 specify inspecting the M/R slip ring by following the
procedures in Moog Service Bulletin No. SB 16-01, Revision 5, undated
(SB 16-01), which is attached as Annex A to both ASB 139-472 and ASB
189-138. ASB 139-472 and ASB 189-138 are proposed for incorporation by
reference in this proposed AD. SB 16-01 is not proposed for
incorporation by reference in this proposed AD.

This service information 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 SB 16-01, which specifies procedures to
visually inspect the M/R slip ring upper (connecter) end and lower
(pigtail or standpipe) end fastener screws and double-twist lock wire.

Proposed AD Requirements in This NPRM

This proposed AD would require, with the M/R slip ring removed,
inspecting each screw and double-twist lock wire of the upper
(connecter) end and lower (pigtail or standpipe) end
fasteners of the M/R slip ring. Depending on the outcome, this proposed
AD would require:

Marking the M/R slip ring;

Removing the M/R slip ring from service; or

Removing screws and washers, lock wire, and ferrule ended
safety cable from service; installing new screws and washers; applying
torque; installing double-twist lock wire; and marking the M/R slip
ring.

This proposed AD would also prohibit the installation of an
affected M/R slip ring unless the proposed requirements have been
completed.

Differences Between This Proposed AD and the EASA ADs

EASA ADs 2017-0083 and 2017-0087 include the compliance time of at
the next M/R slip ring removal, whereas this proposed AD does not
because it could be difficult to track. This proposed AD has a shorter
compliance time for all affected M/R slip rings that have accumulated
900 or more total hours time-in-service, whereas EASA AD 2017-0087
allows a longer compliance time for these affected M/R slip rings that
are installed on Model AW189 helicopters. EASA ADs 2017-0083 and 2017-
0087 specify inspecting for the proper lock wire installed, while this
proposed AD specifies inspecting for correct installation of lock wire
0.20 CRES NAS 33540 part number MS20995C20 (double-twist lock wire) and
any missing double-twist lock wire. If a screw is missing from the
inner diameter (the connector flange) of the upper end of the M/R slip
ring, EASA ADs 2017-0083 and 2017-0087 specify replacing the M/R slip
ring with a serviceable part, whereas this proposed AD would require
removing the M/R slip ring from service instead. If a screw is missing
from the outer diameter of the upper end, from the inner diameter of
the lower end (shaft extension attachment area), or from the outer
diameter of the lower end, this proposed AD would require installing a
new screw and washer, applying torque, and installing lock wire,
whereas corrective action for this condition is not specified in EASA
AD 2017-0083 or 2017-0087.

Costs of Compliance

The FAA estimates that this proposed AD affects 134 helicopters of
U.S. Registry. The FAA estimates that operators may incur the following
costs in order to comply with this proposed AD. Labor costs are
estimated at $85 per work-hour.

Inspecting an M/R slip ring would take about 10 work-hours for an
estimated cost of $850 per helicopter and $113,900 for the U.S. fleet.
Marking an M/R slip ring would take a minimal amount of time and parts
would cost a nominal amount. Replacing an M/R slip ring would take
about 3 work-hours and parts would cost about $65,000 for an estimated
cost of $65,255 per helicopter. Removing any ferrule ended safety
cable; replacing screws and washers; applying torque; and installing
lock wire would take about 1 work-hour and parts would cost a nominal
amount for an estimated cost of $85 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) 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: