DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0689; Project Identifier AD-2020-01589-R]
RIN 2120-AA64

Airworthiness Directives; Sikorsky Aircraft Corporation
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 certain Sikorsky Aircraft Corporation (Sikorsky) Model S-92A
helicopters. This proposed AD was prompted by a cracked main rotor
stationary swashplate assembly (swashplate assembly). This proposed AD
would require visually inspecting the swashplate assembly at specified
intervals and depending on the results, removing the swashplate
assembly from service. 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 October 7, 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 above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this NPRM, contact your local
Sikorsky Field Representative or Sikorsky's Service Engineering Group
at Sikorsky Aircraft Corporation, 124 Quarry Road, Trumbull, CT 06611;
telephone 1-800-946-4337 (1-800-Winged-S); email
wcs_cust_service_eng.gr-sik@lmco.com. Operators may also log on to the
Sikorsky 360 website at https://www.sikorsky360.com. 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-2021-0689; 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.

FOR FURTHER INFORMATION CONTACT: Jared Hyman, Aerospace Engineer,

Boston ACO Branch, Compliance & Airworthiness Division, FAA, 1200
District Avenue, Burlington, Massachusetts 01803; telephone 781-238-
7799; email: Jared.M.Hyman@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-2021-0689; Project Identifier
AD-2020-01589-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
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 Jared
Hyman, Aerospace Engineer, Boston ACO Branch, Compliance &
Airworthiness Division, FAA, 1200 District Avenue, Burlington,
Massachusetts 01803; telephone 781-238-7799; email:
Jared.M.Hyman@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

The FAA was notified of an in-service crack in a swashplate
assembly inner ring. The crack, discovered during a routine inspection,
extended between the uniball bore and near the right-hand trunnion to
servo attach bolt hole. This condition, if not detected and corrected,
could result in fretting wear on the shoulder that supports the clamp-
up of the uniball outer race, failure of the swashplate assembly, and
subsequent loss of control of the helicopter.

FAA's Determination

The FAA is issuing this NPRM after determining that the unsafe
condition described previously is likely to exist or develop on other
products of the same type design.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Sikorsky Aircraft Corporation Alert Service
Bulletin ASB 92-62-009, Basic Issue, dated February 6, 2019 (ASB). The
ASB specifies a one-time visual inspection of the swashplate assembly
to determine if there are any cracks. If cracks are found, the ASB
specifies replacing the swashplate assembly. If there is any other
damage such as nicks, dents, or scratches, the ASB specifies providing
that damage information to Sikorsky. The ASB also specifies returning
the swashplate assembly, uniball bearing, trunnions, and all attachment
hardware to Sikorsky for investigation if cracks are found. 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 ADDRESSES.

Proposed AD Requirements in This NPRM

This proposed AD would require, within 50 hours time-in-service
(TIS), and thereafter at intervals not to exceed 50 hours TIS, visually
inspecting the upper and lower surfaces of the swashplate assembly for
a crack, nick, dent, and scratch. If there is a crack, nick, dent, or
scratch that exceeds allowable limits, this proposed AD would require
removing the swashplate assembly from service before further flight.

Differences Between This Proposed AD and the Service Information

The ASB specifies a one-time visual inspection of the swashplate
assembly; this proposed AD would require repetitive visual inspections
of the swashplate assembly to determine if any crack, nick, dent, or
scratch develops over time. This proposed AD would not require
returning parts to or contacting Sikorsky, while the ASB specifies
performing those actions.

Costs of Compliance

The FAA estimates that this AD would affect 89 helicopters of U.S.
Registry and that operators may incur the following costs in order to
comply with this proposed AD. Labor costs are estimated at $85 per
work-hour.

Visually inspecting a swashplate assembly would take about 0.5
work-hour, for an estimated cost of $43 per helicopter and $3,827 for
the U.S. fleet, per inspection cycle.

Replacing the swashplate assembly, if required, would take about 16
work-hours and parts would cost about $389,720, for an estimated cost
of $391,080 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 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: