DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-1115; Product Identifier 2018-SW-065-AD]
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 two incidents of
erroneous low oil pressure caution cockpit indications and unintended
actuation of the main gearbox (MGB) auto bypass valve. This proposed AD
would require installing auxiliary circuit breaker modification (MOD)
kits and inserting a Rotorcraft Flight Manual (RFM) Supplement into the
RFM for your helicopter. 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 April 3, 2020.

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-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 on the internet at
https://www.regulations.gov by searching for and locating Docket No. FAA-2019-
1115; 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 regulatory evaluation, 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 FURTHER INFORMATION CONTACT: Michael Schwetz, Aviation Safety
Engineer, Boston ACO Branch, Compliance & Airworthiness Division, FAA,
1200 District Avenue, Burlington, MA 01803; telephone 781-238-7761;
email michael.schwetz@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 the ADDRESSES section. Include "Docket No. FAA-2019-1115;
Product Identifier 2018-SW-065-AD" at the beginning of your comments.
The FAA specifically invites comments on the overall regulatory,
economic, environmental, and energy aspects of this NPRM. The FAA will
consider all comments received by the closing date and may amend this
NPRM because of those comments.

The FAA will post all comments received, without change, to
https://www.regulations.gov, including any personal information you provide.
The FAA will also post a report summarizing each substantive verbal
contact received about this NPRM.

Discussion

The FAA proposes to adopt a new AD for Sikorsky Model S-92A
helicopters. This proposed AD is prompted by two incidents of erroneous
low oil pressure caution cockpit indications and unintended actuation
of the MGB auto bypass valve caused by unintended popping of the M XMSN
OIL WARN circuit breaker during flight. The root cause of this circuit
breaker popping is unknown. When this circuit breaker trips, the
following cautions will display "MGB PUMP 1 FAIL, MGB PUMP 2 FAIL, MGB
OIL HOT, MGB MAN COOL, MGB OIL PRES." With the MGB auto bypass valve
actuated, the MGB BYPASS caution will not annunciate. For the given
conditions, the appropriate action for the crew is "land as soon as
possible" in accordance with the RFM Emergency Procedures. The
erroneous indications conflicting with correct gauge readings may
overwhelm the flight crew, resulting in a forced landing of the
helicopter.

To address this unsafe condition, Sikorsky developed MOD kits based
on helicopter serial number (S/N) to introduce a separate circuit
breaker for the MGB last jet pressure switch. These MOD kits specify
reworking the overhead panel to install new clips and brackets, circuit
breaker wiring harnesses, wiring MODs, the auxiliary circuit breaker
panel, and the M XMSN PRESS SWITCH circuit breaker.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Sikorsky Special Service Instructions No. 92-121,
dated October 26, 2017 (SSI 92-121). This service information describes
procedures for installing an auxiliary circuit breaker panel MOD kit
and M XMSN PRESS SWITCH circuit breaker MOD kit based on helicopter S/N.

The FAA also reviewed RFM Supplement No. 45, Revision No. 2,
Sikorsky Model S-92A, Part 1, dated April 27, 2017 (S-92A RFMS 45, Part
1, Revision 2). This service information specifies operating
limitations, preflight checks, normal and emergency procedures, and
malfunction information for helicopters with Avionics Management System
version 7.1 or 8.0 with the MGB OIL OUT warning activated, pump failure
indicating system, MGB auto bypass, and M XMSN PRESS SWITCH circuit
breaker installed.

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 reviewed Sikorsky S-92 Helicopter Alert Service Bulletin
92-63-037, Revision A, dated March 1, 2018. This service information
contains planning information pertaining to the auxiliary circuit
breaker panel and M XMSN PRESS SWITCH circuit breaker MOD kits,
accomplishing SSI 92-121, and inserting S-92A RFMS 45, Part 1, Revision
2 into the helicopter cockpit.

FAA's Determination

The FAA is proposing this AD after evaluating all the relevant
information and determining that the unsafe condition described
previously is likely to exist or develop in other products of the same
type design.

Proposed AD Requirements

This proposed AD would require, within 400 hours time-in-service:

For helicopters S/N 920006 through 920296 inclusive,
installing an auxiliary circuit breaker panel and M XMSN PRESS SWITCH
circuit breaker by installing MOD Kit Clips and Brackets part number
(P/N) 92070-20115-015, MOD Kit Left Hand (LH) Cockpit Auxiliary Power
Unit P/N 92070-55096-012, MOD Kit LH Cabin Auxiliary Power Unit P/N
92070-55096-013, MOD Kit LH Top Deck FLD P/N 92070-55096-016, MOD Kit
MGB XMSN P/N 92070-55096-017, MOD Kit Auxiliary Circuit Break Panel P/N
92070-55075-011, and MOD Kit Auxiliary Cabin Panel Faceplate P/N 92070-
55075-012.

For helicopters S/N 920297 through 920304 inclusive and S/N
920311 through 920314 inclusive, modifying the auxiliary circuit
breaker panel and transmission harness and installing MOD Kit Auxiliary
Cabin Panel Faceplate P/N 92070-55075-012.

Inserting a copy of S-92A RFMS 45, Part 1, Revision 2 into
the RFM for your helicopter.

Costs of Compliance

The FAA estimates that this proposed AD affects 36 helicopters of
U.S. registry. The FAA estimate the following costs to comply with this
proposed AD. Labor costs are estimated at $85 per work-hour.

Modifying helicopters S/N 920006 through 920296 inclusive would
take about 48 work-hours and parts would cost about $1,618 for an
estimated cost of $5,698 per helicopter and $182,336 for the U.S. fleet
size of 32 helicopters.

Modifying helicopters S/N 920297 through 920304 inclusive and S/N
920311 through 920314 inclusive would take about 2 work-hours and parts
would cost about $65 for an estimated cost of $235 per helicopter and
$940 for the U.S. fleet size of 4 helicopters.

Revising the RFM would take about 0.5 work-hour for an estimated
cost of $43 per helicopter and $1,548 for the U.S. fleet.

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. 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.

The FAA prepared an economic evaluation of the estimated costs to
comply with this proposed AD and placed it in the AD docket.

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):