Document ID: FAA-2022-0146-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Sikorsky Aircraft Corporation Helicopters
Posted Date: 2022-02-23T05:00Z

[Federal Register Volume 87, Number 36 (Wednesday, February 23, 2022)]
[Proposed Rules]
[Pages 10115-10119]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-03769]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0146; Project Identifier AD-2021-00449-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 supersede Airworthiness Directive (AD) 
2020-26-13, which applies to certain Sikorsky Aircraft Corporation 
(Sikorsky) Model S-92A helicopters. AD 2020-26-13 requires establishing 
the life limit for certain part-numbered horizontal stabilizer root 
fittings FWD (forward root fittings) and certain part-numbered 
stabilizer strut fittings. AD 2020-26-13 also requires repetitively 
inspecting certain parts, and depending on the inspection results, 
removing parts from service. Finally AD 2020-26-13 prohibits installing 
certain stabilizer assemblies on any helicopter. Since the FAA issued 
AD 2020-26-13, the manufacturer notified the FAA that due to an error 
in the service information, certain part numbers in AD 2020-26-13 are 
incorrect. Also, the FAA determined that additional inspections are 
required to address the unsafe condition. This proposed AD would retain 
certain requirements and the prohibition for installing certain 
stabilizer assemblies on any helicopter from AD 2020-26-13 and would 
correct certain part numbers and require additional repetitive 
inspections. 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 11, 
2022.

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 Sikorsky's 
Engineering Group at Sikorsky Aircraft Corporation, 124 Quarry Road, 
Trumbell, CT 06611, United States; phone: (800) 946-4337; email: 
[email protected]; website: 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-2022-0146; 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: Dorie Resnik, Aerospace Engineer, 
Aviation Safety Section, Boston ACO Branch, Compliance & Airworthiness 
Division, 1200 District Avenue, Burlington, MA 01803; telephone (781) 
238-7693; email [email protected].

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-2022-0146; Project Identifier 
AD-2021-00449-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 
the 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 proposed AD.

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 Dorie 
Resnik, Aerospace Engineer, Aviation Safety Section, Boston ACO Branch, 
Compliance & Airworthiness Division, 1200 District Avenue, Burlington, 
MA 01803; telephone (781) 238-7693; email [email protected]. 
Any commentary that the FAA receives which is not specifically 
designated as CBI will be placed in the public docket for this 
rulemaking.

[[Page 10116]]

Background

    The FAA issued AD 2020-26-13, Amendment 39-21368 (85 FR 84201, 
December 28, 2020) (AD 2020-26-13) for Sikorsky Model S-92A helicopters 
with forward root fitting part number (P/N) 92209-07111-101 or 92070-
20125-101; or stabilizer strut fitting P/N 92209-07404-041, 92209-
07403-041, or 92070-20117-041 installed on horizontal stabilizer 
assembly (stabilizer assembly) P/N 92070-20117-045, 92070-20117-046, 
92070-20125-041, 92070-20125-042, 92070-20125-043, 92070-20125-044, 
92205-07400-043, or 92205-07400-045. AD 2020-26-13 was prompted by 
seven incidents of fatigue cracks in forward root fittings. Fatigue 
cracking in a forward root fitting degrades the load path and increases 
the load on other assembly parts, particularly at the aft horizontal 
stabilizer attachment points; therefore AD 2020-26-13 requires 
determining the total hours time-in-service (TIS) of the forward root 
fitting and the stabilizer strut fitting, establishing a life limit of 
7,900 total hours TIS for certain part-numbered forward root fittings, 
and establishing a life limit of 19,100 total hours TIS for certain 
stabilizer strut fittings. For certain part-numbered stabilizer strut 
fittings, AD 2020-26-13 also requires repetitive inspections of certain 
parts of an affected stabilizer strut assembly. The FAA issued AD 2020-
26-13 to prevent a forward root fitting from remaining in service 
beyond its life limit and to detect fatigue cracking in a forward root 
fitting and prevent increased load and stress cracking in the 
stabilizer root fitting aft.

Actions Since AD 2020-26-13 Was Issued

    Since the FAA issued AD 2020-26-13, Sikorsky notified the FAA that 
incorrect P/Ns are identified in the Applicability and the Required 
Actions paragraphs of AD 2020-26-13. This NPRM would expand the 
applicability of AD 2020-26-13 by adding an additional part-numbered 
stabilizer assembly. This NPRM would correct paragraph (g)(4) of the 
Required Actions so that the installation of the titanium stabilizer 
strut fitting P/N 92209-07404-041 is terminating action for the 50-hour 
TIS inspections of the aluminum stabilizer strut fitting P/N 92070-
20117-04 or 92209-07403-041.
    Sikorsky also notified the FAA that an additional repetitive 
inspection of certain parts of the stabilizer strut assembly is 
required to prevent the unsafe condition; this NPRM includes this 
repetitive inspection. Additionally, since AD 2020-26-13 was issued, 
Sikorsky requested and the FAA approved a global Alternative Method of 
Compliance (AMOC) to allow only removing parts from service that are 
cracked, corroded, or have fretting, deformation, or wear rather than 
require removing the upper and lower support strut rod ends, including 
lug and conical fitting and both upper and lower attachment fittings on 
the stabilizer from service. This NPRM incorporates that global AMOC 
into the proposed requirements.

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

    This proposed AD would continue to require S-92 Maintenance Manual, 
SA S92A-AMM-000, Temporary Revision (TR) 55-33, dated March 24, 2020 
(TR 55-33), which the Director of the Federal Register approved for 
incorporation by reference as of February 1, 2021 (85 FR 84201, 
December 28, 2020).
    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.

Other Related Service Information

    The FAA reviewed S-92 Maintenance Manual SA S92A-AWL-000, TR No. 4-
58, dated October 2, 2017 (TR 4-58), and S-92 Maintenance Manual SA 
S92A-AWL-000, TR No. 4-66 dated November 20, 2019 (TR 4-66). This 
service information revises Task 4-00-00-200-000, Table 1 Replacement 
Schedule, dated November 30, 2015. Both TR 4-58 and 4-66 revise the 
Airworthiness Limitations Schedule by removing certain part-numbered 
components, introducing new part-numbered components, and establishing 
replacement intervals and recurring inspections for the forward root 
fitting and the horizontal stabilizer strut fitting. TR 4-58 also 
specifies inspecting the horizontal stabilizer and attaching hardware 
at a recurring interval of 250 hours TIS.

Proposed AD Requirements in This NPRM

    This proposed AD would require determining the total hours TIS of 
the forward root fitting and the stabilizer strut fitting. This 
proposed AD would also require establishing a life limit of 7,900 total 
hours TIS for certain part-numbered forward root fittings and 
establishing a life limit of 19,100 total hours TIS for stabilizer 
strut fitting P/N 92070-20117-041. Finally, this proposed AD would 
require for certain part-numbered stabilizer strut fittings installed, 
repetitively visually inspecting the following at intervals not to 
exceed 50 hours TIS:
     The hat bushing and both upper and lower fittings for a 
crack, corrosion, fretting, deformation, and wear.
     Both upper and lower support strut rod ends, including 
each lug and conical fitting, and both upper and lower attachment 
fittings on the stabilizer and pylon, including the bushings, for a 
crack, corrosion, fretting, deformation, and wear.
     The surface of each Mylar washer P/N 92070-20117-104 on 
certain stabilizer assemblies.
    This proposed AD would also require repetitively inspecting the 
following at intervals not to exceed 250 hours TIS or one year, 
whichever occurs first:
     Each stabilizer attachment bolt and barrel nut set for 
corrosion, a crack, and damage to the threads indicated by uneven 
threads, missing threads, or cross-threading.
     Each forward root fitting and aft attachment fitting, 
including inspecting the bolt holes and fastener holes for a crack, 
wear, and corrosion; or as an alternative to detect any crack, 
fluorescent penetrant inspecting (FPI) the area.
     Each forward and aft attachment fitting mating surface for 
wear of the abrasion-resistant Teflon coating and degradation. For the 
purposes of this inspection, degradation may be indicated by fretting. 
If there is any wear of the coating or fretting, this proposed AD would 
require stripping the coating and performing a FPI or eddy current 
inspection to inspect for a crack. If there is no crack, this proposed 
AD would require recoating the surfaces.
    Depending on the inspection results, this proposed AD would require 
removing parts from service before further flight.
    Finally, this proposed AD would prohibit installing stabilizer 
assembly P/N 92205-07400-043, 92205-07400-045, and 92205-07400-047 on 
any helicopter.

Differences Between This Proposed AD and the Service Information

    The service information specifies that returning affected parts to 
a Sikorsky specialist is required; whereas this proposed AD would not 
include this requirement.

[[Page 10117]]

Costs of Compliance

    The FAA estimates that this proposed AD would affect 82 helicopters 
of U.S. registry. Labor costs are estimated at $85 per work-hour. Based 
on these numbers, the FAA estimates the following costs to comply with 
this proposed AD.
    Visually inspecting the stabilizer assembly and attached hardware 
would take about 3 work-hours for an estimated cost of $255 per 
helicopter and $20,910 for the U.S. fleet per inspection cycle.
    If required, replacing a hat bushing and both upper fittings and 
lower fittings would take about 1 work-hour and parts would cost about 
$10,000 for an estimated cost of $10,085 per replacement.
    If required, replacing the upper and lower support strut rod ends, 
including lug and conical fitting, would take about 1 work-hour and 
parts would cost about $10,000 for an estimated cost of $10,085 per 
replacement.
    If required, replacing Mylar washers would take about 0.5 work-hour 
and parts would cost about $76 for an estimated cost of $119 per 
replacement.
    If required, performing a fluorescent penetrant inspection would 
take about 3 work-hours for an estimated cost of $255 per inspection.
    If required, replacing a stabilizer assembly would take about 6 
work-hours and parts would cost about $312,000 for an estimated cost of 
$312,510 per replacement.
    If required, replacing a forward root fitting would take about 10 
work-hours and parts would cost about $25,000 for an estimated cost of 
$25,850 per replacement.
    If required, replacing a stabilizer strut fitting would take about 
10 work-hours and parts would cost about $10,000 for an estimated cost 
of $10,850 per replacement.
    If required, replacing a forward root fitting and an aft attachment 
fitting would take about 20 work-hours and parts would cost about 
$50,000 for an estimated cost of $51,700 per replacement.
    If required, removing wear or corrosion and applying corrosion 
preventative compound would take about 0.5 work-hour and parts would 
cost a nominal amount for an estimated cost of $43 per action.
    If required, replacing a stabilizer attachment bolt and barrel nut 
set would take about 1 work-hour and parts would cost about $500 for an 
estimated cost of $585 per replacement.
    If required, replacing a fastener would take about 0.1 work-hour 
and parts would cost a nominal amount for an estimated cost of $9 per 
fastener.
    If required, removing the abrasion-resistant Teflon coating to 
inspect each forward and aft attachment fitting mating surface would 
take about 5 work-hours for an estimated cost of $425 per inspection.
    If required, applying alodine or equivalent and applying abrasion-
resistant Teflon coating would take about 5 work hours with minimal 
parts cost for an estimated cost of $425 per application.
    According to Sikorsky, some of the costs of this proposed AD may be 
covered under warranty, thereby reducing the cost impact on affected 
individuals. The FAA does not control warranty coverage for affected 
individuals. As a result, the FAA has included all costs in this cost 
estimate.

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 that the 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

0
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]

0
2. The FAA amends Sec.  39.13 by:
0
a. Removing Airworthiness Directive AD 2020-26-13, Amendment 39-21368 
(85 FR 84201, December 28, 2020); and
0
b. Adding the following new airworthiness directive:

Sikorsky Aircraft Corporation: Docket No. FAA-2022-0146; Project 
Identifier AD-2021-00449-R.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) action by April 11, 2022.

(b) Affected ADs

    This AD replaces AD 2020-26-13, Amendment 39-21368 (85 FR 84201, 
December 28, 2020) (AD 2020-26-13).

(c) Applicability

    This AD applies to Sikorsky Aircraft Corporation Model S-92A 
helicopters, certificated in any category, with the following 
installed: Horizontal stabilizer root fitting FWD (forward root 
fitting) part number (P/N) 92209-07111-101 or 92070-20125-101; or 
stabilizer strut fitting P/N 92209-07403-041 or 92070-20117-041 
installed on horizontal stabilizer assembly (stabilizer assembly) P/
N 92070-20117-045, 92070-20117-046, 92070-20125-041, 92070-20125-
042, 92070-20125-043, 92070-20125-044, 92205-07400-043, 92205-07400-
045, or 92205-07400-047.

(d) Subject

    Joint Aircraft System Component (JASC) Code 5510, Horizontal 
Stabilizer Structure.

(e) Unsafe Condition

    This AD was prompted by incidents of fatigue cracks in a forward 
root fitting and life limit recalculations for forward root fitting 
P/N 92209-07111-101 and 92070-20125-101. The FAA is issuing this AD 
to prevent a forward root fitting from remaining in service beyond 
its life limit, detect fatigue cracking in a forward root fitting, 
and prevent increased load and stress cracking in the stabilizer 
root fitting aft. The unsafe condition, if not addressed, could 
result in failure of a stabilizer root fitting, separation of the 
stabilizer assembly from the helicopter,

[[Page 10118]]

and subsequent loss of control of the helicopter.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    (1) Within 50 hours time-in-service (TIS) after the effective 
date of this AD:
    (i) Determine the total hours TIS of the forward root fitting P/
N 92209-07111-101 or 92070-20125-101. If the total hours TIS of the 
forward root fitting is unknown, use the total hours TIS of the 
stabilizer assembly instead.
    (A) If the forward root fitting has accumulated 7,900 or more 
total hours TIS, before further flight, remove the forward root 
fitting from service.
    (B) If the forward root fitting has accumulated less than 7,900 
total hours TIS, before exceeding 7,900 total hours TIS, remove the 
forward root fitting from service.
    (ii) Thereafter following paragraph (g)(1)(i) of this AD, remove 
the forward root fitting from service before accumulating 7,900 
total hours TIS.
    (iii) For stabilizer assemblies with stabilizer strut fitting P/
N 92070-20117-041 installed, perform the following actions:
    (A) Determine the total hours TIS of stabilizer strut fitting P/
N 92070-20117-041.
    (B) If the stabilizer strut fitting has accumulated 19,100 or 
more total hours TIS, before further flight, remove the stabilizer 
strut fitting from service.
    (C) If the stabilizer strut fitting has accumulated less than 
19,100 total hours TIS, before exceeding 19,100 total hours TIS, 
remove the stabilizer strut fitting from service.
    (iv) Thereafter following paragraph (g)(1)(iii) of this AD, 
remove the stabilizer strut fitting from service before accumulating 
19,100 total hours TIS.
    (2) For helicopters with stabilizer strut fitting P/N 92070-
20117-041 or 92209-07403-041 installed, within 50 hours TIS after 
the effective date of this AD and thereafter at intervals not to 
exceed 50 hours TIS:
    (i) Remove the support strut and using a cheese cloth (or 
similar cloth) and isopropyl alcohol, clean the upper and lower 
support strut rod ends, horizontal stabilizer attachment fitting, 
and the tail rotor pylon attachment fitting.
    (ii) If installed, visually inspect the surface of each Mylar 
washer P/N 92070-20117-104 (Mylar washer). The surface should be 
smooth and continuous. If there is any visible damage such as any 
tear or scrape, remove the Mylar washer from the peelable-ply washer 
P/N 92070-20117-105 (peelable-ply washer) and remove the Mylar 
washer from service as follows:
    (A) Dampen a low-lint cloth with 3M 6041 adhesive remover and 
place on the top of the Mylar washer.
    (B) Allow the adhesive remover to soften the Mylar washer and 
peel the Mylar washer back.
    (C) Repeat with more solvent until the Mylar washer and adhesive 
are removed.
    (D) Clean the peelable-ply washer with cheese cloth moistened 
with isopropyl alcohol and adhere a new Mylar washer to the 
peelable-ply washer.
    Note 1 to paragraph (g)(2)(ii): Stabilizer assembly P/Ns 92070-
20125-041, 92070-20125-042, 92070-20125-043, and 92070-20125-044 do 
not utilize the Mylar washer. The inspection of the Mylar washer is 
not required on helicopters with stabilizer assembly P/N 92070-
20125-041, 92070-20125-042, 92070-20125-043, or 92070-20125-044 
installed.
    (iii) Using a 10X or higher power magnifying glass, a 
flashlight, and a mirror, visually inspect the hat bushing and both 
upper fittings and lower fittings for a crack, corrosion, fretting, 
deformation, and wear. If there is a crack, corrosion, fretting, 
deformation, or wear on any part, before further flight, remove the 
part from service.
    (iv) Using a 10X or higher power magnifying glass, a flashlight, 
and a mirror, visually inspect both upper and lower support strut 
rod ends, including each lug and conical fitting, and both upper and 
lower attachment fittings on the stabilizer and pylon including the 
bushings for a crack, corrosion, fretting, deformation, and wear. If 
there is a crack, corrosion, fretting, deformation, or wear on any 
part, before further flight, remove the part from service.
    (3) Within 250 hours TIS or one year, whichever occurs first 
after the effective date of this AD, and thereafter at intervals not 
to exceed 250 hours TIS or one year, whichever occurs first:
    (i) Remove the stabilizer assembly and visually inspect each 
stabilizer attachment bolt and barrel nut set for corrosion, a 
crack, and damage to the threads. For the purposes of this 
inspection, damage may be indicated by uneven threads, missing 
threads, or cross-threading.
    (A) If there is corrosion within allowable limits, before 
further flight, treat for corrosion in accordance with FAA-approved 
procedures.
    (B) If there is corrosion that exceeds allowable limits, or a 
crack, or damage to the threads, before further flight, remove the 
bolt and barrel nut set from service.
    (ii) Inspect the forward root fitting and the aft attachment 
fitting by:
    (A) Gaining access to the inside of the horizontal stabilizer.
    (B) Using Brulin Cleaner SD 1291 (or equivalent) and a low-lint 
cloth, remove all traces of sealing compound, oil, and dirt from the 
stabilizer mounting surfaces.
    (C) Using a 10X or higher magnifying glass, inspect for any 
crack, wear, and corrosion.
    (1) If there is a crack, before further flight, remove the 
affected forward root fitting and the affected aft attachment 
fitting from service.
    (2) If there is wear or corrosion that exceeds allowable limits, 
before further flight, remove the affected forward root fitting and 
the affected aft attachment fitting from service.
    (3) If there is wear or corrosion within allowable limits, 
before further flight, treat for corrosion in accordance with FAA-
approved procedures.
    (D) Visually inspect each attachment fitting bolt hole and 
fastener hole for a crack, wear, and corrosion.
    (1) If there is a crack, before further flight, remove the 
affected forward root fitting and the affected aft attachment 
fitting from service.
    (2) If there is wear or corrosion that exceeds allowable limits, 
before further flight, remove the affected forward root fitting and 
the affected aft attachment fitting from service.
    (3) If there is wear or corrosion within allowable limits, 
before further flight, treat for corrosion in accordance with FAA 
approved procedures.
    (E) Inspect for loose or working fasteners. If there is a loose 
or working fastener, before further flight, remove the fastener from 
service.
    (iii) As an alternative means to inspect for cracks in 
paragraphs (g)(3)(i) and (ii) of this AD, perform a florescent 
penetrate inspection (FPI).
    (iv) Visually inspect each forward and aft attachment fitting 
mating surface for wear of the abrasion-resistant Teflon coating and 
degradation. For the purposes of this inspection, degradation may be 
indicated by fretting. Refer to Figure 204, of S-92 Maintenance 
Manual, SA S92A-AMM-000, Temporary Revision 55-33, Task 55-11-01-
210-004, dated March 24, 2020 (TR 55-33), for a depiction of the 
area to be inspected. For the purposes of this inspection, wear may 
be indicated by less than 100% coverage of the abrasion-resistant 
Teflon coating. If there is wear to the abrasion-resistant Teflon 
coating or degradation, before further flight:
    (A) Chemically strip the abrasion-resistant Teflon coating from 
the entire mounting pad in accordance with paragraph 7.A.(7)(a) of 
TR 55-33.
    (B) FPI or eddy current inspect for a crack. If there is a 
crack, before further flight, remove the stabilizer assembly from 
service.
    (C) If there is no crack, treat the affected area by applying 
alodine or equivalent. Apply abrasion-resistant Teflon coating in 
accordance with paragraphs 7.A.(7)(d) through (e) of TR 55-33.
    (4) Installing stabilizer strut fitting P/N 92209-07404-041 is a 
terminating action for the requirements in paragraph (g)(2) of this 
AD.
    (5) As of the effective date of this AD, do not install 
stabilizer assembly P/N 92205-07400-043, 92205-07400-045, or 92205-
07400-047 on any helicopter.

(h) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Boston ACO Branch, FAA, has the authority to 
approve AMOCs for this AD, if requested using the procedures found 
in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request 
to your principal inspector or local Flight Standards District 
Office, as appropriate. If sending information directly to the 
manager of the certification office, send it to the attention of the 
person identified in Related Information.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

[[Page 10119]]

 (i) Related Information

    (1) For more information about this AD, contact Dorie Resnik, 
Aerospace Engineer, Boston ACO Branch, 1200 District Avenue, 
Burlington, Massachusetts 01803; telephone 781-238-7693; email [email protected].
    (2) For service information identified in this AD, contact 
Sikorsky's Engineering Group Sikorsky Aircraft Corporation, 124 
Quarry Road, Trumbell, CT, 06611, United States; phone: (800) 946-
4337; email: [email protected]; website: 
www.sikorsky360.com. You may view this referenced 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.

    Issued on February 16, 2022.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-03769 Filed 2-22-22; 8:45 am]
BILLING CODE 4910-13-P