Document ID: FAA-2022-0146-0004
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Sikorsky Aircraft Corporation Helicopters
Posted Date: 2022-05-23T04:00Z

[Federal Register Volume 87, Number 99 (Monday, May 23, 2022)]
[Rules and Regulations]
[Pages 31125-31129]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-10952]

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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; 
Amendment 39-22054; AD 2022-11-04]
RIN 2120-AA64

Airworthiness Directives; Sikorsky Aircraft Corporation 
Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2020-26-
13, which applied to certain Sikorsky Aircraft Corporation (Sikorsky) 
Model S-92A helicopters. AD 2020-26-13 required 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 required repetitively inspecting certain 
parts, and depending on the inspection results, removing parts from 
service. Finally AD 2020-26-13 prohibited 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 AD retains certain requirements and the 
prohibition for installing certain stabilizer assemblies on any 
helicopter from AD 2020-26-13, corrects certain part numbers, and 
requires additional repetitive inspections. The actions of this AD are 
intended to address an unsafe condition on these products.

DATES: This AD is effective June 27, 2022.

[[Page 31126]]

    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of February 1, 
2021 (85 FR 84201, December 28, 2020).

ADDRESSES: For service information identified in this final rule, 
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. It is also available 
at https://www.regulations.gov by searching for and locating Docket No. 
FAA-2022-0146.

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov in 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 AD, any service 
information that is incorporated by reference, any comments received, 
and other information. The address for Docket Operations is U.S. 
Department of Transportation, Docket Operations, M-30, West Building 
Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 
20590.

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:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to supersede AD 2020-26-13, Amendment 39-21368 (85 FR 
84201, December 28, 2020) (AD 2020-26-13). AD 2020-26-13 applied to 
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. The NPRM 
published in the Federal Register on February 23, 2022 (87 FR 10115). 
The NPRM was prompted by the discovery that incorrect P/Ns were 
identified in the Applicability and the Required Actions paragraphs of 
AD 2020-26-13. Additionally, after the FAA issued AD 2020-26-13, 
Sikorsky notified the FAA that an additional repetitive inspection of 
certain parts of the stabilizer strut assembly is required to prevent 
the unsafe condition. Finally, after the FAA issued AD 2020-26-13, 
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.
    In the NPRM, the FAA proposed to expand the applicability of AD 
2020-26-13 by adding an additional part-numbered stabilizer assembly. 
The NPRM also proposed to correct paragraph (g)(4) of the Required 
Actions so that the installation of the titanium stabilizer strut 
fitting is terminating action for the 50-hour time-in-service (TIS) 
inspections of the aluminum stabilizer strut fitting. The NPRM also 
proposed to require an additional repetitive inspection of certain 
parts of the stabilizer strut assembly. Finally, the NPRM proposed to 
incorporate the FAA approved global AMOC.

Discussion of Final Airworthiness Directive

Comments

    The FAA received a comments from Sikorsky stating that in the 
section titled ``Actions Since AD 2020-26-13 Was Issued'' of the NPRM, 
the part number specified (92070-20117-04) is incorrect and should be 
92070-20117-041. The FAA acknowledges this comment; however, the part 
number is not used in the ``Background'' section of this final rule. In 
light of this, the commenter's request no longer applies.

Conclusion

    The FAA reviewed the relevant data, considered the comments 
received, and determined that air safety requires adopting the AD as 
proposed. Accordingly, the FAA is issuing this AD to address the unsafe 
condition on these products. Except for minor editorial changes, and 
any other changes described previously, this AD is adopted as proposed 
in the NPRM. None of the changes will increase the economic burden on 
any operator.

Related Service Information Under 1 CFR Part 51

    This AD continues 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 the ADDRESSES section.

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.

Differences Between This AD and the Service Information

    The service information requires returning affected parts to a 
Sikorsky specialist; this AD does not.

Costs of Compliance

    The FAA estimates that this AD affects 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 AD.
    Visually inspecting the stabilizer assembly and attached hardware 
takes 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 takes about 1 work-hour and parts cost about $10,000 for 
an estimated cost of $10,085 per replacement.

[[Page 31127]]

    If required, replacing the upper and lower support strut rod ends, 
including lug and conical fitting, takes about 1 work-hour and parts 
cost about $10,000 for an estimated cost of $10,085 per replacement.
    If required, replacing Mylar washers takes about 0.5 work-hour and 
parts cost about $76 for an estimated cost of $119 per replacement.
    If required, performing a fluorescent penetrant inspection takes 
about 3 work-hours for an estimated cost of $255 per inspection.
    If required, replacing a stabilizer assembly takes about 6 work-
hours and parts cost about $312,000 for an estimated cost of $312,510 
per replacement.
    If required, replacing a forward root fitting takes about 10 work-
hours and parts cost about $25,000 for an estimated cost of $25,850 per 
replacement.
    If required, replacing a stabilizer strut fitting takes about 10 
work-hours and parts 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 takes about 20 work-hours and parts cost about $50,000 for an 
estimated cost of $51,700 per replacement.
    If required, removing wear or corrosion and applying corrosion 
preventative compound takes about 0.5 work-hour and parts cost a 
nominal amount for an estimated cost of $43 per action.
    If required, replacing a stabilizer attachment bolt and barrel nut 
set takes about 1 work-hour and parts cost about $500 for an estimated 
cost of $585 per replacement.
    If required, replacing a fastener takes about 0.1 work-hour and 
parts 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 takes 
about 5 work-hours for an estimated cost of $425 per inspection.
    If required, applying alodine or equivalent and applying abrasion-
resistant Teflon coating takes 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 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 has determined that this AD will not have federalism 
implications under Executive Order 13132. This AD will 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 this AD:
    (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 Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 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:

2022-11-04 Sikorsky Aircraft Corporation: Amendment 39-22054; Docket 
No. FAA-2022-0146; Project Identifier AD-2021-00449-R.

(a) Effective Date

    This airworthiness directive (AD) is effective June 27, 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, 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,

[[Page 31128]]

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 
penetrant 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 paragraph (i) of this AD.
    (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.

(i) Related Information

    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].

(j) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (3) The following service information was approved for IBR on 
February 1, 2021 (85 FR 84201, December 28, 2020).

[[Page 31129]]

    (i) S-92 Maintenance Manual, SA S92A-AMM-000, Temporary Revision 
(TR) 55-33, dated March 24, 2020.
    (ii) [Reserved]
    (4) For Sikorsky Aircraft Corporation service information 
identified in this AD, 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.
    (5) You may view this service information at 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.
    (6) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on May 16, 2022.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2022-10952 Filed 5-20-22; 8:45 am]
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