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]
Airworthiness Directives; Sikorsky Aircraft Corporation
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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.
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@example.com; 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.
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
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 9-AVS-AIR-BACO-COS@faa.gov.
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
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.
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
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
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.
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
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
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
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.
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
(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
Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 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:
a. Removing Airworthiness Directive AD 2020-26-13, Amendment 39-21368
(85 FR 84201, December 28, 2020); and
b. Adding the following new airworthiness directive: