DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2020-0791; Project Identifier AD-2020-00676-R]
Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to adopt a new airworthiness directive
for certain Sikorsky Aircraft Corporation (Sikorsky) Model S-92A
helicopters. This proposed AD was prompted by the manufacturer
discovering non-conforming threads, resulting in a life limit reduction
on multiple landing gear components including threaded hinge pins and
main landing gear (MLG) and nose landing gear (NLG) actuator pins. This
proposed AD would require a one-time inspection of the landing gear for
components with non-conforming threads and removal of any
nonconforming threaded hinge pin and MLG and NLG actuator pin. 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
ADDRESSES: You may send comments, using the procedures found in
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow
instructions for submitting comments.
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
Aircraft Corporation, Commercial Systems and Services, 124 Quarry Road,
Trumbull, CT, 06611, United States; phone: (203) 416-4000; email:
email@example.com. Operators may also log on to the
Sikorsky 360 website at website: https://customerportal.sikorsky.com.
You may view the related 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-2020-0791;
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. Comments will be
available in the AD docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: Dorie Resnik, Aerospace Engineer,
Boston ACO Branch, Compliance & Airworthiness Division, FAA, 1200
District Avenue, Burlington, MA 01803; phone: (781) 238-7693; fax:
(781) 238-7199; email: firstname.lastname@example.org.
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-2020-0791;
Project Identifier AD-2020-00676-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 NPRM 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 FAA will also post a report summarizing each substantive
verbal contact received about this proposal.
Confidential Business Information
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, Boston ACO,
FAA, 1200 District Avenue, Burlington, MA 01803. Any commentary that
the FAA receives which is not specifically designated as CBI will be
placed in the public docket for this rulemaking.
The FAA proposes to adopt a new AD for Sikorsky Model S-92A
helicopters, with serial numbers (S/Ns) 920006 through 920334,
inclusive. The FAA learned of a quality escape involving the
manufacture of landing gear components, including the threaded hinge
pin and the MLG and NLG actuator pins, that were not made to
specification and have non-conforming threads that reduce the fatigue
life of the component. Failure of the threaded hinge pin or the
actuator pins on the MLG or NLG may result in collapse of the landing
gear and reduced ability of the flight crew to land the helicopter.
This proposed AD would require the removal from service of certain
serial-numbered threaded hinge pins part number (P/N) 92250-12281-101
and certain serial-numbered MLG and NLG actuator pins P/N 92250-12287-
101 and 92250-12287-103 identified in this proposed AD. This condition,
if not addressed, could result in failure of components on the MLG and
NLG, collapse of the landing gear and damage to the helicopter, and
reduced ability to control the helicopter during landing.
The FAA is issuing this NPRM because the agency evaluated all the
relevant information and determined the unsafe condition described
previously is likely to exist or develop in other products of the same
Related Service Information Under 1 CFR Part 51
The FAA reviewed Sikorsky Aircraft Corporation Alert Service
Bulletin 92-32-008, Basic Issue, dated January 21, 2020 ("the ASB").
The ASB describes procedures for a one-time inspection and replacement
of non-conforming components on the MLG and NLG. 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.
Proposed AD Requirements
This proposed AD would require a one-time inspection of the landing
gear and removal from service of threaded hinge pins and MLG and NLG
actuator pins with non-conforming threads.
Differences Between This Proposed AD and the Service Information
This proposed AD would require replacement of only affected hinge
pins and MLG and NLG actuator pins. The ASB requires replacement of
additional parts, such as the MLG and NLG crossbolt and the MLG and NLG
upper nut. The FAA has determined that the MLG and NLG crossbolt and
the MLG and NLG upper nut fail in a safe and contained manner and
therefore are not subject to this AD.
In addition, this proposed AD would require this one-time
inspection to occur within 300 hours time in service after the
effective date of this AD and any affected hinge pins and MLG and NLG
actuator pins be removed from service before further flight. The ASB
requires that the inspection and replacement of the affected hinge pins
and MLG and NLG actuator pins occur no later than January 21, 2021.
Costs of Compliance
The FAA estimates that this AD, as proposed, would affect 85
helicopters of U.S. registry.
The FAA estimates the following costs to comply with this proposed
||Cost per product
||Cost on U.S. operators
|Visually inspect landing gear
(right MLG assembly, left MLG assembly, and NLG kit).
||1 work-hour x $85 per hour =
$85 (per landing gear)
||$255 (three landing gear installed
on each helicopter)
The FAA estimates the following costs
to do any necessary
replacements that would be required based on the results of the
proposed inspection. The FAA has no way of determining the number of
helicopters that might need these replacements:
||Cost per product
|Replace threaded hinge pin, P/N
||1 work-hour x $85 per hour =
|Replace MLG/NLG actuator pin,
||1 work-hour x $85 = $85
|Replace MLG/NLG actuator pin,
||1 work-hour x $85 = $85
According to the manufacturer, 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
its 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.
The FAA has 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
For the reasons discussed above, I certify this proposed
(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
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