DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0689; Project Identifier AD-2020-01589-R;
Amendment 39-21898; AD 2022-02-01]
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 adopting a new airworthiness directive (AD)
for
certain Sikorsky Aircraft Corporation Model S-92A helicopters. This AD
was prompted by a cracked main rotor stationary swashplate assembly
(swashplate assembly). This AD requires visually inspecting the
swashplate assembly at specified intervals and depending on the
results, removing the swashplate assembly from service. The FAA is
issuing this AD to address the unsafe condition on these products.
DATES: This AD is effective February 18, 2022.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of February 18,
2022.
ADDRESSES: For service information identified in this final rule,
contact your local Sikorsky Field Representative or Sikorsky's Service
Engineering Group at Sikorsky Aircraft Corporation, Mailstop K100, 124
Quarry Road, Trumbull, CT 06611; telephone 1-800-946-4337 (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. It is also available
at https://www.regulations.gov by searching for and locating Docket No.
FAA-2021-0689.
Examining the AD Docket
You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-0689; 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 final rule, any
comments received, and other information. The address for Docket
Operations 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: Jared Hyman, Aerospace Engineer,
Boston ACO Branch, Compliance & Airworthiness Division, FAA, 1200
District Avenue, Burlington, Massachusetts 01803; telephone (781) 238-
7799; email: 9-AVS-AIR-BACO-COS@faa.gov.
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to certain Sikorsky
Aircraft Corporation Model S-92A helicopters. The NPRM published in the
Federal Register on August 23, 2021 (86 FR 47041). The NPRM was
prompted by a notification of an in-service crack in a swashplate
assembly inner ring. The crack, discovered during a routine inspection,
extended between the uniball bore and near the right-hand trunnion to
servo attach bolt hole. This condition, if not detected and corrected,
could result in fretting wear on the shoulder that supports the clamp-
up of the uniball outer race, failure of the swashplate assembly, and
subsequent loss of control of the helicopter. In the NPRM, the FAA
proposed to require, within 50 hours time-in-service (TIS), and
thereafter at intervals not to exceed 50 hours TIS, visually inspecting
the upper and lower surfaces of the swashplate assembly for a crack,
nick, dent, and scratch. If there is a crack, nick, dent, or scratch
that exceeds allowable limits, the NPRM proposed to require removing
the swashplate assembly from service before further flight. The FAA is
issuing this AD to address the unsafe condition on these products.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from one commenter; Sikorsky Aircraft.
Sikorsky Aircraft requested the FAA change the required inspections to
address the unsafe condition. The following presents the comments
received on the NPRM and the FAA's response to each comment.
Request for Changes to the Required Inspections
Sikorsky Aircraft requested the FAA change the repetitive
inspections proposed in the NPRM to more detailed repetitive
inspections. Sikorsky Aircraft stated that the 50-hour repetitive
inspections proposed in the NPRM are insufficient based on recent
fatigue evaluations, which have introduced a new failure mode. Sikorsky
Aircraft further stated that this new failure mode requires improved
detection capability, which will be introduced in a forthcoming
revision to ASB 92-62-009. Sikorsky Aircraft explained that the revised
ASB will specify directed special inspections at 50-hour, 375-hour, and
1,500-hour intervals to visually detect a potential fatigue crack at
specific regions of the swashplate and will include criteria for when
to accomplish a fluorescent penetrant inspection (FPI) or eddy-current
inspection.
The FAA appreciates that additional evaluations have been
accomplished and revised service information is forthcoming; however,
the FAA disagrees with changing the repetitive inspections proposed in
this NPRM at this time. The FAA reviewed the drafted ``Chapter 5 AMM
Revision--Inspection of the Main Rotor Swashplate Assembly'' submitted
as an attachment to Sikorsky Aircraft's comment and determined that the
preliminary data provided is not sufficient to substantiate Sikorsky
Aircraft's request to change the repetitive inspections proposed in the
NPRM. Therefore, it would be inappropriate for the FAA to delay
issuance of this rule in order to allow Sikorsky Aircraft Corporation
to release revised service information. Since an unsafe condition
exists, the FAA must issue an AD; however, in light of the new
information, the FAA has changed this AD action to be an interim action
and might consider further rulemaking if final action is later
identified.
Conclusion
The FAA reviewed the relevant data, considered any comments
received, and determined that air safety requires adopting this AD as
proposed. Accordingly, the FAA is issuing this AD to address the unsafe
condition on these products. Except for minor editorial changes, 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
The FAA reviewed Sikorsky S-92 Helicopter Alert Service Bulletin
ASB 92-62-009, Basic Issue, dated February 6, 2019 (ASB). The ASB
specifies a one-time visual inspection of the swashplate assembly to
determine if there are any cracks. If cracks are found, the ASB
specifies replacing the swashplate assembly. If there is any other
damage such as nicks, dents, or scratches, the ASB specifies providing
that damage information to Sikorsky Customer Service Engineering. The
ASB also specifies returning the swashplate assembly, uniball bearing,
trunnions, and all attachment hardware to Sikorsky for investigation if
cracks are found.
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.
Differences Between This AD and the Service Information
The ASB specifies a one-time visual inspection of the swashplate
assembly; this AD requires repetitive visual inspections of the
swashplate assembly to determine if any crack, nick, dent, or scratch
develops over time. This AD does not require returning parts to or
contacting Sikorsky, while the ASB specifies performing those actions.
Interim Action
The FAA considers this AD to be an interim action. If final action
is later identified, the FAA might consider further rulemaking then.
Costs of Compliance
The FAA estimates that this AD affects 89 helicopters of U.S.
Registry and that operators may incur the following costs in order to
comply with this AD. Labor costs are estimated at $85 per work-hour.
Visually inspecting a swashplate assembly takes about 0.5 work-
hour, for an estimated cost of $43 per helicopter
and $3,827 for the U.S. fleet, per inspection cycle.
Replacing the swashplate assembly, if required, takes about 16
work-hours and parts cost about $389,720, for an estimated cost of
$391,080 per helicopter.
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
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
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:
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