Document ID: FAA-2010-0720-0007
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Sikorsky Aircraft Corporation (Sikorsky) Helicopters
Posted Date: 2021-03-15T04:00Z

[Federal Register Volume 86, Number 48 (Monday, March 15, 2021)]
[Proposed Rules]
[Page 14293]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-05194]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0720; Project Identifier 2010-SW-050-AD]
RIN 2120-AA64

Airworthiness Directives; Sikorsky Aircraft Corporation 
(Sikorsky) Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Proposed rule; withdrawal.

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SUMMARY: The FAA is withdrawing a notice of proposed rulemaking (NPRM) 
that proposed to adopt a new airworthiness directive (AD) that would 
have applied to certain Sikorsky Model S-92A helicopters. The NPRM was 
prompted by a fatigue analysis conducted after a helicopter was found 
with a severed main gearbox (MGB) mounting foot pad (foot pad) that 
failed due to fatigue. The NPRM would have required revising the 
airworthiness limitations section of the existing Instructions for 
Continued Airworthiness (ICA) for your helicopter to reduce the life 
limit of the MGB housing and replacing any MGB housing that exceeds the 
life limit. Since issuance of the NPRM, the FAA has determined that the 
affected MGB housings are no longer in service. Accordingly, the NPRM 
is withdrawn.

DATES: The FAA is withdrawing the proposed rule published July 21, 2010 
(75 FR 42340), as of March 15, 2021.

ADDRESSES:

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-2010-
0720; 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 action, any comments received, and other information. The 
street 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: Michael Schwetz, Aerospace Engineer, 
Aviation Safety Section, Boston ACO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: 781-238-7761; email: 
michael.schwetz@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    The FAA has issued an NPRM that proposed to amend 14 CFR part 39 by 
adding an AD that would apply to the specified products. The NPRM was 
published in the Federal Register on July 21, 2010 (75 FR 42340). The 
NPRM was prompted by a fatigue analysis conducted after a helicopter 
was found with a severed foot pad that failed due to fatigue.
    The NPRM proposed to require revising the existing airworthiness 
limitations section of the ICA for your helicopter to reduce the life 
limit of the MGB housing and replacing any MGB housing that exceeds the 
life limit. The proposed actions were intended to address failure of 
the foot pad, loss of the MGB, and subsequent loss of control of the 
helicopter.

Actions Since the NPRM Was Issued

    Since issuance of the NPRM, the FAA has determined that the 
affected MGB housings are no longer in service and the identified 
unsafe condition no longer exists. Therefore, the FAA has determined 
that AD action is not appropriate.
    Withdrawal of the NPRM constitutes only such action and does not 
preclude the FAA from further rulemaking on this issue, nor does it 
commit the FAA to any course of action in the future.

Comments

    The FAA gave the public the opportunity to comment on the NPRM. The 
following presents the comments received on the NPRM and the FAA's 
response to each comment.

Request To Clarify Certain Language in the NPRM

    Sikorsky Aircraft requested that the FAA clarify certain language 
in the NPRM.
    The FAA acknowledges that, in the event of publication of a final 
rule, Sikorsky Aircraft's request would have been valuable in 
clarifying the language. However, this NPRM will not be published as a 
final rule. The FAA has determined that the affected MGB housings are 
no longer in service, and that the NPRM is no longer necessary.

FAA's Conclusions

    Upon further consideration, the FAA has determined that the NPRM is 
unnecessary. Accordingly, the NPRM is withdrawn.

Regulatory Findings

    Since this action only withdraws an NPRM, it is neither a proposed 
nor a final rule. This action therefore is not covered under Executive 
Order 12866, the Regulatory Flexibility Act, or DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979).

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Withdrawal

    Accordingly, the notice of proposed rulemaking, Docket No. FAA-
2010-0720, which was published in the Federal Register on July 21, 2010 
(75 FR 42340), is withdrawn.

    Issued on January 25, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-05194 Filed 3-12-21; 8:45 am]
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