DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0440; Project Identifier 2016-SW-077-AD]
RIN 2120-AA64

Airworthiness Directives; Scotts-Bell 47 Inc. (Type Certificate
Previously Held by Bell Helicopter Textron Inc.) 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 Scotts-Bell 47 Inc. (Scotts-Bell) (type certificate
previously held by Bell Helicopter Textron Inc.) Model 47, 47B, 47B3,
47D, 47D1, 47E, 47G, 47G-2, 47G-2A, 47G-2A-1, 47G-3, 47G-3B, 47G-3B-1,
47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A, 47H-1, 47J, 47J-2,
47J-2A, and 47K helicopters. The NPRM would have required repetitively
inspecting and adjusting the throttle linkage. The NPRM was prompted by
reports of the throttle linkage separating from the engine carburetor
shaft, which could result in loss of throttle control. Since issuance
of the NPRM, the FAA has determined, based upon the available
information, that there is not an unsafe condition in the product that
is likely to develop in other products of the same type design.
Accordingly, the NPRM is withdrawn.

DATES: As of October 29, 2021 the proposed rule, which was published in
the Federal Register on May 18, 2018 (83 FR 23240), is withdrawn.

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-2018-
0440; 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: Surinder Sangha, COS Program Manager,
FAA, Chicago ACO Branch, Room 107, 2300 E Devon Ave., Des Plaines, IL
60018; telephone 847-294-7010; email surinder.sangha@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

The FAA issued an NPRM that proposed to amend 14 CFR part 39 by
adding an AD that would have applied to certain Scotts-Bell Model 47,
47B, 47B3, 47D, 47D1, 47E, 47G, 47G-2, 47G-2A, 47G-2A-1, 47G-3, 47G-3B,
47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A, 47H-1,
47J, 47J-2, 47J-2A, and 47K helicopters. The NPRM published in the
Federal Register on May 18, 2018 (83 FR 23240). The NPRM was prompted
by reports of the throttle linkage separating from the engine
carburetor shaft, which could result in loss of throttle control.
In the NPRM, the FAA proposed to require repetitively inspecting
and adjusting the throttle linkage. The proposed actions were intended
to address separation of the throttle linkage from an engine carburetor
shaft, which could result in loss of throttle control and subsequent
forced landing of the helicopter.

Actions Since the NPRM Was Issued

Since issuance of the NPRM, the FAA has not received any additional
reports of the throttle linkage separating from the engine carburetor
shaft. The FAA's assessment indicates that there have been few reports
of the throttle linkage separating from the engine carburetor shaft in
the more than 70-year operational history of the Model 47G-3B-1
helicopter. In addition, the FAA determined that in this incident the
throttle linkage separating from the engine carburetor shaft resulted
from maintenance actions that did not follow the established
maintenance standards and were not performed by a certified mechanic.
Based on this information the FAA concluded that an unsafe condition
does not exist on the identified Scotts-Bell helicopter models that is
likely to develop in other products of the same type design. 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 and
received several comments from Scott's-Bell 47, Inc. You may examine
the comments received in the AD docket at https://www.regulations.gov
by searching for and locating Docket No. FAA-2018-0440.

Request To Expand the Applicability

Scott's-Bell 47, Inc. requested that the applicability in the
proposed AD be revised to include helicopter models that are listed in
the ``Serial Numbers Eligible'' section of Type Certificate Data Sheets
(TCDS) H-1, 2H1, and 2H3. The commenter noted that in the proposed AD
only Scotts-Bell Model 47 helicopters are identified. The commenter
stated that many other helicopter models are listed in TCDS H-1, 2H1,
and 2H3 and provided an example that due to a conformity inspection
TCDS H1 lists the Rebel Rotors serial number (S/N) B-101-R
helicopter as eligible to operate as a Model 47D1. The commenter
explained that the Rebel Rotors S/N B-101-R helicopter is not a
Scott's-Bell Model 47D1 helicopter, and as the proposed AD was written,
would not be captured in the applicability, despite the fact that it
likely had the same unsafe condition addressed in the proposed AD. The
commenter suggested that the applicability be changed to mirror what is
in the Scott's-Bell 47, Inc. service information ``All Helicopters
listed on Type Certificate Data Sheets H-1, 2H1, and 2H3, which have
Marvel Schebler carburetors models . . . installed.''
The FAA acknowledges this comment to the NPRM. However, because the
FAA is withdrawing the NPRM, the commenter's request is no longer
necessary.

Request To Clarify the Compliance Time

Scott's-Bell 47, Inc. also requested that the compliance time in
paragraph (e)(3) of the proposed AD be revised to state ``Within 100
hours time-in-service or at the next annual or 100-hour inspection,
whichever occurs first, and thereafter any time the throttle linkage
connection is disassembled.'' The commenter explained that, as written
in the proposed AD, this compliance time does not address disassembly
and, if disassembly were to occur after the first flight of the day and
the helicopter was returned to service on the same day, the current
wording would not require proper rigging to be performed for the second
and subsequent flights of that day. The commenter suggested that its
proposed wording would capture all variables and eliminate unnecessary
re-rigging of the helicopter.
The FAA acknowledges this comment to the NPRM. However, because the
FAA is withdrawing the NPRM, the commenter's request is no longer
necessary.

Request To Include Additional Required Actions

Furthermore, Scott's-Bell 47, Inc. requested that paragraphs
(e)(3)(i) and (ii) of the proposed AD be revised to include additional
required actions. The commenter stated that paragraph (e)(3)(i) of the
proposed AD requires operators to ``adjust and secure the throttle
linkage as specified in Appendix 1 of the Scott's-Bell Maintenance and
Overhaul Instructions Temporary Revision . . . .'' but other vital
functions, including a functionality check after adjusting and
securing, followed by applying anti-sabotage lacquer, are not included,
and, therefore, would not be required. The commenter recommended that
paragraph (e)(3)(i) be revised to ``Adjust, secure, perform
functionality check, and apply anti-sabotage lacquer to the throttle
linkage, as specified in Appendix 1 of the Scott's-Bell Maintenance and
Overhaul Instructions Temporary Revision that is applicable to your
helicopter, as listed in Table 1 of Scott's-Bell Alert Service Bulletin
47-15-27 R1, dated November 1, 2016.''
In regard to paragraph (e)(3)(ii) of the proposed AD, the commenter
proposed that this paragraph be revised to state ``. . . and 47K
helicopters, adjust, secure, perform functionality check and apply
anti-sabotage lacquer to the throttle linkage using a method approved .
. . .''
The FAA acknowledges this comment to the NPRM. However, because the
FAA is withdrawing the NPRM, the commenter's request is no longer
necessary.

FAA's Conclusions

Upon further consideration of the available information, 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.