2021-23514. 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.

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 Accordingly, the NPRM is withdrawn.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As of October 29, 2021 the proposed rule, which was published in the Federal Register on May 18, 2018 (83 FR 23240), is withdrawn.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 [phone]; email [e-mail].

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

The Withdrawal

Accordingly, the notice of proposed rulemaking, Docket No. FAA-2018-0440, which was published in the Federal Register on May 18, 2018 (83 FR 23240), is withdrawn.

Issued on October 22, 2021.

Lance T. Gant,

Director, Compliance & Airworthiness Division, Aircraft Certification Service.