11476 Federal Register / Vol. 86, No. 36 / Thursday, February 25, 2021 / Proposed Rules 

(k) Related Information 

(1) For more information about this AD, 

contact Michael Schwetz, Aviation Safety 

Engineer, Boston ACO Branch, FAA, 1200 

District Avenue, Burlington, MA 01803; 

phone: (781) 238–7761; fax: (781) 238–7199; 

email: michael.schwetz@faa.gov. 

(2) For service information identified in 

this AD, contact Hamilton Sundstrand, 1 

Hamilton Road, Windsor Locks, CT 06096– 

1010; phone: (877) 808–7575; email: CRC@

collins.com. You may view this referenced 

service information at the FAA, 

Airworthiness Products Section, Operational 

Safety Branch, 1200 District Avenue, 

Burlington, MA 01803. For information on 

the availability of this material at the FAA, 

call (781) 238–7759. 

Issued on February 8, 2021. 

Lance T. Gant, 

Director, Compliance & Airworthiness 

Division, Aircraft Certification Service. 

[FR Doc. 2021–03607 Filed 2–24–21; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2005–21679; Directorate 

Identifier 2004–SW–33–AD] 

RIN 2120–AA64 

Airworthiness Directives; Robinson 

Helicopter Company Model R22 Series 

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 Robinson Helicopter 

Company (RHC) Model R22 series 

helicopters. The NPRM was prompted 

by an in-flight break up of a helicopter 

on which both teeter stop brackets 

(brackets) failed. The NPRM would have 

required replacing each main rotor 

blade (blade) droop and teeter stop 

(stop) and bracket and associated 

hardware with redesigned and 

improved airworthy parts. Since 

issuance of the NPRM, the FAA has 

determined that failure of the brackets 

was caused by turbulence and other 

factors that are addressed in AD 95–26– 

04. Accordingly, the NPRM is 

withdrawn. 

DATES: The FAA is withdrawing the 

proposed rule published June 28, 2005 

(70 FR 37059), as of February 25, 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–2005– 

21679; 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: 

James Guo, Aviation Safety Engineer, 

Los Angeles ACO Branch, FAA, 3960 

Paramount Blvd., Lakewood, California 

90712; telephone 562–627–5357; email 

james.guo@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 

June 28, 2005 (70 FR 37059). The NPRM 

was prompted by an accident that 

involved an in-flight breakup of a 

helicopter that had old part-numbered 

stops and brackets installed. While the 

probable cause of the in-flight breakup 

had not been determined, the FAA 

believed failure of the stops or brackets 

may have been a contributing factor. 

Accordingly, the NPRM proposed to 

require replacing the stops and brackets 

with redesigned, airworthy parts. The 

proposed actions were intended to 

prevent failure of the stops and brackets, 

blade contact with the airframe, 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 unsafe 

condition was caused by different 

factors than those stated in the NPRM. 

Previously, RHC had introduced service 

information to replace the stops and 

brackets that were the subject of the 

NPRM with redesigned parts. The 

redesign introduced a material change 

from aluminum to stainless steel. 

However, the redesigned parts were 

mistakenly evaluated as a change that 

would address the unsafe condition. It 

has since been determined that the 

strength increase in the redesign is 

insignificant and would not have 

improved the outcome of the accident. 

It has also been determined that the 

accident was caused by mast bumping, 

which is addressed in AD 95–26–04 (60 

FR 66487, December 22, 1995) (AD 95– 

26–04). Therefore, the FAA has 

determined that AD action is not 

required and the NPRM is withdrawn. 

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. 

Requests 

One commenter stated that the stops 

and droops could not have contributed 

to the accident as contact with those 

items occurs only when operating a 

Model R22 helicopter outside of its 

certificated flight envelope, accordingly 

making it an operational issue. The 

commenter requested the FAA table the 

proposed AD until the accident 

investigation is complete. 

The FAA acknowledges the 

commenter’s request. The FAA further 

determined that the unsafe condition 

was caused by mast bumping, which is 

addressed in AD 95–26–04. Because the 

FAA is withdrawing the NPRM and has 

issued AD 95–26–04, the commenter’s 

request is no longer necessary. 

A second commenter requested that 

the proposed action be modified by 

inclusion of the following or similar 

statement: ‘‘The requirement to install 

certain part-numbered specific parts 

shall be interpreted broadly to include 

any replacements parts approved under 

FAR 21.303 for the original equipment 

parts cited in this action. Nothing in this 

action prevents or precludes the 

installation of such alternatively 

approved parts.’’ 

The FAA acknowledges the 

commenter’s request. 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 

Federal Register / Vol. 86, No. 36 / Thursday, February 25, 2021 / Proposed Rules 11477 

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–2005– 

21679, Directorate Identifier 2004–SW– 

33–AD, which was published in the 

Federal Register on June 28, 2005 (70 

FR 37059), is withdrawn. 

Issued on February 4, 2021. 

Gaetano A. Sciortino, 

Deputy Director for Strategic Initiatives, 

Compliance & Airworthiness Division, 

Aircraft Certification Service. 

[FR Doc. 2021–03655 Filed 2–24–21; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2013–0751; Directorate 

Identifier 2012–SW–051–AD] 

RIN 2120–AA64 

Airworthiness Directives; 

AgustaWestland S.p.A. (Type 

Certificate Formerly Held by Agusta 

S.p.A) (Agusta) 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 supersede 

Airworthiness Directive (AD) 2011–18– 

52, which applies to certain Agusta 

Model AB139 and AW139 helicopters. 

AD 2011–18–52 requires establishing a 

revised life limit for each tail rotor blade 

(blade), updating the existing historical 

records for your helicopter, repetitively 

inspecting each blade for a crack, and 

replacing certain blades. The NPRM was 

prompted by the manufacturer 

developing an improved blade using 

different materials and establishing life 

limits for those newly-designed blades. 

The NPRM proposed to require 

expanding the applicability to include 

the newly-designed blades and establish 

their life limits, and proposed to retain 

the requirement to inspect each blade 

for a crack and, if there is a crack, 

replace each blade with an airworthy 

blade. Since issuance of the NPRM, the 

FAA has determined that the NPRM 

does not adequately address the 

identified unsafe condition. 

Accordingly, the NPRM is withdrawn. 

DATES: The FAA is withdrawing the 

proposed rule published September 5, 

2013 (78 FR 54596), as of February 25, 

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–2013– 

0751; 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, 

the European Aviation Safety Agency 

(now European Union Aviation Safety 

Agency (EASA) AD, 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: Matt 

Fuller, AD Program Manager, 

Operational Safety Branch, 

Airworthiness Products Section, 

General Aviation & Rotorcraft Unit, 

FAA, 10101 Hillwood Pkwy., Fort 

Worth, TX 76177; telephone 817–222– 

5110; email matthew.fuller@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Discussion 

The FAA issued an NPRM to amend 

14 CFR part 39 to supersede AD 2011– 

18–52, Amendment 39–17020 (77 FR 

23109, April 18, 2012) (AD 2011–18– 

52). AD 2011–18–52 applies to Agusta 

Model AB139 and AW139 helicopters 

with a blade part number (P/N) 

3G6410A00131 or P/N 4G6410A00131 

installed. AD 2011–18–52 requires 

establishing a revised life limit for each 

blade, updating the existing historical 

records for your helicopter, repetitively 

inspecting each blade for a crack, and 

replacing certain blades. The NPRM 

published in the Federal Register on 

September 5, 2013 (78 FR 54596). The 

NPRM was prompted by the 

manufacturer first developing two new 

blades with an improved design and 

specified life limits and repetitive 

inspections for the blades. Also, EASA 

issued AD No. 2012–0030, dated 

February 17, 2012, which superseded 

EASA EAD No. 2011–0156–E, dated 

August 25, 2011, to add the new blades 

to the required actions. The 

manufacturer then developed two new 

blades with improved materials and 

specified new life limits and inspections 

for the blades. EASA then issued EASA 

AD No. 2012–0076, dated May 2, 2012, 

revised by EASA AD No. 2012–0076R1, 

dated July 13, 2012 (EASA AD No. 

2012–0076R1), to require the repetitive 

inspections and reduced life limits on 

the additional new blades. 

Actions Since the NPRM Was Issued 

After issuance of the NPRM, EASA 

issued EASA AD No. 2012–0076R2, 

dated February 20, 2014, which revises 

EASA AD No. 2012–0076R1, to remove 

the repetitive 25 flight-hour inspections 

for blades P/N 3G6410A00132, P/N 

4G6410A00132, P/N 3G6410A00133, 

and P/N 4G6410A00133 and extend the 

life limits for T/R blades P/N 

3G6410A00133 and P/N 

4G6410A00133. Additionally, EASA 

advised that the life limits for T/R 

blades P/N 3G6410A00132 and P/N 

4G6410A00132 have been incorporated 

in the Chapter 4 airworthiness 

limitations section of the maintenance 

manual. Further, since the FAA issued 

the NPRM, a significant amount of time 

has elapsed, which would require the 

FAA to reopen the comment period to 

allow the public an opportunity to 

comment on the proposed actions. 

Accordingly, the FAA has determined 

the NPRM does not adequately address 

the identified unsafe condition and has 

determined to withdraw the published 

NPRM and proceed with a separate 

rulemaking to address this unsafe 

condition. 

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 FAA received comments from one 

commenter. 

One commenter requested the FAA 

adjust the life limit for certain partnumbered blades to be more consistent 

with aviation standard practices and 

gave the examples of ‘‘3 years since 

initial installation’’ and ‘‘5 years since 

manufacture.’’ Since the FAA is 

withdrawing the NPRM, the 

commenter’s request to adjust the 

compliance time is no longer necessary. 

FAA’s Conclusions 

Upon further consideration, the FAA 

has determined that the NPRM does not 

adequately address the identified unsafe 

condition and the unsafe condition will 

be addressed in a separate AD. 

Accordingly, the NPRM is withdrawn.