This section of the FEDERAL REGISTER

contains notices to the public of the proposed

issuance of rules and regulations. The

purpose of these notices is to give interested

persons an opportunity to participate in the

rule making prior to the adoption of the final

rules.

Proposed Rules Federal Register

11473 

Vol. 86, No. 36 

Thursday, February 25, 2021 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2021–0032; Project 

Identifier AD–2020–01314–P] 

RIN 2120–AA64 

Airworthiness Directives; Hamilton 

Sundstrand Corporation Propellers 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to 

supersede Airworthiness Directive (AD) 

2020–12–07, which applies to certain 

Hamilton Sundstrand Corporation 

(Hamilton Sundstrand) 54H model 

propellers. AD 2020–12–07 requires 

initial and repetitive eddy current 

inspections (ECI) of certain propeller 

blades and replacement of the propeller 

blades that fail the inspection. Since the 

FAA issued AD 2020–12–07, the 

manufacturer determined that all 

propeller blades installed on Hamilton 

Sundstrand 54H model propellers with 

a 54H60 model propeller hub are 

susceptible to intergranular corrosion 

cracking in the blade taper bore. This 

proposed AD would require initial and 

repetitive ECI of all propeller blades 

installed on Hamilton Sundstrand 

54H60 propeller hubs and replacement 

of any propeller blade that fails 

inspection. The FAA is proposing this 

AD to address the unsafe condition on 

these products. 

DATES: The FAA must receive comments 

on this proposed AD by April 12, 2021. 

ADDRESSES: You may send comments, 

using the procedures found in 14 CFR 

11.43 and 11.45, by any of the following 

methods: 

• Federal eRulemaking Portal: Go to

https://www.regulations.gov. Follow the 

instructions for submitting comments. 

• Fax: (202) 493–2251.

• Mail: U.S. Department of

Transportation, Docket Operations, M– 

30, West Building Ground Floor, Room 

W12–140, 1200 New Jersey Avenue SE, 

Washington, DC 20590. 

• Hand Delivery: Deliver to Mail

address above between 9 a.m. and 5 

p.m., Monday through Friday, except

Federal holidays.

For service information identified in 

this NPRM, contact Hamilton 

Sundstrand, 1 Hamilton Road, Windsor 

Locks, CT 06096–1010; phone: (877) 

808–7575; email: CRC@collins.com. You 

may view this service information at 

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. 

Examining the AD Docket 

You may examine the AD docket at 

https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2021–0032; 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 

NPRM, any comments received, and 

other information. The street address for 

Docket Operations is listed above. 

FOR FURTHER INFORMATION 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. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

The FAA invites you to send any 

written relevant data, views, or 

arguments about this proposal. Send 

your comments to an address listed 

under ADDRESSES. Include ‘‘Docket No. 

FAA–2021–0032; Project Identifier AD– 

2020–01314–P’’ at the beginning of your 

comments. The most helpful comments 

reference a specific portion of the 

proposal, explain the reason for any 

recommended change, and include 

supporting data. The FAA will consider 

all comments received by the closing 

date and may amend the proposal 

because of those comments. 

Except for Confidential Business 

Information (CBI) as described in the 

following paragraph, and other 

information as described in 14 CFR 

11.35, the FAA will post all comments 

received, without change, to https://

www.regulations.gov, including any 

personal information you provide. The 

agency will also post a report 

summarizing each substantive verbal 

contact we receive about this proposed 

AD. 

Confidential Business Information 

CBI is commercial or financial 

information that is both customarily and 

actually treated as private by its owner. 

Under the Freedom of Information Act 

(FOIA) (5 U.S.C. 552), CBI is exempt 

from public disclosure. If your 

comments responsive to this NPRM 

contain commercial or financial 

information that is customarily treated 

as private, that you actually treat as 

private, and that is relevant or 

responsive to this NPRM, it is important 

that you clearly designate the submitted 

comments as CBI. Please mark each 

page of your submission containing CBI 

as ‘‘PROPIN.’’ The FAA will treat such 

marked submissions as confidential 

under the FOIA, and they will not be 

placed in the public docket of this 

NPRM. Submissions containing CBI 

should be sent to Michael Schwetz, 

Aviation Safety Engineer, Boston ACO 

Branch, FAA, 1200 District Avenue, 

Burlington, MA 01803. Any 

commentary that the FAA receives 

which is not specifically designated as 

CBI will be placed in the public docket 

for this rulemaking. 

Background 

The FAA issued AD 2020–12–07, 

Amendment 39–21142 (85 FR 36145, 

June 15, 2020) (AD 2020–12–07) for 

certain Hamilton Sundstrand 54H 

model propellers. Note that AD 2020– 

12–07 and the Hamilton Sundstrand 

service information reference 54H60 

model propellers whereas this AD 

references 54H model propellers. 

Hamilton Sundstrand 54H60 model 

propellers are 54H model propellers 

with a 54H60 model propeller hub. 

AD 2020–12–07 was prompted by a 

report of the separation of a 54H60 

model propeller blade installed on a 

United States Marine Corps Reserve 

(USMCR) KC–130T airplane during a 

flight in July 2017. The USMCR 

investigation of this event revealed the 

Hamilton Sundstrand 54H60 model 

propeller blade separated due to 

corrosion pitting and a resultant 

intergranular radial crack that was not 

corrected at the last propeller overhaul. 

From this intergranular crack, a fatigue 

11474 Federal Register / Vol. 86, No. 36 / Thursday, February 25, 2021 / Proposed Rules 

crack initiated and grew under service 

loading until the Hamilton Sundstrand 

54H60 model propeller blade could no 

longer sustain the applied loads and 

ultimately the blade separated. The 

separation of the blade resulted in the 

loss of the airplane and 17 fatalities. The 

investigation further revealed that 

54H60 model propeller blades 

manufactured before 1971 are 

susceptible to cracks of the propeller 

blade in the area of the internal taper 

bore. The applicability of AD 2020–12– 

07 was therefore limited to those 

Hamilton Sundstrand 54H60 model 

propellers blades with a blade serial 

number (S/N) below 813320, which are 

those propeller blades manufactured 

before 1971. AD 2020–12–07 required 

initial and repetitive ECI of the affected 

propeller blades and replacement of any 

propeller blade that fails inspection. 

The agency issued AD 2020–12–07 to 

detect cracking in the propeller blade 

taper bore. 

Actions Since AD 2020–12–07 Was 

Issued 

Since the FAA issued AD 2020–12– 

07, the manufacturer determined that all 

propeller blades installed on Hamilton 

Sundstrand 54H model propellers with 

a 54H60 model propeller hub are 

susceptible to intergranular corrosion 

cracking in the blade taper bore. As a 

result, the manufacturer published 

Hamilton Sundstrand Alert Service 

Bulletin (ASB) 54H60–61–A154, 

Revision 1, dated May 29, 2020, to 

expand the effectivity of the ASB to 

include all propeller blades installed on 

a propeller that contains a blade S/N 

below 813320, and all propeller blades 

installed on a propeller that has not 

been overhauled within ten years. 

Hamilton Sundstrand ASB 54H60–61– 

A154, Revision 1, dated May 29, 2020, 

also provides instructions for 

concurrent compliance with Hamilton 

Sundstrand ASB 54H60–61–A155, 

dated May 29, 2020, to ECI an expanded 

and deeper taper bore area. 

FAA’s Determination 

The FAA is issuing this NPRM after 

determining that the unsafe condition 

described previously is likely to exist or 

develop on other products of the same 

type design. 

Related Service Information Under 1 

CFR Part 51 

The FAA reviewed Hamilton 

Sundstrand ASB 54H60–61–A154, 

Revision 1, dated May 29, 2020. This 

ASB identifies the affected propeller 

models and specifies procedures for 

performing an ECI of the propeller blade 

taper bore. The FAA also reviewed 

Hamilton Sundstrand ASB 54H60–61– 

A155, dated May 29, 2020. This ASB 

also identifies affected propeller models 

and specifies procedures for performing 

an expanded ECI of the propeller blade 

taper bore. 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 

ADDRESSES. 

Proposed AD Requirements in This 

NPRM 

This proposed AD would retain 

certain requirements of AD 2020–12–07. 

This proposed AD would require initial 

and repetitive ECI of all propeller blades 

installed on Hamilton Sundstrand 

54H60 propeller hubs and replacement 

of any propeller blade that fails 

inspection. 

Interim Action 

The FAA considers that this proposed 

AD would be an interim action. This 

unsafe condition is still under 

investigation by the manufacturer and, 

depending on the results of that 

investigation, the FAA may consider 

further rulemaking action. 

Costs of Compliance 

The FAA estimates that this AD, if 

adopted as proposed, would affect 212 

propellers installed on 53 aircraft of 

U.S. registry. 

The FAA estimates the following 

costs to comply with this proposed AD: 

ESTIMATED COSTS

Action Labor cost Parts cost Cost per 

product 

Cost on U.S. 

operators 

ECI all propeller blades installed on propeller 16 work-hours × $85 per hour = $1,360 ........ $700 $2,060 $436,720 

Report results of ECI ...................................... 1 work-hour × $85 per hour = $85 ................. 0 85 18,020 

The FAA estimates the following 

costs to do any necessary replacement 

that would be required based on the 

results of the proposed inspection. The 

agency has no way of determining the 

number of aircraft that might need this 

replacement: 

ON-CONDITION COSTS

Action Labor cost Parts cost Cost per 

product 

Replace propeller blade ............................................... 1 work-hour × $85 per hour = $85 ............................... $63,500 $63,585 

Paperwork Reduction Act 

A federal agency may not conduct or 

sponsor, and a person is not required to 

respond to, nor shall a person be subject 

to a penalty for failure to comply with 

a collection of information subject to the 

requirements of the Paperwork 

Reduction Act unless that collection of 

information displays a currently valid 

OMB Control Number. The OMB 

Control Number for this information 

collection is 2120–0056. Public 

reporting for this collection of 

information is estimated to be 

approximately 1 hour per response, 

including the time for reviewing 

instructions, searching existing data 

sources, gathering and maintaining the 

data needed, completing and reviewing 

the collection of information. All 

responses to this collection of 

information are mandatory. Send 

comments regarding this burden 

estimate or any other aspect of this 

collection of information, including 

suggestions for reducing this burden to: 

Information Collection Clearance 

Officer, Federal Aviation 

Administration, 10101 Hillwood 

Parkway, Fort Worth, TX 76177–1524. 

Federal Register / Vol. 86, No. 36 / Thursday, February 25, 2021 / Proposed Rules 11475 

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 

The FAA determined that this 

proposed AD would not have federalism 

implications under Executive Order 

13132. This proposed AD would 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 the proposed regulation: 

(1) Is not a ‘‘significant regulatory 

action’’ under Executive Order 12866, 

(2) Would not affect intrastate 

aviation in Alaska, and 

(3) Would 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 Proposed Amendment 

Accordingly, under the authority 

delegated to me by the Administrator, 

the FAA proposes to amend 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. 

§ 39.13 [Amended] 

■ 2. The FAA amends § 39.13 by: 

■ a. Removing Airworthiness Directive 

2020–12–07, Amendment 39–21142 (85 

FR 36145, June 15, 2020); and 

■ b. Adding the following new 

airworthiness directive: 

Hamilton Sundstrand Corporation: Docket 

No. FAA–2021–0032; Project Identifier 

AD–2020–01314–P. 

(a) Comments Due Date 

The FAA must receive comments on this 

airworthiness directive (AD) action by April 

12, 2021. 

(b) Affected ADs 

This AD replaces AD 2020–12–07, 

Amendment 39–21142 (85 FR 36145, June 

15, 2020). 

(c) Applicability 

This AD applies to all Hamilton 

Sundstrand Corporation (Hamilton 

Sundstrand) 54H model propellers with a 

propeller hub, model 54H60, installed. 

Note to paragraph (c): Hamilton 

Sundstrand references propeller model 

54H60 in Hamilton Sundstrand Alert Service 

Bulletin (ASB) 54H60–61–A154, Revision 1, 

dated May 29, 2020. These are model 54H 

propellers with a 54H60 model propeller 

hub. 

(d) Subject 

Joint Aircraft System Component (JASC) 

Code 6111, Propeller Blade Section. 

(e) Unsafe Condition 

This AD was prompted by the separation 

of a propeller blade that resulted in the loss 

of an airplane and 17 fatalities. The FAA is 

issuing this AD to detect cracking in the 

propeller blade taper bore. The unsafe 

condition, if not addressed, could result in 

failure of the propeller blade, blade 

separation, and loss of the airplane. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Required Actions 

(1) For propellers with an installed 

propeller blade having a blade serial number 

(S/N) below 813320, that has not been 

overhauled within the past sixty (60) months, 

within one year or 500 flight hours (FHs) 

after July 20, 2020 (the effective date of AD 

2020–12–07), whichever occurs first, perform 

an eddy current inspection (ECI) of all blades 

installed on the propeller. 

(2) For propellers with an installed 

propeller blade having a blade S/N below 

813320, that has been overhauled within the 

past sixty (60) months, within two years or 

1,000 FHs after July 20, 2020 (the effective 

date of AD 2020–12–07), whichever occurs 

first, perform an ECI of all blades installed on 

the propeller. 

(3) For propellers with an installed 

propeller blade, blade S/N 813320 and above, 

that has not been overhauled within ten years 

since new or since last overhaul, within one 

year or 500 FHs after the effective date of this 

AD, whichever occurs first, perform an ECI 

of all blades installed on the propeller. 

(4) Perform the ECI of the propeller blades 

required by paragraphs (g)(1) through (3) of 

this AD in accordance with the 

Accomplishment Instructions, paragraph 

3.C.(5), of both Hamilton Sundstrand ASB 

54H60–61–A154, Revision 1, dated May 29, 

2020, and of Hamilton Sundstrand ASB 

54H60–61–A155, dated May 29, 2020. 

(5) For all propellers identified in 

paragraphs (g)(1) through (3) of this AD, 

repeat the inspection required by paragraphs 

(g)(1) through (4) of this AD at intervals not 

exceeding 3 years or 1,500 FHs, whichever 

comes first, from the previous inspection. 

(6) If a propeller blade fails any inspection 

required by this AD, based on the criteria in 

Accomplishment Instructions, paragraph 

3.C.(5)(g) of Hamilton Sundstrand ASB 

54H60–61–A154, Revision 1, dated May 29, 

2020, and paragraph 3.C.(5)(j) of Hamilton 

Sundstrand ASB 54H60–61–A155, dated May 

29, 2020, remove the blade from service 

before further flight and replace with a blade 

eligible for installation. 

(7) Report the results of the ECI required 

by paragraphs (g)(1) through (5) of this AD in 

accordance with the Accomplishment 

Instructions, paragraph 3.C.(6), of Hamilton 

Sundstrand ASB 54H60–61–A154, Revision 

1, dated May 29, 2020. 

(h) Installation Prohibition 

(1) After the effective date of this AD, do 

not install onto any propeller a Hamilton 

Sundstrand propeller blade identified in 

paragraphs (g)(1) through (4) of this AD, 

unless the blade has first passed the initial 

inspection required by paragraphs (g)(1) 

through (4) of this AD. 

(2) After the effective date of this AD, do 

not install any propeller assembly with a 

propeller blade identified in paragraphs (g)(1) 

through (4) of this AD onto any aircraft 

unless the propeller blades have passed the 

initial inspection required by paragraphs 

(g)(1) through (4) of this AD. 

(i) Credit for Previous Actions 

You may take credit for the initial ECI of 

a propeller blade required by paragraphs 

(g)(1) and (2) of this AD and the replacement 

of a propeller blade required by paragraph 

(g)(6) of this AD if the actions were 

completed before the effective date of this AD 

using Hamilton Sundstrand ASB 54H60–61– 

A154, dated August 26, 2019. 

(j) Alternative Methods of Compliance 

(AMOCs) 

(1) The Manager, Boston ACO Branch, 

FAA, has the authority to approve AMOCs 

for this AD, if requested using the procedures 

found in 14 CFR 39.19. In accordance with 

14 CFR 39.19, send your request to your 

principal inspector or local Flight Standards 

District Office, as appropriate. If sending 

information directly to the manager of the 

certification office, send it to the attention of 

the person identified in Related Information. 

(2) Before using any approved AMOC, 

notify your appropriate principal inspector, 

or lacking a principal inspector, the manager 

of the local flight standards district office/ 

certificate holding district office. 

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