34166 Federal Register / Vol. 86, No. 122 / Tuesday, June 29, 2021 / Proposed Rules 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2021–0515; Project 

Identifier AD–2021–00191–E] 

RIN 2120–AA64 

Airworthiness Directives; Pratt & 

Whitney Turbofan Engines 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for all 

Pratt & Whitney PW1500G and 

PW1900G series turbofan engines with a 

certain high-pressure turbine (HPT) 1ststage hub or HPT rotor 1st-stage blade 

retaining plate installed. This proposed 

AD was prompted by a report from the 

manufacturer who determined that the 

HPT 1st-stage hub and HPT rotor 1ststage blade retaining plate fail to meet 

the published life-cycle limits for each 

part. This proposed AD would require 

removal and replacement of the HPT 

1st-stage hub and HPT rotor 1st-stage 

blade retaining plate prior to reaching 

certain cycle limits. 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 June 29, 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 Pratt & Whitney, 

400 Main Street, East Hartford, CT 

06118; phone: (800) 565–0140; fax: (860) 

565–5442; email: help24@pw.utc.com; 

website: https://fleetcare.pw.utc.com. 

You may view this 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. 

Examining the AD Docket 

You may examine the AD docket at 

https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2021–0515; 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: 

Mark Taylor, Aviation Safety Engineer, 

ECO Branch, FAA, 1200 District 

Avenue, Burlington, MA 01803; phone: 

(781) 238–7229; fax: (781) 238–7199; 

email: Mark.Taylor@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–2021–0515; Project Identifier AD– 

2021–00191–E’’ 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 this 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 received about this NPRM. 

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 Mark Taylor, Aviation 

Safety Engineer, ECO 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 received a report from the 

manufacturer, who determined after 

recalculating life limits using a thermal 

match model and other life-calculation 

methodology updates, the HPT 1st-stage 

hub and HPT rotor 1st-stage blade 

retaining plate failed to meet the 

published life-cycle limits for each part. 

This condition, if not addressed, could 

result in the release of the HPT 1st-stage 

hub or HPT rotor 1st-stage blade 

retaining plate, damage to the engine, 

and damage to the aircraft. 

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 

The FAA reviewed Pratt & Whitney 

Service Bulletin (SB) PW1000G–A–72– 

00–0115–00B–930A–D, Issue No. 001, 

dated April 26, 2021, and Pratt & 

Whitney SB PW1000G–A–72–00–0168– 

00A–930A–D, Issue No. 001, dated 

April 26, 2021. These SBs describe 

procedures for removing and replacing 

the HPT 1st-stage hub and HPT rotor 

1st-stage blade retaining plate. 

Proposed AD Requirements in This 

NPRM 

This proposed AD would require 

removal and replacement of the HPT 

1st-stage hub and HPT rotor 1st-stage 

blade retaining plate prior to reaching 

certain cycle limits. 

Costs of Compliance 

The FAA estimates that this AD, if 

adopted as proposed, would affect 88 

engines installed on airplanes of U.S. 

registry. The FAA estimates that in most 

cases the affected HPT 1st-stage hub and 

the affected HPT 1st-stage blade 

retaining plate will both be replaced 

during the same disassembly of the 

engine. This cost estimate therefore 

reflects the cost of replacing both parts 

during the same engine disassembly. 

The FAA estimates the following 

costs to comply with this proposed AD: 


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Federal Register / Vol. 86, No. 122 / Tuesday, June 29, 2021 / Proposed Rules 34167 

ESTIMATED COSTS

Action Labor cost Parts cost Cost per 

product 

Cost on U.S. 

operators 

Replace HPT 1st-stage hub and HPT rotor 1st-stage 

blade retaining plate (pro-rated part cost).

300 work-hours × $85 per hour = 

$25,500.

$86,252 $111,752 $9,834,176 

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 this 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 adding 

the following new airworthiness 

directive: 

Pratt & Whitney: Docket No. FAA–2021– 

0515; Project Identifier AD–2021– 

00191–E. 

(a) Comments Due Date 

The FAA must receive comments on this 

airworthiness directive (AD) by August 13, 

2021. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to Pratt & Whitney 

PW1519G, PW1521G, PW1521G–3, 

PW1521GA, PW1524G, PW1524G–3, 

PW1525G, PW1525G–3, PW1919G, 

PW1921G, PW1922G, PW1923G, and 

PW1923G–A model turbofan engines with a 

high-pressure turbine (HPT) 1st-stage hub, 

part number (P/N) 30G5701, or an HPT rotor 

1st-stage blade retaining plate, P/N 30G1692, 

installed. 

(d) Subject 

Joint Aircraft System Component (JASC) 

Code 7250, Turbine Section. 

(e) Unsafe Condition 

This AD was prompted by a report from 

the manufacturer who determined that the 

HPT 1st-stage hub and HPT rotor 1st-stage 

blade retaining plate fail to meet the 

published life-cycle limits for each part. The 

FAA is issuing this AD to prevent failure of 

the HPT 1st-stage hub or HPT rotor 1st-stage 

blade retaining plate. The unsafe condition, 

if not addressed, could result in the release 

of the HPT 1st-stage hub or HPT rotor 1ststage blade retaining plate, damage to the 

engine, and damage to the aircraft. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Required Actions 

(1) For PW1519G, PW1521G, PW1521G–3, 

PW1521GA, PW1524G, and PW1524G–3 

model turbofan engines: 

(i) For an affected HPT 1st-stage hub and 

an affected HPT rotor 1st-stage blade 

retaining plate with 3,000 cycles since new 

(CSN) or fewer on the effective date of this 

AD, before the affected part exceeds 4,700 

CSN, remove the affected part, as applicable, 

and replace with a part eligible for 

installation. 

(ii) For an affected HPT 1st-stage hub and 

an affected HPT rotor 1st-stage blade 

retaining plate with greater than 3,000 CSN 

but fewer than 4,960 CSN on the effective 

date of the AD, at the next engine shop visit 

after accumulating 4,700 CSN or before the 

affected part exceeds 5,260 CSN, whichever 

occurs first, remove the affected part, as 

applicable, and replace with a part eligible 

for installation. 

(iii) For an affected HPT 1st-stage hub and 

an affected HPT rotor 1st-stage blade 

retaining plate with 4,960 CSN or greater on 

the effective date of the AD, at the next 

engine shop visit or within 300 cycles after 

the effective date of this AD, whichever 

occurs first, remove the affected part, as 

applicable, and replace with a part eligible 

for installation. 

(2) For PW1919G and PW1921G model 

turbofan engines: 

(i) For an affected HPT 1st-stage hub and 

an affected HPT rotor 1st-stage blade 

retaining plate with 3,000 CSN or fewer on 

the effective date of this AD, before the 

affected part exceeds 4,700 CSN, remove the 

affected part, as applicable, and replace with 

a part eligible for installation. 

(ii) For an affected HPT 1st-stage hub and 

an affected HPT rotor 1st-stage blade 

retaining plate with greater than 3,000 CSN 

but fewer than 4,700 CSN on the effective 

date of the AD, at the next engine shop visit 

after the affected part accumulates 4,700 CSN 

or before the affected part exceeds 5,000 

CSN, whichever occurs first, remove the 

affected part, as applicable, and replace with 

a part eligible for installation. 

(iii) For an affected HPT 1st-stage hub and 

an affected HPT rotor 1st-stage blade 

retaining plate with 4,700 CSN or greater on 

the effective date of the AD, at the next 

engine shop visit or within 300 cycles after 

the effective date of this AD, whichever 

occurs first, remove the affected part, as 

applicable, and replace with a part eligible 

for installation. 

(3) For PW1525G and PW1525G–3 model 

turbofan engines: 

(i) Before the affected HPT 1st-stage hub 

and affected HPT rotor 1st-stage blade 

retaining plate exceeds 2,800 CSN, 

respectively, or within 300 cycles after the 

effective date of this AD, whichever occurs 

later, remove the affected part, as applicable, 

and replace with a part eligible for 

installation. 

(ii) [Reserved] 

(4) For PW1922G, PW1923G, and 

PW1923G–A model turbofan engines: 

(i) Before the affected HPT 1st-stage hub 

and affected HPT rotor 1st-stage blade 

retaining plate exceeds 3,000 CSN, 


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34168 Federal Register / Vol. 86, No. 122 / Tuesday, June 29, 2021 / Proposed Rules 

respectively, or within 300 cycles after the 

effective date of this AD, whichever occurs 

later, remove the affected part, as applicable, 

and replace with a part eligible for 

installation. 

(ii) [Reserved] 

(h) Definition 

(1) For the purpose of this AD, an ‘‘engine 

shop visit’’ is the induction of an engine into 

the shop for maintenance involving the 

separation of pairs of major mating engine 

case flanges, except for the following, which 

do not constitute an engine shop visit: 

(i) Separation of engine flanges solely for 

the purposes of transportation without 

subsequent maintenance does not constitute 

an engine shop visit. 

(ii) Separation of engine flanges solely for 

the purpose of replacing the fan without 

subsequent maintenance does not constitute 

an engine shop visit. 

(2) For the purpose of this AD, a ‘‘part 

eligible for installation’’ is: 

(i) For PW1519G, PW1521G, PW1521G–3, 

PW1521GA, PW1524G, PW1524G–3, 

PW1919G, and PW1921G model turbofan 

engines: 

(A) Any HPT 1st-stage hub with P/N 

30G5701 with 4,700 CSN or fewer, or with 

a P/N not listed in this AD. 

(B) Any HPT rotor 1st-stage blade retaining 

plate with P/N 30G1692 with 4,700 CSN or 

fewer, or with a P/N not listed in this AD. 

(ii) For PW1525G and PW1525G–3 model 

turbofan engines: 

(A) Any HPT 1st-stage hub with P/N 

30G5701 with 2,800 CSN or fewer, or with 

a P/N not listed in this AD. 

(B) Any HPT rotor 1st-stage blade retaining 

plate with P/N 30G1692 with 2,800 CSN or 

fewer, or with a P/N not listed in this AD. 

(iii) For PW1922G, PW1923G, and 

PW1923G–A model turbofan engines: 

(A) Any HPT 1st-stage hub with P/N 

30G5701 with 3,000 CSN or fewer, or with 

a P/N not listed in this AD. 

(B) Any HPT rotor 1st-stage blade retaining 

plate with P/N 30G1692 with 3,000 CSN or 

fewer, or with a P/N not listed in this AD. 

(i) Alternative Methods of Compliance 

(AMOCs) 

(1) The Manager, ECO 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. You may 

email your request to: ANE-AD-AMOC@

faa.gov. 

(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. 

(j) Related Information 

(1) For more information about this AD, 

contact Mark Taylor, Aviation Safety 

Engineer, ECO Branch, FAA, 1200 District 

Avenue, Burlington, MA 01803; phone: (781) 

238–7229; fax: (781) 238–7199; email: 

Mark.Taylor@faa.gov. 

(2) For service information identified in 

this AD, contact Pratt & Whitney, 400 Main 

Street, East Hartford, CT 06118; phone: (800) 

565–0140; fax: (860) 565–5442; email: 

help24@pw.utc.com; website: https://

fleetcare.pw.utc.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 June 23, 2021. 

Lance T. Gant, 

Director, Compliance & Airworthiness 

Division, Aircraft Certification Service. 

[FR Doc. 2021–13709 Filed 6–28–21; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 71 

[Docket No. FAA–2021–0518; Airspace 

Docket No. 21–ASW–12] 

RIN 2120–AA66 

Proposed Amendment Class E 

Airspace; Oklahoma City, OK 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: This action proposes to 

amend the Class E airspace at Sundance 

Airport, Oklahoma City, OK. The FAA 

is proposing this action as the result of 

an airspace review due to the 

decommissioning of the Sundance 

Localizer (LOC). 

DATES: Comments must be received on 

or before August 13, 2021. 

ADDRESSES: Send comments on this 

proposal to the U.S. Department of 

Transportation, Docket Operations, 

West Building Ground Floor, Room 

W12–140, 1200 New Jersey Avenue SE, 

Washington, DC 20590; telephone (202) 

366–9826, or (800) 647–5527. You must 

identify FAA Docket No. FAA–2021– 

0518/Airspace Docket No. 21–ASW–12, 

at the beginning of your comments. You 

may also submit comments through the 

internet at https://www.regulations.gov. 

You may review the public docket 

containing the proposal, any comments 

received, and any final disposition in 

person in the Dockets Office between 

9:00 a.m. and 5:00 p.m., Monday 

through Friday, except federal holidays. 

FAA Order 7400.11E, Airspace 

Designations and Reporting Points, and 

subsequent amendments can be viewed 

online at https://www.faa.gov/air_

traffic/publications/. For further 

information, you can contact the 

Airspace Policy Group, Federal Aviation 

Administration, 800 Independence 

Avenue SW, Washington, DC 20591; 

telephone: (202) 267–8783. The Order is 

also available for inspection at the 

National Archives and Records 

Administration (NARA). For 

information on the availability of FAA 

Order 7400.11E at NARA, email 

fedreg.legal@nara.gov or go to https://

www.archives.gov/federal-register/cfr/ 

ibr-locations.html. 

FOR FURTHER INFORMATION CONTACT: 

Jeffrey Claypool, Federal Aviation 

Administration, Operations Support 

Group, Central Service Center, 10101 

Hillwood Parkway, Fort Worth, TX 

76177; telephone (817) 222–5711. 

SUPPLEMENTARY INFORMATION: 

Authority for This Rulemaking 

The FAA’s authority to issue rules 

regarding aviation safety is found in 

Title 49 of the United States Code. 

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. This rulemaking is 

promulgated under the authority 

described in Subtitle VII, Part A, 

Subpart I, Section 40103. Under that 

section, the FAA is charged with 

prescribing regulations to assign the use 

of airspace necessary to ensure the 

safety of aircraft and the efficient use of 

airspace. This regulation is within the 

scope of that authority as it would 

amend the Class E airspace extending 

upward from 700 feet above the surface 

at Sundance Airport, Oklahoma City, 

OK, to support instrument flight rule 

operations at this airport. 

Comments Invited 

Interested parties are invited to 

participate in this proposed rulemaking 

by submitting such written data, views, 

or arguments, as they may desire. 

Comments that provide the factual basis 

supporting the views and suggestions 

presented are particularly helpful in 

developing reasoned regulatory 

decisions on the proposal. Comments 

are specifically invited on the overall 

regulatory, aeronautical, economic, 

environmental, and energy-related 

aspects of the proposal. 

Communications should identify both 

docket numbers and be submitted in 

triplicate to the address listed above. 

Commenters wishing the FAA to 

acknowledge receipt of their comments 

on this notice must submit with those 

comments a self-addressed, stamped 


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