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

58114 

Vol. 88, No. 164 

Friday, August 25, 2023 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2023–1640; Project 

Identifier AD–2022–00283–E] 

RIN 2120–AA64 

Airworthiness Directives; Pratt & 

Whitney 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 (PW) Model PW2037, 

PW2037M, and PW2040 engines with a 

certain high-pressure turbine (HPT) 2nd 

stage blade assembly installed. This 

proposed AD was prompted by an inflight shutdown (IFSD) caused by the 

fracture of HPT 2nd stage turbine hub 

assembly lugs, which resulted in blade 

liberation and a titanium fire in the 

high-pressure compressor (HPC). This 

proposed AD would require a visual 

inspection of the HPT 2nd stage blade 

assemblies for missing contact marks, a 

dimensional shadowgraph inspection of 

the HPT 2nd stage blade assemblies for 

blade root profile dimensional 

inspection, and an eddy current 

inspection (ECI) of the HPT 2nd stage 

turbine hub assembly for conforming 

slot flatness. This proposed AD would 

also require removal and replacement of 

any HPT 2nd stage turbine hub 

assembly or HPT 2nd stage blade 

assembly that does not pass any 

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 September 25, 

2023. 

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 

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. 

AD Docket: You may examine the AD 

docket at regulations.gov by searching 

for and locating Docket No. FAA–2023– 

1640; 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. 

Material Incorporated by Reference: 

• For service information identified 

in this NPRM, contact Pratt & Whitney, 

400 Main Street, East Hartford, CT 

06118; phone: (800) 565–0140; email: 

help24@pw.utc.com; website: 

connect.prattwhitney.com. 

• You may view this service 

information at the FAA, Airworthiness 

Products Section, 1200 District Avenue, 

Burlington, MA 01803. For information 

on the availability of this material at the 

FAA, call (817) 222–5110. 

FOR FURTHER INFORMATION CONTACT: 

Carol Nguyen, Aviation Safety Engineer, 

FAA, 2200 South 216th Street, Des 

Moines, WA 98198; phone: (781) 238– 

7655; email: carol.nguyen@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–2023–1640; Project Identifier AD– 

2022–00283–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. 

The FAA has been informed that PW 

has done some outreach with affected 

operators regarding the proposed 

corrective actions for this unsafe 

condition. As a result, affected operators 

are already aware of the proposed 

corrective actions and, in some cases, 

have already begun planning for 

replacement of certain HPT 2nd stage 

turbine hub assemblies and HPT 2nd 

stage blade assemblies. Therefore, the 

FAA has determined that a 30-day 

comment period is appropriate given 

the particular circumstances related to 

the proposed correction of this unsafe 

condition. 

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 

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 Carol Nguyen, 

Aviation Safety Engineer, FAA, 2200 

South 216th Street, Des Moines, WA 

98198. 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 of an IFSD 

of a Model PW2037 engine installed on 

a Boeing Model 757 airplane that 

occurred on September 8, 2020. 

Subsequent investigation by the 

manufacturer found that two turbine 

hub assembly lug fractures on the HPT 

2nd stage turbine hub assembly caused 


ddrumheller on DSK120RN23PROD with PROPOSALS1
Federal Register / Vol. 88, No. 164 / Friday, August 25, 2023 / Proposed Rules 58115 

the release of four HPT 2nd stage blade 

assemblies part number (P/N) 1B7522, 

which caused damage upstream in the 

HPC, resulting in a titanium fire. 

Further investigation by the 

manufacturer revealed the blade root 

profile of certain HPT 2nd stage blade 

assemblies did not conform to the 

manufacturer’s type design. The nonconforming blades installed in the HPT 

2nd stage turbine hub assembly caused 

uneven contact on the HPT 2nd stage 

turbine hub assembly lug leading to 

increased attachment stress resulting in 

failure of the HPT 2nd stage turbine hub 

assembly lug and HPT 2nd stage turbine 

hub assembly. This condition, if not 

addressed, could result in the 

uncontained release of the HPT 2nd 

stage blade assemblies, damage to the 

engine, and damage to the airplane. 

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 PW Turbojet 

Engine Service Bulletin PW2000 A72– 

777, Revision 2, dated April 11, 2023 

(PW2000 A72–777 Rev. 2). This service 

information specifies procedures for 

performing a visual inspection of the 

HPT 2nd stage blade assemblies, 

dimensional shadowgraph inspection of 

the HPT 2nd stage blade assemblies, and 

an ECI of the HPT 2nd stage turbine hub 

assembly. 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 require 

accomplishing the actions identified as 

‘‘RC’’ (required for compliance) in the 

Accomplishment Instructions of 

PW2000 A72–777 Rev. 2, except for any 

differences identified as exceptions in 

the regulatory text of this proposed AD. 

Costs of Compliance 

The FAA estimates that this AD, if 

adopted as proposed, would affect 425 

engines installed on airplanes 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 of the HPT 2nd stage turbine hub assembly ................... 8 work-hours × $85 per hour 

= $680.

$0 $680 $289,000 

Visual inspection of HPT 2nd stage blade assembly ............. 8 work-hours × 85 per hour = 

680.

0 680 289,000 

Dimensional shadowgraph inspection of HPT 2nd stage 

blade assemblies.

8 work-hours × 85 per hour = 

680.

0 680 289,000 

The FAA estimates the following 

costs to do any necessary replacements 

that would be required based on the 

results of the proposed inspections. The 

agency has no way of determining the 

number of aircraft that might need these 

replacements: 

ON-CONDITION COSTS

Action Labor cost Parts cost Cost per 

product 

Replace HPT 2nd stage turbine hub assembly ........................................ 0 work-hours × $85 per hour = $0 .. $456,000 $456,000 

Replace HPT 2nd stage blade assembly .................................................. 0 work-hours × $85 per hour = $0 .. 17,000 17,000 

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: 


ddrumheller on DSK120RN23PROD with PROPOSALS1
58116 Federal Register / Vol. 88, No. 164 / Friday, August 25, 2023 / Proposed Rules 

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–2023– 

1640; Project Identifier AD–2022–00283– 

E. 

(a) Comments Due Date 

The FAA must receive comments on this 

airworthiness directive (AD) by September 

25, 2023. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to Pratt & Whitney (PW) 

Model PW2037, PW2037M, and PW2040 

engines with a high-pressure turbine (HPT) 

2nd stage blade assembly, part number (P/N) 

1B7522 installed. 

(d) Subject 

Joint Aircraft System Component (JASC) 

Code 7250, Turbine Section. 

(e) Unsafe Condition 

This AD was prompted by an in-flight 

shutdown caused by the fracture of HPT 2nd 

stage turbine hub assembly lugs. The FAA is 

issuing this AD to prevent failure of the HPT 

2nd stage turbine hub assembly lug and HPT 

2nd stage blade assemblies. The unsafe 

condition, if not addressed, could result in 

the uncontained release of the HPT 2nd stage 

blade assemblies, damage to the engine, and 

damage to the airplane. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Required Actions 

Before exceeding the applicable 

compliance times specified in Planning 

Information, Compliance, page 2, of PW 

Turbojet Engine Service Bulletin PW2000 

A72–777, Revision 2, dated April 11, 2023 

(PW2000 A72–777 Rev. 2), or before 

accumulating 500 cycles after the effective 

date of this AD, whichever occurs later, 

perform all applicable actions identified as 

‘‘RC’’ (required for compliance) in, and in 

accordance with, the Accomplishment 

Instructions of PW2000 A72–777 Rev. 2. 

(h) Credit for Previous Actions 

You may take credit for the actions 

required by paragraph (g) of this AD if you 

performed these actions before the effective 

date of this AD in accordance with PW 

Turbojet Engine Service Bulletin PW2000 

A72–777, Initial Issue, dated September 29, 

2021, or PW Turbojet Engine Service Bulletin 

PW2000 A72–777, Revision 1, dated 

December 21, 2022. 

(i) Alternative Methods of Compliance 

(AMOCs) 

(1) The Manager, AIR–520 Continued 

Operational Safety 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 paragraph (j) of this AD and 

email 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. 

(3) Except as required by paragraph (g) of 

this AD: For service information that 

contains steps that are labeled as Required 

for Compliance (RC), the following 

provisions apply. 

(i) The steps labeled as RC, including 

substeps under an RC step and any figures 

identified in an RC step, must be done to 

comply with the AD. An AMOC is required 

for any deviations to RC steps, including 

substeps and identified figures. 

(ii) Steps not labeled as RC may be 

deviated from using accepted methods in 

accordance with the operator’s maintenance 

or inspection program without obtaining 

approval of an AMOC, provided the RC steps, 

including substeps and identified figures, can 

still be done as specified, and the airplane 

can be put back in an airworthy condition. 

(j) Related Information 

For more information about this AD, 

contact Carol Nguyen, Aviation Safety 

Engineer, FAA, 2200 South 216th Street, Des 

Moines, WA 98198; phone: (781) 238–7655; 

email: carol.nguyen@faa.gov. 

(k) Material Incorporated by Reference 

(1) The Director of the Federal Register 

approved the incorporation by reference 

(IBR) of the service information listed in this 

paragraph under 5 U.S.C. 552(a) and 1 CFR 

part 51. 

(2) You must use this service information 

as applicable to do the actions required by 

this AD, unless the AD specifies otherwise. 

(i) Pratt & Whitney Turbojet Engine Service 

Bulletin PW2000 A72–777, Revision 2, dated 

April 11, 2023. 

(ii) [Reserved] 

(3) For service information identified in 

this AD, contact Pratt & Whitney, 400 Main 

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

565–0140; email: help24@pw.utc.com; 

website: connect.prattwhitney.com. 

(4) 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 (817) 222–5110. 

(5) You may view this service information 

that is incorporated by reference at the 

National Archives and Records 

Administration (NARA). For information on 

the availability of this material at NARA, 

email: fr.inspection@nara.gov, or go to: 

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

Issued on July 24, 2023. 

Victor Wicklund, 

Deputy Director, Compliance & Airworthiness 

Division, Aircraft Certification Service. 

[FR Doc. 2023–18259 Filed 8–24–23; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2023–0009; Project 

Identifier MCAI–2022–00789–T] 

RIN 2120–AA64 

Airworthiness Directives; Airbus SAS 

Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Supplemental notice of 

proposed rulemaking (SNPRM). 

SUMMARY: The FAA is revising a notice 

of proposed rulemaking (NPRM) that 

would have applied to certain Airbus 

SAS Model A319–115 airplanes; Model 

A320–214, –216, –232, –251N, and 

–271N airplanes; and Model A321–211, 

–231, –251N, –251NX, –252NX, –253N, 

–253NX, –271N, –271NX, and –272N 

airplanes. This action revises the NPRM 

by adding Model A321–213 airplanes, 

which were inadvertently left out of the 

applicability. The FAA is proposing this 

airworthiness directive (AD) to address 

the unsafe condition on these products. 

Since these actions would impose an 

additional burden over those in the 

NPRM, the FAA is requesting comments 

on this SNPRM. 

DATES: The FAA must receive comments 

on this SNPRM by October 10, 2023. 

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 

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. 

AD Docket: You may examine the AD 

docket at regulations.gov under Docket 

No. FAA–2023–0009; or in person at 

Docket Operations between 9 a.m. and 


ddrumheller on DSK120RN23PROD with PROPOSALS1