[Federal Register Volume 88, Number 99 (Tuesday, May 23, 2023)]
[Proposed Rules]
[Pages 32978-32980]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-10908]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 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.
 
 ========================================================================
 

  Federal Register / Vol. 88, No. 99 / Tuesday, May 23, 2023 / Proposed 
Rules  

[[Page 32978]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-0940; Project Identifier AD-2022-01521-E]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Division Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD) 
2018-21-11, which applies to all Pratt & Whitney Division (PW) Model 
PW4074D, PW4077D, PW4084D, PW4090, and PW4090-3 engines with a low-
pressure compressor (LPC) fan hub, part number (P/N) 51B821 or P/N 
52B521, installed. AD 2018-21-11 requires performing repetitive eddy 
current inspections (ECIs) and fluorescent penetrant inspections (FPIs) 
for cracks in certain LPC fan hubs and removing LPC fan hubs from 
service that fail any inspection. Since the FAA issued AD 2018-21-11, 
the FAA determined that affected LPC fan hub assemblies can meet the 
published certificated life limit without the need for the required 
repetitive FPI inspections in AD 2018-21-11, and the repetitive ECI 
inspections require shortened intervals. Based on a report of another 
incident, the FAA determined that the unsafe condition is likely to 
exist or develop on additional LPC fan hub assemblies and PW model 
engines. This proposed AD would expand the applicability to include 
Model PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 
engines with any part number LPC fan hub assembly installed and would 
require performing repetitive ECIs of the LPC fan hub assembly and, 
depending on the results of the inspections, removal of the LPC fan hub 
assembly from service. 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 July 7, 
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-2023-0940; 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 Pratt & Whitney Division service information 
identified in this NPRM, contact Pratt & Whitney Division, 400 Main 
Street, East Hartford, CT 06118; phone: (860) 565-0140; email: 
[email protected]; website: connect.prattwhitney.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 (817) 222-5110.

FOR FURTHER INFORMATION CONTACT: Carol Nguyen, Aviation Safety 
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; 
phone: (781) 238-7655; email: [email protected].

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-2023-0940; Project Identifier 
AD-2022-01521-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 
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 
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, 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 issued AD 2018-21-11, Amendment 39-19469 (83 FR 54663, 
October 31, 2018), (``AD 2018-21-11''), for all Pratt & Whitney 
Division (PW) PW4074D, PW4077D, PW4084D, PW4090, and PW4090-3 turbofan 
engines with low-pressure compressor (LPC) fan hub assembly, part 
number (P/N) 51B821 or P/N 52B521, installed. AD 2018-21-11 was 
prompted by low-cycle fatigue analysis techniques, updated by the 
engine manufacturer, which

[[Page 32979]]

indicated certain LPC fan hub assemblies could crack before their 
published life limit. AD 2018-21-11 requires performing initial and 
repetitive FPI and ECIs of the LPC fan hub assembly and removing the 
LPC fan hub assembly from service if it fails any inspection. The 
agency issued AD 2018-21-11 to prevent failure of the LPC fan hub 
assembly.

Actions Since AD 2018-21-11 Was Issued

    Since the FAA issued AD 2018-21-11, the FAA determined that 
affected LPC fan hub assemblies can meet the published certificated 
life limit without the need for the required repetitive FPI inspections 
in AD 2018-21-11, and the repetitive ECI inspections require shortened 
intervals. The FAA also received a report of an uncontained failure of 
the fan hub assembly on an Engine Alliance GP7270 engine on an Air 
France flight. Investigation of this uncontained failure revealed that, 
due to the similarity of design and material processing for the LPC fan 
hub assembly, the ECI inspections should be done on all LPC fan hub 
assembly part numbers installed on PW Model PW4074, PW4074D, PW4077, 
PW4077D, PW4084D, PW4090, and PW4090-3 engines.
    This condition, if not addressed, could result in uncontained 
debris release, 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 Under 1 CFR Part 51

    The FAA reviewed Pratt & Whitney Division Alert Service Bulletin 
PW4G-112-A72-362, Revision 1 dated January 20, 2023. This service 
information specifies procedures for ECIs of the LPC fan hub assembly 
for cracks. This service information also specifies reporting 
inspection results to PW.
    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 none of the requirements of AD 2018-
21-11. This proposed AD would expand the applicability to include Model 
PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 engines 
with any P/N LPC fan hub assembly installed. This proposed AD would 
also require performing repetitive ECIs of the LPC fan hub assembly 
and, depending on the results of the inspections, removing the LPC fan 
hub assembly from service.

Differences Between This Proposed AD and the Service Information

    Where the service information specifies reporting certain 
information to PW, this proposed AD does not include that requirement.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 65 engines installed on airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this proposed 
AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
              Action                      Labor cost             Parts cost           product        operators
----------------------------------------------------------------------------------------------------------------
Perform ECI of LPC fan hub          14 work-hours x $85    Not Applicable.......          $1,190         $77,350
 assembly.                           per hour = $1,190.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
replacements that would be required based on the results of the 
proposed inspection. The agency has no way of determining the number of 
engines that might need this replacement:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace LPC fan hub assembly..................  65 work-hours x $85 per hour =        $1,194,000      $1,199,525
                                                 $5,525.
----------------------------------------------------------------------------------------------------------------

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.

[[Page 32980]]

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

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by:
0
a. Removing Airworthiness Directive 2018-21-11, Amendment 39-19469 (83 
FR 54663, October 31, 2018); and
0
b. Adding the following new airworthiness directive:

Pratt & Whitney Division: Docket No. FAA-2023-0940; Project 
Identifier AD-2022-01521-E.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) action by July 7, 2023.

(b) Affected ADs

    This AD replaces AD 2018-21-11, Amendment 39-19469 (83 FR 54663, 
October 31, 2018); (AD 2018-21-11).

(c) Applicability

    This AD applies to all Pratt & Whitney Division (PW) Model 
PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 
engines.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7230, Turbine Engine 
Compressor Section.

(e) Unsafe Condition

    This AD was prompted by an updated analysis by the engine 
manufacturer, which indicated certain low-pressure compressor (LPC) 
fan hubs could crack before their published life limit. We are 
issuing this AD to prevent failure of the LPC fan hub. The unsafe 
condition, if not addressed, could result in uncontained hub 
release, 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

    (1) Before accumulating 550 flight cycles (FC) after the 
effective date of this AD, and thereafter at intervals not to exceed 
550 FC since the last eddy current inspection (ECI), perform an ECI 
of the LPC fan hub assembly, in accordance with the Accomplishment 
Instructions, For Engines Installed on Aircraft, paragraph 2., or 
For Engines Not Installed on Aircraft, paragraph 3; of PW Alert 
Service Bulletin PW4G-112-A72-362, Revision 1 dated January 20, 2023 
(ASB PW4G-112-A72-362, Revision 1).
    (2) If a rejectable or reportable indication is found during the 
inspections required by paragraph (g)(1) of this AD, before further 
flight, replace the LPC fan hub assembly with a part eligible for 
installation.

(h) Installation Prohibition

    After the effective date of this AD, do not install an LPC fan 
hub assembly on any engine, unless it is a part eligible for 
installation as defined in paragraph (j) of this AD.

(i) No Reporting Requirement

    This AD does not require reporting certain information to the 
manufacturer as specified in ASB PW4G-112-A72-362, Revision 1.

(j) Definitions

    For the purposes of this AD, a ``part eligible for 
installation'' is an affected LPC fan hub assembly that has been 
inspected as required by paragraph (g)(1) of this AD and does not 
have a rejectable or reportable indication or a LPC fan hub assembly 
with zero cycles since new.

(k) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, 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 (l) of this AD.
    (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.

(l) Related Information

    For more information about this AD, contact Carol Nguyen, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue; 
phone: (781) 238-7655; email: [email protected].

(m) 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 Division Alert Service Bulletin PW4G-112-
A72-362, Revision 1, dated January 20, 2023.
    (ii) [Reserved]
    (3) For service information identified in this AD, contact Pratt 
& Whitney Division, 400 Main Street, East Hartford, CT 06118; phone: 
(860) 565-0140; email: [email protected]; 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: [email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on May 4, 2023.
Michael Linegang,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-10908 Filed 5-22-23; 8:45 am]
BILLING CODE 4910-13-P