[Federal Register Volume 89, Number 60 (Wednesday, March 27, 2024)]
[Rules and Regulations]
[Pages 21190-21196]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-06433]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-2523; Project Identifier AD-2023-01086-E; 
Amendment 39-22709; AD 2024-06-04]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Pratt & Whitney (PW) Model PW1519G, PW1521G, PW1521GA, PW1521G-
3, PW1524G, PW1524G-3, PW1525G, PW1525G-3, PW1919G, PW1921G, PW1922G, 
PW1923G, and PW1923G-A engines. This AD was prompted by an updated 
analysis of an event involving an International Aero Engines, LLC (IAE 
LLC) Model PW1127GA-JM engine, which experienced a high-pressure 
compressor (HPC) 7th-stage integrally bladed rotor (IBR-7) separation 
that resulted in an engine shutdown and aborted takeoff. This AD 
requires performing an angled ultrasonic inspection (AUSI) of certain 
high-pressure turbine (HPT) 1st-stage hubs, HPT 2nd-stage hubs, and HPC 
8th-stage disks for cracks and, depending on the results of the 
inspections, replacing the HPT 1st-stage hubs, HPT 2nd-stage hubs, or 
HPC 8th-stage disks. This AD also requires accelerated replacement of 
certain HPC 7th-stage rotors, HPC 8th-stage disks, HPC rear hubs, HPT 
1st-stage hubs, HPT 2nd-stage hubs, HPT 1st-stage air seals, HPT 2nd-
stage air seals, HPT 1st-stage blade retaining plates, and HPT 2nd-
stage blade retaining plates. The FAA is issuing this AD to address the 
unsafe condition on these products.

DATES: This AD is effective April 11, 2024.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of April 11, 
2024.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2023-2523; 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 final rule, any comments received, and other 
information. The address for Docket Operations is U.S. Department of 
Transportation, Docket

[[Page 21191]]

Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
    Material Incorporated by Reference:
     For Pratt & Whitney service information identified in this 
AD, contact International Aero Engines, LLC, 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. It is 
also available at regulations.gov under Docket No. FAA-2023-2523.

FOR FURTHER INFORMATION CONTACT: Carol Nguyen, Aviation Safety 
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: 
(781) 238-7655; email: [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to certain PW Model 
PW1519G, PW1521G, PW1521GA, PW1521G-3, PW1524G, PW1524G-3, PW1525G, 
PW1525G-3, PW1919G, PW1921G, PW1922G, PW1923G, and PW1923G-A engines. 
The NPRM published in the Federal Register on January 9, 2024 (89 FR 
1038). The NPRM was prompted by an incident involving an Airbus Model 
A320neo airplane powered by IAE LLC Model PW1127GA-JM engines that 
experienced a failure of the HPC IBR-7 resulting in an engine shutdown 
and aborted take-off. Following this event, the manufacturer conducted 
a records review of production and field-returned parts and re-
evaluated their engineering analysis methodology. The new analysis 
found that the failure of the HPC IBR-7 was caused by a nickel powdered 
metal anomaly, similar in nature to an anomaly previously observed. The 
analysis also concluded that there is an increased risk of failure for 
additional nickel powdered metal parts in certain nickel powdered metal 
production campaigns, and these parts are susceptible to failure much 
earlier than previously determined. In the NPRM, the FAA proposed to 
require performing an AUSI of certain HPT 1st-stage hubs, HPT 2nd-stage 
hubs, and HPC 8th-stage disks for cracks and, depending on the results 
of the inspections, replacing the HPT 1st-stage hubs, HPT 2nd-stage 
hubs, or HPC 8th-stage disks. The FAA also proposed to require 
accelerated replacement of certain HPC 7th-stage rotors, HPC 8th-stage 
disks, HPC rear hubs, HPT 1st-stage air seals, HPT 2nd-stage air seals, 
HPT 1st-stage hubs, HPT 2nd-stage hubs, HPT 1st-stage blade retaining 
plates, and HPT 2nd-stage blade retaining plates. The FAA is issuing 
this AD to address the unsafe condition on these products.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from five commenters. The commenters were 
the Air Line Pilots Association, International (ALPA), Delta Air Lines, 
Inc. (DAL), Lufthansa Technik AG (Lufthansa), PW, and Transport Canada 
Civil Aviation (TCCA). ALPA supported the NPRM without change. DAL, 
Lufthansa, PW, and TCCA requested changes to the proposed AD. The 
following presents the comments received on the NPRM and the FAA's 
response to each comment.

Request To Clarify Unsafe Condition

    DAL requested that the FAA update paragraph (e) of the proposed AD 
or create a new paragraph to clarify why the HPC IBR-7 does not require 
repetitive AUSIs. Delta noted that the HPC IBR-7 was the part that 
originally separated during an event outlined in the proposed AD, 
leading to engine shutdown and aborted takeoff, which prompted this AD.
    The FAA disagrees with the request to update paragraph (e) or add a 
paragraph to the AD that clarifies why there are no repetitive AUSIs 
for the HPC IBR-7. The AUSI for the HPC IBR-7 was not available when 
the NPRM was written and to address the unsafe condition quickly, the 
FAA did not want to delay the issuance of this AD in order to add the 
AUSI for the HPC IBR-7. Since this AD is considered an interim action, 
the FAA will consider adding the AUSI for the HPC IBR-7 or other 
actions in the future. The FAA did not change this AD as a result of 
this comment.

Request To Update Definition for Parts Eligible for Installation

    DAL requested that the FAA update paragraph (i)(3) of the proposed 
AD to clarify installation eligibility for new/not service run HPC/HPT 
hardware that is not currently installed on an engine. Delta stated 
that HPC/HPT hardware scanned at production are scanned per the non-
destructive inspection procedure (NDIP) and may not list service 
bulletin status so clarification is needed to determine hardware 
eligibility based off service bulletin status as well as NDIP status.
    The FAA disagrees with the request to update the definition of 
parts eligible for installation to include new/not service run parts 
because new parts inspected at production would not have the NDIP 
listed in their paperwork. The service documents require the AUSI of 
new parts prior to installation with no allowance for parts inspected 
at production. The FAA did not change this AD as a result of this 
comment.

Request To Update Definition of Engine Shop Visit and HPC Engine Shop 
Visit

    DAL requested that the FAA update the definitions for ``engine shop 
visit'' and ``HPC engine shop visit'' in paragraph (i)(5) and (6) of 
the proposed AD to provide clarity and avoid ambiguity. Delta noted 
that the definition for ``engine shop visit'' includes the term 
``pairs'' when defining separation of major mating engine flanges. 
Delta stated that this does not clearly define what constitutes an 
``engine shop visit,'' as the term ``pairs'' may be interpreted as 
separation of two or more different lettered flanges. Delta also stated 
that the phrase ``when the HPC rotor assembly is removed from the 
engine'' used in the definition for an ``HPC engine shop visit'' does 
not clearly describe the different scenarios that may constitute HPC 
engine shop visits since the HPC rotor assembly can be at different 
levels of exposure depending on the shop visit type.
    The FAA partially agrees with the request. The FAA agrees to update 
the definition of an ``HPC shop visit'' in paragraph (i)(6) of this AD 
to: ``For the purposes of this AD, an `HPC engine shop visit' is when 
the HPC rotor assembly is removed from the HPC module.'' The FAA 
disagrees with the request to update the definition for an ``engine 
shop visit'' because the definition used in this AD is standard and 
taken from the World Airlines Technical Operations Glossary. The FAA 
notes that the term ``pairs'' of major mating engine flanges refers to 
the mating surfaces on each individual part of the bolted joint.

Request To Include Alert Service Bulletin (ASB) Issue Numbers in Tables

    DAL requested that the FAA update Table 1 to Paragraph (g)(3) and 
Table 2 to Paragraph (g)(7) of the proposed AD to include the issue 
numbers of the ASBs that are listed in the Applicable (serial number) 
S/N listing, Applicable service bulletin and the Table S/N is listed in 
columns. DAL noted that certain ASBs, such as 72-00-0196 Issue 002, 
were revised to include additional

[[Page 21192]]

serial numbers in the effectivity, so different ASB issue numbers 
contain different serial number effectivity.
    The FAA agrees with the request and has updated Table 1 to 
paragraph (g)(3) and Table 2 to paragraph (g)(7) of this AD to include 
the issue numbers of the applicable ASBs.

Request To Edit Service Bulletin References

    Lufthansa requested that the FAA merge paragraph (g)(1) of the 
proposed AD with paragraph (g)(4)(i) of the proposed AD and paragraph 
(g)(2) of the proposed AD with paragraph (g)(4)(ii) of the proposed AD 
and refer to ASBs PW1000G-A-72-00-0204 and PW1000G-A-72-00-0205, as 
applicable. Lufthansa noted that all of the ASBs referenced in these 
paragraphs refer to NDIP-1260 for 8th-stage discs, NDIP-1254 for 1st-
stage hubs, and NDIP-1257 for 2nd-stage hubs. Lufthansa also noted that 
this aligns with the PW ASB set-up, which requires inspections during 
shop visits in accordance with ASBs PW1000G-A-72-00-0204 and PW1000G-A-
72-00-0205 for all less affected hardware and stricter inspections for 
parts more affected and listed in ASBs PW1000G-A-72-00-0196 and 
PW1000G-A-72-00-0197 only.
    The FAA disagrees with the request to merge steps within paragraph 
(g) of this AD. The FAA notes that several service information 
documents are referenced within paragraph (g) of this AD in order to 
account for both initial AUSI and repetitive AUSIs. The FAA did not 
change this AD as a result of this comment.

Request To Clarify 100 Flight Cycle Threshold

    TCCA requested that the FAA clarify the intention of the condition 
``or within 100 FCs after the effective date of this AD'' that is 
proposed in paragraph (g)(3) of the proposed AD and to clarify if it is 
related to the intent of paragraph (g)(13) of the proposed AD.
    For clarification, the intention of the condition ``or within 100 
FCs after the effective date of this AD'' is to provide a grace period 
for affected parts that are over the cycle limits listed in Table 1 to 
Paragraph (g)(3) of this AD, and the condition is not related to 
paragraph (g)(13) of this AD. The FAA did not change this AD as a 
result of this comment.

Request To Add Definition for Affected Part

    TCCA requested that the FAA update the proposed AD by adding a 
definition for ``affected part'' in order to avoid misinterpretation 
since there are multiple parts with different part numbers and a 
subpopulation of part SNs and inspection thresholds involved.
    The FAA disagrees with the request to add a definition for 
``affected part'' to this AD because the affected parts and part 
numbers are already specified within paragraph (g) of this AD. The FAA 
did not change this AD as a result of this comment.

Request To Update Number of Affected U.S. Products

    PW requested that the FAA update the NPRM by changing the number of 
engines installed on airplanes of U.S. registry from 430 to 121.
    The FAA agrees and has updated the number of engines installed on 
airplanes of U.S. registry from 430 to 121 in the Cost of Compliance 
paragraph of this final rule and updated the estimated costs 
accordingly.

Request To Incorporate Updated Service Information

    PW requested that the FAA incorporate PW Special Instruction (SI) 
No. 240F-23A, dated February 7, 2024, into the final rule. PW noted 
that they have refined this SI, which lists a limited number of 
affected HPT hubs by S/N, and this information has already been 
provided to affected operators.
    The FAA agrees with the request and has updated this final rule to 
reference PW SI No. 240F-23A, dated February 7, 2024, in paragraphs (h) 
and (m)(2)(ix) of this AD.

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, and determined that air safety requires adopting this AD as 
proposed. Accordingly, the FAA is issuing this AD to address the unsafe 
condition on these products. Except for minor editorial changes, and 
any other changes described previously, this AD is adopted as proposed 
in the NPRM. None of the changes will increase the economic burden on 
any operator.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed the following service information:
     PW ASB PW1000G-A-72-00-0196-00A-930A-D, Issue No: 002, 
dated November 30, 2023, and PW ASB PW1000G-A-72-00-0141-00B-930A-D, 
Issue No: 002, dated November 30, 2023. This service information 
specifies a list of affected HPT 1st-stage hubs and HPT 2nd-stage hubs 
that are identified by serial number (S/N) and installed on certain PW 
engines; and instructions for performing an AUSI on affected HPT 1st-
stage hubs and HPT 2nd-stage hubs.
     PW ASB PW1000G-A-72-00-0197-00A-930A-D, Issue No: 004, 
dated November 30, 2023, and PW ASB PW1000G-A-72-00-0142-00B-930A-D, 
Issue No: 004, dated November 30, 2023. This service information 
specifies a list of affected HPC 8th-stage disks that are identified by 
S/N and installed on certain PW engines; and instructions for 
performing an AUSI on affected HPC 8th-stage disks.
     PW ASB PW1000G-A-72-00-0204-00A-930A-D, Issue No: 001, 
dated November 30, 2023, and PW ASB PW1000G-A-72-00-0150-00B-930A-D, 
Issue No: 001, dated November 30, 2023, which specifies procedures for 
performing repetitive AUSIs on affected HPC 8th-stage disks.
     PW ASB PW1000G-A-72-00-0205-00A-930A-D, Issue No: 001, 
dated November 30, 2023, and PW ASB PW1000G-A-72-00-0151-00B-930A-D, 
Issue No: 001, dated November 30, 2023, which specify procedures for 
performing repetitive AUSIs on affected HPT 1st-stage hubs and HPT 2nd-
stage hubs.
     PW SI No. 240F-23A, dated February 7, 2024, which 
specifies a list of affected HPT 1st-stage hubs and HPT 2nd-stage hubs 
that are identified by S/N and installed on certain PW engines. 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 the ADDRESSES section.

Interim Action

    The FAA considers this AD to 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.

Justification for Determination of the Effective Date

    Section 553(d) of the Administrative Procedure Act (APA) (5 U.S.C. 
551 et seq.) authorizes agencies to make rules effective in less than 
thirty days, upon a finding of ``good cause.'' The FAA has found that 
the risk to the flying public justifies a shortened effective date for 
this rule due to powdered metal anomalies in HPT 1st-stage hub, HPT 
2nd-stage hub, and HPC IBR-8 that could lead to premature fracture and 
uncontained failure, which could lead to the release of high-energy 
debris, damage to the engine, damage to the airplane, and loss of the 
airplane. The compliance time for replacement of certain parts is 
within 100 flight cycles after the effective date of this AD, which

[[Page 21193]]

is on average one calendar month of operation. The longer these parts 
remain in service, the higher the probability of failure. Accordingly, 
the FAA finds that good cause exists pursuant to 5 U.S.C. 553(d) for 
making this amendment effective in less than 30 days.

Costs of Compliance

    The FAA estimates that this AD affects 121 engines installed on 
airplanes of U.S. registry. The FAA estimates that 121 engines will 
need the AUSI of the HPT 1st-stage hub, HPT 2nd-stage hub, and HPC 8th-
stage disk; 121 engines will need replacement of the HPT 1st-stage hub; 
121 engines will need replacement of the HPT 2nd-stage hub; 121 engines 
will need replacement of the HPC 7th-stage rotor; 121 engines will need 
replacement of the HPC 8th-stage disk; 121 engines would need 
replacement of the HPC rear hub; 121 engines will need replacement of 
the HPT 1st-stage air seal; 121 engines will need replacement of the 
HPT 2nd-stage air seal; 121 engines will need replacement of the HPT 
1st-stage blade retaining plate; and 121 engines will need replacement 
of the HPT 2nd-stage blade retaining plate.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                        Parts cost
                 Action                          Labor cost            (average pro-    Cost per   Cost on U.S.
                                                                        rated cost)     product      operators
----------------------------------------------------------------------------------------------------------------
Perform AUSI of HPT 1st-stage hub, HPT   60 work-hours x $85 per                   $0     $5,100        $617,100
 2nd-stage hub, and HPC 8th-stage disk.   hour = $5,100.
Replace HPT 1st-stage hub..............  10 work-hours x 85 per                49,500     50,350       6,092,350
                                          hour = 850.
Replace HPT 2nd-stage hub..............  10 work-hours x 85 per                25,500     26,350       3,188,350
                                          hour = 850.
Replace HPC 7th-stage rotor............  10 work-hours x 85 per                48,000     48,850       5,910,850
                                          hour = 850.
Replace HPC 8th-stage disk.............  10 work-hours x 85 per                35,500     36,350       4,398,350
                                          hour = 850.
Replace HPC rear hub...................  10 work-hours x 85 per                83,000     83,850      10,145,850
                                          hour = 850.
Replace HPT 1st-stage air seal.........  10 work-hours x 85 per                21,000     21,850       2,643,850
                                          hour = 850.
Replace HPT 2nd-stage air seal.........  10 work-hours x 85 per                36,000     36,850       4,458,850
                                          hour = 850.
Replace HPT 1st-stage blade retaining    10 work-hours x 85 per                34,000     34,850       4,216,850
 plate.                                   hour = 850.
Replace HPT 2nd-stage blade retaining    10 work-hours x 85 per                13,000     13,850       1,675,850
 plate.                                   hour = 850.
----------------------------------------------------------------------------------------------------------------

    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some of the costs of this AD 
may be covered under warranty, thereby reducing the cost impact on 
affected operators.

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

    This AD will not have federalism implications under Executive Order 
13132. This AD will 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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will 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 Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 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 adding the following new airworthiness 
directive:

2024-06-04 Pratt & Whitney: Amendment 39-22709; Docket No. FAA-2023-
2523; Project Identifier AD-2023-01086-E.

(a) Effective Date

    This airworthiness directive (AD) is effective April 11, 2024.

(b) Affected ADs

    None.

(c) Applicability

    Pratt & Whitney (PW) Model PW1519G, PW1521G, PW1521GA, PW1521G-
3, PW1524G, PW1524G-3, PW1525G, PW1525G-3, PW1919G, PW1921G, 
PW1922G, PW1923G, and PW1923G-A engines.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7230, Turbine Engine 
Compressor Section; 7250, Turbine Section.

(e) Unsafe Condition

    This AD was prompted by an updated analysis of an event 
involving an International Aero Engines, LLC Model PW1127GA-JM 
engine, which experienced a high-pressure compressor (HPC) 7th-stage 
integrally bladed rotor separation that resulted in an engine 
shutdown and aborted takeoff. The FAA is issuing this AD to prevent 
failure of the high-pressure turbine (HPT) 1st-stage hub, HPT 2nd-
stage hub, and HPC 8th-stage disk. The unsafe condition, if not 
addressed, could result in uncontained hub failure, release of high-
energy debris, damage to the engine, damage to the airplane, and 
possible loss of the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

[[Page 21194]]

(g) Required Actions

    (1) For PW1500G engines with an installed HPC 8th-stage disk 
having part number (P/N) 30G7208, at the next HPC engine shop visit, 
except as required by paragraph (g)(3) of this AD, perform an angled 
ultrasonic inspection (AUSI) of the affected HPC 8th-stage disk for 
cracks in accordance with the Accomplishment Instructions, paragraph 
8., of PW Alert Service Bulletin (ASB) PW1000G-A-72-00-0197-00A-
930A-D, Issue No: 004, dated November 30, 2023 (PW1000G-A-72-00-
0197-00A-930A-D, Issue No: 004).
    (2) For PW1500G engines with an installed HPT 1st-stage hub 
having P/N 30G8501 or an installed HPT 2nd-stage hub having P/N 
30G7202, at the next engine shop visit, except as required by 
paragraph (g)(3) of this AD, perform an AUSI of the affected HPT 
1st-stage hub or HPT 2nd-stage hub, as applicable, for cracks in 
accordance with the Accomplishment Instructions, paragraph 8.A. or 
8.B., of PW ASB PW1000G-A-72-00-0196-00A-930A-D, Issue No: 002, 
dated November 30, 2023 (PW1000G-A-72-00-0196-00A-930A-D, Issue No: 
002).
    (3) For PW1500G engines with an installed part, P/N and serial 
number (S/N) listed in Table 1 to paragraph (g)(3) of this AD with 
no AUSI performed prior to the effective date of this AD, within the 
applicable compliance time listed in Table 1 to paragraph (g)(3) of 
this AD or within 100 flight cycles (FCs) after the effective date 
of this AD, whichever occurs later, perform an AUSI of the affected 
part for cracks in accordance with the applicable service bulletin 
listed in Table 1 to paragraph (g)(3) of this AD.

                               Table 1 to Paragraph (g)(3)--AUSI Compliance Times
----------------------------------------------------------------------------------------------------------------
                                                                                            Applicable service
                 Part                   Applicable S/N listing      Compliance time      bulletin (see paragraph
                                                                                            (m)(2) of this AD)
----------------------------------------------------------------------------------------------------------------
HPC 8th-stage disk P/N 30G7208.......  Table 1 of PW ASB        Next HPC engine shop     Accomplishment
                                        PW1000G-A-72-00-0197-0   visit not to exceed      Instructions,
                                        0A-930A-D, Issue No:     10,000 part cycles       paragraph 8., of PW
                                        004.                     since new (CSN).         ASB PW1000G-A-72-00-
                                                                                          0197-00A-930A-D, Issue
                                                                                          No: 004.
HPT 1st-stage hub P/N 30G8501........  Table 2 of PW ASB        Next engine shop visit   Accomplishment
                                        PW1000G-A-72-00-0196-0   not to exceed 5,000      Instructions,
                                        0A-930A-D, Issue No:     part CSN.                paragraph 8.A. of PW
                                        002.                                              ASB PW1000G-A-72-00-
                                                                                          0196-00A-930A-D, Issue
                                                                                          No: 002.
HPT 2nd-stage hub P/N 30G7202........  Table 3 of PW ASB        Next engine shop visit   Accomplishment
                                        PW1000G-A-72-00-0196-0   not to exceed 5,000      Instructions,
                                        0A-930A-D, Issue No:     part CSN.                paragraph 8.B, of PW
                                        002.                                              ASB PW1000G-A-72-00-
                                                                                          0196-00A-930A-D, Issue
                                                                                          No: 002.
HPT 1st-stage hub P/N 30G8501........  Table 4 of PW ASB        Next engine shop visit   Accomplishment
                                        PW1000G-A-72-00-0196-0   not to exceed 4,000      Instructions,
                                        0A-930A-D, Issue No:     part CSN.                paragraph 8.A, of PW
                                        002.                                              ASB PW1000G-A-72-00-
                                                                                          0196-00A-930A-D, Issue
                                                                                          No: 002.
HPT 2nd-stage hub P/N 30G7202........  Table 5 of PW ASB        Next engine shop visit   Accomplishment
                                        PW1000G-A-72-00-0196-0   not to exceed 4,000      Instructions,
                                        0A-930A-D, Issue No:     part CSN.                paragraph 8.B., of PW
                                        002.                                              ASB PW1000G-A-72-00-
                                                                                          0196-00A-930A-D, Issue
                                                                                          No: 002.
----------------------------------------------------------------------------------------------------------------

    (4) Thereafter at each piece-part exposure of the affected part 
for PW1500G engines with an installed HPC 8th-stage disk having P/N 
30G7208, an installed HPT 1st-stage hub having P/N 30G8501, or an 
installed HPT 2nd-stage hub having P/N 30G7202, do the following:
    (i) Perform an AUSI of the affected HPC 8th-stage disk for 
cracks in accordance with the Accomplishment Instructions, paragraph 
5.B., PW ASB PW1000G-A-72-00-0204-00A-930A-D, Issue No: 001, dated 
November 30, 2023.
    (ii) Perform an AUSI of the affected HPT 1st-stage hub and HPT 
2nd-stage hub, as applicable, for cracks in accordance with the 
Accomplishment Instructions, paragraph 7.A. or 7.B., of PW ASB 
PW1000G-A-72-00-0205-00A-930A-D, Issue No: 001, dated November 30, 
2023.
    (5) For PW1900G engines with an installed HPC 8th-stage disk 
having P/N 30G7208, at the next HPC engine shop visit, except as 
required by paragraph (g)(7) of this AD, perform an AUSI of the 
affected HPC 8th-stage disk for cracks in accordance with the 
Accomplishment Instructions, paragraph 8., of Pratt & Whitney PW ASB 
PW1000G-A-72-00-0142-00B-930A-D, Issue No: 004, dated November 30, 
2023 (PW1000G-A-72-00-0142-00B-930A-D, Issue No: 004).
    (6) For PW1900G engines with an installed HPT 1st-stage hub 
having P/N 30G8501 or an installed HPT 2nd-stage hub having P/N 
30G7202, at the next engine shop visit, except as required by 
paragraph (g)(7) of this AD, perform an AUSI of the affected HPT 
1st-stage hub and HPT 2nd-stage hub, as applicable, for cracks in 
accordance with the Accomplishment Instructions, paragraph 8.A. or 
8.B., of PW ASB PW1000G-A-72-00-0141-00B-930A-D, Issue No: 002, 
dated November 30, 2023 (PW1000G-A-72-00-0141-00B-930A-D, Issue No: 
002).
    (7) For PW1900G engines with an installed part, P/N and S/N 
listed in Table 2 to paragraph (g)(7) of this AD, with no AUSI 
performed prior to the effective date of this AD, within the 
compliance time listed in Table 2 to paragraph (g)(7) of this AD or 
within 100 FCs after the effective date of this AD, whichever occurs 
later, perform an AUSI of the affected parts for cracks in 
accordance with the applicable service bulletin listed in Table 2 to 
paragraph (g)(7) of this AD.

                               Table 2 to Paragraph (g)(7)--AUSI Compliance Times
----------------------------------------------------------------------------------------------------------------
                                                                                            Applicable service
                 Part                   Table S/N is listed in      Compliance time      bulletin (see paragraph
                                                                                            (m)(2) of this AD)
----------------------------------------------------------------------------------------------------------------
HPC 8th-stage disk having P/N 30G7208  Table 1 of PW ASB        Next HPC engine shop     Accomplishment
                                        PW1000G-A-72-00-0142-0   visit not to exceed      Instructions,
                                        0B-930A-D, Issue No:     10,000 part CSN.         paragraph 8., of PW
                                        004.                                              ASB PW1000G-A-72-00-
                                                                                          0142-00B-930A-D, Issue
                                                                                          No: 004.
HPT 1st-stage hub having P/N 30G8501.  Table 2 of PW ASB        Next engine shop visit   Accomplishment
                                        PW1000G-A-72-00-0141-0   not to exceed 5,000      Instructions,
                                        0B-930A-D, Issue No:     part CSN.                paragraph 8.A., of PW
                                        002.                                              ASB PW1000G-A-72-00-
                                                                                          0141-00B-930A-D, Issue
                                                                                          No: 002.
HPT 2nd-stage hub having P/N 30G7202.  Table 3 of PW ASB        Next engine shop visit   Accomplishment
                                        PW1000G-A-72-00-0141-0   not to exceed 5,000      Instructions,
                                        0B-930A-D, Issue No:     part CSN.                paragraph 8.B, of PW
                                        002.                                              ASB PW1000G-A-72-00-
                                                                                          0141-00B-930A-D, Issue
                                                                                          No: 002.
HPT 1st-stage hub having P/N 30G8501.  Table 4 of PW ASB        Next engine shop visit   Accomplishment
                                        PW1000G-A-72-00-0141-0   not to exceed 4,000      Instructions,
                                        0B-930A-D, Issue No:     part CSN.                paragraph 8.A., of PW
                                        002.                                              ASB PW1000G-A-72-00-
                                                                                          0141-00B-930A-D, Issue
                                                                                          No: 002.
HPT 2nd-stage hub having P/N 30G7202.  Table 5 of PW ASB        Next engine shop visit   Accomplishment
                                        PW1000G-A-72-00-0141-0   not to exceed 4,000      Instructions,
                                        0B-930A-D, Issue No:     part CSN.                paragraph 8.B., of PW
                                        002.                                              ASB PW1000G-A-72-00-
                                                                                          0141-00B-930A-D, Issue
                                                                                          No: 002.
----------------------------------------------------------------------------------------------------------------


[[Page 21195]]

    (8) Thereafter at each piece-part exposure of the affected part 
for PW1900G engines with an installed HPC 8th-stage disk having P/N 
30G7208, or an installed HPT 1st-stage hub having P/N 30G8501, or an 
installed HPT 2nd-stage hub having P/N 30G7202, do the following:
    (i) Perform an AUSI of the affected HPC 8th-stage disk for 
cracks in accordance with the Accomplishment Instructions, paragraph 
5.B., of PW ASB PW1000G-A-72-00-0150-00B-930A-D, Issue No: 001, 
dated November 30, 2023.
    (ii) Perform an AUSI of the affected HPT 1st-stage hub and HPT 
2nd-stage hub, as applicable, for cracks in accordance with the 
Accomplishment Instructions, paragraph 7.A. or 7.B., of PW ASB 
PW1000G-A-72-00-0151-00B-930A-D, Issue No: 001, dated November 30, 
2023.
    (9) If any crack is found during the inspections required by 
paragraph (g) of this AD, before further flight, remove the affected 
part from service and replace with a part eligible for installation.
    (10) For engines with an installed part and P/N listed in Table 
3 to paragraph (g)(10) of this AD having 3,300 CSN or less on the 
effective date of this AD, before the part accumulates 4,000 CSN or 
at the next engine shop visit after the effective date of this AD, 
whichever occurs first, remove the part from service and replace 
with a part eligible for installation.

               Table 3 to Paragraph (g)(10)--Part Numbers
------------------------------------------------------------------------
                          Part name                               P/N
------------------------------------------------------------------------
HPC 7th-stage rotor.........................................     30G3307
HPC 8th-stage disk..........................................     30G3248
HPC rear hub................................................     30G2902
HPT 1st-stage hub...........................................     30G5701
HPT 2nd-stage hub...........................................     30G5002
HPT 1st-stage air seal......................................     30G3132
HPT 2nd-stage air seal......................................     30G3451
HPT 1st-stage blade retaining plate.........................     30G1692
HPT 2nd-stage blade retaining plate.........................     30G1698
------------------------------------------------------------------------

    (11) For engines with an installed part and P/N listed in Table 
3 to paragraph (g)(10) of this AD having more than 3,300 CSN on the 
effective date of this AD, at the next engine shop visit or within 
700 FCs after the effective date of this AD, whichever occurs first, 
remove the part from service and replace it with a part eligible for 
installation.
    (12) For engines with an installed HPT 1st-stage hub having P/N 
30G8501 or an installed HPT 2nd-stage hub having P/N 30G7202 and an 
S/N listed in Table 1 of PW Special Instruction (SI) No. 240F-23A, 
dated February 7, 2024, within 100 FCs from the effective date of 
this AD, remove the hub from service and replace it with a part 
eligible for installation.
    (13) If an affected part has accumulated 100 FCs or less since 
the last AUSI, reinspection is not required provided that the part 
was not damaged during removal from the engine.

(h) Installation Prohibition

    After the effective date of this AD, do not install an HPT 1st-
stage hub having P/N 30G8501 or an HPT 2nd-stage hub having P/N 
30G7202 and an S/N listed in Table 1 of PW SI No. 240F-23A, dated 
February 7, 2024, in any engine.

(i) Definitions

    (1) For the purposes of this AD, ``PW1500G'' engines are PW 
Model PW1519G, PW1521G, PW1521GA, PW1521G-3, PW1524G, PW1524G-3, 
PW1525G, and PW1525G-3 engines.
    (2) For the purposes of this AD, ``PW1900G'' engines are PW 
Model PW1919G, PW1921G, PW1922G, PW1923G, and PW1923G-A engines.
    (3) For the purposes of this AD, a ``part eligible for 
installation'' is:
    (i) Any HPC 7th-stage rotor, P/N 30G5307 or later approved P/N.
    (ii) Any HPC 8th-stage disk, P/N 30G7208, that has passed the 
AUSI required by paragraph (g) of this AD or later approved P/N.
    (iii) Any HPC rear hub, P/N 30G7308 or later approved P/N.
    (iv) Any HPT 1st-stage hub, P/N 30G8501, that has passed the 
AUSI required by paragraph (g) of this AD or later approved P/N.
    (v) Any HPT 2nd-stage hub, P/N 30G7202, that has passed the AUSI 
required by paragraph (g) of this AD or later approved P/N.
    (vi) Any HPT 1st-stage air seal, P/N 30G5195 or later approved 
P/N.
    (vii) Any HPT 2nd-stage air seal, P/N 30G5196 or later approved 
P/N.
    (viii) Any HPT 1st-stage blade retaining plate, P/N 30G5193 or 
later approved P/N.
    (ix) Any HPT 2nd-stage blade retaining plate, P/N 30G5194 or 
later approved P/N.
    (4) For the purposes of this AD, a ``piece-part exposure'' is 
when the part is disassembled from the rotor assembly.
    (5) For the purposes 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 flanges, except for the 
following situations, which do not constitute an engine shop visit.
    (i) The separation of engine flanges solely for the purposes of 
transportation without subsequent engine maintenance.
    (ii) Fan case maintenance or replacement.
    (6) For the purposes of this AD, an ``HPC engine shop visit'' is 
when the HPC rotor assembly is removed from the HPC module.

(j) Credit for Previous Actions

    This paragraph provides credit for the initial AUSI of the HPC 
8th-stage disk, HPT 1st-stage hub and HPT 2nd-stage hub specified in 
paragraph (g)(1), (2), (4) and (5) of this AD, if the initial AUSI 
was performed before the effective date of this AD using the 
following service information.
    (1) PW ASB PW1000G-A-72-00-0196-00A-930A-D, Issue No: 001, dated 
March 16, 2023; or
    (2) PW ASB PW1000G-A-72-00-0197-00A-930A-D, Issue No: 001, dated 
March 22, 2023; or
    (3) PW ASB PW1000G-A-72-00-0197-00A-930A-D, Issue No: 002, dated 
June 19, 2023; or
    (4) PW ASB PW1000G-A-72-00-0197-00A-930A-D, Issue No: 003, dated 
August 14, 2023; or
    (5) PW ASB PW1000G-A-72-00-0141-00B-930A-D, Issue No: 001, dated 
March 16, 2023; or
    (6) PW ASB PW1000G-A-72-00-0142-00B-930A-D, Issue No: 001, dated 
March 22, 2023; or
    (7) PW ASB PW1000G-A-72-00-0142-00B-930A-D, Issue No: 002, dated 
June 19, 2023.; or
    (8) PW ASB PW1000G-A-72-00-0142-00B-930A-D, Issue No: 003, dated 
August 14, 2023.

(k) 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 AIR-520 Continued Operational 
Safety Branch, 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) Additional 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: [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 (PW) Alert Service Bulletin (ASB) PW1000G-A-
72-00-0141-00B-930A-D, Issue No: 002, dated November 30, 2023.
    (ii) PW ASB PW1000G-A-72-00-0142-00B-930A-D, Issue No: 004, 
dated November 30, 2023.
    (iii) PW ASB PW1000G-A-72-00-0150-00B-930A-D, Issue No: 001, 
dated November 30, 2023.
    (iv) PW ASB PW1000G-A-72-00-0151-00B-930A-D, Issue No: 001, 
dated November 30, 2023.
    (v) PW ASB PW1000G-A-72-00-0196-00A-930A-D, Issue No: 002, dated 
November 30, 2023.
    (vi) PW ASB PW1000G-A-72-00-0197-00A-930A-D, Issue No: 004, 
dated November 30, 2023.
    (vii) PW ASB PW1000G-A-72-00-0204-00A-930A-D, Issue No: 001, 
dated November 30, 2023.
    (viii) PW ASB PW1000G-A-72-00-0205-00A-930A-D, Issue No: 001, 
dated November 30, 2023.
    (ix) PW Special Instruction No. 240F-23A, dated February 7, 
2024.

[[Page 21196]]

    (3) For PW service information identified in this AD, contact 
International Aero Engines, LLC, 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 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.
    (5) You may view this material at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].

    Issued on March 21, 2024.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-06433 Filed 3-22-24; 4:15 pm]
BILLING CODE 4910-13-P