[Federal Register Volume 90, Number 104 (Monday, June 2, 2025)]
[Proposed Rules]
[Pages 23294-23297]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-09896]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-0918; Project Identifier AD-2024-00526-E]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Pratt & Whitney (PW) Model F117-PW-100, PW2037, PW2037D,
PW2037M, PW2040, PW2040D, PW2043, PW2143, and PW2643 engines. This
proposed 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 proposed AD would require repetitive angled
ultrasonic inspections (AUSIs) of certain high-pressure turbine (HPT)
1st-stage disks and turbine hubs for any crack indications, and if
necessary, removal from service and replacement, and removal from
service of certain HPT lenticular seal assemblies. 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 17,
2025.
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-2025-0918; 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 PW material identified in this proposed AD, contact
PW, 400 Main Street, East Hartford, CT 06118; phone:
[[Page 23295]]
(860) 565-0140; email: [email protected]; website:
connect.prattwhitney.com.
You may view this material 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: Molly Sturgis, Aviation Safety
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone:
(562) 627-5373; 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 the ADDRESSES section. Include ``Docket No. FAA-2025-0918;
Project Identifier AD-2024-00526-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 revise 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
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 Molly
Sturgis, 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
On December 24, 2022, an Airbus Model A320neo airplane powered by
IAE LLC Model PW1127GA-JM engines, experienced a failure of the HPC
IBR-7 that resulted in an engine shutdown and aborted takeoff.
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 revealed 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. As a result, the FAA is proposing additional
AUSIs for certain affected nickel powdered metal parts and removal from
service of certain affected nickel powdered metal parts. Certain PW
Model F117-PW-100, PW2037, PW2037D, PW2037M, PW2040, PW2040D, PW2043,
PW2143, and PW2643 engines are among the products affected by this
condition. This condition, if not addressed, could result in
uncontained disk failure, release of high-energy debris, damage to the
engine, damage to the airplane, and possible loss of 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.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed PW Alert Service Bulletin (ASB) PW2000 A72-779,
dated May 2, 2024, and PW ASB PWF117 A72-434, dated May 1, 2024, which
specifies procedures for a repetitive AUSIs of the HPT 1st-stage disk
for crack indications. This material is distinct since each applies to
different engine models.
The FAA also reviewed PW ASB PW2000 A72-780, dated May 2, 2024, and
PW ASB PWF117 A72-433, dated May 1, 2024, which specifies procedures
for repetitive AUSIs of the turbine hub. This material is distinct
since each applies to different engine models.
This material 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.
Proposed AD Requirements in This NPRM
This proposed AD would require repetitive AUSIs of certain HPT 1st-
stage disks and turbine hubs for any crack indications, and if
necessary, removal from service and replacement, and removal from
service of certain HPT lenticular seal assemblies.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 484 engines installed on airplanes of U.S. registry. The FAA
estimates that 13 engines will require replacement of the HPT
lenticular seal assembly.
The FAA estimates the following costs to comply with this proposed
AD:
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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AUSI of HPT 1st-stage disk............... 5 work-hours x $85 per hour $0 $425 $205,700
= $425.
AUSI of turbine hub...................... 5 work-hours x $85 per hour 0 425 205,700
= $425.
Replacement of HPT lenticular seal 13 work-hours x $85 per 511,240 12,345 6,660,485
assembly (13 engines). hour = $1,105.
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[[Page 23296]]
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 engines that might need these replacements:
On-Condition Costs
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Cost per
Action Labor cost Parts cost product
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Replacement of HPT 1st-stage 10 work-hours x $730,000 $730,850
disk. $85 per hour =
$850.
Replacement of turbine hub... 10 work-hours x 500,000 500,850
$85 per hour =
$850.
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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
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:
Pratt & Whitney: Docket No. FAA-2025-0918; Project Identifier AD-
2024-00526-E.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by July 17, 2025.
(b) Affected ADs
None.
(c) Applicability
This AD applies to Pratt & Whitney (PW) Model F117-PW-100,
PW2037, PW2037D, PW2037M, PW2040, PW2040D, PW2043, PW2143, and
PW2643 engines.
(d) Subject
Joint Aircraft System Component (JASC) Code 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 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 disk, and
turbine hub. The unsafe condition, if not addressed, could result in
uncontained disk 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.
(g) Required Actions
(1) At the next piece-part exposure after the effective date of
this AD and thereafter at every piece-part exposure, do an angled
ultrasonic inspection (AUSI) of the HPT 1st-stage disk for any crack
indications in accordance with Paragraph 4. of the Accomplishment
Instructions of PW Alert Service Bulletin (ASB) PW2000 A72-779,
dated May 2, 2024, or Paragraph 4. of the Accomplishment
Instructions of PW ASB PWF117 A72-434, dated May 1, 2024, as
applicable to the engine model.
(2) At the next piece-part exposure after the effective date of
this AD and thereafter at every piece-part exposure, do an AUSI of
the turbine hub for any crack indications in accordance with
Paragraph 4. of the Accomplishment Instructions of PW ASB PW2000
A72-780, dated May 2, 2024, or Paragraph 4. of the Accomplishment
Instructions of PW ASB PWF117 A72-433, dated May 1, 2024, as
applicable to the engine model.
(3) If, during any inspection required by paragraph (g)(1) or
(2) of this AD, any crack indication is found, remove the affected
part from service and replace with a part eligible for installation.
(4) For engines with an installed HPT lenticular seal assembly
having a part number and serial number identified in figure 1 to
paragraph (g)(4) of this AD: At the next piece-part exposure after
the effective date of this AD, remove the HPT lenticular seal
assembly from service and replace with a part eligible for
installation.
Figure 1 to Paragraph (g)(4)--Affected HPT Lenticular Seal Assemblies
------------------------------------------------------------------------
Part No. (P/N) Serial No.
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1B8575.................................. DKLBGY5919
1B8575.................................. DKLBGY5922
1B8575.................................. DKLBGY5945
1B8575.................................. DKLBGY5936
1B8575.................................. DKLBGY5944
1B8575.................................. DKLBGY5946
1B8575.................................. DKLBGY5948
1B8575.................................. DKLBGY5949
1B8575.................................. DKLBGY5952
1B8575.................................. DKLBGY5953
1B8575.................................. DKLBGY5959
1B8575.................................. DKLBG48210
1B8575.................................. DKLBG48244
1B8575.................................. DKLBG48292
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(h) Definitions
(1) For the purpose of this AD, a ``piece-part exposure'' is:
(i) For paragraph (g)(1) of this AD, when the HPT 1st-stage disk
is removed from the engine and all the blades are removed from the
HPT 1st-stage disk.
[[Page 23297]]
(ii) For paragraph (g)(2) of this AD, when the turbine hub is
removed from the engine and all the blades are removed from the
turbine hub.
(iii) For paragraph (g)(4) of this AD, when the HPT lenticular
seal assembly is removed from either the HPT 1st-stage disk or the
HPT 2nd-stage hub.
(2) For the purpose of this AD, a ``part eligible for
installation'' is:
(i) An HPT 1st-stage disk having P/N 1B7801, 1B3601, or 1B3601-
001 that has passed the AUSI required by paragraph (g)(1) of this
AD.
(ii) An HPT 1st-stage disk having P/N 1B7801, 1B3601, or 1B3601-
001, that has a certificate of conformance that shows compliance
with Non-Destructive Inspection Procedure (NDIP) NDIP-1282.
(iii) A new zero-time HPT 1st-stage disk having P/N 1B7801,
1B3601, or 1B3601-001 that has passed an AUSI at new part
production.
(iv) A turbine hub having P/N 1B4902, 1B6602, or 1B8002 that has
passed the AUSI required by paragraph (g)(2) of this AD.
(v) A turbine hub having P/N 1B4902, 1B6602, or 1B8002 that has
a certificate of conformance that shows compliance with NDIP-1283.
(vi) A new zero-time turbine hub having P/N 1B4902, 1B6602, or
1B8002 that has passed an AUSI at new part production.
(vii) Any HPT lenticular seal assembly that does not have a part
number and serial number identified in figure 1 to paragraph (g)(4)
of this AD.
(i) Installation Prohibition
(1) As of the effective date of this AD, no person may install
on any engine, an HPT 1st-stage disk having P/N 1B7801, 1B3601, or
1B3601-001, unless it is a part eligible for installation as defined
in paragraph (h)(2) of this AD.
(2) As of the effective date of this AD, no person may install
on any engine, a turbine hub having P/N 1B4902, 1B6602, or 1B8002,
unless it is a part eligible for installation as defined in
paragraph (h)(2) of this AD.
(3) As of the effective date of this AD, no person may install
on any engine, an HPT lenticular seal assembly having a part number
and serial number identified in figure 1 to paragraph (g)(4) of this
AD.
(j) 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 AIR-520 Continued
Operational Safety Branch, send it to the attention of the person
identified in paragraph (k) of this AD and email to: [email protected].
(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.
(k) Additional Information
For more information about this AD, contact Molly Sturgis,
Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines,
WA 98198; phone: (562) 627-5373; email: [email protected].
(l) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference (IBR) of the material listed in this
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this material as applicable to do the actions
required by this AD, unless the AD specifies otherwise.
(i) Pratt & Whitney (PW) Alert Service Bulletin (ASB) PW2000
A72-779, dated May 2, 2024.
(ii) PW ASB PW2000 A72-780, dated May 2, 2024.
(iii) PW ASB PWF117 A72-434, dated May 1, 2024.
(iv) PW ASB PWF117 A72-433, dated May 1, 2024.
(3) For PW material identified in this AD, contact PW, 400 Main
Street, East Hartford, CT 06118; phone: (860) 565-0140; email:
[email protected]; website: connect.prattwhitney.com.
(4) You may view this material 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 May 23, 2025.
Lona C. Saccomando,
Acting Deputy Director, Integrated Certificate Management Division,
Aircraft Certification Service.
[FR Doc. 2025-09896 Filed 5-30-25; 8:45 am]
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