Proposed Rule2026-21298
Airworthiness Directives; Pratt & Whitney RTX Corporation (Type Certificate Previously Held by Pratt & Whitney Division United Technologies Corporation) Engines
Primary source
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Published
October 19, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to supersede Airworthiness Directive (AD) 2026-09-02, which applies to certain Pratt & Whitney RTX Corporation (PW) Model PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 engines. AD 2026-09-02 requires repetitive angle ultrasonic scan inspections (AUSIs) of the high-pressure compressor (HPC) 15th- stage disks, front turbine hubs, high-pressure turbine (HPT) 1st-stage air seals, and HPT 2nd-stage hubs for crack indications, and removal from service and replacement if necessary, and for certain serial numbers, removal from service and replacement of the HPT 1st-stage air seal. Since the FAA issued AD 2026-09-02, the FAA was notified that a certain part number was omitted from AD 2026-09-02 and the applicability of the optional terminating action was matched to an unrelated requirement. This proposed AD would require repetitive AUSIs of the HPC 15th-stage disks, front turbine hubs, HPT 1st-stage air seals, and HPT 2nd-stage hubs for crack indications, and removal from service and replacement if necessary, and for certain serial numbers, removal from service and replacement of the HPT 1st-stage air seal. The FAA is proposing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 91 Issue 200 (Monday, October 19, 2026)</title>
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[Federal Register Volume 91, Number 200 (Monday, October 19, 2026)]
[Proposed Rules]
[Pages 66012-66016]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-21298]
========================================================================
Proposed Rules
Federal Register
________________________________________________________________________
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. 91, No. 200 / Monday, October 19, 2026 /
Proposed Rules
[[Page 66012]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-11811; Project Identifier AD-2026-00667-E]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney RTX Corporation (Type
Certificate Previously Held by Pratt & Whitney Division United
Technologies Corporation) Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
2026-09-02, which applies to certain Pratt & Whitney RTX Corporation
(PW) Model PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and
PW4090-3 engines. AD 2026-09-02 requires repetitive angle ultrasonic
scan inspections (AUSIs) of the high-pressure compressor (HPC) 15th-
stage disks, front turbine hubs, high-pressure turbine (HPT) 1st-stage
air seals, and HPT 2nd-stage hubs for crack indications, and removal
from service and replacement if necessary, and for certain serial
numbers, removal from service and replacement of the HPT 1st-stage air
seal. Since the FAA issued AD 2026-09-02, the FAA was notified that a
certain part number was omitted from AD 2026-09-02 and the
applicability of the optional terminating action was matched to an
unrelated requirement. This proposed AD would require repetitive AUSIs
of the HPC 15th-stage disks, front turbine hubs, HPT 1st-stage air
seals, and HPT 2nd-stage hubs for crack indications, and removal from
service and replacement if necessary, and for certain serial numbers,
removal from service and replacement of the HPT 1st-stage air seal. 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 December 3,
2026.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
<bullet> Federal eRulemaking Portal: Go to <a href="http://regulations.gov">regulations.gov</a>. Follow
the instructions for submitting comments.
<bullet> Fax: (202) 493-2251.
<bullet> 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.
<bullet> 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 <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-11811; 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:
<bullet> For PW material identified in this proposed AD, contact
PW, 400 Main Street, East Hartford, CT 06118; phone: (800) 565-0140;
email: <a href="/cdn-cgi/l/email-protection#5b333e372b696f1b2b293a2f2f2c33322f353e2275383436"><span class="__cf_email__" data-cfemail="9cf4f9f0ecaea8dceceefde8e8ebf4f5e8f2f9e5b2fff3f1">[email protected]</span></a>; website: <a href="http://connect.prattwhitney.com">connect.prattwhitney.com</a>.
<bullet> 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: <a href="/cdn-cgi/l/email-protection#523f3d3e3e2b7c337c21262720353b21123433337c353d24"><span class="__cf_email__" data-cfemail="7f1210131306511e510c0b0a0d18160c3f191e1e51181009">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments using a method listed
under the ADDRESSES section. Include ``Docket No. FAA-2026-11811;
Project Identifier AD-2026-00667-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
<a href="http://regulations.gov">regulations.gov</a>, 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
The FAA issued AD 2026-09-02, Amendment 39-23322 (91 FR 30191, May
22, 2026) (AD 2026-09-02), for PW Model PW4074, PW4074D, PW4077,
PW4077D, PW4084D, PW4090, and PW4090-3 engines. AD 2026-09-02 was
prompted by an analysis of an event involving an International Aero
Engines, LLC (IAE LLC) Model PW1127GA-JM engine, which experienced an
HPC 7th-stage integrally bladed rotor (IBR-7) separation that resulted
in an aborted takeoff. Following this event, the manufacturer analysis
found that the failure of the HPC IBR-7 was caused by a nickel powdered
metal anomaly,
[[Page 66013]]
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. AD 2026-09-02 requires repetitive AUSIs of the
HPC 15th-stage disks, front turbine hubs, HPT 1st-stage air seals, and
HPT 2nd-stage hubs for crack indications, and removal from service and
replacement if necessary, and for certain serial numbers, removal from
service and replacement of the HPT 1st-stage air seal. The FAA issued
AD 2026-09-02 to prevent failure of the HPC 15th-stage disk, front
turbine hub, HPT 1st-stage air seal, and HPT 2nd-stage 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.
Actions Since AD 2026-09-02 Was Issued
Since the FAA issued AD 2026-09-02, the FAA has become aware that
the manufacturer revised PW Alert Service Bulletin (ASB) PW4G-112-A72-
368, dated June 20, 2024 (PW ASB PW4G-112-A72-368) to include HPT 2nd-
stage hub part number (P/N) 53L402, which was not identified in PW ASB
PW4G-112-A72-368 and inadvertently omitted from AD 2026-09-02.
Additionally, the applicability of the optional terminating action was
matched to paragraph (g)(1) of AD 2026-09-02, which is an unrelated
requirement.
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 ASB PW4G-112-A72-368, Revision No. 1, dated
September 20, 2024, which specifies procedures for performing
repetitive AUSIs on affected HPT 2nd-stage hubs.
This proposed AD would also require the following material, which
the Director of the Federal Register approved for incorporation by
reference as of June 26, 2026 (91 FR 30191, May 22, 2026).
<bullet> PW ASB PW4G-112-A72-365, Revision No. 1, dated June 20,
2024, which specifies procedures for performing repetitive AUSIs on
affected HPC 15th-stage disks.
<bullet> PW ASB PW4G-112-A72-366, dated June 20, 2024, which
specifies procedures for performing repetitive AUSIs on affected HPT
1st-stage air seals.
<bullet> PW ASB PW4G-112-A72-367, dated June 20, 2024, which
specifies procedures for performing repetitive AUSIs on affected front
turbine hubs.
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 the HPC 15th-
stage disks, front turbine hubs, HPT 1st-stage air seals, and HPT 2nd-
stage hubs for crack indications, and removal from service and
replacement if necessary. This proposed AD would also require, for
certain serial numbers, removal from service and replacement of the HPT
1st-stage air seal.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 124 engines installed on airplanes of U.S. registry. The FAA
estimates that 124 engines will need AUSIs of the HPC 15th-stage disk,
front turbine hub, HPT 2nd-stage hub, and HPT 1st-stage air seal; and 6
engines will need replacement of the HPT 1st-stage air seals.
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
----------------------------------------------------------------------------------------------------------------
AUSI of HPC 15th-stage disk.............. 4 work-hours x $85 per hour $0 $340 $42,160
= $340.
AUSI of front turbine hub................ 5 work-hours x 85 per hour 0 425 52,700
= 425.
AUSI of HPT 2nd-stage hub................ 5 work-hours x 85 per hour 0 425 52,700
= 425.
AUSI of HPT 1st-stage air seal........... 5 work-hours x 85 per hour 0 425 52,700
= 425.
Replace certain HPT 1st-stage air seals 1 work-hour x 85 per hour = 763,000 763,085 4,578,510
(6 engines). 85.
----------------------------------------------------------------------------------------------------------------
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 these replacements:
On-Condition Costs
----------------------------------------------------------------------------------------------------------------
Action Labor cost Parts cost Cost per product
----------------------------------------------------------------------------------------------------------------
Replace HPC 15th-stage disk.................. 10 work-hours x $85 per hour = $312,000 $312,850
$850.
Replace front turbine hub.................... 10 work-hours x 85 per hour = 910,000 910,850
850.
Replace HPT 2nd-stage hub.................... 10 work-hours x 85 per hour = 816,000 816,850
850.
Replace HPT 1st-stage air seal............... 10 work-hours x 85 per hour = 763,000 763,850
850.
----------------------------------------------------------------------------------------------------------------
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
[[Page 66014]]
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.
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 2026-09-02, Amendment 39-23322 (91
FR 30191, May 22, 2026); and
0
b. Adding the following new airworthiness directive:
Pratt & Whitney RTX Corporation (Type Certificate Previously Held by
Pratt & Whitney Division United Technologies Corporation): Docket
No. FAA-2026-11811; Project Identifier AD-2026-00667-E.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by December 3, 2026.
(b) Affected ADs
This AD replaces AD 2026-09-02, Amendment 39-23322 (91 FR 30191,
May 22, 2026) (AD 2026-09-02).
(c) Applicability
This AD applies to all Pratt & Whitney RTX Corporation (PW)
Model PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-
3 engines.
(d) Subject
Joint Aircraft System Component (JASC) Code 7250, Turbine
Section; 7230, Turbine Engine Compressor Section.
(e) Unsafe Condition
This AD was prompted by an 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 aborted takeoff. The FAA
is issuing this AD to prevent failure of the HPC 15th-stage disk,
front turbine hub, high-pressure turbine (HPT) 1st-stage air seal,
and HPT 2nd-stage 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) For HPT 1st-stage air seals with a serial number identified
in table 1 to paragraph (g)(1) of this AD: At the next piece part
opportunity after the effective date of this AD, remove the HPT 1st-
stage air seal from service and replace with a part eligible for
installation.
Table 1 to Paragraph (g)(1)--HPT 1st-Stage Air Seals Affected Serial
Numbers
------------------------------------------------------------------------
Part No. (P/
Serial No. N)
------------------------------------------------------------------------
CKLBME2702................................................. 50L663
CKLBME2703................................................. 50L663
CKLBME2704................................................. 50L663
CKLBME2705................................................. 50L663
CKLBME2711................................................. 50L663
CKLBMS8019................................................. 50L959
------------------------------------------------------------------------
(2) At the next piece part opportunity after the effective date
of this AD and thereafter at every piece part opportunity, perform
angle ultrasonic scan inspections (AUSIs) of the HPC 15th-stage
disk, front turbine hub, HPT 1st-stage air seal, and HPT 2nd-stage
hub for crack indications in accordance with the applicable service
material specified in paragraph (g)(2)(i) through (iv) of this AD.
(i) For HPC 15th-stage disks: Accomplishment Instructions,
paragraph 4.A or 4.B., of PW Alert Service Bulletin (ASB) PW4G-112-
A72-365, Revision No. 1, dated June 20, 2024.
(ii) For front turbine hubs: Accomplishment Instructions,
paragraph 4.A or 4.B., of PW ASB PW4G-112-A72-367, dated June 20,
2024.
(iii) For HPT 1st-stage air seals: Accomplishment Instructions,
paragraph 4.A or 4.B., of PW ASB PW4G-112-A72-366, dated June 20,
2024.
(iv) For HPT 2nd-stage hubs: Accomplishment Instructions,
paragraph 4.A or 4.B., of PW ASB PW4G-112-A72-368, Revision No. 1,
dated September 20, 2024.
(3) If during any inspection required by paragraph (g)(2) of
this AD, any crack indication is found, before further flight,
remove the part from service and replace with a part eligible for
installation.
(h) Definitions
For the purpose of this AD:
(1) A ``piece part opportunity'' is one of the conditions
specified in paragraph (h)(1)(i) through (iv).
(i) The HPC 15th-stage disk is removed from the engine and all
blades are removed.
(ii) The front turbine hub is removed from the engine and all
blades are removed.
(iii) The HPT 2nd-stage hub is removed from the engine and all
blades are removed.
(iv) The HPT 1st-stage air seal is fully disassembled from the
engine.
(2) A ``part eligible for installation'' is:
(i) An HPC 15th-stage disk having P/N 51S115, 51S315, 55H615, or
56H015 that has passed the angle ultrasonic scan inspection (AUSI)
required by paragraph (g)(2)(i) of this AD.
(ii) An HPC 15th-stage disk having P/N 51S115 or 56H015 that has
a certificate of conformance that shows compliance with Non-
Destructive Inspection Procedure (NDIP)-1276.
(iii) An HPC 15th-stage disk having P/N 51S315 or 55H615 that
has a certificate of conformance that shows compliance with NDIP-
1289.
(iv) A front turbine hub having P/N 55L801 or 55L901 that has
passed the AUSI required by paragraph (g)(2)(ii) of this AD.
(v) A front turbine hub having P/N 55L801 that has a certificate
of conformance that shows compliance with NDIP-1273.
(vi) A front turbine hub having P/N 55L901 that has a
certificate of conformance that shows compliance with NDIP-1288.
(vii) An HPT 1st-stage air seal having P/N 50L663 or 50L959 that
has passed the AUSI required by paragraph (g)(2)(iii) of this AD.
(viii) An HPT 1st-stage air seal having P/N 50L663 that has a
certificate of conformance that shows compliance with NDIP-1286.
(ix) An HPT 1st-stage air seal having P/N 50L959 that has a
certificate of conformance that shows compliance with NDIP-1287.
(x) An HPT 2nd-stage hub having P/N 53L202, 53L402, or 54L802
that has passed the AUSI required by paragraph (g)(2)(iv) of this
AD.
(xi) An HPT 2nd-stage hub having P/N 53L202 that has a
certificate of conformance that shows compliance with NDIP-1274.
[[Page 66015]]
(xii) An HPT 2nd-stage hub having P/N 53L402 or 54L802 that has
a certificate of conformance that shows compliance with NDIP-1275.
(xiii) Any HPC 15th-stage disk, front turbine hub, HPT 1st-stage
air seal, or HPT 2nd-stage hub that is new, zero-time, and that has
an FAA Form 8130-3 from the original equipment manufacturer for new
production dated July 1, 2025, or later.
(i) Optional Terminating Action--Airworthiness Limitations Section
(ALS) Revision
Revising the ALS of the existing engine manual and the
operator's existing approved maintenance program or inspection
program, as applicable, by incorporating the information in figure 1
to paragraph (i) of this AD, constitutes terminating action for the
actions required by paragraphs (g)(2) and (3) of this AD.
Figure 1 to Paragraph (i)--ALS Additional Inspections
----------------------------------------------------------------------------------------------------------------
B. Parts requiring CIR Manual 51A750 inspection check-02
Engine manuals P/N 51A345 and 51A751 inspection description update to include
----------------------------------------------------------------------------------------------------------------
Chapter/Section 05-10-00 PW4000 SERIES Seal--Air, HPT 1st-Stage... TASK 72-52-19-200-001. 1. Non-Destructive
ENGINE MANUAL ENGINE--AIRWORTHINESS Inspection--Stage 1 HPT Airseal Angle
LIMITATIONS--TIME LIMITS. Ultrasonic Inspection (1) Do an Angle
Ultrasonic Inspection for P/N 50L663 by
NDIP-1286 and for P/N 50L959 by NDIP-
1287.
P/N 51A345 TASK 05-10-01-990-004. 5.
Critical Life Limited Part Inspection
and Critical Part Inspection.
P/N 51A751 TASK 05-10-01-990-007. 5.
Critical Life Limited Part Inspection
and Critical Part Inspection.
Chapter/Section 05-10-00 PW4000 SERIES Hub, Turbine Front Assembly TASK 72-52-05-200-001. 1. Non-Destructive
ENGINE MANUAL ENGINE--AIRWORTHINESS (1st-Stage). Inspection--Turbine Front Hub (Stage 1)
LIMITATIONS--TIME LIMITS. Angle Ultrasonic Inspection (1) Do an
Angle Ultrasonic Inspection for Assembly
P/N 55L221 or Detail P/N 55L801 by NDIP-
1273 and for Assembly P/N 55L521 or
Detail P/N 55L901 by NDIP-1288.
P/N 51A345 TASK 05-10-01-990-004. 5.
Critical Life Limited Part Inspection
and Critical Part Inspection..
P/N 51A751 TASK 05-10-01-990-007. 5.
Critical Life Limited Part Inspection
and Critical Part Inspection.
Chapter/Section 05-10-00 PW4000 SERIES Hub, Turbine Rear Assembly TASK 72-52-06-200-001. 1. Non-Destructive
ENGINE MANUAL ENGINE--AIRWORTHINESS (2nd-Stage). Inspection--Turbine Intermediate Hub
LIMITATIONS--TIME LIMITS. (Stage 2) Angle Ultrasonic Inspection
(1) Do an Angle Ultrasonic Inspection
for Assembly P/N 53L232 and Detail P/N
53L202 by NDIP-1274 and for Assembly P/N
53L332 and Detail P/N 53L402 or Assembly
P/N 54L832 or 54L932 and Detail P/N
54L802 by NDIP-1275.
P/N 51A345 TASK 05-10-01-990-004. 5.
Critical Life Limited Part Inspection
and Critical Part Inspection.
P/N 51A751 TASK 05-10-01-990-007. 5.
Critical Life Limited Part Inspection
and Critical Part Inspection.
Chapter/Section 05-10-00 PW4000 SERIES HPC Disk 15th-Stage........ TASK 72-35-92-200-001. 1. Non-Destructive
ENGINE MANUAL ENGINE--AIRWORTHINESS Inspection--HPC Disk 15th-Stage Angle
LIMITATIONS--TIME LIMITS. Ultrasonic Inspection (1) Do an Angle
Ultrasonic Inspection for P/N 55H615 and
P/N 51S315 by NDIP-1289. TASK 72-35-92-
200-001-A. 1. Non-Destructive
Inspection--HPC Disk 15th-Stage Angle
Ultrasonic Inspection (1) Do an Angle
Ultrasonic Inspection for P/N 56H015 and
P/N 51S115 by NDIP-1276.
P/N 51A345..............................
TASK 05-10-01-990-004. 5. Critical Life
Limited Part Inspection and Critical
Part Inspection.
P/N 51A751..............................
TASK 05-10-01-990-007. 5. Critical Life
Limited Part Inspection and Critical
Part Inspection.
----------------------------------------------------------------------------------------------------------------
(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: <a href="/cdn-cgi/l/email-protection#46070b09050620272768212930"><span class="__cf_email__" data-cfemail="73323e3c30331512125d141c05">[email protected]</span></a>.
(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: <a href="/cdn-cgi/l/email-protection#4c2123202035622d623f38393e2b253f0c2a2d2d622b233a"><span class="__cf_email__" data-cfemail="9df0f2f1f1e4b3fcb3eee9e8effaf4eeddfbfcfcb3faf2eb">[email protected]</span></a>.
(l) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference
[[Page 66016]]
(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.
(3) The following material was approved for IBR on [DATE 35 DAYS
AFTER PUBLICATION OF THE FINAL RULE].
(i) Pratt & Whitney RTX Corporation (PW) Alert Service Bulletin
(ASB) PW4G-112-A72-368, Revision No. 1, dated September 20, 2024.
(ii) [Reserved]
(4) The following material was approved for IBR on June 26, 2026
(91 FR 30191, May 22, 2026).
(i) PW ASB PW4G-112-A72-365, Revision No. 1, dated June 20,
2024.
(ii) PW ASB PW4G-112-A72-366, dated June 20, 2024.
(iii) PW ASB PW4G-112-A72-367, dated June 20, 2024.
(5) For PW material identified in this AD, contact PW, 400 Main
Street, East Hartford, CT 06118; phone: (800) 565-0140; email:
<a href="/cdn-cgi/l/email-protection#fa929f968ac8ceba8a889b8e8e8d92938e949f83d4999597"><span class="__cf_email__" data-cfemail="a4ccc1c8d49690e4d4d6c5d0d0d3cccdd0cac1dd8ac7cbc9">[email protected]</span></a>; website: <a href="http://connect.prattwhitney.com">connect.prattwhitney.com</a>.
(6) 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.
(7) You may view this material at the National Archives and
Records Administration (NARA). For information on the availability
of this material at NARA, visit <a href="http://www.archives.gov/federal-register/cfr/ibr-locations">www.archives.gov/federal-register/cfr/ibr-locations</a> or email <a href="/cdn-cgi/l/email-protection#9ff9edb1f6f1eceffafcebf6f0f1dff1feedfeb1f8f0e9"><span class="__cf_email__" data-cfemail="d1b7a3ffb8bfa2a1b4b2a5b8bebf91bfb0a3b0ffb6bea7">[email protected]</span></a>.
Issued on October 14, 2026.
Lona C. Saccomando,
Acting Deputy Director, Integrated Certificate Management Division,
Aircraft Certification Service.
[FR Doc. 2026-21298 Filed 10-16-26; 8:45 am]
BILLING CODE 4910-13-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on October 19, 2026.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.