Proposed Rule2026-10408
Airworthiness Directives; Pratt & Whitney Division Engines
Primary source
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Published
May 26, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for all Pratt & Whitney Division (PW) Model PW4052, PW4056, PW4060, PW4060A, PW4060C, PW4062, PW4062A, PW4152, PW4156, PW4156A, PW4158, PW4460, and PW4462 engines. This proposed AD was prompted by multiple reports of tailpipe fire, loss of thrust control, and engine in-flight shutdown due to undetected deterioration of pressure burner (Pb) sensors. This proposed AD would require replacing Pb sensors. 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 100 (Tuesday, May 26, 2026)</title>
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[Federal Register Volume 91, Number 100 (Tuesday, May 26, 2026)]
[Proposed Rules]
[Pages 30514-30516]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-10408]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-4643; Project Identifier AD-2025-01612-E]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney Division 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 all Pratt & Whitney Division (PW) Model PW4052, PW4056, PW4060,
PW4060A, PW4060C, PW4062, PW4062A, PW4152, PW4156, PW4156A, PW4158,
PW4460, and PW4462 engines. This proposed AD was prompted by multiple
reports of tailpipe fire, loss of thrust control, and engine in-flight
shutdown due to undetected deterioration of pressure burner (Pb)
sensors. This proposed AD would require replacing Pb sensors. 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 10,
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-2026-4643; 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.
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#a5c8cac9c9dc8bc48bd6d1d0d7c2ccd6e5c3c4c48bc2cad3"><span class="__cf_email__" data-cfemail="a5c8cac9c9dc8bc48bd6d1d0d7c2ccd6e5c3c4c48bc2cad3">[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-2026-4643;
Project Identifier AD-2025-01612-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
[[Page 30515]]
should be sent to Molly Sturgis, 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 was notified of multiple events involving PW PW4000-94
engines in which tailpipe fire, loss of thrust control, or engine in-
flight shutdown occurred. A manufacturer investigation revealed that
these events were caused by undetected deterioration of Pb sensors due
to epoxy deterioration, which can lead to erroneous Pb sensor
measurements and incorrect fuel commands. This condition, if not
addressed, could result in engine fire, loss of thrust control, and
engine in-flight shutdown.
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.
Proposed AD Requirements in This NPRM
This proposed AD would require replacing Pb sensors within certain
compliance times.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 210 engines installed on airplanes of U.S. registry.
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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Replace Pb sensors.................... 2 work-hours x $85 per $15,694 $15,864 $3,331,440
hour = $170.
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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 Division: Docket No. FAA-2026-4643; Project
Identifier AD-2025-01612-E.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by July 10, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all Pratt & Whitney Division (PW) Model
PW4052, PW4056, PW4060, PW4060A, PW4060C, PW4062, PW4062A, PW4152,
PW4156, PW4156A, PW4158, PW4460, and PW4462 engines.
(d) Subject
Joint Aircraft System Component (JASC) Code 7300, Engine Fuel
and Control.
(e) Unsafe Condition
This AD was prompted by multiple reports of tailpipe fire, loss
of thrust control, and engine in-flight shutdown due to undetected
deterioration of pressure burner (Pb) sensors. The FAA is issuing
this AD to detect and correct the deterioration of Pb sensors. The
unsafe condition, if not addressed, could result in engine fire,
loss of thrust control, and engine in-flight shutdown.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Definitions
For the purpose of this AD, a ``part eligible for installation''
is a Pb sensor that has accumulated less than 30,000 flight hours
(FH) since new or since repair and less than 10 years in service
since new or since repair.
(h) Required Actions
(1) Replace the Pb sensor within the electronic engine control
(EEC) with a part eligible for installation within the applicable
number of months after the effective date of this AD, as specified
in table 1 to paragraph (h) of this AD, and thereafter before
accumulating 30,000 FH since new or since repair, or before
accumulating 10 years in service, whichever occurs first.
[[Page 30516]]
Table 1 to Paragraph (h)--Pb Sensor Replacement Times
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Less than
60,000 FH or 50,000-59,999 40,000-49,999 30,000-39,999 30,000 FH Unknown FH
more since new FH since new FH since new FH since new since new or since new or
Years in service since new or since repair as of the or since or since or since or since since repair since repair
effective date of this AD repair as of repair as of repair as of repair as of as of the as of the
the effective the effective the effective the effective effective date effective date
date of this date of this date of this date of this of this AD * of this AD *
AD * (months) AD * (months) AD* * (months) AD * (months) (months) (months)
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16 or more years........................................ 10 10 10 10 10 10
At or more than 14 years but less than 16 years......... 10 14 14 14 14 10
At or more than 12 years but less than 14 years......... 10 14 21 21 21 10
At or more than 10 years but less than 12 years......... 10 14 21 30 30 10
Less than 10 years...................................... 10 14 21 30 Refer to 10
paragraph
(h)(2) of this
AD
Unknown years........................................... 10 10 10 10 10 10
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* Flight hours since new or since repair: Calculate by rounding to the nearest hour.
(2) For Pb sensors that have accumulated less than 30,000 FH
since new or since repair and less than 10 years in service since
new or since repair as of the effective date of this AD, replace the
Pb sensor within the EEC with a part eligible for installation as
follows, whichever occurs later:
(i) Before accumulating 30,000 FH or 10 years in service since
new or since repair as applicable, whichever occurs first.
(ii) Within 30 months after the effective date of this AD.
Note 1 to paragraph (h): Guidance for determining the age of Pb
sensors may be found in PW Service Bulletin PW4ENG 73-221, Revision
No. 3, dated July 1, 2024.
(i) Alternative Methods of Compliance (AMOCs)
(1) The Manager, AIR-520 Continued Operational Safety Branch,
FAA, has the authority to approve AMOCs for this AD, if requested
using the procedures found in 14 CFR 39.19. In accordance with 14
CFR 39.19, send your request to your principal inspector or local
Flight Standards District Office, as appropriate. If sending
information directly to the manager of the AIR-520 Continued
Operational Safety Branch, send it to the attention of the person
identified in paragraph (j) of this AD and email to: <a href="/cdn-cgi/l/email-protection#b5f4f8faf6f5d3d4d49bd2dac3"><span class="__cf_email__" data-cfemail="5f1e12101c1f393e3e71383029">[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.
(j) Additional Information
(1) 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#0e6361626277206f207d7a7b7c69677d4e686f6f20696178"><span class="__cf_email__" data-cfemail="95f8faf9f9ecbbf4bbe6e1e0e7f2fce6d5f3f4f4bbf2fae3">[email protected]</span></a>.
(2) For material identified in this AD that is not incorporated
by reference, contact PW, 400 Main Street, East Hartford, CT 06118;
phone: (800) 565-0140; email: <a href="/cdn-cgi/l/email-protection#4b232e273b797f0b3b392a3f3f3c23223f252e3265282426"><span class="__cf_email__" data-cfemail="6008050c105254201012011414170809140e05194e030f0d">[email protected]</span></a>; website:
<a href="http://connect.prattwhitney.com">connect.prattwhitney.com</a>.
(k) Material Incorporated by Reference
None.
Issued on May 21, 2026.
Lona C. Saccomando,
Acting Deputy Director, Integrated Certificate Management Division,
Aircraft Certification Service.
[FR Doc. 2026-10408 Filed 5-22-26; 8:45 am]
BILLING CODE 4910-13-P
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