Proposed Rule2026-01047
Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
January 21, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for certain Pilatus Aircraft Ltd. (Pilatus) Model PC-12/47E airplanes. This proposed AD was prompted by a report that, during an engine start on the ground, the airplane battery voltage dropped to a value that resulted in an avionic system shutdown. This proposed AD would require incorporating a temporary revision into the existing pilot's operating handbook (POH) for the affected airplanes to provide operators with instructions for an enhanced engine start procedure. 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 13 (Wednesday, January 21, 2026)</title>
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[Federal Register Volume 91, Number 13 (Wednesday, January 21, 2026)]
[Proposed Rules]
[Pages 2510-2512]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-01047]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-0015; Project Identifier MCAI-2025-01528-A]
RIN 2120-AA64
Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes
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 Pilatus Aircraft Ltd. (Pilatus) Model PC-12/47E airplanes.
This proposed AD was prompted by a report that, during an engine start
on the ground, the airplane battery voltage dropped to a value that
resulted in an avionic system shutdown. This proposed AD would require
incorporating a temporary revision into the existing pilot's operating
handbook (POH) for the affected airplanes to provide operators with
instructions for an enhanced engine start procedure. The FAA is
proposing this AD to address the unsafe condition on these products.
DATES: The FAA must receive comments on this NPRM by March 9, 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-2026-0015; 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, the mandatory continuing airworthiness
information (MCAI), any comments received, and other information. The
street address for Docket Operations is listed above.
Material Incorporated by Reference:
<bullet> For European Union Aviation Agency (EASA) material
identified in this NPRM, contact EASA, Konrad-Adenauer-Ufer 3, 50668
Cologne, Germany; phone: +49 221 8999 000; email: <a href="/cdn-cgi/l/email-protection#3170754271545042501f5444435e41501f5444"><span class="__cf_email__" data-cfemail="5312172013363220327d3626213c23327d3626">[email protected]</span></a>;
website: easa.europa.eu. You may find this material on the EASA website
at ad.easa.europa.eu.
<bullet> You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 901 Locust, Kansas City,
MO 64106. For information on the availability of this material at the
FAA, call (817) 222-5110.
FOR FURTHER INFORMATION CONTACT: Doug Rudolph, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: (816) 329-4059; email: <a href="/cdn-cgi/l/email-protection#c0a4afb5a7eeb2b5a4afacb0a880a6a1a1eea7afb6"><span class="__cf_email__" data-cfemail="1f7b706a78316d6a7b70736f775f797e7e31787069">[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 ADDRESSES. Include ``Docket No. FAA-2026-0015; Project Identifier
MCAI-2025-01528-A'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
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 Doug
Rudolph, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590. Any commentary that the FAA receives which is not
specifically designated as CBI will be placed in the public docket for
this rulemaking.
Background
EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2025-0201, dated September 18, 2025
(EASA AD 2025-0201) (also referred to as the MCAI), to correct an
unsafe condition on certain Pilatus Model PC-12/47E airplanes. The MCAI
states that there was an occurrence reported where during an engine
start on the ground, the airplane battery voltage dropped to a value
that resulted in an avionic system shutdown. As a result, the engine
parameters, including the interstage turbine temperature (ITT)
indications were undetectable, and the ITT exceedance protection during
the engine ground start procedure was deactivated. Under these
conditions, an ITT exceedance could occur with the aircrew having no
means to detect it. The MCAI also states that the AD is considered an
interim action and further AD action may follow. This condition, if not
addressed, could result in reduced turbine blade structural integrity
with possible engine failure and loss of thrust.
You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-0015.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed EASA AD 2025-0201, which specifies procedures for
incorporating Pilatus PC-12/47E POH Temporary Revision (TR) No. 31
(also referred to as POH-TR) into the POH and allows for the
incorporation of a later POH revision that includes the same POH
amendment content. 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.
FAA's Determination
These products have been approved by the civil aviation authority
(CAA) of another country and are approved for operation in the United
States. Pursuant to the FAA's bilateral agreement with this State of
Design Authority, that authority has notified the FAA of the unsafe
condition described in the MCAI referenced above. The FAA is issuing
[[Page 2511]]
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 accomplishing the actions specified
in the MCAI described previously, except for any differences identified
as exceptions in the regulatory text of this proposed AD. See
``Differences Between this Proposed AD and the MCAI'' for a discussion
of the general differences included in this AD. The owner/operator
(pilot) holding at least a private pilot certificate may revise the
existing POH for your airplane and must enter compliance with the
applicable paragraph of this proposed AD into the airplane maintenance
records in accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The
pilot may perform this action because it only involves revising the
POH. This action could be performed equally well by a pilot or a
mechanic. This is an exception to the FAA's standard maintenance
regulations.
Differences Between This Proposed AD and the MCAI
The MCAI requires operators to ``inform all flight crew'' of the
revisions to the POH, and thereafter to ``operate the airplane
accordingly.'' However, this proposed AD would not specifically require
those actions as those actions are already required by FAA regulations.
FAA regulations require operators to furnish pilots with any changes to
the POH (for example, 14 CFR 135.21), and require pilots to comply with
the POH (14 CFR 91.9). As with any other flight crew training
requirement, training on the updated POH content is tracked by the
operators and recorded in each pilot's training record, which is
available for the FAA to review. FAA regulations also require pilots to
follow the procedures in the existing POH including all updates.
Therefore, including a requirement in this AD to inform the flight crew
and operate the airplane according to the revised POH would be
redundant and unnecessary.
Explanation of Required Compliance Information
In the FAA's ongoing efforts to improve the efficiency of the AD
process, the FAA developed a process to use some CAA ADs as the primary
source of information for compliance with requirements for
corresponding FAA ADs. The FAA has since coordinated with other
manufacturers and CAAs to use this process. As a result, the FAA
proposes to incorporate by reference EASA AD 2025-0201 in the FAA final
rule. This proposed AD would, therefore, require compliance with EASA
AD 2025-0201 in its entirety through that incorporation, except for any
differences identified as exceptions in the regulatory text of this
proposed AD. Using common terms that are the same as the heading of a
particular section in the EASA AD does not mean that operators need
comply only with that section. For example, where the AD requirement
refers to ``all required actions and compliance times,'' compliance
with this AD requirement is not limited to the section titled
``Required Action(s) and Compliance Time(s)'' in EASA AD 2025-0201.
Service information required by the EASA AD for compliance will be
available at <a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2026-0015 after the
FAA final rule is published.
Interim Action
The FAA considers that this proposed AD would 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.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 265 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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Revise POH............................ 1 work-hour x $85 per $0 $85 $22,525
hour = $85.
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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.
[[Page 2512]]
Sec. 39.13 [Amended]
0
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive:
Pilatus Aircraft Ltd.: Docket No. FAA-2026-0015; Project Identifier
MCAI-2025-01528-A.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by March 9, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to Pilatus Aircraft Ltd Model PC-12/47E
airplanes, manufacturer serial numbers 1720, and 2001 through 2999,
certificated in any category.
(d) Subject
Joint Aircraft System Component (JASC) Code 7720, Engine Temp.
Indicating System.
(e) Unsafe Condition
This AD was prompted by a report that during an engine start on
the ground, the airplane battery voltage dropped to a value that
resulted in an avionic system shutdown. The FAA is issuing this AD
to prevent takeoff when an undetected interstage turbine temperature
(ITT) exceedance occurs during engine start. The unsafe condition,
if not addressed, could result in reduced turbine blade structural
integrity with possible engine failure and loss of thrust.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
(1) Except as specified in paragraph (h) of this AD: Comply with
all required actions and compliance times specified in, and in
accordance with, European Union Aviation Safety Agency AD 2025-0201,
dated September 18, 2025 (EASA AD 2025-0201).
(2) The actions required by paragraph (g)(1) of this AD may be
performed by the owner/operator (pilot) holding at least a private
pilot certificate and must be entered into the aircraft records
showing compliance with this AD in accordance with 14 CFR 43.9(a)
and 91.417(a)(2)(v). The record must be maintained as required by 14
CFR 91.417, 121.380, or 135.439.
(h) Exceptions to EASA AD 2025-0201
(1) Where EASA AD 2025-0201 refers to its effective date, this
AD requires using the effective date of this AD.
(2) Where paragraph (1) of EASA AD 2025-0201 specifies to
``implement the POH-TR, as defined in this AD'', this AD requires
replacing that text with ``revise the Normal Procedures Section of
the existing pilot's operating handbook (POH) for your airplane by
inserting a copy of the POH-TR as defined in EASA AD 2025-0201.''
(3) Where paragraph (1) of EASA AD 2025-0201 specifies to inform
all flight crews and, thereafter, operate the [airplane]
accordingly, this AD does not require those actions (see 14 CFR
91.9, 91.103, and 135.21).
(4) This AD does not adopt the ``Remarks'' section of EASA AD
2025-0201.
(i) Alternative Methods of Compliance (AMOCs)
(1) The Manager, International Validation 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 International Validation 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#30717d7f73705651511e575f46"><span class="__cf_email__" data-cfemail="87c6cac8c4c7e1e6e6a9e0e8f1">[email protected]</span></a>.
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the responsible Flight Standards Office/certificate holding
district office.
(j) Additional Information
For more information about this AD, contact Doug Rudolph,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: (816) 329-4059; email:
<a href="/cdn-cgi/l/email-protection#8de9e2f8eaa3fff8e9e2e1fde5cdebececa3eae2fb"><span class="__cf_email__" data-cfemail="61050e14064f1314050e0d1109210700004f060e17">[email protected]</span></a>.
(k) 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) European Union Aviation Safety Agency (EASA) AD 2025-0201,
dated September 18, 2025.
(ii) [Reserved]
(3) For EASA material identified in this AD, contact EASA,
Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999
000; email: <a href="/cdn-cgi/l/email-protection#c18085b281a4a0b2a0efa4b4b3aeb1a0efa4b4"><span class="__cf_email__" data-cfemail="df9e9bac9fbabeacbef1baaaadb0afbef1baaa">[email protected]</span></a>; website: easa.europa.eu. You may
find this EASA AD on the EASA website at ad.easa.europa.eu.
(4) You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 901 Locust, Kansas
City, MO 64106. 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 <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#8ceafea2e5e2fffce9eff8e5e3e2cce2edfeeda2ebe3fa"><span class="__cf_email__" data-cfemail="d8beaaf6b1b6aba8bdbbacb1b7b698b6b9aab9f6bfb7ae">[email protected]</span></a>.
Issued on January 13, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-01047 Filed 1-20-26; 8:45 am]
BILLING CODE 4910-13-P
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