[Federal Register Volume 91, Number 53 (Thursday, March 19, 2026)]
[Proposed Rules]
[Pages 13240-13243]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-05364]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-2715; Project Identifier MCAI-2025-01779-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 AD was prompted by a report of the stall warning protection system
(SWPS) engaging when not appropriate. This proposed AD would require
updating operational software and incorporating a pilot's operating
handbook (POH) temporary revision. The proposed AD would also prohibit
the installation of affected software. The FAA is proposing this AD to
address the unsafe condition on these products.
DATES: The FAA must receive comments on this NPRM by May 4, 2026.
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-2026-2715; 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.
[[Page 13241]]
Material Incorporated by Reference:
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: [email protected];
website: easa.europa.eu. You may find this material on the EASA website
at ad.easa.europa.eu.
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: [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 using a method listed
under ADDRESSES. Include ``Docket No. FAA-2026-2715; Project Identifier
MCAI-2025-01779-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
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 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 2025-0271, dated December 2, 2025
(EASA AD 2025-0271) (also referred to as the MCAI), to correct an
unsafe condition on certain Pilatus Model PC-12/47E airplanes. The MCAI
states that during a test flight on a Pilatus Model PC-12/47E airplane
in which the airplane flew specific maneuvers where gravitational loads
(g-loads) were close to 0 g, during landing the SWPS triggered at a
higher-than-expected airspeed. The SWPS included the aural warning,
stick shaker, and stick pusher. This same software is on the delivered
airplanes that are affected by this AD.
This condition, if not addressed, could result in reduced safety
margins of the airplane, increased pilot workload, and reduced control
of the airplane.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2026-2715.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed EASA AD 2025-0271, which specifies procedures for
updating the Honeywell Primus Apex operational software, and for
incorporating Pilatus PC-12/47E POH Temporary Revision (TR) No. 32
(also referred to as POH-TR 32) into the POH. EASA AD 2025-0271 also
allows for the incorporation of a later POH revision that includes the
same POH amendment content and prohibits the installation of affected
software. 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
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. The owner/
operator (pilot) holding at least a private pilot certificate may
revise the existing POH for the 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.
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 been coordinating this process with
manufacturers and CAAs. As a result, the FAA proposes to incorporate
EASA AD 2025-0271 by reference in the FAA final rule. This proposed AD
would, therefore, require compliance with EASA AD 2025-0271 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 2025-0271 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 2025-0271.
Material required by EASA AD 2025-0271 for compliance will be available
at regulations.gov under Docket No. FAA-2026-2715 after the FAA final
rule is published.
[[Page 13242]]
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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Update software........................ 3 work-hours x $85 per $0 $255 $67,575
hour = $255.
Revise POH............................. 1 work-hour x $85 per hour 0 85 22,525
= $85.
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The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some of the costs of this
proposed 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
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:
Pilatus Aircraft Ltd.: Docket No. FAA-2026-2715; Project Identifier
MCAI-2025-01779-A.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by May 4, 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 2476,
certificated in any category.
(d) Subject
Joint Aircraft System Component (JASC) Code 4500, Central
Maint., Computer.
(e) Unsafe Condition
This AD was prompted by a report of the stall warning protection
system (SWPS) engaging when not appropriate. The FAA is issuing this
AD to ensure the update of the certified operational software and
prevent the inappropriate activation of the SWPS. The unsafe
condition, if not addressed, could result in reduced safety margins
of the airplane, increased pilot workload, and reduced control of
the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
(1) Except as specified in paragraphs (h) and (i) of this AD:
Comply with all required actions and compliance times specified in,
and in accordance with, European Union Aviation Safety Agency (EASA)
AD 2025-0271, dated December 2, 2025 (EASA AD 2025-0271).
(2) The owner/operator (pilot) holding at least a private pilot
certificate may revise the existing pilot's operating handbook (POH)
for the airplane and must enter compliance with this requirement
into the aircraft records 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 2025-0271
(1) Where EASA AD 2025-0271 refers to its effective date, this
AD requires using the effective date of this AD.
(2) Where paragraph (4) of EASA AD 2025-0271 specifies to
``implement the instructions of the POH-TR, as required by paragraph
(4.1) or (4.2) of this AD, as applicable'', this AD requires
replacing that text with ``revise the Emergency Procedures Section
and Airplane and Systems Description of the existing POH for the
airplane by inserting a copy of the POH-TR as defined in EASA AD
2025-0271.''
(3) This AD does not adopt the ``Remarks'' section of EASA AD
2025-0271.
(i) No Reporting Requirement
Although the service material referenced in EASA AD 2025-0271
specifies to submit certain information to the manufacturer, this AD
does not include those requirements.
(j) 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 (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 responsible Flight Standards Office/certificate holding
district office.
[[Page 13243]]
(k) 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:
[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) European Union Aviation Safety Agency (EASA) AD 2025-0271,
dated December 2, 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: [email protected]; 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 www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].
Issued on March 12, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-05364 Filed 3-18-26; 8:45 am]
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