Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

[Federal Register Volume 91, Number 110 (Tuesday, June 9, 2026)]
[Rules and Regulations]
[Pages 34752-34754]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-11528]


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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; 
Amendment 39-23371; AD 2026-12-01]
RIN 2120-AA64


Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting 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 AD requires updating 
operational software and incorporating a pilot's operating handbook 
(POH) temporary revision (TR). This AD also prohibits the installation 
of affected software. The FAA is issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective July 14, 2026.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of July 14, 
2026.

ADDRESSES: 
    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 final rule, the mandatory continuing airworthiness 
information (MCAI), any comments received, and other information. The 
address for Docket Operations is U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue SE, Washington, DC 20590.
    Material Incorporated by Reference:
    <bullet> For European Union Aviation Safety Agency (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 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, 1100 Main, Kansas City, MO 
64105. For information on the availability of this material at the FAA, 
call (817) 222-5110. It is also available at regulations.gov under 
Docket No. FAA-2026-2715.

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:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to certain Pilatus Model 
PC-12/47E airplanes. The NPRM was published in the Federal Register on 
March 19, 2026 (91 FR 13240). The NPRM was prompted by AD 2025-0271, 
dated December 2, 2025 (EASA AD 2025-0271) (also referred to as the 
MCAI), issued by EASA, which is the Technical Agent for the Member 
States of the European Union. 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 with flaps at 40 degrees, the SWPS triggered at a 
higher-than-expected airspeed, including 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.
    In the NPRM, the FAA proposed to require updating operational 
software and incorporating a POH TR. The NPRM also proposed to prohibit 
the installation of affected software, as specified in EASA AD 2025-
0271. The FAA is issuing this AD to address the unsafe condition on 
these products.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2026-2715.

Discussion of Final Airworthiness Directive

Comments

    The FAA received no comments on the NPRM or on the determination of 
the costs.

Conclusion

    These products have been approved by the civil aviation authority 
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 reviewed the relevant 
data, considered any comments received, and determined that air safety 
requires adopting this AD as proposed. Accordingly, the FAA is issuing 
this AD to address the unsafe condition on these products. This AD is 
adopted as proposed in the NPRM.

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 TR No. 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.

Costs of Compliance

    The FAA estimates that this AD affects 265 airplanes of U. S. 
registry.
    The FAA estimates the following costs to comply with this AD:

[[Page 34753]]



                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                         Cost per   Cost on U.S.
                  Action                              Labor cost            Parts cost    product     operators
----------------------------------------------------------------------------------------------------------------
Update software...........................  3 work-hours x $85 per hour =           $0        $255       $67,575
                                             $255.
Revise POH................................  1 work-hour x $85 per hour =             0          85        22,525
                                             $85.
----------------------------------------------------------------------------------------------------------------

    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some of the costs of this 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

    This AD will not have federalism implications under Executive Order 
13132. This AD will 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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will 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 Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 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:

2026-12-01 Pilatus Aircraft Ltd.: Amendment 39-23371; Docket No. 
FAA-2026-2715; Project Identifier MCAI-2025-01779-A.

(a) Effective Date

    This airworthiness directive (AD) is effective July 14, 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 section of the existing POH for 
the airplane by inserting a copy of the POH TR [Temporary Revision] 
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 district office/certificate 
holding district office.

(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 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.

[[Page 34754]]

    (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, 1100 Main, Kansas City, 
MO 64105. 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 June 2, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2026-11528 Filed 6-8-26; 8:45 am]
BILLING CODE 4910-13-P

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