Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

[Federal Register Volume 90, Number 225 (Tuesday, November 25, 2025)]
[Rules and Regulations]
[Pages 53208-53210]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-21090]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-0917; Project Identifier MCAI-2024-00740-A; 
Amendment 39-23155; AD 2025-20-02]
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 all 
Pilatus Aircraft Ltd. (Pilatus) Model PC-24 airplanes. This AD was 
prompted by a report of an inaccurate flight director calculation on 
approach. This AD requires incorporating a temporary revision into the 
existing airplane flight manual (AFM) for the affected airplanes, which 
revises the Abnormal Procedures Section. The FAA is issuing this AD to 
address the unsafe condition on these products.

DATES: This AD is effective December 30, 2025.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of December 30, 
2025.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2025-0917; 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:

[[Page 53209]]

    <bullet> For European Union Aviation 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, 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:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to all Pilatus Model PC-24 
airplanes. The NPRM was published in the Federal Register on June 18, 
2025 (90 FR 25909). The NPRM was prompted by AD 2024-0240, dated 
December 10, 2024, issued by EASA, which is the Technical Agent for the 
Member States of the European Union (also referred to as the MCAI). The 
MCAI states there was a report of an inaccurate flight director 
calculation on approach with APEX Build 5.3 and below software 
installed. Further investigation revealed that heading splits can cause 
errors in the flight director calculation, resulting in lateral offsets 
to the desired approach course. The MCAI also states that the AD is 
considered an interim action and further AD action may follow.
    In the NPRM, the FAA proposed to require incorporating a temporary 
revision into the existing airplane flight manual (AFM) for the 
affected airplanes, which revises the Abnormal Procedures Section. 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-2025-0917.

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 2024-0240, which specifies procedures for 
incorporating Pilatus PC-24 AFM Temporary Revision 02371-075 (also 
referred to as AFM-TR) into the AFM, which revises the Abnormal 
Procedures Section. EASA AD 2024-0240 also specifies informing all 
flight crews of the change, and, thereafter, operating the airplane 
accordingly, and allows for the incorporation of a later AFM revision 
that includes the same AFM 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.

Differences Between This AD and the MCAI

    EASA AD 2024-0240 includes requirements to ``inform all flight 
crews and, thereafter, operate the [airplane] accordingly'', and this 
AD does not specifically require those actions because those actions 
are already required by existing FAA regulations (see 14 CFR 91.9, 
91.505, and 135.21).

Interim Action

    The FAA considers this AD 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 affects 150 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                    Cost per       Cost on U.S.
               Action                        Labor cost           Parts cost        product         operators
----------------------------------------------------------------------------------------------------------------
Revise AFM..........................  1 work-hour x $85 per                $0              $85          $12,750
                                       hour = $85.
----------------------------------------------------------------------------------------------------------------

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.

[[Page 53210]]

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:

2025-20-02 Pilatus Aircraft Ltd.: Amendment 39-23155; Docket No. 
FAA-2025-0917; Project Identifier MCAI-2024-00740-A.

(a) Effective Date

    This airworthiness directive (AD) is effective December 30, 
2025.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Pilatus Aircraft Ltd Model PC-24 airplanes, 
certificated in any category.

(d) Subject

    Joint Aircraft System Component (JASC) Code 3400, Navigation 
System.

(e) Unsafe Condition

    This AD was prompted by a report of an inaccurate flight 
director calculation on approach. The FAA is issuing this AD to 
prevent heading splits that can cause errors in flight director 
calculations resulting in lateral offsets to the desired approach 
course. The unsafe condition, if not addressed, could result in an 
increased pilot workload, resulting in a reduction of the safety 
margins.

(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 2024-0240, 
dated December 10, 2024 (EASA AD 2024-0240).
    (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 2024-0240

    (1) Where EASA AD 2024-0240 refers to its effective date, this 
AD requires using the effective date of this AD.
    (2) Where paragraph (1) of EASA AD 2024-0240 specifies to 
implement the AFM-TR, this AD requires revising the Abnormal 
Procedures Section of the existing AFM for your airplane by 
inserting a copy of the AFM-TR as defined in EASA AD 2024-0240.
    (3) Where paragraph (1) of EASA AD 2024-0240 specifies to inform 
all flight crews and, thereafter, operate the [airplane] 
accordingly, this AD does not require those actions as those actions 
are already required by existing FAA regulations (see 14 CFR 91.9, 
91.505, and 135.21).
    (4) This AD does not adopt the Remarks section of EASA AD 2024-
0240.

(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 International Validation Branch, send it to the 
attention of the person identified in paragraph (j) 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.

(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: 
[email protected].

(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 2024-0240, 
dated December 10, 2024.
    (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 November 21, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2025-21090 Filed 11-24-25; 8:45 am]
BILLING CODE 4910-13-P

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