[Federal Register Volume 90, Number 185 (Friday, September 26, 2025)]
[Proposed Rules]
[Pages 46365-46368]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-18705]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-2553; Project Identifier MCAI-2025-00186-T]
RIN 2120-AA64


Airworthiness Directives; Dassault Aviation 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 Dassault Aviation Model FALCON 2000EX airplanes. This 
proposed AD was prompted by a report of simultaneous failures of the 
main DC buses powered by Generator 1 (GEN1), and Generator 2 (GEN2) 
after flap extension during approach. This proposed AD would require 
revising the existing airplane flight manual (AFM). The FAA is 
proposing this AD to address the unsafe condition on these products.

[[Page 46366]]


DATES: The FAA must receive comments on this proposed AD by November 
10, 2025.

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-2025-2553; 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:
     For European Union Aviation Safety Agency (EASA) material 
identified in this proposed AD, contact EASA, Konrad-Adenauer-Ufer 3, 
50668 Cologne, Germany; telephone +49 221 8999 000; email 
[email protected]. You may find this material on the EASA website at 
ad.easa.europa.eu. It is also available at regulations.gov under Docket 
No. FAA-2025-2553.
     You may view this material at the FAA, Airworthiness 
Products Section, Operational Safety Branch, 2200 South 216th St., Des 
Moines, WA. For information on the availability of this material at the 
FAA, call 206-231-3195.

FOR FURTHER INFORMATION CONTACT: Steven Dzierzynski, Aviation Safety 
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
phone: 516-228-7367; 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 the ADDRESSES section. Include ``Docket No. FAA-2025-2553; 
Project Identifier MCAI-2025-00186-T'' 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 
Steven Dzierzynski, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, 
Suite 410, Westbury, NY 11590; phone: 516-228-7367; email: [email protected]. 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 2025-0042, dated February 19, 2025 
(EASA AD 2025-0042) (also referred to as the MCAI), to correct an 
unsafe condition for certain Dassault Aviation Model FALCON 2000EX 
airplanes. The MCAI states there was a report of simultaneous failures 
of the main DC buses powered by GEN1 and GEN2 after flap extension 
during approach. This event resulted in intermittent crew alerting 
system (CAS) messages, including the red CAS message ``2 GEN'S FAIL,'' 
data flickering on the display units, and flashing lights on the 
overhead panel, which led to the loss of the main DC buses after a 
short period.
    The FAA is issuing this AD to address intermittent and flickering 
data, as well as CAS messages. The unsafe condition, if not addressed, 
could lead to increased pilot workload, possibly during a critical 
phase of flight. You may examine the MCAI in the AD docket at 
regulations.gov under Docket No. FAA-2025-2553.

Material Incorporated by Reference Under 1 CFR Part 51

    EASA AD 2025-0042 specifies procedures for revising the AFM to 
provide flightcrew with emergency procedures to address intermittent 
and flickering data and CAS messages.
    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 
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 in other products of the same type design.

Proposed AD Requirements in This NPRM

    This proposed AD would be accomplishing the actions specified in 
EASA AD 2025-0042 described previously, except for any differences 
identified as exceptions in the regulatory text of this proposed AD.

Compliance With AFM Revisions

    EASA AD 2025-0042 requires operators to ``inform all flight crews, 
and, thereafter, 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 that operators furnish to pilots any changes to the AFM (for 
example, 14 CFR 121.137), and to ensure the pilots are familiar with 
the AFM (for example, 14 CFR 91.505). As with any other flightcrew 
training requirement, training on the updated AFM 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 AFM including all updates. 14 CFR 
91.9 requires that any person operating a civil aircraft must comply 
with the operating limitations

[[Page 46367]]

specified in the AFM. Therefore, including a requirement in this 
proposed AD to operate the airplane according to the revised AFM 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 civil aviation 
authority (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 2025-0042 by reference in the FAA 
final rule. This proposed AD would, therefore, require compliance with 
EASA AD 2025-0042 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 EASA AD 2025-0042 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-
0042. Material required by EASA AD 2025-0042 for compliance will be 
available at regulations.gov by searching for and locating Docket No. 
FAA-2025-2553 after the FAA final rule is published.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 304 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.
                          Labor cost                              Parts cost        product         operators
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1 work-hour x $85 per hour = $85.............................              $0              $85          $25,840
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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:

Dassault Aviation: Docket No. FAA-2025-2553; Project Identifier 
MCAI-2025-00186-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by November 10, 2025.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Dassault Aviation Model FALCON 2000EX 
airplanes, certificated in any category, as identified in European 
Union Aviation Safety Agency (EASA) AD 2025-0042, dated February 19, 
2025 (EASA AD 2025-0042).

(d) Subject

    Air Transport Association (ATA) of America Code 24, Electrical 
Power.

(e) Unsafe Condition

    This AD was prompted by a report of simultaneous failures of the 
main DC buses powered by Generator 1 (GEN1), and Generator 2 (GEN2) 
after flap extension during approach, which initially resulted in 
intermittent display of crew alerting system (CAS) messages, and led 
to the loss of the main DC buses. The FAA is issuing this AD to 
address intermittent and flickering data, as well as CAS messages. 
The unsafe condition, if not addressed, could lead to increased 
pilot workload, possibly during a critical phase of flight.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Requirements

    Except as specified in paragraph (h) of this AD: Comply with all 
required actions and compliance times specified in, and in 
accordance with EASA AD 2025-0042.

(h) Exceptions to EASA AD 2025-0042

    (1) Where paragraph (1) of EASA AD 2025-0042 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 operating regulations 
(see 14 CFR 91.9, 14 CFR 91.505, and 14 CFR 121.137).
    (2) Where EASA AD 2025-0042 refers to its effective date, this 
AD requires using the effective date of this AD.
    (3) This AD does not adopt the ``Remarks'' section of EASA AD 
2025-0042.

(i) Additional AD Provisions

    The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, 
International

[[Page 46368]]

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 responsible Flight Standards 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: [email protected]. Before using 
any approved AMOC, notify your appropriate principal inspector, or 
lacking a principal inspector, the manager of the responsible Flight 
Standards Office.
    (2) Contacting the Manufacturer: For any requirement in this AD 
to obtain instructions from a manufacturer, the instructions must be 
accomplished using a method approved by the Manager, International 
Validation Branch, FAA; or EASA; or Dassault Aviation's EASA Design 
Organization Approval (DOA). If approved by the DOA, the approval 
must include the DOA-authorized signature.

(j) Additional Information

    For more information about this AD, contact Steven Dzierzynski, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; phone: 516-228-7367; email: [email protected].

(k) 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 this AD specifies otherwise.
    (i) European Union Aviation Safety Agency (EASA) AD 2025-0042, 
dated February 19, 2025.
    (ii) Reserved.
    (3) For EASA material identified in this AD, contact EASA, 
Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +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.
    (4) You may view this material at the FAA, Airworthiness 
Products Section, Operational Safety Branch, 2200 South 216th St., 
Des Moines, WA. For information on the availability of this material 
at the FAA, call 206-231-3195.
    (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 September 23, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2025-18705 Filed 9-25-25; 8:45 am]
BILLING CODE 4910-13-P