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Rule2026-06627

Airworthiness Directives; Dassault Aviation Airplanes

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Published

April 6, 2026

Effective

May 11, 2026

Issuing agencies

Transportation DepartmentFederal Aviation Administration

Abstract

The FAA is adopting a new airworthiness directive (AD) for certain Dassault Aviation Model FALCON 2000EX airplanes. 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. This AD requires revising the existing airplane flight manual (AFM). The FAA is issuing this AD to address the unsafe condition on these products.

Full Text

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<title>Federal Register, Volume 91 Issue 65 (Monday, April 6, 2026)</title>
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[Federal Register Volume 91, Number 65 (Monday, April 6, 2026)]
[Rules and Regulations]
[Pages 17137-17141]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-06627]

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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;
Amendment 39-23297; AD 2026-07-02]
RIN 2120-AA64

Airworthiness Directives; Dassault Aviation 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 Dassault Aviation Model FALCON 2000EX airplanes. 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. This AD requires revising the existing
airplane flight manual (AFM). The FAA is issuing this AD to address the
unsafe condition on these products.

DATES: This AD is effective May 11, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of May 11,
2026.

ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> 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 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; telephone +49 221 8999 000; email <a href="/cdn-cgi/l/email-protection#2e6f6a5d6e4b4f5d4f004b5b5c415e4f004b5b">[email&#160;protected]</a>.
You may find this material on the EASA website at ad.easa.europa.eu.

[[Page 17138]]

<bullet> 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. It is also available at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-2553.

FOR FURTHER INFORMATION CONTACT: Steven Dzierzynski, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: 516-228-7367; email: <a href="/cdn-cgi/l/email-protection#dde4f09c8b8ef09c948ff09f9c9e92f09e928e9dbbbcbcf3bab2ab">[email&#160;protected]</a>.

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 Dassault
Aviation Model FALCON 2000EX airplanes. The NPRM was published in the
Federal Register on September 26, 2025 (90 FR 46365). The NPRM was
prompted by AD 2025-0042, dated February 19, 2025 (EASA AD 2025-0042)
(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
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.
In the NPRM, the FAA proposed to require revising the existing AFM,
as specified in EASA AD 2025-0042. 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 <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-2553.

Discussion of Final Airworthiness Directive

Comments

The FAA received comments from the Citizens Rulemaking Alliance.
The following presents the comments received on the NPRM and the FAA's
response to each comment.

Request To Issue an NPRM or Delay Effective Date for Non-Immediate
Tasks

The commenter requested that the FAA either convert this action to
an NPRM or delay the effective date for non-immediate tasks by 60 to
120 days and request comments for those non-immediate tasks. The
commenter asserted the FAA's use of the good cause exemption appears
overbroad given the compliance is 1 month instead of before further
flight.
The FAA notes the comment was submitted in response to an NPRM for
which the FAA provided a 45-day comment period. This final rule is
effective 35 days after its publication in the Federal Register.
Therefore, no change to this AD is necessary.

Request To Make Incorporation by Reference (IBR) Materials Reasonably
Available

The commenter stated that the FAA's current practices for IBR
frequently fail to meet the legal and regulatory standards for
reasonable availability. The commenter called on the FAA to guarantee
that all IBR materials are easily and freely accessible to the public
and affected parties for both commenting and compliance purposes. They
also requested that this access be documented in the rulemaking record.
The FAA's practices comply with 5 U.S.C. 552(a) of the
Administrative Procedure Act and 1 CFR part 51. The FAA makes IBR
materials available in the AD docket when the final rule is published
in the Federal Register, following formal approval of the IBR by the
Office of the Federal Register. Materials may only be posted before the
final rule's publication if they are already publicly available or if
there is written consent from the owner of the IBR material. All
relevant materials incorporated by reference will be accessible in the
AD docket on Regulations.gov, which the public can access without
registration or fees.
The FAA also provides summaries and access details in the preamble
and regulatory text, makes materials available for inspection at FAA
and National Archives and Records Administration (NARA) offices, offers
publisher contact information, and obtains formal IBR approval from the
Office of the Federal Register. These efforts are intended to ensure
that all IBR materials meet the ``reasonably available'' standard
required by 1 CFR part 51. The FAA did not change this AD as a result
of this comment.

Request To Comply With the Paperwork Reduction Act (PRA)

The commenter requested that the FAA revise the AD to comply with
the PRA if reporting is required or remove any reporting provisions
until PRA requirements are satisfied. If reporting is not required, the
commenter requested the FAA clarify that in the AD.
The FAA notes this AD does not require reporting. If an AD were to
require reporting, the preamble of the AD would include a paragraph
titled ``Paperwork Reduction Act'' that would provide the applicable
OMB control number, required PRA statements, and the estimated time to
collect the required information (burden). Any costs associated with
the reporting requirement would be included in the Costs of Compliance
section in the preamble of the AD. Therefore, the FAA did not change
this AD as a result of this comment.

Request To Consider Impact on Small Entities

The commenter requested that the FAA either provide the factual
basis for its Regulatory Flexibility Act (RFA) certification that the
AD will not have a significant economic impact on a substantial number
of small entities, or prepare an initial regulatory flexibility
analysis and consider less burdensome alternatives for small operators
and small repair stations.
The FAA provides the following clarification. The RFA of 1980 (5
U.S.C. 601-612), as amended by the Small Business Regulatory
Enforcement Fairness Act of 1996 (Pub. L. 104-121) and the Small
Business Jobs Act of 2010 (Pub. L. 111-240), requires Federal agencies
to consider the effects of the regulatory action on small business and
other small entities and to minimize any significant economic impact.
The term ``small entities'' comprises small businesses and not-for-
profit organizations that are independently owned and operated and are
not dominant in their fields, and governmental jurisdictions with
populations of less than 50,000.
This AD will affect 230 small and non-small entities, 1 Tribal
government, and 3 individuals. Of the affected entities, FAA identified
143 small entities in multiple industries as follows:

[[Page 17139]]

Number of Small Entities Affected per Industry and Cost Significance
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Number of small Cost per AD/
NAICS code Description entities annual revenue
affected (%)
----------------------------------------------------------------------------------------------------------------
481211................................. Nonscheduled Chartered Passenger Air 89 0.00 to 0.02
Transportation.
481219................................. Other Nonscheduled Air Transportation. 13 0.00 to 0.02
532411................................. Commercial Air, Rail, and Water 11 0.01
Transportation Equipment Rental and
Leasing.
488190................................. Other Support Activities for Air 4 0.00 to 0.01
Transportation.
551112................................. Offices of Other Holding Companies.... 4 0.01
211120................................. Crude Petroleum Extraction............ 1 0.00
326299................................. All Other Rubber Product Manufacturing 1 0.01
334511................................. Search, Detection, Navigation, 1 n.a.
Guidance, Aeronautical, and Nautical
System and Instrument Manufacturing.
336411................................. Aircraft Manufacturing................ 1 0.01
336414................................. Guided Missile and Space Vehicle 1 0.01
Manufacturing.
423820................................. Farm and Garden Machinery and 1 0.01
Equipment Merchant Wholesalers.
423860................................. Transportation Equipment and Supplies 1 0.00
Merchant Wholesalers.
425120................................. Wholesale Trade Agents and Brokers.... 1 0.00
484121................................. General Freight Trucking, Long- 1 0.01
Distance, Truckload.
523120................................. Securities Brokerage.................. 1 0.00
525990................................. Other Investment Pools and Funds...... 1 n.a.
531190................................. Lessors of Other Real Estate Property. 1 0.01
531390................................. Other Activities Related to Real 1 0.00
Estate.
532310................................. General Rental Centers................ 1 n.a.
532490................................. Other Commercial and Industrial 1 0.00
Machinery and Equipment Rental and
Leasing.
541110................................. Offices of Lawyers.................... 1 0.00
541511................................. Custom Computer Programming Services.. 1 0.00
541512................................. Computer Systems Design Services...... 1 0.00
541611................................. Administrative Management and General 1 0.01
Management Consulting Services.
551114................................. Corporate, Subsidiary, and Regional 1 0.01
Managing Offices.
611512................................. Flight Training....................... 1 n.a.
811310................................. Commercial and Industrial Machinery 1 0.00
and Equipment (except Automotive and
Electronic) Repair and Maintenance.
--------------------------------
Total.............................. ...................................... 143 ..............
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While FAA has determined that this final AD affects a substantial
number of small entities, the compliance cost of the AD per small
entity to their annual revenue is de minimis. Therefore, as provided in
section 605(b) and based on the foregoing, the head of FAA certifies
that this AD will not result in a significant economic impact on a
substantial number of small entities. The FAA did not change this AD as
a result of this comment.

Request To Revise the Cost Estimate

The commenter requested that the FAA update the labor rate and
downtime assumptions in the cost estimate, consider alternatives that
minimize downtime and scheduling disruptions, and revise the FAA's
certification that the AD is not a significant regulatory action under
Executive Order 12866 if the updated costs justify it.
The FAA has determined that the current labor rate of $85 per hour
remains accurate for this AD. The FAA evaluates this rate periodically,
based on U.S. Department of Labor Statistic (BLS) data found at <a href="https://data.bls.gov/oes">https://data.bls.gov/oes</a>, and will change the rate when appropriate. The FAA
used a blended wage rate to estimate the labor rate for this AD, where
the FAA assumes 60 percent weight for aircraft mechanics (at a fully
burdened mean wage rate of $69.85 per hour) and 40 percent for general
and operations managers (at a fully burdened mean wage rate of $108.15
per hour). To calculate the blended wage rate, the FAA multiplied each
wage rate by its corresponding weight and added up the products to
obtain a wage rate of $85.17, which the FAA rounded down to $85.
Additionally, the FAA considered the impact that this AD will have on
affected operators and determined that this AD will not trigger any
downtime costs because AFM revisions are administrative actions that do
not normally lead to burdensome scheduling disruptions. Therefore, the
FAA did not change this AD as a result of this comment.

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. Except for
minor editorial changes, this AD is adopted as proposed in the NPRM.
None of the changes will increase the economic burden on any operator.

Material Incorporated by Reference Under 1 CFR Part 51

The FAA reviewed EASA AD 2025-0042, which 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.

Costs of Compliance

The FAA estimates that this AD affects 304 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:

[[Page 17140]]

Estimated Costs
----------------------------------------------------------------------------------------------------------------
Labor cost Parts cost Cost per product Cost on U.S. operators
----------------------------------------------------------------------------------------------------------------
1 work-hour x $85 per hour = $85.................... $0 $85 $25,840
----------------------------------------------------------------------------------------------------------------

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:

2026-07-02 Dassault Aviation: Amendment 39-23297; Docket No. FAA-
2025-2553; Project Identifier MCAI-2025-00186-T.

(a) Effective Date

This airworthiness directive (AD) is effective May 11, 2026.

(b) Affected ADs

None.

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 and 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 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:
<a href="/cdn-cgi/l/email-protection#2b6a6664686b4d4a4a054c445d">[email&#160;protected]</a>. 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: <a href="/cdn-cgi/l/email-protection#51687c1007027c1018037c1310121e7c121e02113730307f363e27">[email&#160;protected]</a>.

(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 <a href="/cdn-cgi/l/email-protection#b1f0f5c2f1d4d0c2d09fd4c4c3dec1d09fd4c4">[email&#160;protected]</a>. 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

[[Page 17141]]

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 <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#bddbcf93d4d3cecdd8dec9d4d2d3fdd3dccfdc93dad2cb">[email&#160;protected]</a>.

Issued on March 25, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-06627 Filed 4-3-26; 8:45 am]
BILLING CODE 4910-13-P

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