Rule2025-19393
Airworthiness Directives; ATR-GIE Avions de Transport Régional Airplanes
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
October 2, 2025
Effective
November 6, 2025
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for certain ATR--GIE Avions de Transport R[eacute]gional Model ATR42-500 and ATR72 airplanes. This AD was prompted by an investigation indicating that an erroneous monitoring of the travel limitation unit (TLU) could occur when the airplane is flying above a certain speed as a result of the logic input from either air data computer (ADC) 1 or ADC2 input. This AD requires modifying airplanes by installing one or two relays and associated wiring and testing of the TLU monitoring logic. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 90 Issue 189 (Thursday, October 2, 2025)</title>
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[Federal Register Volume 90, Number 189 (Thursday, October 2, 2025)]
[Rules and Regulations]
[Pages 47544-47546]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-19393]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-1354; Project Identifier MCAI-2025-00012-T;
Amendment 39-23154; AD 2025-20-01]
RIN 2120-AA64
Airworthiness Directives; ATR--GIE Avions de Transport
R[eacute]gional 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 ATR--GIE Avions de Transport R[eacute]gional Model ATR42-500
and ATR72 airplanes. This AD was prompted by an investigation
indicating that an erroneous monitoring of the travel limitation unit
(TLU) could occur when the airplane is flying above a certain speed as
a result of the logic input from either air data computer (ADC) 1 or
ADC2 input. This AD requires modifying airplanes by installing one or
two relays and associated wiring and testing of the TLU monitoring
logic. The FAA is issuing this AD to address the unsafe condition on
these products.
DATES: This AD is effective November 6, 2025.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of November 6,
2025.
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-1354; 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#0a4b4e794a6f6b796b246f7f78657a6b246f7f"><span class="__cf_email__" data-cfemail="f3b2b780b396928092dd9686819c8392dd9686">[email protected]</span></a>.
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, 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-2025-1354.
FOR FURTHER INFORMATION CONTACT: Jonathan Duong, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: 516-228-7362; email: <a href="/cdn-cgi/l/email-protection#c0f9ed819693ed818992ed8281838fed838f9380a6a1a1eea7afb6"><span class="__cf_email__" data-cfemail="261f0b6770750b676f740b646765690b6569756640474708414950">[email protected]</span></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 ATR--GIE Avions
de Transport R[eacute]gional Model ATR42-500 and ATR72 airplanes. The
NPRM was published in the Federal Register on July 7, 2025 (90 FR
29802). The NPRM was prompted by AD 2025-0004, dated January 7, 2025
(EASA AD 2025-0004) (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 an ATR internal review of the TLU new
avionics suite design identified an erroneous behavior of core
processing module (CPM) 2, hosting the data concentration application
(DCA) 2, that might affect the TLU command, monitoring, and indication.
Further investigation results indicated that an erroneous monitoring of
the TLU could occur when the airplane is flying above a certain speed
due to the logic input from either ADC1 or ADC2 input.
In the NPRM, the FAA proposed to require modification of airplanes
by installing one or two relays and associated wiring and testing of
the TLU monitoring logic, as specified in EASA AD 2025-0004. The FAA is
issuing this AD to address erroneous behavior of CPM 2, hosting the DCA
2, that could affect the TLU command, monitoring, and indication. This
condition, if not corrected, could result in the rudder deflection not
being limited at high airplane speed, which, if combined with a large
rudder pedal input, could lead to the loss of control of the airplane.
You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-1354.
Discussion of Final Airworthiness Directive
Comments
The FAA received a comment from the Air Line Pilots Association,
International (ALPA) who supported the NPRM without change.
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 2025-0004, which specifies procedures for
modifying airplanes by installing one or two relays and associated
wiring. EASA AD 2025-0004 also specifies procedures for an operational
test of the TLU monitoring logic after the modification, a functional
test of the rudder travel limiter unit, and obtaining and following
instructions to correct any failed test. For airplanes on which a
previous revision of the applicable service information has been
accomplished, EASA AD 2025-0004 specifies accomplishing ``Additional
Work,'' which consists of a functional test of the rudder travel
limiter unit. 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.
[[Page 47545]]
Costs of Compliance
The FAA estimates that this AD affects 43 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
Labor cost Parts cost Cost per product Cost on U.S. operators
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Up to 15 work-hours x $85 per hour = Up to $2,889........... Up to $4,164........... Up to $179,052.
$1,275.
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The FAA has received no definitive data on which to base the cost
estimates for the on-condition actions specified in this AD.
The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some or all 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:
2025-20-01 ATR--GIE Avions de Transport R[eacute]gional: Amendment
39-23154; Docket No. FAA-2025-1354; Project Identifier MCAI-2025-
00012-T.
(a) Effective Date
This airworthiness directive (AD) is effective November 6, 2025.
(b) Affected ADs
None.
(c) Applicability
This AD applies to the ATR--GIE Avions de Transport
R[eacute]gional airplanes identified in paragraphs (c)(1) and (2) of
this AD, certificated in any category, as identified in European
Union Aviation Safety Agency (EASA) AD 2025-0004, dated January 7,
2025 (EASA AD 2025-0004).
(1) ATR42-500 airplanes.
(2) ATR72-101, -102, -201, -202, -211, -212, and -212A
airplanes.
(d) Subject
Air Transport Association (ATA) of America Code 27, Flight
Controls.
(e) Unsafe Condition
This AD was prompted by an investigation indicating that an
erroneous monitoring of the travel limitation unit (TLU) could occur
when the airplane is flying above a certain speed as a result of the
logic input from either air data computer (ADC) 1 or ADC2 input. The
FAA is issuing this AD to address this condition, which if not
detected and corrected, could result in the rudder deflection not
being limited at high airplane speed, which, if combined with a
large rudder pedal input, could lead to the loss of control of the
airplane.
(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 2025-0004.
(h) Exceptions to EASA AD 2025-0004
(1) Where EASA AD 2025-0004 refers to its effective date, this
AD requires using the effective date of this AD.
(2) Paragraph (1) of EASA AD 2025-0004 applies to all airplanes
except for airplanes identified in paragraph (4) of EASA AD 2025-
0004.
(3) Where paragraph (3) of EASA AD 2025-0004 specifies ``as
required by paragraph (2) of this AD'', this AD requires replacing
that text with ``as required by paragraphs (2) and (4) of this AD''.
(4) Where paragraph (4) of EASA AD 2025-0004 specifies ``the
additional work'', this AD requires replacing that text with ``the
functional test of the rudder Travel Limiter Unit''.
(5) This AD does not adopt the ``Remarks'' section of EASA AD
2025-0004.
(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#3d7c70727e7d5b5c5c135a524b"><span class="__cf_email__" data-cfemail="e7a6aaa8a4a7818686c9808891">[email protected]</span></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 ATR--GIE Avions de Transport
R[eacute]gional's EASA Design Organization Approval (DOA). If
approved by
[[Page 47546]]
the DOA, the approval must include the DOA-authorized signature.
(j) Additional Information
For more information about this AD, contact Jonathan Duong,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: 516-228-7362; email: <a href="/cdn-cgi/l/email-protection#053c2844535628444c57284744464a28464a56456364642b626a73"><span class="__cf_email__" data-cfemail="271e0a6671740a666e750a656664680a6468746741464609404851">[email protected]</span></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 2025-0004,
dated January 7, 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#37767344775256445619524245584756195242"><span class="__cf_email__" data-cfemail="4b0a0f380b2e2a382a652e3e39243b2a652e3e">[email protected]</span></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 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#2c4a5e0245425f5c494f584543426c424d5e4d024b435a"><span class="__cf_email__" data-cfemail="abcdd985c2c5d8dbcec8dfc2c4c5ebc5cad9ca85ccc4dd">[email protected]</span></a>.
Issued on September 26, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2025-19393 Filed 10-1-25; 8:45 am]
BILLING CODE 4910-13-P
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