[Federal Register Volume 91, Number 136 (Friday, July 17, 2026)]
[Rules and Regulations]
[Pages 44740-44744]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-14511]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-7216; Project Identifier MCAI-2026-00693-A;
Amendment 39-23409; AD 2026-14-08]
RIN 2120-AA64
Airworthiness Directives; Diamond Aircraft Industries GmbH
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all
Diamond Aircraft Industries GmbH (DAI) Model DA 42, DA 42 NG, and DA 42
M-NG airplanes. This AD was prompted by occurrences of uncommanded
rudder deflection caused by a cracked nose landing gear (NLG) hydraulic
actuator rod end, which could lead to failure of the NLG actuator and
interference with the rudder control system, forcing the rudder into
left-hand deflection. This AD requires revising the existing airplane
flight manual (AFM) for your airplane to provide the flight crew with
revised operating limitations, repetitively inspecting certain NLG
hydraulic actuator rod ends for cracks, deformation, corrosion, damage,
and free movement of the spherical bearing, and depending on the
results of any inspection, replacing the affected NLG hydraulic
actuator rod end with a serviceable part. This AD also prohibits the
installation of an affected NLG hydraulic actuator rod end unless
certain conditions are met. The FAA is issuing this AD to address the
unsafe condition on these products.
DATES: This AD is effective July 20, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of July 20,
2026.
The FAA must receive comments on this AD by August 31, 2026.
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-2026-7216; 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
street address for Docket Operations is listed above.
Material Incorporated by Reference:
For Diamond Aircraft material identified in this AD,
contact DAI, N.A. Otto-Stra[beta]e 5, A-2700 Wiener Neustadt, Austria;
phone: +43 2622 26700; email: [email protected]; website:
diamondaircraft.com/.
You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 1100 Main, Kansas City, MO
64105. For information
[[Page 44741]]
on the availability of this material at the FAA, call (817) 222-5110.
It is also available at regulations.gov under Docket No. FAA-2026-7216.
FOR FURTHER INFORMATION CONTACT: Zakaria Abdi, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: (316) 946-4141; email: [email protected].
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written data, views, or arguments
about this final rule. Send your comments using a method listed under
the ADDRESSES section. Include ``Docket No. FAA-2026-7216; Project
Identifier MCAI-2026-00693-A'' at the beginning of your comments. The
most helpful comments reference a specific portion of the final rule,
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 final rule 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 final rule.
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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to Zakaria
Abdi, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590. Any commentary that the FAA receives which is not
specifically designated as CBI will be placed in the public docket for
this rulemaking.
Background
The European Union Aviation Safety Agency (EASA), which is the
Technical Agent for the Member States of the European Union, has issued
EASA Emergency AD 2026-0125-E, dated June 29, 2026 (EASA Emergency AD
2026-0125-E). EASA Emergency AD 2026-0125-E states that occurrences of
uncommanded rudder deflection were reported due to a cracked NLG
hydraulic actuator rod end. Investigation revealed that a crack in the
NLG hydraulic actuator rod end could lead to failure of the NLG
actuator and interference with the rudder control system, forcing the
rudder into left-hand deflection. The affected parts are installed on
DAI Model DA 42, DA-42 M, DA 42 NG, and DA 42 M-NG airplanes. This
condition, if not detected and corrected, could lead to restricted
rudder travel in the landing gear retracted configuration and result in
reduced control of the airplane. EASA later revised EASA Emergency AD
2026-0125 with EASA AD 2026-0125R1, dated June 30, 2026 (EASA AD 2026-
0125R1) (also referred to as the MCAI) to revise the applicability of
certain actions. The MCAI requires revising the existing AFM for your
airplane to provide the flight crew with revised operating limitations,
repetitively inspecting certain NLG hydraulic actuator rod ends for
cracks, corrosion, deformation, damage, and free movement of the
spherical bearing, and depending on the results of any inspection,
replacing the affected NLG hydraulic actuator rod end with a
serviceable part. The MCAI also prohibits the installation of an
affected NLG hydraulic actuator rod end unless certain conditions are
met.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2026-7216.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed Diamond Aircraft Mandatory Service Bulletin (MSB)
42-154 and MSB 42NG-101, dated June 29, 2026 (issued as one document),
published with Diamond Aircraft Work Instruction WI-MSB 42-154 and WI-
MSB 42NG-101, dated June 29, 2026 (issued as one document). This
material specifies procedures for inspecting certain NLG hydraulic
actuator rod ends for cracks, deformation, corrosion, damage, and free
movement of the spherical bearing. This material also specifies
replacing any NLG hydraulic actuator rod end found with cracks,
corrosion, deformation, damage, or lack of free movement of the
spherical bearing with a serviceable part. This material also includes
a reporting requirement of the results of the first inspection. In
addition, the material specifies sending any damaged parts to DAI. 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 and material referenced above. The FAA is issuing
this AD after determining that the unsafe condition described
previously is likely to exist or develop on other products of the same
type design.
AD Requirements
This AD requires revising the Limitations section of the existing
AFM for your airplane to provide the flight crew with revised operating
limitations, repetitively inspecting certain NLG hydraulic actuator rod
ends cracks, deformation, corrosion, damage, and free movement of the
spherical bearing, and, depending on the results of the inspection,
replacing the affected NLG hydraulic actuator rod end with a
serviceable part. This AD also prohibits the installation of an
affected NLG hydraulic actuator rod end unless certain conditions are
met.
The owner/operator (pilot) holding at least a private pilot
certificate may revise the existing AFM and must enter compliance with
the applicable paragraph of this AD into the airplane maintenance
records in accordance with 14 CFR 43.9(a) and 14 CFR 91.417(a)(2)(v).
The record must be maintained as required by 14 CFR 91.417, 121.380, or
135.439. This action can be performed equally well by a pilot or a
mechanic. This is an exception to the FAA's standard maintenance
regulations.
Differences Between This AD and the MCAI and Referenced Material
The MCAI applies to DAI Model 42 M airplanes, but this AD does not
include this model because it does not have an FAA type certificate.
The referenced material specifies to return damaged parts to the
manufacturer. However, this AD does not require this action.
[[Page 44742]]
Interim Action
The FAA considers that this AD is an interim action. If final
action is later identified, the FAA might consider further rulemaking.
Justification for Immediate Adoption and Determination of the Effective
Date
Section 553(b) of the Administrative Procedure Act (APA) (5 U.S.C.
551 et seq.) authorizes agencies to dispense with notice and comment
procedures for rules when the agency, for ``good cause,'' finds that
those procedures are ``impracticable, unnecessary, or contrary to the
public interest.'' Under this section, an agency, upon finding good
cause, may issue a final rule without providing notice and seeking
comment prior to issuance. Further, section 553(d) of the APA
authorizes agencies to make rules effective in less than thirty days,
upon a finding of good cause.
An unsafe condition exists that requires the immediate adoption of
this AD without providing an opportunity for public comments prior to
adoption. The FAA has found that the risk to the flying public
justifies forgoing notice and comment prior to adoption of this rule
because the FAA has determined that a cracked NLG hydraulic actuator
rod end could lead to failure of the NLG actuator and interference with
the rudder control system. This can result in restricted rudder travel
in the landing gear retracted configuration and reduced control of the
airplane. Because this condition can occur without warning and vary
from airplane to airplane, the FAA is requiring an immediate flight
operating restriction for those airplanes that have 1,000 hours total
time-in-service and a compliance time for inspections for some
airplanes as low as 5 flight cycles. These compliance times are shorter
than the time necessary for the public to comment and for publication
of the final rule. Accordingly, notice and opportunity for prior public
comment are impracticable and contrary to the public interest pursuant
to 5 U.S.C. 553(b).
In addition, the FAA finds that good cause exists pursuant to 5
U.S.C. 553(d) for making this amendment effective in less than 30 days,
for the same reasons the FAA found good cause to forgo notice and
comment.
Regulatory Flexibility Act
The requirements of the Regulatory Flexibility Act (RFA) do not
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt
a rule without prior notice and comment. Because the FAA has determined
that it has good cause to adopt this rule without prior notice and
comment, RFA analysis is not required.
Costs of Compliance
The FAA estimates that this AD affects 267 airplanes of U.S.
registry.
The FAA estimates the following costs to comply with this AD:
Estimated Costs
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Cost on U.S.
Action Labor cost Parts cost Cost per product operators
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Inspect the NLG actuator rod end. 4 work-hours x $85 $0 $340 per inspection $90,780 per
per hour = $340 cycle. inspection cycle
per inspection
cycle.
Revise the AFM................... 1 work-hour x $85 0 $85................ $22,695
per hour = $85.
Report inspection results (first 1 work-hour x $85 0 $85................ $22,695
inspection only). per hour = $85.
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The FAA estimates the following costs to do any necessary
replacements that would be required based on the results of the
inspection. The agency has no way of determining the number of
airplanes that might need replacements.
On-Condition Costs
----------------------------------------------------------------------------------------------------------------
Cost per
Action Labor cost Parts cost product
----------------------------------------------------------------------------------------------------------------
Replace NLG hydraulic actuator rod end........ 1 work-hour x $85 per hour = $85 $126 $211
Replace the entire NLG hydraulic actuator..... 6 work-hours x $85 per hour = 4,161 4,671
$510.
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*Only one replacement action would be required.
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.
Paperwork Reduction Act
A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to a penalty for
failure to comply with a collection of information subject to the
requirements of the Paperwork Reduction Act unless that collection of
information displays a currently valid OMB Control Number. The OMB
Control Number for this information collection is 2120-0056. Public
reporting for this collection of information is estimated to take
approximately 1 hour per response, including the time for reviewing
instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the
collection of information. All responses to this collection of
information are mandatory. Send comments regarding this burden estimate
or any other aspect of this collection of information, including
suggestions for reducing this burden, to: Information Collection
Clearance Officer, Federal Aviation Administration, 10101 Hillwood
Parkway, Fort Worth, TX 76177-1524.
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
[[Page 44743]]
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, and
(2) Will not affect intrastate aviation in Alaska.
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:
2026-14-08 Diamond Aircraft Industries GmbH: Amendment 39-23409;
Docket No. FAA-2026-7216; Project Identifier MCAI-2026-00693-A.
(a) Effective Date
This airworthiness directive (AD) is effective July 20, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all Diamond Aircraft Industries GmbH (DAI)
Model DA 42, DA 42 M-NG, and DA 42 NG airplanes, certificated in any
category.
(d) Subject
Joint Aircraft System Component (JASC) Codee 3233, Landing Gear
Actuator.
(e) Unsafe Condition
This AD was prompted by occurrences of uncommanded rudder
deflection caused by a cracked nose landing gear (NLG) hydraulic
actuator rod end. The FAA is issuing this AD to prevent cracked rod
ends from leading to the failure of the NLG actuator and
interference with the rudder control system. The unsafe condition,
if not addressed, could result in restricted rudder travel in the
landing gear retracted configuration and result in reduced control
of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Definitions
For the purpose of this AD, the following definitions apply:
(1) An ``affected part'' is an NLG hydraulic actuator rod end
having part number (P/N) X11-0006-SMRCD10IRMR.7403 or P/N X11-0006-
GARSW-10RR.
(2) A ``serviceable part'' is an affected part that is new
(never previously installed on an airplane) or that, before
installation, has been inspected and corrected as required by
paragraphs (h)(2) and (3) of this AD.
(3) A ``flight cycle'' is defined as one takeoff and one
landing. Each additional takeoff and landing associated with a
touch-and-go, or a go-around, is accounted for as an additional
take-off and landing.
(h) Required Actions
(1) Before accumulating 1,000 hours total time-in-service (TTIS)
on the airplane or before further flight after the effective date of
this AD, whichever occurs later, incorporate the information in
figure 1 of this AD into the Limitations section of your existing
airplane flight manual (AFM). Incorporating a copy of this AD into
the Limitations Section of your AFM is an acceptable method for this
action.
Figure 1 to Paragraph (h)(1)--AFM Limitation
[GRAPHIC] [TIFF OMITTED] TR17JY26.000
(i) This operating limitation may be removed after the first
inspection required by paragraph (h)(2) of this AD has been
accomplished. The first inspection required by paragraph (h)(2) of
this AD may be done in lieu of this operating limitation provided it
is done within the compliance times specified in paragraph (h)(1) of
this AD.
(ii) The owner/operator (pilot) holding at least a private pilot
certificate may revise the existing AFM for your airplane and must
enter compliance with the applicable paragraph of this AD into the
airplane maintenance records in accordance with 14 CFR 43.9(a) and
14 CFR 91.417(a)(2)(v). The record must be maintained as required by
14 CFR 91.417, 121.380, or 135.439.
(2) Within the compliance times specified in table 1 to
paragraph (h)(2) of this AD and thereafter at intervals not to
exceed 4,000 flight cycles, inspect the affected part for cracks,
deformation, corrosion, damage, and free movement of the spherical
bearing in accordance with Section III of Diamond Aircraft Work
Instruction WI-MSB 42-154 and WI-MSB 42NG-101, dated June 29, 2026
(issued as one document), published with Diamond Aircraft Mandatory
Service Bulletin MSB 42-154 and MSB 42NG-101, dated June 29, 2026
(issued as one document).
Table 1 Paragraph (h)(2)--Initial Inspection Compliance Time
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Aircraft hours TTIS accumulated on the
effective date of this AD Compliance time
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More than 4,000........................ Within 5 flight cycles after
the effective date of this AD.
4,000 or less and more than 1,000...... Within 50 flight cycles after
the effective date of this AD.
Up to and including 1,000.............. Within 2,000 flight cycles
after the effective date of
this AD.
[[Page 44744]]
Aircraft having an original Within 4,000 flight cycles
airworthiness certificate issued on or since issuance of the original
after the effective date of this AD. airworthiness certificate.
------------------------------------------------------------------------
(3) If, during any inspection as required by paragraph (h)(2) of
this AD, any crack, deformation, corrosion, damage, or lack of free
movement of the spherical bearing is found, before further flight,
replace the affected part with a serviceable part as specified in
Section III of Diamond Aircraft Work Instruction WI-MSB 42-154 and
WI-MSB 42NG-101, dated June 29, 2026 (issued as one document),
published with Diamond Aircraft Mandatory Service Bulletin MSB 42-
154 and MSB 42NG-101, dated June 29, 2026 (issued as one document).
Replacing the NLG hydraulic actuator with an NLG hydraulic actuator
that is equipped with a serviceable part is an acceptable method to
comply with this requirement.
(4) Within 14 days after performing any inspection required by
paragraph (h)(2) of this AD or within 14 days after the effective
date of this AD, whichever occurs later, report the inspection
results (including no findings, for the first inspection only),
using the Execution Report in Diamond Aircraft Mandatory Service
Bulletin MSB 42-154 and MSB 42NG-101, dated June 29, 2026 (issued as
one document)), published with Diamond Aircraft Work Instruction WI-
MSB 42-154 and WI-MSB 42NG-101, dated June 29, 2026 (issued as one
document).
(i) Parts Installation Limitation
As of the effective date of this AD, do not install an affected
part on any airplane unless it is a serviceable part as defined in
paragraph (g)(2) of this AD.
(j) No Return of Parts
Where Diamond Aircraft Work Instruction WI-MSB 42-154 and WI-MSB
42NG-101, dated June 29, 2026 (issued as one document), published
with Diamond Aircraft Mandatory Service Bulletin MSB 42-154 and MSB
42NG-101, dated June 29, 2026 (issued as one document), specifies to
return damaged parts to DAI, this AD does not require this action.
(k) 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 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 (l) 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 local flight standards district
office/certificate holding district office.
(l) Additional Information
For more information about this AD, contact Zakaria Abdi,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: (316) 946-4141; email:
[email protected].
(m) 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.
(i) Diamond Aircraft Mandatory Service Bulletin MSB 42-154 and
MSB 42NG-101, dated June 29, 2026 (issued as one document),
published with Diamond Aircraft Work Instruction WI-MSB 42-154 and
WI-MSB 42NG-101, dated June 29, 2026 (issued as one document).
(ii) [Reserved]
(3) For Diamond Aircraft material identified in this AD, contact
Diamond Aircraft Industries GmbH, N.A. Otto-Stra[beta]e 5, A-2700
Wiener Neustadt, Austria; phone: +43 2622 26700; email:
[email protected]; website: diamondaircraft.com/.
(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 July 13, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-14511 Filed 7-15-26; 4:15 pm]
BILLING CODE 4910-13-P