Rule2026-05883
Airworthiness Directives; Diamond Aircraft Industries Inc. 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
March 26, 2026
Effective
April 30, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is superseding Airworthiness Directive (AD) 2020-14- 06, which applied to all Diamond Aircraft Industries Inc. (DAI) Model DA 40, DA 40 F, and DA 40 NG airplanes. AD 2020-14-06 required replacing affected parts, inspecting the fuel tank chambers, and removing rubber material that has detached from the fuel tank connection hoses. AD 2020-14-06 also prohibited installing an affected part on any airplane. Since the FAA issued AD 2020-14-06, additional affected parts installed during production on Model DA 40 NG airplanes have been reported. As a result, the manufacturer has published updated service material for the Model DA 40 NG. This AD requires the same actions as AD 2020-14-06 and requires updated service material to be used for the Model DA 40 NG airplanes. 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 58 (Thursday, March 26, 2026)</title>
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[Federal Register Volume 91, Number 58 (Thursday, March 26, 2026)]
[Rules and Regulations]
[Pages 14643-14645]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-05883]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-5397; Project Identifier MCAI-2025-00972-A;
Amendment 39-23291; AD 2026-06-03]
RIN 2120-AA64
Airworthiness Directives; Diamond Aircraft Industries Inc.
Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2020-14-
06, which applied to all Diamond Aircraft Industries Inc. (DAI) Model
DA 40, DA 40 F, and DA 40 NG airplanes. AD 2020-14-06 required
replacing affected parts, inspecting the fuel tank chambers, and
removing rubber material that has detached from the fuel tank
connection hoses. AD 2020-14-06 also prohibited installing an affected
part on any airplane. Since the FAA issued AD 2020-14-06, additional
affected parts installed during production on Model DA 40 NG airplanes
have been reported. As a result, the manufacturer has published updated
service material for the Model DA 40 NG. This AD requires the same
actions as AD 2020-14-06 and requires updated service material to be
used for the Model DA 40 NG airplanes. The FAA is issuing this AD to
address the unsafe condition on these products.
DATES: This AD is effective April 30, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of April 30,
2026.
The Director of the Federal Register approved the incorporation by
reference of certain other publications listed in this AD as of August
4, 2020 (85 FR 42687, July 15, 2020).
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-5397; 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 Diamond Aircraft Industries material identified in
this AD, contact DAI, 1560 Crumlin Sideroad, London, Ontario, Canada,
N5V 1S2; phone: (519) 457-4041, fax: (519) 457-4045; email: <a href="/cdn-cgi/l/email-protection#70030500001f02045d13111e111411301419111d1f1e1411190213021116045e131f1d"><span class="__cf_email__" data-cfemail="cab9bfbabaa5b8bee7a9aba4abaeab8aaea3aba7a5a4aeaba3b8a9b8abacbee4a9a5a7">[email protected]</span></a>.
<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. It is also available at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-5397.
FOR FURTHER INFORMATION CONTACT: Joseph Catanzaro, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: (516) 228-7366; email: <a href="/cdn-cgi/l/email-protection#4c26233f293c24622f2d382d22362d3e230c2a2d2d622b233a"><span class="__cf_email__" data-cfemail="8fe5e0fceaffe7a1eceefbeee1f5eefde0cfe9eeeea1e8e0f9">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2020-14-06, Amendment 39-21160 (85 FR
42687, July 15, 2020), (AD 2020-14-06). AD 2020-14-06 applied to DAI
Model DA 40, DA 40 F, and DA 40 NG airplanes (including Model DA 40 NG
airplanes that have been converted from the Model DA 40 D). AD 2020-14-
06 required replacing affected parts, inspecting the fuel tank
chambers, and removing rubber material that has detached from the fuel
tank connection hoses. AD 2020-14-06 also prohibited installing an
affected part on any airplane. The FAA issued AD 2020-14-06 to detect
and prevent fuel starvation and reduced control of the airplane. AD
2020-14-16 was prompted by Transport Canada CF-2019-39, dated October
31, 2019 (Transport Canada AD CF-2019-39) issued by Transport Canada,
which is the aviation authority for Canada.
The NPRM was published in the Federal Register on December 23, 2025
(90 FR 60031). The NPRM was prompted by Transport Canada AD CF-2019-
39R1, dated May 21, 2025 (also referred to as the MCAI), which
superseded Transport Canada AD CF-2019-39 based on reports of
additional affected parts installed during production on DAI Model DA
40 NG airplanes. As a result, the manufacturer published updated
service material for the Model DA 40 NG. The MCAI also continues to
require replacing affected fuel tank connection hoses, inspecting the
fuel tank chambers, and removing rubber material that has detached from
the fuel tank connection hoses.
In the NPRM, the FAA proposed to require the same actions as AD
2020-14-06 and to require updated service material to be used for the
Model DA 40 NG airplanes.
You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-5397.
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. Except for
minor editorial changes, and any other changes described previously,
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 Diamond Aircraft Industries Mandatory Service
Bulletin
[[Page 14644]]
No. MSB 40NG-064 Rev. 3, dated January 23, 2025, which specifies
procedures for replacing affected parts, inspecting the fuel tank
chambers, and removing rubber material that has detached from the
hoses. This material also specifies the service centers from which the
affected parts could have been obtained and the serial numbers for
additional DAI Model DA 40 NG airplanes that are affected by the unsafe
condition and were not in the previous version of the material.
This AD also requires the following Diamond Aircraft Industries
Mandatory Service Bulletins, which the Director of the Federal Register
approved for incorporation by reference as of August 4, 2020 (85 FR
42687, July 15, 2020):
<bullet> Diamond Aircraft Industries Mandatory Service Bulletin No.
MSB 40-087, Revision 3, dated November 5, 2019.
<bullet> Diamond Aircraft Industries Mandatory Service Bulletin No.
MSB F4-037, Revision 3, dated November 5, 2019.
<bullet> Diamond Aircraft Industries Work Instruction WI-MSB 40-
087, Revision 0, dated July 1, 2019.
<bullet> Diamond Aircraft Industries Work Instruction WI-MSB F4-
037, Revision 0, dated July 1, 2019.
<bullet> Diamond Aircraft Industries Work Instruction WI-MSB 40 NG-
064, Revision 0, dated July 1, 2019.
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 987 airplanes of U.S.
registry.
The FAA estimates the following costs to comply with this AD:
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Inspect the fuel tank chambers........... 1 work-hour x $85 per hour $0 $85 $83,895
= $85.
Remove detached rubber material.......... 5 work hours x $85 per hour 0 425 419,475
= $425.
Replace fuel tank connection hose........ 10 work hours x $85 per 383 1,233 1,216,971
hour = $850.
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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.
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 has determined that 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:
0
a. Removing Airworthiness Directive 2020-14-06, Amendment 39-21160 (85
FR 42687, July 15, 2020); and
0
b. Adding the following new airworthiness directive:
2026-06-03 Diamond Aircraft Industries Inc: Amendment 39-23291;
Docket No. FAA-2025-5397; Project Identifier MCAI-2025-00972-A.
(a) Effective Date
This airworthiness directive (AD) is effective April 30, 2026.
(b) Affected ADs
This AD replaces AD 2020-14-06, Amendment 39-21160 (85 FR 42687,
July 15, 2020); (AD 2020-14-06).
(c) Applicability
This AD applies to all Diamond Aircraft Industries Inc. Model DA
40, DA 40 F, and DA 40 NG airplanes (including Model DA 40 NG
airplanes that have been converted from the Model DA 40 D),
certificated in any category.
(d) Subject
Joint Aircraft System Component (JASC) Code 1410, Hoses and
tubes.
(e) Unsafe Condition
This AD was prompted by reports of fuel tank connection hose
deterioration and reports of affected parts that were installed
during production on Model DA 40 NG airplanes. The FAA is issuing
this AD to detect and address such deterioration, which, if not
corrected, could result in contamination of the fuel system and
restriction of fuel flow and could lead to fuel starvation and
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, ``affected part'' means a fuel tank
connection hose that meets the criteria in paragraph (g)(1), (2), or
(3) of this AD.
(1) Part number (P/N) D4D-2817-10-70 installed during production
on Model DA 40 NG airplanes with a serial number listed in
[[Page 14645]]
Section I.2. of Diamond Aircraft Industries Mandatory Service
Bulletin MSB 40NG-064 Rev. 3, dated January 23, 2025; or
(2) P/N D4D-2817-10-70 or BENOLPRESS (no part number) purchased
between July 13, 2017, and February 26, 2019, as listed in Section
I.11 of Diamond Aircraft Industries Mandatory Service Bulletin No.
MSB 40-087, Revision 3, dated November 5, 2019; Diamond Aircraft
Industries Mandatory Service Bulletin No. MSB 40NG-064 Rev. 3, dated
January 23, 2025; or Diamond Aircraft Industries Mandatory Service
Bulletin No. MSB F4-037, Revision 3, dated November 5, 2019; or
(3) P/N D4D-2817-10-70 installed as a replacement part on or
after July 13, 2017, if it is unknown whether the part meets the
criteria in paragraph (g)(1) or (2) of this AD.
(h) Required Actions
Within 100 hours time-in-service or within 2 months, whichever
occurs first after the effective date of this AD, replace each
affected part as defined in paragraph (g) of this AD, inspect the
main fuel tank chambers, and remove any detached rubber material in
accordance with Sections III.1 and III.2 of the Instructions in
Diamond Aircraft Industries Work Instruction WI-MSB 40-087, Revision
0, dated July 1, 2019; Diamond Aircraft Industries Work Instruction
WI-MSB F4-037, Revision 0, dated July 1, 2019; or Diamond Aircraft
Industries Work Instruction WI-MSB 40NG-064, Revision 0, dated July
1, 2019; as applicable to your model airplane.
(i) No Reporting Requirement
Although the service material specifies to submit information to
the manufacturer, this AD does not require that action.
(j) Installation Prohibition
As of the effective date of this AD, do not install an affected
part, as defined in paragraph (g) of this AD, on any airplane.
(k) Credit for Previous Actions
This paragraph provides credit for the actions required by
paragraph (h) of this AD if those actions were performed before the
effective date of this AD, and the affected part for the Model DA 40
NG airplane was identified using Diamond Aircraft Industries
Mandatory Service Bulletin No. MSB 40NG-064, Revision 2, dated
August 29, 2019.
(l) 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 manager of the International Validation Branch, send
it to the attention of the person identified in paragraph (m)(1) of
this AD and email it to: <a href="/cdn-cgi/l/email-protection#9bdad6d4d8dbfdfafab5fcf4ed"><span class="__cf_email__" data-cfemail="0445494b47446265652a636b72">[email protected]</span></a>.
(2) 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.
(m) Additional Information
(1) For more information about this AD, contact Joseph
Catanzaro, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite
410, Westbury, NY 11590; phone: (516) 228-7366; email:
<a href="/cdn-cgi/l/email-protection#83e9ecf0e6f3ebade0e2f7e2edf9e2f1ecc3e5e2e2ade4ecf5"><span class="__cf_email__" data-cfemail="dfb5b0acbaafb7f1bcbeabbeb1a5beadb09fb9bebef1b8b0a9">[email protected]</span></a>.
(2) Material identified in this AD that is not incorporated by
reference is available at the address specified in paragraph (n)(5)
of this AD.
(n) 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.
(3) The following material was approved for IBR on April 30,
2026.
(i) Diamond Aircraft Industries Mandatory Service Bulletin MSB
40NG-064 Rev. 3, dated January 23, 2025.
(ii) [Reserved]
(4) The following material was approved for IBR on August 4,
2020 (85 FR 42687, July 15, 2020).
(i) Diamond Aircraft Industries Mandatory Service Bulletin No.
MSB 40-087, Revision 3, dated November 5, 2019.
(ii) Diamond Aircraft Industries Mandatory Service Bulletin No.
MSB F4-037, Revision 3, dated November 5, 2019.
(iii) Diamond Aircraft Industries Work Instruction WI-MSB 40-
087, Revision 0, dated July 1, 2019.
(iv) Diamond Aircraft Industries Work Instruction WI-MSB 40NG-
064, Revision 0, dated July 1, 2019.
(v) Diamond Aircraft Industries Work Instruction WI-MSB F4-037,
Revision 0, dated July 1, 2019.
(5) For Diamond Aircraft Industries material identified in this
AD, contact Diamond Aircraft Industries Inc., 1560 Crumlin Sideroad,
London, Ontario, Canada, N5V 1S2; phone: (519) 457-4041, fax: (519)
457-4045; email: <a href="/cdn-cgi/l/email-protection#6d1e181d1d021f19400e0c030c090c2d09040c000203090c041f0e1f0c0b19430e0200"><span class="__cf_email__" data-cfemail="4d3e383d3d223f39602e2c232c292c0d29242c202223292c243f2e3f2c2b39632e2220">[email protected]</span></a>.
(6) 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.
(7) 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#f69084d89f9885869395829f9998b698978497d8919980"><span class="__cf_email__" data-cfemail="dfb9adf1b6b1acafbabcabb6b0b19fb1beadbef1b8b0a9">[email protected]</span></a>.
Issued on March 18, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-05883 Filed 3-25-26; 8:45 am]
BILLING CODE 4910-13-P
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