Rule2026-08303
Airworthiness Directives; De Havilland Aircraft of Canada Limited (Type Certificate Previously Held by Bombardier, 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
April 29, 2026
Effective
June 3, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for certain De Havilland Aircraft of Canada Limited Model DHC-8-401 and - 402 airplanes. This AD was prompted by multiple in-service reports of cracks in elevator power control unit (PCU) brackets (fittings) and the elevator front spar. This AD requires replacing bushings and installing new washers on the elevator PCU arm fitting assembly, installing doublers at the front spar of the elevator structure assembly, replacing horizontal stabilizer rear spar elevator PCU fittings, and applicable on-conditions actions. 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 82 (Wednesday, April 29, 2026)</title>
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[Federal Register Volume 91, Number 82 (Wednesday, April 29, 2026)]
[Rules and Regulations]
[Pages 23009-23011]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-08303]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-5402; Project Identifier MCAI-2025-00425-T;
Amendment 39-23315; AD 2026-08-07]
RIN 2120-AA64
Airworthiness Directives; De Havilland Aircraft of Canada Limited
(Type Certificate Previously Held by Bombardier, Inc.) 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 De Havilland Aircraft of Canada Limited Model DHC-8-401 and -
402 airplanes. This AD was prompted by multiple in-service reports of
cracks in elevator power control unit (PCU) brackets (fittings) and the
elevator front spar. This AD requires replacing bushings and installing
new washers on the elevator PCU arm fitting assembly, installing
doublers at the front spar of the elevator structure assembly,
replacing horizontal stabilizer rear spar elevator PCU fittings, and
applicable on-conditions actions. The FAA is issuing this AD to address
the unsafe condition on these products.
DATES: This AD is effective June 3, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of June 3,
2026.
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-5402; 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 Transport Canada material identified in this AD,
contact Transport Canada, Transport Canada National Aircraft
Certification, 159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada;
telephone 888-663-3639; email <a href="/cdn-cgi/l/email-protection#4115026f002833362e333529282f243232052833242235283724326c022e2f3228262f243225242f203728262023282d2835246f15020135226f26226f2220"><span class="__cf_email__" data-cfemail="3367701d725a41445c41475b5a5d564040775a415650475a4556401e705c5d405a545d564057565d52455a5452515a5f5a47561d67707347501d54501d5052">[email protected]</span></a>. You may find this material on the
Transport Canada website at tc.canada.ca/en/aviation.
<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-2025-5402.
FOR FURTHER INFORMATION CONTACT: Yaser Osman, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: 516-
228-7300; email: <a href="/cdn-cgi/l/email-protection#172e3a7661643a796e7674783a7478645771767639707861"><span class="__cf_email__" data-cfemail="d0e9fdb1a6a3fdbea9b1b3bffdb3bfa390b6b1b1feb7bfa6">[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 De Havilland
Aircraft of Canada Limited Model DHC-8-401 and -402 airplanes. The NPRM
was published in the Federal Register on January 7, 2026 (91 FR 454).
The NPRM was prompted by AD CF-2025-19, dated March 24, 2025 (Transport
Canada AD CF-2025-19) (also referred to as the MCAI), issued by
Transport Canada, which is the aviation authority for Canada. The MCAI
states there have been reports of multiple instances of in-service
cracking in the elevator PCU brackets (fittings) located on the
horizontal stabilizer rear spar, as well as four cases of cracking on
the elevator front spar. In one case, the cracking progressed to the
point where the PCU bracket detached. An investigation determined that
the common contributing factor in all cases was force-fight loads
generated during elevator movement by the PCUs. Potential root causes
identified include elevator system mis-rigging, improper clamping of
PCU brackets due to insufficient shimming, and misalignment of the
horizontal stabilizer and elevator hinges during assembly.
In the NPRM, the FAA proposed to require replacing bushings and
installing new washers on the elevator PCU arm fitting assembly,
installing doublers at the front spar of the elevator structure
assembly, replacing horizontal stabilizer rear spar elevator PCU
fittings, and applicable on-conditions actions, as specified in
Transport Canada AD CF-2025-19. The FAA is issuing this AD to address
cracks in the elevator PCU brackets (fittings) and the elevator front
spar, which could result in failure of an elevator PCU bracket and lead
to an elevator jam. The unsafe condition, if not addressed, could, if
both elevators are affected, result in the loss of pitch control.
You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-5402.
Discussion of Final Airworthiness Directive
Comments
The FAA received a comment from 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.
Terminating Action Explanation for Related Transport Canada AD
The accomplishment of certain actions required by this AD, as
specified in Transport Canada AD CF-2025-19, terminates inspections
required by Transport Canada AD CF-2024-10, dated March 1, 2024, which
corresponds to FAA AD 2025-19-05, Amendment 39-23145 (90 FR 46340,
September 26, 2025) (AD 2025-19-05). Paragraph (j) of AD 2025-19-05
provides the terminating action that corresponds to the terminating
action specified in paragraph C of Part I and paragraph D of Part II of
Transport Canada AD CF-2025-19.
Material Incorporated by Reference Under 1 CFR Part 51
Transport Canada AD CF-2025-19 specifies the following procedures:
<bullet> Replacing bushings and installing new washers on the
elevator PCU arm fitting assembly, which includes inspecting bushing
holes in the arm fitting assembly for corrosion, scoring, and
structural degradation (i.e., hole diameters are not within specified
diameters).
<bullet> Installing doublers between ribs 12 and 13 and between
ribs 13 and 14 at the front spar of the elevator structure assembly and
applicable on-condition actions. The installation includes a detailed
visual inspection of the
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elevator front spar caps and detailed inspection of the upper skin
panel for damage (i.e., cracking or corrosion), a bolt hole eddy
current inspection for cracking at certain fastener holes, a high
frequency eddy current for radial cracking at bend radius of certain
rib lightening holes, and an inspection of the pressure sensitive
lightening tape on certain lightening holes for missing or torn tape.
On-condition actions include contacting the DHC technical helpdesk for
an approved repair, contacting DHC technical helpdesk for support, and
replacing pressure sensitive lightening tape with new tape.
<bullet> Replacing horizontal stabilizer rear spar elevator PCU
fittings, which includes an eddy current inspection, if fittings are
removed, for cracking at all mating holes on the spar web assembly and
the lower skin.
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 54 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions
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Labor cost Parts cost Cost per product Cost on U.S. operators
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Up to 81 work-hours x $85 per hour = Up to $14,233.......... Up to $21,118.......... Up to $1,140,372.
$6,885.
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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:
2026-08-07 De Havilland Aircraft of Canada Limited (Type Certificate
Previously Held by Bombardier, Inc.): Amendment 39-23315; Docket No.
FAA-2025-5402; Project Identifier MCAI-2025-00425-T.
(a) Effective Date
This airworthiness directive (AD) is effective June 3, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to De Havilland Aircraft of Canada Limited (type
certificate previously held by Bombardier, Inc.) Model DHC-8-401 and
-402 airplanes, certificated in any category, as identified in
Transport Canada AD CF-2025-19, dated March 24, 2025 (Transport
Canada AD CF-2025-19).
(d) Subject
Air Transport Association (ATA) of America Code 55, Stabilizers.
(e) Unsafe Condition
This AD was prompted by multiple in-service reports of cracks
found in the elevator power control unit (PCU) brackets (fittings)
and the elevator front spar. The FAA is issuing this AD to address
such cracks, which could result in failure of an elevator PCU
bracket and lead to an elevator jam. The unsafe condition, if not
addressed, could, if both elevators are affected, result in the loss
of pitch control.
(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, Transport Canada AD CF-2025-19.
(h) Exceptions to Transport Canada AD CF-2025-19
(1) Where Transport Canada AD CF-2025-19 refers to its effective
date, this AD requires using the effective date of this AD.
(2) Where Transport Canada AD CF-2025-19 refers to hours air
time, this AD requires using flight hours.
(3) If, during any inspection required by paragraph (g) of this
AD, any corrosion, scoring, or structural degradation of the bushing
holes in the arm fitting assembly is found, before further flight,
repair using a method approved by the Manager, International
Validation Branch, FAA; or Transport Canada; or De Havilland
Aircraft of Canada Limited's Transport Canada Design Approval
Organization (DAO). If approved by the DAO, the approval must
include the DAO-authorized signature.
(4) Where the material referenced in Transport Canada AD CF-
2025-19 specifies contacting the DHC technical helpdesk for an
approved repair or support, for this AD, a repair must be done
before further flight using a method approved by the Manager,
International Validation Branch, FAA; or Transport Canada; or De
Havilland Aircraft of
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Canada Limited's Transport Canada DAO. If approved by the DAO, the
approval must include the DAO-authorized signature.
(5) Where the material referenced in Transport Canada AD CF-
2025-19 specifies replacing pressure sensitive lightening tape if
required, for this AD, replace the pressure sensitive lightening
tape before further flight if tape is missing or torn.
(6) If, during any inspection required by paragraph (g) of this
AD, any cracking at any mating hole on the spar web assembly or the
lower skin is found, before further flight, repair using a method
approved by the Manager, International Validation Branch, FAA; or
Transport Canada; or De Havilland Aircraft of Canada Limited's
Transport Canada DAO. If approved by the DAO, the approval must
include the DAO-authorized signature.
(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#6b2a2624282b0d0a0a450c041d"><span class="__cf_email__" data-cfemail="70313d3f33301611115e171f06">[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 Transport Canada; or De Havilland
Aircraft of Canada Limited's Transport Canada DAO. If approved by
the DAO, the approval must include the DAO-authorized signature.
(j) Additional Information
For more information about this AD, contact Yaser Osman,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: 516-228-7300; email: <a href="/cdn-cgi/l/email-protection#dfe6f2bea9acf2b1a6bebcb0f2bcb0ac9fb9bebef1b8b0a9"><span class="__cf_email__" data-cfemail="261f0b4750550b485f4745490b4549556640474708414950">[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) Transport Canada AD CF-2025-19, dated March 24, 2025.
(ii) [Reserved]
(3) For Transport Canada material identified in this AD, contact
Transport Canada, Transport Canada National Aircraft Certification,
159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada; telephone 888-
663-3639; email <a href="/cdn-cgi/l/email-protection#2c786f026d455e5b435e58444542495f5f68455e494f58455a495f016f43425f454b42495f4849424d5a454b4d4e454045584902786f6c584f024b4f024f4d"><span class="__cf_email__" data-cfemail="d18592ff90b8a3a6bea3a5b9b8bfb4a2a295b8a3b4b2a5b8a7b4a2fc92bebfa2b8b6bfb4a2b5b4bfb0a7b8b6b0b3b8bdb8a5b4ff859291a5b2ffb6b2ffb2b0">[email protected]</span></a>. You may find this material on
the Transport Canada website at tc.canada.ca/en/aviation.
(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#5c3a2e7235322f2c393f283533321c323d2e3d723b332a"><span class="__cf_email__" data-cfemail="0b6d79256265787b6e687f6264654b656a796a256c647d">[email protected]</span></a>.
Issued on April 24, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-08303 Filed 4-28-26; 8:45 am]
BILLING CODE 4910-13-P
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