Airworthiness Directives; De Havilland Aircraft of Canada Limited (Type Certificate Previously Held by Bombardier, Inc.) Airplanes

[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 [www.gpo.gov]
[FR Doc No: 2026-08303]



[[Page 23009]]

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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 regulations.gov 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 [email protected]. 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 regulations.gov 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: [email protected].

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 regulations.gov 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

[[Page 23010]]

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
----------------------------------------------------------------------------------------------------------------
              Labor cost                      Parts cost            Cost per product      Cost on U.S. operators
----------------------------------------------------------------------------------------------------------------
Up to 81 work-hours x $85 per hour =   Up to $14,233..........  Up to $21,118..........  Up to $1,140,372.
 $6,885.
----------------------------------------------------------------------------------------------------------------

    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

[[Page 23011]]

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: 
[email protected]. 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: [email protected].

(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 [email protected]. 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 www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].

    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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