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

[Federal Register Volume 90, Number 185 (Friday, September 26, 2025)]
[Rules and Regulations]
[Pages 46340-46343]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-18757]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-0482; Project Identifier MCAI-2024-00152-T; 
Amendment 39-23145; AD 2025-19-05]
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.

-----------------------------------------------------------------------

SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2019-16-
09, which applied to certain De Havilland Aircraft of Canada Limited 
Model DHC-8-400 series airplanes. AD 2019-16-09 required one-time 
inspections for cracks and damage of the elevator power control unit 
(PCU) brackets and surrounding area, horizontal stabilizer rear spar, 
elevator

[[Page 46341]]

front spar, and related investigative and corrective actions if 
necessary. Since the FAA issued AD 2019-16-09, new findings have been 
reported as a result of maintenance activities and/or inspections. This 
AD continues to require certain actions in AD 2019-16-09 and requires 
repeating the inspections one time and performing applicable on-
condition actions. This AD also removes an airplane model from the 
applicability and provides optional terminating action for repetitive 
inspections. The FAA is issuing this AD to address the unsafe condition 
on these products.

DATES: This AD is effective October 31, 2025.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of October 31, 
2025.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2025-0482; 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-2025-0482.

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 to supersede AD 2019-16-09, Amendment 39-19712 (84 FR 
46434, September 4, 2019) (AD 2019-16-09). AD 2019-16-09 applied to 
certain De Havilland Aircraft of Canada Limited Model DHC-8-400, -401, 
and -402 airplanes. AD 2019-16-09 required one-time inspections for 
cracks and damage of the elevator PCU fittings (brackets) and 
surrounding area, horizontal stabilizer rear spar, elevator front spar, 
and related investigative and corrective actions if necessary. The FAA 
issued AD 2019-16-09 to address failure of an elevator PCU fitting 
(bracket) or fracture of the front spar into two segments; either 
structural failure may cause a jam in one elevator or a loss of 
airplane pitch control if both elevators are affected.
    The NPRM was published in the Federal Register on June 23, 2025 (90 
FR 26466). The NPRM was prompted by AD CF-2024-10, dated March 1, 2024 
(Transport Canada AD CF-2024-10), issued by Transport Canada, which is 
the aviation authority for Canada. Transport Canada AD CF-2024-10 
states that new findings have been reported as a result of maintenance 
activities and/or inspections performed in accordance with De Havilland 
Aircraft of Canada Service Bulletin 84-55-09, dated June 7, 2018 (the 
service information originally issued by Bombardier as required by FAA 
AD 2019-16-09). Transport Canada AD CF-2024-10 requires repeating the 
inspections one time and performing applicable on-condition actions, 
while maintaining the requirements of AD 2019-16-09. Transport Canada 
AD CF-2024-10 also removes the requirement to report findings to the 
manufacturer. Transport Canada also issued AD CF-2025-19, dated March 
24, 2025 (Transport Canada AD CF-2025-19), which provides a new design 
solution to address the unsafe condition in this AD and terminates the 
actions specified in Transport Canada AD CF-2024-10.
    In the NPRM, the FAA proposed to continue to require certain 
actions in AD 2019-16-09, require repeating the inspections one time 
and performing applicable on-condition actions, remove the reporting 
requirement, and remove an airplane model from the applicability, as 
specified in Transport Canada AD CF-2024-10. In the NPRM, the FAA also 
proposed to provide an optional terminating action for the repetitive 
inspections, as specified in Transport Canada AD CF-2025-19. The FAA is 
issuing this AD to address the unsafe condition on these products.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2025-0482.

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 Transport Canada AD CF-2024-10, which specifies 
procedures for performing detailed visual and fluorescent penetrant 
inspections for cracks and damage of the elevator PCU fittings 
(brackets), horizontal stabilizer rear spar, and elevator front spar; 
repeating the inspections one time; rectifying any cracked or damaged 
elevator PCU fitting (bracket) (which includes replacing the elevator 
PCU fitting (bracket) and performing related investigative and 
corrective actions including performing an eddy current inspection for 
cracking of certain mating holes of the horizontal stabilizer rear 
spar); and repairing any cracked or damaged horizontal stabilizer rear 
spar assembly.
    The FAA reviewed Transport Canada AD CF-2025-19, which specifies 
procedures for, among other actions, replacement of existing PCU 
fittings with redesigned PCU fittings. The replacement includes 
detailed inspections for damage and eddy current inspections for 
cracking, repair, installation of new bushings, and installation of 
doublers.
    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 46342]]

Interim Action

    The FAA considers this AD an interim action. The FAA is considering 
mandating the optional terminating action specified in Transport Canada 
AD CF-2025-19.

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
----------------------------------------------------------------------------------------------------------------
13 work-hours x $85 per hour =              $0  Up to $1,105...............  Up to $59,670.
 $1,105.
----------------------------------------------------------------------------------------------------------------


                  Estimated Costs for Optional Actions
------------------------------------------------------------------------
           Labor cost                 Parts cost       Cost per product
------------------------------------------------------------------------
48 work-hours x $85 per hour =              $16,343             $20,423
 $4,080.........................
------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary on-
condition actions that would be required based on the results of any 
required actions. The FAA has no way of determining the number of 
aircraft that might need these on-condition actions:

                 Estimated Costs of On-Condition Actions
------------------------------------------------------------------------
           Labor cost                 Parts cost       Cost per product
------------------------------------------------------------------------
18 work-hours x $85 per hour =              $14,233             $15,763
 $1,530.........................
------------------------------------------------------------------------

    The FAA has received no definitive data on which to base the cost 
estimates for the on-condition repairs specified in this AD.
    According to the manufacturer, some or all of the costs of this AD 
may be covered under warranty, thereby reducing the cost impact on 
affected individuals. The FAA does not control warranty coverage for 
affected individuals. As a result, the FAA has included all known costs 
in the cost estimate.

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:
0
a. Removing Airworthiness Directive (AD) 2019-16-09, Amendment 39-19712 
(84 FR 46434, September 4, 2019); and
0
b. Adding the following new AD:

2025-19-05 De Havilland Aircraft of Canada Limited (Type Certificate 
Previously Held by Bombardier, Inc.): Amendment 39-23145; Docket No. 
FAA-2025-0482; Project Identifier MCAI-2024-00152-T.

(a) Effective Date

    This airworthiness directive (AD) is effective October 31, 2025.

(b) Affected ADs

    This AD replaces AD 2019-16-09, Amendment 39-19712 (84 FR 46434, 
September 4, 2019) (AD 2019-16-09).

(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-2024-10, dated March 1, 2024 (Transport 
Canada AD CF-2024-10).

(d) Subject

    Air Transport Association (ATA) of America Code 27, Flight 
controls.

(e) Unsafe Condition

    This AD was prompted by reports of cracked elevator power 
control unit (PCU) fittings (brackets) on the horizontal stabilizer

[[Page 46343]]

rear spar and cracking on the elevator front spar. The FAA is 
issuing this AD to address this condition, which, if not detected 
and corrected, may cause failure of an elevator PCU fitting 
(bracket) or fracture the front spar into two segments; either 
structural failure may cause a jam in one elevator or a loss of 
airplane pitch control if both elevators are affected.

(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-2024-10.

(h) Exceptions to Transport Canada AD CF-2024-10

    (1) Where Transport Canada AD CF-2024-10 refers to the effective 
date of AD CF-2018-34 (December 31, 2018), this AD requires using 
October 9, 2019 (the effective date of AD 2019-16-09).
    (2) Where Transport Canada AD CF-2024-10 refers to hours air 
time, this AD requires using flight hours.
    (3) Where Transport Canada AD CF-2024-10 refers to ``if cracks 
or damage'', this AD requires replacing that text with ``if any 
crack or damage''.
    (4) Where Transport Canada AD CF-2024-10 specifies actions if 
certain conditions are found on ``rear spar assembly P/N 85517044 
and/or elevator assembly P/N 85527021'', this AD requires replacing 
that text with ``rear spar assembly P/N 85517044 or elevator 
assembly P/N 85527021''.
    (5) Where Transport Canada AD CF-2024-10 specifies ``after 
inspecting as required by AD CF-2018-34'', this AD requires 
replacing that text with ``after inspecting as specified in 
Bombardier Service Bulletin 84-55-09 or de Havilland Aircraft of 
Canada Limited Service Bulletin 84-55-09''.
    (6) Where paragraph B. of Part I and paragraph A. of Part II of 
Transport Canada AD CF-2024-10 specify a compliance time to do a 
repeat inspection, this AD allows the inspection to be done within 
90 days after the effective date of this AD.

(i) No Reporting Requirement

    Although the material referenced in Transport Canada AD CF-2024-
10 specifies to submit certain information to the manufacturer, this 
AD does not include that requirement.

(j) Optional Terminating Action for Repetitive Inspections

    (1) For airplane serial numbers 4001 and 4003 through 4058 
inclusive on which any inspection specified in Section 3.B. of the 
Accomplishment Instructions of Bombardier Service Bulletin 84-55-09 
or de Havilland Aircraft of Canada Limited Service Bulletin 84-55-09 
has been done: Replacement of existing PCU fittings with redesigned 
PCU fittings in accordance with Part I, paragraph B., of Transport 
Canada AD CF-2025-19, dated March 24, 2025, terminates the 
requirements of paragraph (g) of this AD.
    (2) For airplane serial numbers 4059 through 4580 inclusive on 
which any inspection specified in Section 3.B. of the Accomplishment 
Instructions of Bombardier Service Bulletin 84-55-09 or de Havilland 
Aircraft of Canada Limited Service Bulletin 84-55-09 has been done: 
Replacement of existing PCU fittings with redesigned PCU fittings in 
accordance with Part II, paragraphs B. and C., of Transport Canada 
AD CF-2025-19, dated March 24, 2025, terminates the requirements of 
paragraph (g) of this AD.

(k) Credit for Previous Actions

    This paragraph provides credit for the actions specified in 
paragraph A. of Part I of Transport Canada AD CF-2024-10, as 
required by paragraph (g) of this AD, if those actions were 
performed before the effective date of this AD using Bombardier 
Service Bulletin 84-55-09, dated June 7, 2018; or de Havilland 
Aircraft of Canada Limited Service Bulletin 84-55-09, Revision A, 
dated January 10, 2020.

(l) 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, 
International Validation Branch, send it to the attention of the 
person identified in paragraph (m)(1) of this AD and email to: 
[email protected].
    (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 Design Approval 
Organization (DAO). If approved by the DAO, the approval must 
include the DAO-authorized signature.

(m) Additional Information

    (1) 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].
    (2) For Bombardier or De Havilland Aircraft of Canada Limited 
material identified in this AD that is not incorporated by 
reference, contact De Havilland Aircraft of Canada Limited, Dash 8 
Series Customer Response Centre, 5800 Explorer Drive, Mississauga, 
Ontario, L4W 5K9, Canada; telephone North America (toll-free): 855-
310-1013, Direct: 647-277-5820; email dehavilland.com">thd@dehavilland.com; website 
dehavilland.com.

(n) 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-2024-10, dated March 1, 2024.
    (ii) Transport Canada AD CF-2025-19, dated March 24, 2025.
    (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 September 16, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2025-18757 Filed 9-25-25; 8:45 am]
BILLING CODE 4910-13-P

The complete text was extracted from the official GovInfo HTML edition for this publication. Acquired 2026-10-09T01:22:08.024998+00:00. Text extraction preserves the recorded source wording; it does not determine current requirements.

Open the captured official edition

Source SHA-256

a2f2e2a9f973e9fb4dd01f59bc70ff602e1b54f65ce43e4b6357835885835691

Text SHA-256

2086c1a572a4bd5c8f765b69a40afe2be6b888e9edef75aa49a64beec9d31dd2