90 FR 118 pgs. 26466-26469 - Airworthiness Directives; De Havilland Aircraft of Canada Limited (Type Certificate Previously Held by Bombardier, Inc.) Airplanes
Type: PRORULEVolume: 90Number: 118Pages: 26466 - 26469
Pages: 26466, 26467, 26468, 26469Docket number: [Docket No. FAA-2025-0482; Project Identifier MCAI-2024-00152-T]
FR document: [FR Doc. 2025-11417 Filed 6-20-25; 8:45 am]
Agency: Transportation Department
Sub Agency: Federal Aviation Administration
Official PDF Version: PDF Version
[top]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-0482; Project Identifier MCAI-2024-00152-T]
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:
Notice of proposed rulemaking (NPRM).
SUMMARY:
The FAA proposes to supersede Airworthiness Directive (AD) 2019-16-09, which applies to certain De Havilland Aircraft of Canada Limited Model DHC-8-400 series airplanes. AD 2019-16-09 requires one-time inspections for cracks and damage of the elevator power control unit (PCU) brackets and surrounding area, horizontal stabilizer rear spar, and elevator 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 proposed AD would continue to require certain actions in AD 2019-16-09, and would also require repeating the inspections one time and performing applicable on-condition actions, remove an airplane from the applicability, and provide optional terminating action for the repetitive inspections. The FAA is proposing this AD to address the unsafe condition on these products.
DATES:
The FAA must receive comments on this proposed AD by August 7, 2025.
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.
• 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-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 NPRM, 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 Transport Canada material identified in this proposed AD, contact Transport Canada, Transport Canada National Aircraft Certification, 159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada; telephone 888-663-3639; email TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.gc.ca . You may find this material on the Transport Canada website at tc.canada.ca/en/aviation. It is also available at regulations.gov under Docket No. FAA-2025-0482.
• 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.
FOR FURTHER INFORMATION CONTACT:
Yaser Osman, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7300; email 9-avs-nyaco-cos@faa.gov.
SUPPLEMENTARY INFORMATION:
Comments Invited
[top] The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the ADDRESSES section. Include "Docket No. FAA-2025-0482; Project Identifier MCAI-2024-00152-T" at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change,
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 NPRM.
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 NPRM 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 NPRM, 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 NPRM. Submissions containing CBI should be sent to Yaser Osman, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7300; email 9-avs-nyaco-cos@faa.gov. 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 FAA issued AD 2019-16-09, Amendment 39-19712 (84 FR 46434, September 4, 2019) (AD 2019-16-09), for certain De Havilland Aircraft of Canada Limited Model DHC-8-400, -401, and -402 airplanes. AD 2019-16-09 was prompted by an MCAI originated by Transport Canada, which is the aviation authority for Canada. Transport Canada issued AD CF-2018-34, dated December 17, 2018 (Transport Canada AD CF-2018-34), to correct an unsafe condition.
AD 2019-16-09 requires one-time inspections for cracks and damage of the elevator PCU fittings (brackets) and surrounding area, horizontal stabilizer rear spar, and 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.
Actions Since AD 2019-16-09 Was Issued
Since the FAA issued AD 2019-16-09, Transport Canada superseded AD CF-2018-34 and issued Transport Canada AD CF-2024-10, dated March 1, 2024 (Transport Canada AD CF-2024-10), to correct an unsafe condition for certain De Havilland Aircraft of Canada Limited Model DHC-8-401 and -402 airplanes. 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 Limited Service Bulletin 84-55-09, dated June 7, 2018 (the service information 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 identified in this NPRM and terminates the actions specified in Transport Canada AD CF-2024-10.
The FAA is proposing this AD to address the unsafe condition on these products. You may examine Transport Canada ADs CF-2024-10 and CF-2025-19 in the AD docket at regulations.gov under Docket No. FAA-2025-0482.
Explanation of Retained Requirements
Although this proposed AD does not explicitly restate the requirements of AD 2019-16-09, this proposed AD would retain certain requirements of AD 2019-16-09. Those requirements are referenced in Transport Canada AD CF-2024-10, which, in turn, is referenced in paragraph (g) of this proposed AD.
Material Incorporated by Reference Under 1 CFR Part 51
Transport Canada AD CF-2024-10 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.
Transport Canada AD CF-2025-19 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.
FAA's Determination
This product has been approved by the aviation authority of another country and is approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, it has notified the FAA of the unsafe condition described in Transport Canada AD CF-2024-10 referenced above. The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop in other products of the same type design.
Proposed AD Requirements in This NPRM
This proposed AD would retain certain requirements of AD 2019-16-09. This proposed AD would remove an airplane from the applicability and require accomplishing the actions specified in Transport Canada AD CF-2024-10 described previously, except for any differences identified as exceptions in the regulatory text of this proposed AD. This proposed AD would also provide optional terminating action for the repetitive inspections, as specified in Transport Canada AD CF-2025-19.
Explanation of Required Compliance Information
[top] In the FAA's ongoing efforts to improve the efficiency of the AD process, the FAA developed a process to use some civil aviation authority (CAA) ADs as the primary source of information for compliance with requirements for corresponding FAA ADs. The FAA has been coordinating this process with manufacturers and CAAs. As a result, the FAA proposes to
Interim Action
The FAA considers that this proposed AD would be 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, if adopted as proposed, would affect 54 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:
| Labor cost | Parts cost | Cost per product | Cost on U.S. operators |
|---|---|---|---|
| 13 work-hours × $85 per hour = $1,105 | $0 | Up to $1,105 | Up to $59,670. |
| Labor cost | Parts cost | Cost per product |
|---|---|---|
| 48 work-hours × $85 per hour = $4,080 | $16,343 | $20,423 |
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 this on-condition action:
| Labor cost | Parts cost | Cost per product |
|---|---|---|
| 18 work-hours × $85 per hour = $1,530 | $14,233 | $15,763 |
The FAA has received no definitive data on which to base the cost estimates for the on-condition repairs specified in this proposed AD.
According to the manufacturer, some or all of the costs of this proposed 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
The FAA determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 this proposed regulation:
(1) Is not a "significant regulatory action" under Executive Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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 Proposed Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
PART 39-AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority:
49 U.S.C. 106(g), 40113, 44701.
§?39.13 [Amended]
2. The FAA amends §?39.13 by:
a. Removing Airworthiness Directive (AD) 2019-16-09, Amendment 39-19712 (84 FR 46434, September 4, 2019); and
b. Adding the following new AD:
De Havilland Aircraft of Canada Limited (Type Certificate Previously Held by Bombardier, Inc.): Docket No. FAA-2025-0482; Project Identifier MCAI-2024-00152-T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive (AD) by August 7, 2025.
(b) Affected ADs
[top] 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 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 (31 December 2018)," this AD requires using October 8, 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: AMOC@faa.gov .
(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; telephone 516-228-7300; email 9-avs-nyaco-cos@faa.gov.
(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 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 TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.gc.ca. 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 fr.inspection@nara.gov .
Issued on June 16, 2025.
Paul R. Bernado,
Acting Director, Compliance & Airworthiness Division, Aircraft Certification Service.
[FR Doc. 2025-11417 Filed 6-20-25; 8:45 am]
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