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

<RULE> DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-0482; Project Identifier MCAI-2024-00152-T; Amendment 39-23145; AD 2025-19-05]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; De Havilland Aircraft of Canada Limited (Type Certificate Previously Held by Bombardier, Inc.) Airplanes</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), DOT. <HD SOURCE="HED">ACTION:</HD> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> 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 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. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> 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. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> <E T="03">AD Docket:</E> You may examine the AD docket at <E T="03">regulations.gov</E> 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. <E T="03">Material Incorporated by Reference:</E> • 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 <E T="03">TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.gc.ca</E> . You may find this material on the Transport Canada website at <E T="03">tc.canada.ca/en/aviation</E> . • 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 <E T="03">regulations.gov</E> under Docket No. FAA-2025-0482. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Yaser Osman, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: 516-228-7300; email: <E T="03">9-avs-nyaco-cos@faa.gov</E> . </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Background</HD> 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 <E T="04">Federal Register</E> 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 <E T="03">regulations.gov</E> under Docket No. FAA-2025-0482. <HD SOURCE="HD1">Discussion of Final Airworthiness Directive</HD> <HD SOURCE="HD1">Comments</HD> The FAA received a comment from the Air Line Pilots Association, International (ALPA) who supported the NPRM without change. <HD SOURCE="HD1">Conclusion</HD> 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. <HD SOURCE="HD1">Material Incorporated by Reference Under 1 CFR Part 51</HD> 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 <E T="02">ADDRESSES</E> section. <HD SOURCE="HD1">Interim Action</HD> 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. <HD SOURCE="HD1">Costs of Compliance</HD> The FAA estimates that this AD affects 54 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: <GPOTABLE COLS="4" OPTS="L2,nj,i1" CDEF="s50,10,xs66,xs90"> <TTITLE>Estimated Costs for Required Actions</TTITLE> <CHED H="1">Labor cost</CHED> <CHED H="1">Parts cost</CHED> <CHED H="1">Cost per product</CHED> <CHED H="1">Cost on U.S. operators</CHED> <ROW> <ENT I="01">13 work-hours × $85 per hour = $1,105</ENT> <ENT>$0</ENT> <ENT>Up to $1,105</ENT> <ENT>Up to $59,670.</ENT> </ROW> </GPOTABLE> <GPOTABLE COLS="3" OPTS="L2,nj,i1" CDEF="s100,15C,15C"> <TTITLE>Estimated Costs for Optional Actions</TTITLE> <CHED H="1">Labor cost</CHED> <CHED H="1">Parts cost</CHED> <CHED H="1">Cost per product</CHED> <ROW> <ENT I="01">48 work-hours × $85 per hour = $4,080</ENT> <ENT>$16,343</ENT> <ENT>$20,423</ENT> </ROW> </GPOTABLE> 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: <GPOTABLE COLS="3" OPTS="L2,nj,i1" CDEF="s100,15C,15C"> <TTITLE>Estimated Costs of On-Condition Actions</TTITLE> <CHED H="1">Labor cost</CHED> <CHED H="1">Parts cost</CHED> <CHED H="1">Cost per product</CHED> <ROW> <ENT I="01">18 work-hours × $85 per hour = $1 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 21k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━