2026-14110: Airworthiness Directives; Bombardier, Inc., Airplanes

Federal Register, Volume 91 Issue 133 (Tuesday, July 14, 2026) [Federal Register Volume 91, Number 133 (Tuesday, July 14, 2026)] [Rules and Regulations] [Pages 43025-43032] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 2026-14110] ======================================================================== Rules and Regulations Federal Register ________________________________________________________________________ This section of the FEDERAL REGISTER contains regulatory documents having general applicability and legal effect, most of which are keyed to and codified in the Code of Federal Regulations, which is published under 50 titles pursuant to 44 U.S.C. 1510. The Code of Federal Regulations is sold by the Superintendent of Documents. ======================================================================== Federal Register / Vol. 91, No. 133 / Tuesday, July 14, 2026 / Rules and Regulations [[Page 43025]] DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2025-3435; Project Identifier MCAI-2025-01602-T; Amendment 39-23410; AD 2026-14-09] RIN 2120-AA64 Airworthiness Directives; Bombardier, Inc., Airplanes

Agency

Federal Aviation Administration (FAA), DOT.

Action

Final rule. -----------------------------------------------------------------------

Summary

The FAA is superseding Airworthiness Directive (AD) 2025-17- 12, which applied to all Bombardier, Inc., Model CL-600-1A11 (600) and CL-600-2A12 (601) airplanes and certain Model CL-600-2B16 (601-3A, 601- 3R, and 604 Variants) airplanes. AD 2025-17-12 required revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations. Since the FAA issued AD 2025-17-12, the FAA has determined that certain serial numbers for affected Model CL-600-2B16 (604 Variants) airplanes are not included in the applicability of AD 2025-17-12. This AD continues to require the actions specified in AD 2025-17-12 and adds airplanes to the applicability. The FAA is issuing this AD to address the unsafe condition on these products.

Dates

This AD is effective August 18, 2026. The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of October 31, 2025 (90 FR 46330, September 26, 2025).

Addresses

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2025-3435; 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 street 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: For Bombardier material identified in this AD, contact Bombardier Business Aircraft Customer Response Center, 400 C[ocirc]te- Vertu Road West, Dorval, Qu[eacute]bec H4S 1Y9, Canada; telephone 514- 855-2999; email [email protected]; website https://my.bombardier.com/. 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-2025-3435.

For Further Information Contact

Brenda L. Buitrago, 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 2025-17-12, Amendment 39-23122 (90 FR 46330, September 26, 2025) (AD 2025-17-12). AD 2025-17-12 applied to all Bombardier, Inc., Model CL-600-1A11 (600) and CL-600-2A12 (601) airplanes and certain Model CL-600-2B16 (601-3A, 601-3R, and 604 Variants) airplanes. AD 2025-17-12 required revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations. The NPRM was published in the Federal Register on October 21, 2025 (90 FR 48414). The NPRM was prompted by AD CF-2024-16, dated May 23, 2024 (Transport Canada AD CF-2024-16) (also referred to as the MCAI), issued by Transport Canada, which is the aviation authority for Canada. The MCAI states that new or more restrictive airworthiness limitations have been developed. In the NPRM, the FAA proposed to continue to require the actions specified in AD 2025-17-12 and add airplanes to the applicability. The FAA is issuing this AD to address new or more restrictive limitations. Failure to comply with these new or more restrictive limitations could adversely affect the continued airworthiness of the airplane. You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2025-3435. Discussion of Final Airworthiness Directive Comments The FAA received comments from an anonymous commenter who supported the NPRM without change. The FAA also received comments from Bombardier and the Citizens Rulemaking Alliance. The following presents those comments and the FAA's responses. Request To Expand the Applicability Bombardier requested that the FAA expand the applicability of the proposed AD to include Model CL-600-2B16 (604 Variant) airplanes, serial numbers (S/Ns) 6193 through 6202 and 6204. Paragraph (c)(3) of the proposed AD specifies S/Ns 6050 through 6192 inclusive. The FAA does not agree with this request. The adjusted serial number range of Model CL-600-2B16 (604 Variant) airplanes would address airplanes not delivered with Revision 10 of the Bombardier Challenger 650 Time Limit Maintenance Check (TLMC), Publication No. CH 650 TLMC. However, this AD addresses the Model CL-600-2B16 (604 Variant) airplanes not delivered with Revision 9 of the Bombardier Challenger 650 TLMC, Publication No. CH 650 TLMC. To add airplanes and mandate Revision 10 of the TLMC would expand the AD scope beyond what was proposed in the original notice and would necessitate reissuing the notice, reopening the period for public comment, considering additional comments subsequently received, and issuing a final rule. In light of this, and in consideration of the amount of time that has already elapsed, the FAA has determined that further delay of this AD would not be in the interest of safety. However, the FAA may consider additional action, including further rulemaking, on this [[Page 43026]] issue. The FAA has not changed this AD in this regard. Request To Revise the Service Information Bombardier requested that the FAA mandate the latest revisions of the TLMC documents: Bombardier Challenger 600 TLMC, Publication No. PSP 605, Revision 40, dated September 30, 2025; Bombardier Challenger 601 TLMC, Publication No. PSP 601-5, Revision 47, dated September 30, 2025; Bombardier Challenger 601 TLMC, Publication No. PSP 601A-5, Revision 43, dated September 30, 2025. Bombardier also requested that the FAA refer to the latest revision of the TLMCs instead of the temporary revisions (TRs) identified in the proposed AD because all of the TRs have been published and included in the last published revision of the TLMC. The FAA does not agree with these requests. Mandating the newest TLMC revisions would expand the AD scope beyond the original notice. However, the FAA may consider further rulemaking on this issue. The FAA also provides the following clarification for the requirement to incorporate the information specified in the TRs. If operators incorporate the newest TLMC revisions into the maintenance or inspection program, as applicable, they are in compliance with the requirement to incorporate the TRs, provided the TLMC contains the same information as specified in the TRs. Similarly, if operators incorporate later TLMC revisions into the maintenance or inspection program, as applicable, they are in compliance with the requirement to incorporate the TLMCs specified in this AD, provided the language is identical to the information specified in the TLMCs identified in this AD. The FAA has not changed this AD in this regard. Request To Justify Forgoing Notice and Comment or Issue an NPRM The Citizens Rulemaking Alliance requested that the FAA either provide its justification for finding good cause to bypass notice and comment procedures, or convert this action to an NPRM and stay the effective date for non-critical compliance elements. The commenter asserted the FAA has not adequately justified use of the good cause exemption to bypass notice and comment and the 30-day delayed effective date. The FAA notes the comment was submitted in response to an NPRM for which the FAA provided a 45-day comment period. This final rule is effective 35 days after its publication in the Federal Register. Therefore, no change to this AD is necessary. Request To Make Incorporation by Reference (IBR) Materials Reasonably Available The Citizens Rulemaking Alliance requested that the FAA make IBR material available and free to the public during the comment period. The commenter asserted that this AD incorporates by reference proprietary service information that is not reasonably available to the public. The FAA's practices comply with 5 U.S.C. 552(a) of the Administrative Procedure Act and 1 CFR part 51. The FAA makes IBR materials available in the AD docket when the final rule is published in the Federal Register, following formal approval of the IBR by the Office of the Federal Register. Materials may only be posted before the final rule's publication if they are already publicly available or if there is written consent from the owner of the IBR material. All relevant materials incorporated by reference will be accessible in the AD docket on Regulations.gov, which the public can access without registration or fees. The FAA also provides summaries and access details in the preamble and regulatory text, makes materials available for inspection at FAA and National Archives and Records Administration (NARA) offices, offers publisher contact information, and obtains formal IBR approval from the Office of the Federal Register. These efforts are intended to ensure that all IBR materials meet the ``reasonably available'' standard required by 1 CFR part 51. The FAA did not change this AD as a result of this comment. Request To Comply With the Paperwork Reduction Act (PRA) The Citizens Rulemaking Alliance requested that the FAA revise the AD to comply with the PRA if reporting is required or remove or suspend any reporting provisions until PRA requirements are satisfied. If reporting is intended to be voluntary, the commenter requested the FAA clarify that in the AD. The FAA notes this AD does not require reporting. If an AD were to require reporting, the preamble of the AD would include a paragraph titled ``Paperwork Reduction Act'' that would provide the applicable OMB control number, required PRA statements, and the estimated time to collect the required information (burden). Any costs associated with the reporting requirement would be included in the Costs of Compliance section in the preamble of the AD. Therefore, the FAA did not change this AD as a result of this comment. Request To Consider Impact on Small Entities The Citizens Rulemaking Alliance requested that the FAA either provide the factual basis for its Regulatory Flexibility Act (RFA) certification that the AD will not have a significant economic impact on a substantial number of small entities, or prepare an initial regulatory flexibility analysis. The FAA provides the following clarification. The RFA of 1980 (5 U.S.C. 601-612), as amended by the Small Business Regulatory Enforcement Fairness Act of 1996 (Pub. L. 104-121) and the Small Business Jobs Act of 2010 (Pub. L. 111-240), requires Federal agencies to consider the effects of the regulatory action on small business and other small entities and to minimize any significant economic impact. The term ``small entities'' comprises small businesses and not-for- profit organizations that are independently owned and operated and are not dominant in their fields, and governmental jurisdictions with populations of less than 50,000. Small Entities to Which This AD Applies The FAA used the definition of small entities in the RFA for this analysis. The RFA defines small entities as small businesses, small governmental jurisdictions, or small organizations. In 5 U.S.C. 601(3), the RFA defines ``small business'' to have the same meaning as ``small business concern'' under section 3 of the Small Business Act. The Small Business Act authorizes the Small Business Administration (SBA) to define ``small business'' by issuing regulations. The SBA (2023) has established size standards for various types of economic activities, or industries, under the North American Industry Classification System (NAICS). These size standards generally define small businesses based on the number of employees or annual receipts. The SBA definition of a small business applies to the parent company and all affiliates as a single entity. To identify small entities, the FAA first identified the primary NAICS of the entity or parent company, and then used data from different sources (e.g., company annual reports, Bureau of Transportation Statistics) to determine whether the entity meets the applicable size standard. The following table provides the SBA size standards for all industries with at least 1 impacted domestic entity and the estimated [[Page 43027]] number of affected small entities within each NAICS industry. Small Business Size Standards and Estimated Number of Small Entities \1\ -------------------------------------------------------------------------------------------------------------------------------------------------------- Number of Number of Percent small NAICS code Description Size standard entities small entities entities -------------------------------------------------------------------------------------------------------------------------------------------------------- 112990................................... All Other Animal Production..... $2.75 million.............. 1 0 0 115112................................... Soil Preparation, Planting, and $9.5 million............... 1 1 100 Cultivating. 211120................................... Crude Petroleum Extraction...... 1,250 employees............ 1 1 100 236118................................... Residential Remodelers.......... $45.0 million.............. 1 1 100 237120................................... Oil and Gas Pipeline and Related $45.0 million.............. 1 1 100 Structures Construction. 321113................................... Sawmills........................ 550 employees.............. 1 1 100 325180................................... Other Basic Inorganic Chemical 1,000 employees............ 1 0 0 Manufacturing. 332410................................... Power Boiler and Heat Exchanger 750 employees.............. 1 0 0 Manufacturing. 332510................................... Hardware Manufacturing.......... 750 employees.............. 1 1 100 333111................................... Farm Machinery and Equipment 1,250 employees............ 1 0 0 Manufacturing. 334519................................... Other Measuring and Controlling 600 employees.............. 1 0 0 Device Manufacturing. 335220................................... Major Household Appliance 1,500 employees............ 1 0 0 Manufacturing. 336110................................... Automobile and Light Duty Motor 1,500 employees............ 2 1 50 Vehicle Manufacturing. 336411................................... Aircraft Manufacturing.......... 1,500 employees............ 1 1 100 336412................................... Aircraft Engine and Engine Parts 1,500 employees............ 2 0 0 Manufacturing. 336510................................... Railroad Rolling Stock 1,500 employees............ 1 0 0 Manufacturing. 336611................................... Ship Building and Repairing..... 1,300 employees............ 1 0 0 339112................................... Surgical and Medical Instrument 1,000 employees............ 1 0 0 Manufacturing. 423860................................... Transportation Equipment and 175 employees.............. 2 2 100 Supplies (except Motor Vehicle) Merchant Wholesalers. 441110................................... New Car Dealers................. 200 employees.............. 1 0 0 441227................................... Motorcycle, ATV, and All Other $40.0 million.............. 2 2 100 Motor Vehicle Dealers. 441330................................... Automotive Parts and Accessories $28.5 million.............. 1 0 0 Retailers. 445110................................... Supermarkets and Other Grocery $40.0 million.............. 1 0 0 Retailers (except Convenience Retailers). 481211................................... Nonscheduled Chartered Passenger 1,500 employees............ 76 76 100 Air Transportation. 481212................................... Nonscheduled Chartered Freight 1,500 employees............ 2 2 100 Air Transportation. 481219................................... Other Nonscheduled Air $25.0 million.............. 1 1 100 Transportation. 485111................................... Mixed Mode Transit Systems...... $29.0 million.............. 1 0 0 485999................................... All Other Transit and Ground $19.0 million.............. 1 1 100 Passenger Transportation. 487990................................... Scenic and Sightseeing $25.0 million.............. 1 1 100 Transportation, Other. 488190................................... Other Support Activities for Air $40.0 million.............. 2 2 100 Transportation. 488510................................... Freight Transportation $20.0 million.............. 2 0 0 Arrangement. 516120................................... Television Broadcasting Stations $47.0 million.............. 1 1 100 518210................................... Computing Infrastructure $40.0 million.............. 1 1 100 Providers, Data Processing, Web Hosting, and Related Services. 522299................................... International, Secondary Market, $47.0 million.............. 1 1 100 and All Other Nondepository Credit Intermediation. 523910................................... Miscellaneous Intermediation.... $47.0 million.............. 2 2 100 523940................................... Portfolio Management and $47.0 million.............. 4 4 100 Investment Advice. 523991................................... Trust, Fiduciary and Custody $47.0 million.............. 1 0 0 Activities. 524126................................... Direct Property and Casualty 1,500 employees............ 1 0 0 Insurance Carriers. 524210................................... Insurance Agencies and $15.0 million.............. 1 1 100 Brokerages. 525990................................... Other Financial Vehicles........ $40.0 million.............. 1 1 100 531210................................... Offices of Real Estate Agents $15.0 million.............. 1 0 0 and Brokers. 532411................................... Commercial Air, Rail, and Water $45.5 million.............. 1 1 100 Transportation Equipment Rental and Leasing. 532490................................... Other Commercial and Industrial $40.0 million.............. 2 2 100 Machinery and Equipment Rental and Leasing. 541320................................... Landscape Architectural Services $9.0 million............... 1 1 100 541512................................... Computer Systems Design Services $34.0 million.............. 1 0 0 541611................................... Administrative Management and $24.5 million.............. 1 1 100 General Management Consulting Services. 541618................................... Other Management Consulting $19.0 million.............. 1 1 100 Services. 551112................................... Offices of Other Holding $45.5 million.............. 1 0 0 Companies. 561499................................... All Other Business Support $21.5 million.............. 1 0 0 Services. 562920................................... Materials Recovery Facilities... $25.0 million.............. 1 0 0 621111................................... Offices of Physicians (except $16.0 million.............. 1 1 100 Mental Health Specialists). 621910................................... Ambulance Services.............. $22.5 million.............. 1 0 0 622110................................... General Medical and Surgical $47.0 million.............. 1 0 0 Hospitals. 624190................................... Other Individual and Family $16.0 million.............. 1 1 100 Services. 624410................................... Child Care Services............. $9.5 million............... 1 1 100 711211................................... Sports Teams and Clubs.......... $47.0 million.............. 1 1 100 721110................................... Hotels (except Casino Hotels) $40.0 million.............. 1 1 100 and Motels. 721120................................... Casino Hotels................... $40.0 million.............. 1 0 0 [[Page 43028]] 811310................................... Commercial and Industrial $12.5 million.............. 1 0 0 Machinery and Equipment (except Automotive and Electronic) Repair and Maintenance. 812332................................... Industrial Launderers........... $47.0 million.............. 1 0 0 813110................................... Religious Organizations......... $13.0 million.............. 1 0 0 N/A...................................... Government Jurisdiction......... 50,000 population.......... 1 0 0 ----------------------------------------------- Total................................ ........................... 149 117 79 -------------------------------------------------------------------------------------------------------------------------------------------------------- \1\ Source: Sources: SBA, Table of Small Business Size Standards (2023). sba.gov; Dun & Bradstreet D&B Hoovers, retrieved June 6, 2026. app.hoovers.dnb.com; Rocketreach, retrieved June 6, 2026. rocketreach.co; Zoominfo, retrieved June 6, 2026. zoominfo.com; Prospeo, retrieved June 6, 2026. prospeo.io. Projected Reporting, Recordkeeping, and Other Compliance Requirements The FAA estimates the total cost of the maintenance or inspection program actions required from this AD to be $7,650. Since operators incorporate maintenance or inspection program changes for their affected fleet(s), the FAA has determined that a per-entity estimate is more accurate than a per-airplane estimate. The following table provides the estimated per-entity compliance cost by each affected NAICS industry. Average Cost of Compliance per Small Entity \1\ ---------------------------------------------------------------------------------------------------------------- Average cost Range of cost NAICS industry Number of small Average revenue ($) as a percent as a percent entities of revenue of revenue ---------------------------------------------------------------------------------------------------------------- Administrative Management and 1 $251,230 3.05 3.05-3.05 General Management Consulting Services...................... Aircraft Manufacturing......... 1 89,460,000,000 0.00 0-0 All Other Transit and Ground 1 2,510,000 0.30 0.3-0.3 Passenger Transportation...... Automobile and Light Duty Motor 1 2,220,000 0.34 0.34-0.34 Vehicle Manufacturing......... Child Care Services............ 1 6,160,000 0.12 0.12-0.12 Commercial Air, Rail, and Water 1 71,600 10.68 10.68-10.68 Transportation Equipment Rental and Leasing............ Computing Infrastructure 1 19,250,000 0.04 0.04-0.04 Providers, Data Processing, Web Hosting, and Related Services...................... Crude Petroleum Extraction..... 1 28,780,000 0.03 0.03-0.03 Hardware Manufacturing......... 1 50,030,000 0.02 0.02-0.02 Hotels (except Casino Hotels) 1 36,970,000 0.02 0.02-0.02 and Motels.................... Insurance Agencies and 1 3,250,000 0.24 0.24-0.24 Brokerages.................... International, Secondary 1 2,500,000 0.31 0.31-0.31 Market, and All Other Nondepository Credit Intermediation................ Landscape Architectural 1 6,560,000 0.12 0.12-0.12 Services...................... Miscellaneous Intermediation... 2 13,140,000 0.76 0.03-1.5 Motorcycle, ATV, and All Other 2 357,755 2.40 1.61-3.2 Motor Vehicle Dealers......... Nonscheduled Chartered Freight 2 9,805,000 0.18 0.04-0.32 Air Transportation............ Nonscheduled Chartered 76 7,155,127 0.47 0.01-3.44 Passenger Air Transportation.. Offices of Physicians (except 1 9,060,000 0.08 0.08-0.08 Mental Health Specialists).... Oil and Gas Pipeline and 1 10,780,000 0.07 0.07-0.07 Related Structures Construction.................. Other Commercial and Industrial 2 400,305 2.18 1.42-2.94 Machinery and Equipment Rental and Leasing................... Other Financial Vehicles....... 1 22,720,000 0.03 0.03-0.03 Other Individual and Family 1 999,000 0.77 0.77-0.77 Services...................... Other Management Consulting 1 147,490 5.19 5.19-5.19 Services...................... Other Nonscheduled Air 1 1,100,000 0.70 0.7-0.7 Transportation................ Other Support Activities for 2 1,969,810 1.00 0.22-1.78 Air Transportation............ Portfolio Management and 4 6,604,335 3.24 0.03-10.36 Investment Advice............. Residential Remodelers......... 1 435,450 1.76 1.76-1.76 Sawmills....................... 1 2,490,000 0.31 0.31-0.31 Scenic and Sightseeing 1 6,846,561 0.11 0.11-0.11 Transportation, Other......... Soil Preparation, Planting, and 1 2,370,000 0.32 0.32-0.32 Cultivating................... Sports Teams and Clubs......... 1 21,270,000 0.04 0.04-0.04 Television Broadcasting 1 1,060,000 0.72 0.72-0.72 Stations...................... Transportation Equipment and 2 1,711,740 7.27 0.23-14.3 Supplies (except Motor Vehicle) Merchant Wholesalers. ---------------------------------------------------------------------------------------------------------------- \1\ Source: Sources: SBA, Table of Small Business Size Standards (2023). sba.gov; Dun & Bradstreet D&B Hoovers, retrieved June 6, 2026. app.hoovers.dnb.com; Rocketreach, retrieved June 6, 2026. rocketreach.co; Zoominfo, retrieved June 6, 2026. zoominfo.com; Prospeo, retrieved June 6, 2026. prospeo.io. [[Page 43029]] Significant Alternatives Considered The FAA evaluated the alternative of not promulgating this AD but ultimately deemed that this alternative would create a significant safety hazard. The FAA is issuing this AD to address unsafe conditions, and this AD is necessary to maintain safety in air commerce. RFA Conclusions Based on average compliance costs, the FAA has determined that the financial impacts of this AD are not disproportionate to small entities. The FAA did not change this AD as a result of this comment. Request To Provide Additional Cost Information The Citizens Rulemaking Alliance requested that the FAA provide transparent cost assumptions including airplane downtime, logistical constraints, and supply chain risks. The FAA recognizes that, in doing the actions required by an AD, operators might incur indirect costs in addition to the direct costs. The FAA considered the impact that this AD will have on affected operators and determined this AD will not trigger any downtime costs, logistical constraints, or supply chain risks because revising the existing maintenance or inspection program, as applicable, is an administrative action that can be performed without impacting operations. Since the FAA has assessed and disclosed all known costs of the AD requirements in the Costs of Compliance section of the proposed AD, and the commenter did not provide additional cost data for the FAA to consider in its cost analysis, the FAA determined that the existing analysis is complete. The FAA did not change this AD as a result of this comment. 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 This AD requires the following Bombardier material, which the Director of the Federal Register approved for incorporation by reference as of October 31, 2025 (90 FR 46333, September 26, 2025): Section 5-10-00, ``Airworthiness Limitations,'' of Bombardier Challenger 600 Time Limits/Maintenance Checks (TLMC), Publication No. PSP 605, Revision 39, dated January 8, 2018. (For obtaining these sections of Bombardier Challenger 600 TLMC, Publication No. PSP 605, use Document Identification No. CH 600 TLMC.) Section 5-10-00, ``Airworthiness Limitations,'' of Bombardier Challenger 601 TLMC, Publication No. PSP 601-5, Revision 46, dated January 8, 2018. (For obtaining these sections of Bombardier Challenger 601 TLMC, Publication No. PSP 601-5, use Document Identification No. CH 601 TLMC.) Section 5-10-00, ``Airworthiness Limitations,'' of Bombardier Challenger 601 TLMC, Publication No. PSP 601A-5, Revision 42, dated January 8, 2018. (For obtaining these sections of Bombardier Challenger 601 TLMC, Publication No. PSP 601A-5, use Document Identification No. CH 601 TLMC-1.) Part 2, ``Airworthiness Limitations,'' of Bombardier Challenger 604 TLMC, Publication No. CH 604 TLMC, Revision 33, dated November 22, 2022. (The document identification number for ordering Bombardier Challenger 604 TLMC, Publication No. CH 604 TLMC is incorrectly identified as ``CH 600 TLMC'' on page 2 of the TLMC. For obtaining Part 2 of Bombardier Challenger 604 TLMC, Publication No. CH 604 TLMC, use Document Identification No. CH 604 TLMC.) Part 2, ``Airworthiness Limitations,'' of Bombardier Challenger 605 TLMC, Publication No. CH 605 TLMC, Revision 22, dated November 22, 2022. Part 2, ``Airworthiness Limitations,'' of Bombardier Challenger 650 TLMC, Publication No. CH 650 TLMC, Revision 9, dated November 22, 2022. Temporary Revision No. 5-2-5, dated October 16, 2023, which includes new Task 32-51-04-101*, ``Discard of the Nosewheel- Steering Control Potentiometer Coupling Setscrews, Part No. B0201102-2- 220 (A/C 6194 and Subs or Post SB 650-32-007).'' Temporary Revision No. 5-2-29, dated October 25, 2023, which includes new Task 32-51-04-101*, ``Discard of the Nosewheel- Steering Control Potentiometer Coupling Setscrews, Part No. B0201102-2- 220 (Post SB 605-32-010).'' Temporary Revision No. 5-2-73, dated October 25, 2023, which includes new Task 32-51-04-101*, ``Discard of the Nosewheel- Steering Control Potentiometer Coupling Setscrews, Part No. B0201102-2- 220 (Post SB 604-32-033).'' Temporary Revision No. TR 5-164, dated December 23, 2022, which includes new Task 53-10-01-102*, ``Forward Pressure Bulkhead Cap Angle--Aft Side.'' Temporary Revision No. TR 5-165, dated October 25, 2023. Temporary Revision No. TR 5-268, dated December 23, 2022, which includes new Task 53-10-01-103*, ``Forward Pressure Bulkhead Cap Angle--Aft Side.'' Temporary Revision No. TR 5-269, dated October 25, 2023. Temporary Revision No. TR 5-282, dated December 23, 2022, which includes new Task 53-10-01-103*, ``Forward Pressure Bulkhead Cap Angle--Aft Side.'' Temporary Revision No. TR 5-283, dated October 25, 2023. (The asterisk (or ``one star'') with the last three digits of the task numbers listed above indicates that the task is an airworthiness limitation task.) 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 573 airplanes of U.S. registry and 390 operators. The FAA estimates the following costs to comply with this AD: The FAA estimates the total cost per operator for the retained actions from AD 2025-17-12 to be $7,650 (90 work-hours x $85 per work- hour). The FAA has determined that revising the maintenance or inspection program takes an average of 90 work-hours per operator, although the agency recognizes that this number may vary from operator to operator. Since operators incorporate maintenance or inspection program changes for their affected fleet(s), the FAA has determined that a per-operator estimate is more accurate than a per-airplane estimate. Therefore, the FAA estimates the total cost per operator for the actions to be $7,650 (90 work-hours x $85 per work-hour). The FAA estimates the total industry cost of this AD to be $2,983,500 ($7,650 x 390 operators). [[Page 43030]] 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 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