FAA AD 2026-14-09: Bombardier CL-600 Series Airworthiness Limitations Expanded — Certain Challenger 604 Serial Numbers Added

Quick Answers

What does FAA AD 2026-14-09 require for Bombardier Challenger 604 operators?

FAA AD 2026-14-09, effective August 18, 2026, supersedes AD 2025-17-12 and adds Challenger 604 serial numbers 6050 through 6192 to the airworthiness limitations requirement. Affected operators must revise their maintenance or inspection program to incorporate the new or more restrictive airworthiness limitations in Bombardier CH 650 TLMC Revision 9.

Which Challenger 604 serial numbers are newly added to FAA AD 2026-14-09?

FAA AD 2026-14-09 adds Bombardier CL-600-2B16 (604 Variant) serial numbers 6050 through 6192, inclusive, which were previously excluded from AD 2025-17-12. Challenger 604 serial numbers 5301–5665 and 5701–6049 were already in scope under the prior AD and remain subject to the same requirement.

Quick Compliance Summary

Regulatory bodyFederal Aviation Administration (FAA)
AD number2026-14-09 — Amendment 39-23410
DocketFAA-2025-3435
Aircraft affectedAll CL-600-1A11 (600), CL-600-2A12 (601), CL-600-2B16 (601-3A and 601-3R variants); CL-600-2B16 (604 Variant) S/Ns 5301–5665, 5701–6049, and 6050–6192
What changedSupersedes AD 2025-17-12. Adds Challenger 604 serial numbers 6050–6192 to applicability. Continues existing airworthiness limitations requirement
Required actionRevise maintenance or inspection program to incorporate new or more restrictive airworthiness limitations
Compliance deadlineAugust 18, 2026
Who must actOperators, CAMOs, MROs supporting Challenger 600/601/604 fleets
SourceFederal Register Vol. 91, No. 133, July 14, 2026 — FR Doc 2026-14110

Who Should Read This

This update is directly relevant to:

  • Continuing Airworthiness Managers (CAMs) for Challenger 600/601/604 fleets
  • Directors of Maintenance
  • Part 145 MRO organizations with Challenger 600 series capability
  • Bombardier Authorized Service Centers
  • Aircraft owners and operators of Challenger 604 aircraft at the newly added serial numbers

If you operate, maintain, or manage airworthiness for any CL-600 series airplane, check your serial number against the applicability below. The newly added Challenger 604 serial numbers (6050–6192) are the key change in this AD.

At a Glance

ItemDetails
AD Number2026-14-09
Amendment39-23410
DocketFAA-2025-3435
ATA Code05 — Time Limits / Maintenance Checks
Effective DateAugust 18, 2026
SupersedesAD 2025-17-12 (Amendment 39-23122, effective October 31, 2025)
Originating authorityTransport Canada AD CF-2024-16, May 23, 2024
Key changeAdds CL-600-2B16 (604 Variant) S/Ns 6050–6192 to applicability
Required actionRevise maintenance or inspection program to incorporate new or more restrictive airworthiness limitations
Service informationBombardier Challenger 604 CH 650 TLMC, Revision 9

What Changed

The FAA published AD 2026-14-09 on July 14, 2026. It is effective August 18, 2026.

This AD supersedes AD 2025-17-12, which was published September 26, 2025, and became effective October 31, 2025.

AD 2025-17-12 required revising the maintenance or inspection program to incorporate new or more restrictive airworthiness limitations on all CL-600-1A11 (600) and CL-600-2A12 (601) airplanes, and on Challenger 604 serial numbers 5301–5665 and 5701–6049.

Since that AD was issued, the FAA determined that certain Challenger 604 serial numbers were incorrectly excluded. The 604 Variant airplanes with serial numbers 6050 through 6192 were not included in the applicability of AD 2025-17-12. This AD adds them.

The required action remains the same. No new type of maintenance task is introduced. The compliance obligation — incorporating new or more restrictive airworthiness limitations into the maintenance or inspection program — carries over from AD 2025-17-12 into this AD.

Why It Matters

New or more restrictive airworthiness limitations are introduced by manufacturers — in this case, Bombardier — when the original limitations no longer adequately protect against fatigue cracking or structural degradation that fleet experience has revealed.

Airworthiness limitations are mandatory. They define inspection thresholds, intervals, and life limits that an operator must comply with under the Instructions for Continued Airworthiness. They are not advisory. Failure to incorporate them into your maintenance or inspection program leaves the aircraft out of compliance.

For Challenger 604 operators with serial numbers in the newly added range (6050–6192), this is the most significant aspect of the AD. Those aircraft were not subject to the airworthiness limitations revision under AD 2025-17-12. They are now subject as of August 18, 2026.

Who Is Affected

The AD applies to three groups:

Group 1: All CL-600-1A11 (Challenger 600) and CL-600-2A12 (Challenger 601) airplanes, and all CL-600-2B16 (601-3A and 601-3R Variants) — certificated in any category. All serial numbers in these models are in scope.

Group 2: CL-600-2B16 (604 Variant) airplanes, serial numbers 5301 through 5665 inclusive and 5701 through 6049 inclusive. These were already in scope under AD 2025-17-12. The requirement carries forward.

Group 3 — New addition: CL-600-2B16 (604 Variant) airplanes, serial numbers 6050 through 6192 inclusive. These airplanes were incorrectly excluded from AD 2025-17-12. They are now in scope under this AD.

Not in scope: CL-600-2B16 (604 Variant) airplanes with serial numbers above 6192. Bombardier requested the FAA extend the applicability to include S/Ns 6193 through 6202 and 6204. The FAA declined. Those aircraft would require a different revision level (Revision 10) of the TLMC, which is a separate action that would require a new NPRM. Further rulemaking on this may follow.

Required Action

Revise the existing maintenance or inspection program to incorporate the new or more restrictive airworthiness limitations specified in:

  • Bombardier Challenger 604 CH 650 Time Limit Maintenance Check (TLMC), Revision 9

For aircraft already in compliance with AD 2025-17-12 under Groups 1 and 2 above: the required action has already been accomplished. Confirm your maintenance program documentation reflects this and carry forward without additional action for those aircraft.

For Group 3 aircraft (604 Variant, S/Ns 6050–6192): accomplish the revision before August 18, 2026. Contact Bombardier for the applicable TLMC revision documentation.

For all in-scope aircraft: ensure the revised airworthiness limitations are incorporated into your approved maintenance program and are being tracked and scheduled accordingly. The limitations are mandatory — they cannot be deferred, extended, or omitted without an approved AMOC.

Operational Impact

The August 18, 2026 effective date gives operators five weeks from publication to accomplish the revision for newly added aircraft. The revision itself is a maintenance program documentation change — it does not require an immediate aircraft inspection or aircraft-on-ground event.

The practical impact is in the ongoing compliance obligations created. Once the new or more restrictive airworthiness limitations are incorporated, operators must comply with all new thresholds and intervals. Some of those may be more restrictive than previous limitations, potentially affecting maintenance intervals and heavy check scheduling for affected aircraft.

Review the TLMC Revision 9 content carefully against your current approved maintenance program to identify any new or tightened tasks before incorporating and scheduling.

Note on Bombardier’s Request to Expand Applicability

Bombardier specifically requested that the FAA expand the AD to also include Challenger 604 serial numbers 6193 through 6202 and 6204. The FAA declined this request.

Those aircraft were not delivered with Revision 9 of the CH 650 TLMC — they require Revision 10. Mandating Revision 10 would exceed the scope of the original NPRM and require a new public comment period. The FAA noted it may consider further rulemaking on this issue. Operators of 604 Variant aircraft with S/Ns above 6192 should monitor for a potential follow-on AD.

Key Dates

EventDate
Transport Canada AD CF-2024-16 issuedMay 23, 2024
AD 2025-17-12 published (prior AD)September 26, 2025
AD 2025-17-12 effectiveOctober 31, 2025
NPRM publishedOctober 21, 2025
FAA AD 2026-14-09 publishedJuly 14, 2026
AD 2026-14-09 effectiveAugust 18, 2026

Source Documents

  • Federal Register Vol. 91, No. 133, July 14, 2026 — FR Doc 2026-14110
  • Superseded: AD 2025-17-12, Amendment 39-23122 (90 FR 46330, September 26, 2025)
  • Transport Canada AD CF-2024-16, May 23, 2024 — available at tc.canada.ca/en/aviation
  • Bombardier Challenger 604 CH 650 TLMC, Revision 9 — contact Bombardier at bombardier.com
  • AD Docket: regulations.gov, Docket No. FAA-2025-3435

FAQ

My Challenger 604 is already in compliance with AD 2025-17-12. Do I need to do anything?

If your aircraft serial number falls within S/Ns 5301–5665 or 5701–6049, and you completed the revision under AD 2025-17-12, no new action is required. Confirm your maintenance records reflect compliance and carry forward. If your aircraft is S/N 6050–6192, you were not in scope under AD 2025-17-12 and must accomplish the revision before August 18, 2026.

My Challenger 604 has a serial number above 6192. Does this AD apply?

No. S/Ns above 6192 are not included in this AD. Bombardier requested they be included, but the FAA declined. A separate AD addressing those aircraft may follow.

What are airworthiness limitations and why are they mandatory?

Airworthiness limitations are part of the Instructions for Continued Airworthiness. They define inspection thresholds, repeat intervals, and life limits that must be incorporated into your maintenance program. They are mandatory by regulation and cannot be altered without an FAA-approved AMOC.

What is the TLMC?

The TLMC is the Time Limit Maintenance Check document for Challenger 604 aircraft. It is produced by Bombardier and defines the airworthiness limitations applicable to each aircraft configuration. Revision 9 is the revision applicable to aircraft with S/Ns 6050–6192 under this AD.

Could further rulemaking add more Challenger 604 serial numbers?

Possibly. The FAA acknowledged it may consider further rulemaking to address S/Ns 6193 through 6202 and 6204. Operators of those aircraft should monitor the FAA docket for a potential new NPRM.

Related Reading


aviationregwatch.com publishes regulatory intelligence for aviation compliance professionals. This article is an informational summary, not legal or airworthiness advice. Consult your aircraft manufacturer, CAMO, or legal counsel for compliance decisions.

About the Author
Raju KP  ·  Founder & Principal Analyst, Aviation Reg Watch

Raju founded Aviation Reg Watch, an independent publication covering aviation regulation, airline policy, airport governance, safety oversight and industry developments. His goal is to explain complex aviation regulations and policy changes in a clear, balanced, and practical way for aviation professionals, investors, and informed readers.

He brings more than 30 years of professional experience across banking, financial journalism, and management consulting. During more than nine years with a Big Four global advisory firm, he supported aviation-sector clients on research and consulting assignments involving airlines, airports, and aviation policy. Earlier in his career, he worked as a financial journalist covering macroeconomic data, financial markets, and policy developments.