{"id":"F2009L03904","name":"AD/CL-600/123 - Wing Anti-Ice System - Outboard Low-Heat Detection Switches","slug":"ad-cl-600-123-wing-anti-ice-system-outboard-low-heat-detection-switches","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":81246,"registerId":"commonwealth-F2009L03904-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Bombardier (Canadair) CL-600 (Challenger","sectionType":"division","heading":"Bombardier (Canadair) CL-600 (Challenger) Series Aeroplanes","content":"### Bombardier (Canadair) CL-600 (Challenger) Series Aeroplanes\n\n| AD/CL-600/123 | Wing Anti-Ice System - OutboardLow-Heat Detection Switches | 21/2009 |\n| ------------- | ---------------------------------------------------------- | ------- |\n\n| Applicability: | Model CL-600-2B19 aeroplanes, Serial Numbers (S/N) 7003 through 8101. |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Amend the Aircraft Flight Manual (AFM), CSP A-012, by inserting Temporary Revision (TR) No RJ/164-2, dated 12 May 2009, or later approved changes to this TR. Advise all flight crews of the changes introduced by the AFM TR. |\n| | 2. Revise the approved maintenance schedule by incorporating the inspection requirements contained in TR 2A-46, dated 24 July 2009, of the Maintenance Requirements Manual, CSP A-053, Part 2, Appendix A, Certification Maintenance Requirements. |\n| | 3. Replace the existing Data Concentrator Units (DCU) (Part Numbers (P/N) 622-9820-007 and/or -008 and/or -009) with modified DCUs (P/N 622-9820-010) and also, if applicable, modify the Configuration Strapping Units (CSUs), in accordance with the Accomplishment Instructions in Bombardier Service Bulletin (SB) 601R-31-034, Revision A, dated 10 April 2008, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada. |\n| | Note 1: The modified DCUs have been installed in production on CL-600-2B19 aircraft, serial numbers 8096 and subsequent. |\n| | Note 2: Accomplishment in accordance with the original issue of Bombardier SB 601R-31-034, dated 19 November 2007, also meets the intent of Requirement 3 of this Directive. |\n| | 4. Install the outboard low-heat detection switches, wing A/ICE box assembly and associated wires in accordance with the Accomplishment Instructions in Parts A, C, D and E of Bombardier SB 601R-30-031, Revision A, dated 8 September 2009, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada. |\n| | Note 3: Accomplishment of Parts A, C, D and E of Bombardier SB 601R-30-031, Revision A, dated 8 September 2009, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada, may be performed separately from each other. |\n\n| | Note 4: Accomplishment in accordance with Part A of the original issue of Bombardier SB 601R-30-031, dated 15 May 2009, also meets the intent of Requirement 4 of this Directive. |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | Note 5: There have been a small number of cases reported in which piccolo ducts were found to have been installed in the opposite wing, resulting in the incorrect orientation of the bleed holes. During reinstallation of the piccolo ducts and leading edge assemblies after installation of the low-heat detection switches, particular attention should be paid to the correct alignment of the piccolo ducts (Refer Aircraft Maintenance Manual Task 30-11-41-820-801). |\n| | 5. Activate the outboard low-heat detection switches in accordance with the Accomplishment Instructions in Part F of Bombardier SB 601R-30-031, Revision A, dated 8 September 2009, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada. |\n| | Note 6: Accomplishment in accordance with Part B of the original issue of Bombardier SB 601R-30-031, dated 15 May 2009, also meets the intent of Requirement 5 of this Directive. |\n| | Note 7: Within the constraints of the compliance times specified below, each Requirement of this Directive may be accomplished separately from the other Requirements. |\n| | Note 8: Transport Canada AD CF-2009-0037 refers. |\n| Compliance: | For Requirements 1 and 2 - Within 30 days after the effective date of this Directive. |\n| | For Requirements 3 and 4 - Prior to accomplishment Requirement 5 of this Directive, but no later than 1 November 2010. |\n| | For Requirement 5 - Following accomplishment of Requirements 3 and 4 of this Directive, but no later than 1 November 2010. |\n| | This Airworthiness Directive becomes effective on 16 October 2009. |\n| Background: | At present, the Wing Anti-Ice System (WAIS) sufficient heat switches/sensors on CL-600-2B19 aircraft are located at the inboard end of each wing and require a simultaneous low-pressure signal to generate a L or R WING A/ICE amber caution. However, there have recently been several in-service occurrences that have highlighted the inability of the existing system to detect a low-heat condition in the wing leading edge at all times, with the potential consequence of unannunciated asymmetric ice build-up on the wing. These have included partial failure of several piccolo ducts [AD/CL-600/83 (Transport Canada AD CF-2008-30) refers] and partial (not fully closed or open) failure of a modulating and shut-off valve, the latter resulting in unannunciated asymmetric ice build-up on the wing leading edge. Such a condition, in combination with manoeuvres close to stick shaker activation, could possibly result in reduced controllability of the aircraft. |\n| | This Directive mandates:a) Revision of the AFM to notify the flight crew that, following installation and activation of the low-heat detection switches, certain WAIS mode selection changes may result in a two-minute inhibition of the wing anti-ice message, if posted;b) Revision of the approved maintenance schedule to include one revised and three new functional checks that are required following activation of the low-heat detection switches;c) Replacement of the DCUs with DCUs incorporating a software update that caters for the new outboard low-heat detection switches and generates the appropriate anti-ice message for the flight crew when a low-heat condition is detected; |\n| | Note 9: Although not related to this Directive, the software update also corrects the sampling rate of two previously non-compliant Flight Data Recorder (FDR) parameters, normal acceleration and pitch attitude. |\n| | d) Installation of the low-heat detection switches in the wing outboard leading edges, the wing A/ICE box assembly and associated wires; ande) Activation of the low-heat detection switches. |\n\n![](image.001.png) \nDavid Villiers \nDelegate of the Civil Aviation Safety Authority\n\n9 October 2009","sortOrder":0},{"sectionNumber":"AD/CL-600/123","sectionType":"part","heading":"AD/CL-600/123","content":"## AD/CL-600/123","sortOrder":1},{"sectionNumber":"Wing Anti-Ice System - OutboardLow-Heat ","sectionType":"part","heading":"Wing Anti-Ice System - OutboardLow-Heat Detection Switches","content":"## Wing Anti-Ice System \\- Outboard \nLow-Heat Detection Switches","sortOrder":2},{"sectionNumber":"21/2009","sectionType":"part","heading":"21/2009","content":"## 21/2009","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":6,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original scope as a targeted safety intervention for a specific aircraft model's wing anti-ice system. The document addresses a well-defined technical problem (inadequate heat detection in outboard wing sections) with prescribed technical solutions. There is no evidence of scope creep beyond the original safety intent."},"complexity_factors":["Multiple interdependent requirements (5 distinct requirements with specific sequencing constraints)","Extensive cross-referencing to external technical documents (Bombardier Service Bulletins, Maintenance Requirements Manual, Aircraft Flight Manual)","Conditional logic and alternative compliance paths (Notes 2, 4, and 6 allow compliance via earlier document versions)","Specific part numbers and serial number ranges (P/N 622-9820-007/-008/-009/-010, S/N 7003–8101, S/N 8096+)","Staggered compliance deadlines with dependencies (Requirements 3&4 must precede Requirement 5)","Technical aviation terminology requiring domain knowledge (piccolo ducts, Data Concentrator Units, Configuration Strapping Units, modulating and shut-off valves)","Dual regulatory reference (Transport Canada AD CF-2009-0037 mentioned as related)","Embedded safety warnings (Note 5 regarding piccolo duct orientation during reinstallation)"],"plain_english_summary":"This CASA Airworthiness Directive affects Bombardier Challenger 600 series CL-600-2B19 (s/n 7003–8101) and mandates fixes to the wing anti‑ice sensing system to prevent undetected outer‑wing ice buildup. Operators must update the flight manual and maintenance schedule and install/activate new outer‑wing heat detection switches and related DCU hardware so pilots get correct warnings. Manual/maintenance updates are due within 30 days; hardware installation and activation must be completed by 1 November 2010."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":false,"description":"The directive remains focused on correcting a WAIS detection gap by adding outboard low‑heat detection switches, updating DCU software, and imposing procedural checks and crew notices. It does not materially broaden the subject beyond the WAIS detection and annunciation issue. The only incidental expansion is that the DCU software update also corrects FDR parameter sampling rates (Background Note 9), but that correction is recorded as incidental and does not change the primary scope or purpose."},"complexity_factors":["Multiple distinct mandatory actions (5 numbered Requirements) with different technical scopes (AFM change, maintenance schedule change, hardware replacement, installation, activation).","Cross‑reference to multiple Bombardier Service Bulletins (SB 601R-31-034 and SB 601R-30-031) with Parts A–F and allowance for later approved revisions.","Specific part numbers for replacement and conditional modification (DCU P/Ns 622-9820-007/-008/-009 → 622-9820-010; possible CSU modifications).","Sequencing constraints and staggered compliance windows (Reqs 1–2 within 30 days; Reqs 3–5 must be completed in order and by 1 November 2010).","Applicability limited to a serial‑number range (S/N 7003–8101), producing non‑uniform fleet impact.","Several explanatory notes that permit older SB issues to comply and that allow separate accomplishment of SB Parts, increasing acceptable procedural variants.","Operational detail and maintenance caution (piccolo duct orientation) that add inspection complexity and potential rework.","Reference to a foreign regulator's AD (Transport Canada AD CF-2009-0037) and dependence on Chief, Continuing Airworthiness approvals for later revisions, introducing inter‑jurisdictional approval steps.","Mix of hardware, software and procedural (AFM and maintenance schedule) changes, requiring coordination across flight operations and maintenance functions."],"plain_english_summary":"**What this instrument does (mechanically)\n\n- Requires operators of certain Bombardier CL-600-2B19 (Challenger) aeroplanes, serial numbers 7003–8101, to change flight and maintenance documentation, replace and/or modify specified hardware and software items, install additional sensors and wiring, and activate those sensors.\n\n- Specifically it mandates:\n - Amend the Aircraft Flight Manual (AFM) by inserting a Temporary Revision so flight crews are notified of WAIS message behaviour after the modification (Requirement 1).\n - Update the approved maintenance schedule to include new and revised functional checks required after activation of the new switches (Requirement 2).\n - Replace existing Data Concentrator Units (DCUs) (P/N 622-9820-007/-008/-009) with updated DCUs (P/N 622-9820-010) and, if needed, modify Configuration Strapping Units (Requirement 3) in accordance with Bombardier Service Bulletin (SB) 601R-31-034.\n - Install outboard low-heat detection switches, the wing anti‑ice (A/ICE) box assembly and associated wiring, using Parts A, C, D and E of Bombardier SB 601R-30-031 (Requirement 4).\n - Activate the newly installed outboard low-heat detection switches per Part F of SB 601R-30-031 (Requirement 5).\n - The directive allows certain older issues of the service bulletins to satisfy the requirements if they meet the stated intent (several notes).\n\n- Compliance timing: AFM and maintenance-schedule changes within 30 days of the directive; hardware/software replacements and installations must be done before activation and no later than 1 November 2010; activation follows installation and must also be done by 1 November 2010.\n\nWhy the regulator requires this (official rationale)\n\n- The regulator says the existing Wing Anti‑Ice System (WAIS) only has low‑heat (low‑bleed) detectors at the inboard wing. Several in‑service events showed the system could fail to detect a low‑heat condition outboard, allowing unannunciated asymmetric ice build-up on a wing leading edge. That combination, especially during flight close to stall‑warning conditions, could reduce controllability. The directive therefore adds outboard low‑heat detection switches, updates DCU software to report low‑heat correctly, and imposes new functional checks and crew information.\n\nTesting the regulator's claims against costs, incentives and practical effects\n\n- Who pays: aircraft operators/owners must buy parts, perform the installations, update manuals and perform new checks. Those are direct costs in parts and labour and indirect costs in aircraft downtime. (See Requirements 3–5 and Compliance times.)\n- Who decides: the work must be done to the Bombardier SBs or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada. That means operators rely on approved SB content and on approved maintenance organisations or licensed engineers to perform the work.\n- Behaviour changes required: flight crews must be advised of AFM changes (temporary revision) and may see a two‑minute inhibition of the wing anti‑ice message after certain WAIS mode selections once the new switches are installed and activated (background text). Maintenance organisations must add specified functional checks to the maintenance schedule and perform them.\n- Incentives and trade‑offs: the directive concentrates safety benefit on all affected aircraft (diffuse benefit). Costs are concentrated on the aircraft operators who must retrofit equipment and absorb downtime. Maintenance providers with approvals and Bombardier SB familiarity gain business (concentrated benefit to MRO shops). Operators will weigh retrofit cost and scheduling against aircraft utilisation—there is no optionality once the compliance date passes.\n- Implementation risks and compliance burden: the AD cross‑references several SB Parts (A–F) and permits separate accomplishment of certain parts; it also notes historical maintenance errors (piccolo duct orientation) that require attention during reassembly, increasing inspection scope and potential shop labour. Operators must ensure correct DCU P/N replacement and potential CSU modification—incorrect parts or installation could leave the WAIS uninformed or generate false messages. The AD also depends on the availability of replacement DCUs and trained personnel; supply or capacity bottlenecks will increase downtime.\n- Effects on markets and competition: MROs certified to carry out Bombardier SBs will receive retrofit work; smaller independent shops without approvals may be excluded unless they obtain approvals or subcontract. The directive does not change ownership, pricing regulation or market entry rules, but it does impose a mandated compliance market for parts and labour.\n- Side effects noted by the regulator: the updated DCU software also corrects Flight Data Recorder (FDR) parameter sampling rates (normal acceleration and pitch attitude). The AD records this as incidental and not part of the WAIS safety rationale (Background Note 9).\n\nOther concrete implementation notes\n\n- The AD allows earlier (original) versions of the cited service bulletins to meet requirements where noted, but only if they meet the intent (several Notes).\n- Work may be staged: Parts A, C, D and E of SB 601R-30-031 may be done separately (Note 3), but sequencing constraints apply because activation must follow installation and DCU replacement (Compliance section).\n- Watch for piccolo duct alignment during reinstallation (Note 5) to avoid creating another maintenance‑induced issue.\n\nBottom line (who is affected and what to do)\n\n- Affected parties: owners/operators of Bombardier CL‑600‑2B19 serials 7003–8101; maintenance organisations performing Bombardier SB work; flight crews of the affected aircraft.\n- Required actions: update AFM and maintenance schedule quickly (30 days), obtain and install modified DCUs and other hardware, install and activate outboard low‑heat detection switches, and perform the new functional checks by the stated deadline.\n\n"},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-cl-600-123-wing-anti-ice-system-outboard-low-heat-detection-switches","history":"/api/acts/ad-cl-600-123-wing-anti-ice-system-outboard-low-heat-detection-switches/history","analysis":"/api/acts/ad-cl-600-123-wing-anti-ice-system-outboard-low-heat-detection-switches/analysis","conflicts":"/api/acts/ad-cl-600-123-wing-anti-ice-system-outboard-low-heat-detection-switches/conflicts","importantCases":"/api/acts/ad-cl-600-123-wing-anti-ice-system-outboard-low-heat-detection-switches/important-cases","documents":"/api/acts/ad-cl-600-123-wing-anti-ice-system-outboard-low-heat-detection-switches/documents"}}