{"id":"F2007L01773","name":"AD/CL-600/41 Amdt 1 - Fire Warning Control Unit","slug":"ad-cl-600-41-amdt-1-fire-warning-control-unit","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":66520,"registerId":"commonwealth-F2007L01773-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-600/41 Amdt 1 | Fire Warning Control Unit | 8/2007 DM |\n| ------------------- | ------------------------- | --------- |\n\n| Applicability: | CL-600-2B19 Regional Jet (RJ) aircraft, serial numbers 7003 through 7067 inclusive, and 7069 through 7545 inclusive. |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. If not previously accomplished in accordance with the original issue of this Directive, install protective tape on the fire and overheat control unit, part number (P/N) 472597-01, in accordance with Bombardier Alert Service Bulletin (ASB) A601R-26-17 Revision A, dated 8 September 2000 or ASBA601R-26-017 Revision B, dated 6 February 2003. |\n| | 2. Inspect the condition of the protective tape on the fire and overheat control unit P/N 472597-01 to ensure that the tape makes a satisfactory seal to prevent entry of liquid at the fasteners and the hinge of the unit, in accordance with ASB A601R-26-017 Revision B. If the seal is not in satisfactory condition, remove damaged tape and install new protective tape in accordance with ASBA601R-26-017 Revision B. |\n| | 3. Repeat the Requirement 2 inspection and, if the seal is not in satisfactory condition, remove damaged tape and install new protective tape in accordance with ASB A601R-26-017 Revision B. |\n| | 4. Remove the fire and overheat control unit, P/N 472597-01, and replace it with fire and overheat control unit, P/N 472597-02, in accordance with Bombardier Service Bulletin (SB) 601R-26-018, dated 2 December 2002, or SB 601R 26-018 Revision A, dated 27 February 2003. |\n| | Installation of fire and overheat control unit, P/N 472597-02, in accordance with Requirement 4 constitutes terminating action for this Directive. |\n| | Later revisions of the service bulletins referenced in Requirements 1 through 4 may be utilised for compliance with this Amendment if they are approved by the Chief, Continuing Airworthiness, Aircraft Certification, Transport Canada. |\n| | Note: Transport Canada AD CF-2000-35-R1 refers. |\n| Compliance: | For Requirement 1 - Within 250 hours time in service (TIS) or 30 days after the effective date of this Amendment, whichever occurs first. |\n\n| | For Requirement 2 - Within 5,000 hours TIS or at the next “C” check after compliance with Requirement 1 of this Amendment, whichever occurs later. |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | For Requirement 3 - Following accumulation of a further 5,000 hours TIS after the initial accomplishment of Requirement 2 or at the next “C”, whichever occurs later. |\n| | For Requirement 4 - Within 20,000 hours TIS after the effective date of this Amendment, or before 31 December 2010, whichever occurs first. |\n| | This Amendment becomes effective on 29 June 2007. |\n| Background: | Transport Canada has advised that there have been incidents of false fire alarms on the Regional Jet engines and/or auxiliary power units. Investigations have revealed fluid contamination inside the fire and overheat control unit in the flight compartment caused by accidental fluid spillage. Bombardier has issued ASB A601R-26-017 to introduce the installation of protective tape to prevent fluid ingress into the fire and overheat control unit. The installation of protective tape was considered to be an interim corrective action. |\n| | The original issue of this Directive mandated the installation of the protective tape. This Amendment introduces repeat inspections of the protective tape and, if necessary, reapplication of the protective tape. The Amendment also introduces a terminating action. |\n| | The original issue of this Directive became effective on 21 February 2001. |\n\n![](image.001.png) \nDavid Punshon \nDelegate of the Civil Aviation Safety Authority\n\n14 June 2007","sortOrder":0},{"sectionNumber":"AD/CL-600/41 Amdt 1","sectionType":"part","heading":"AD/CL-600/41 Amdt 1","content":"## AD/CL-600/41 Amdt 1","sortOrder":1},{"sectionNumber":"Fire Warning Control Unit","sectionType":"part","heading":"Fire Warning Control Unit","content":"## Fire Warning Control Unit","sortOrder":2},{"sectionNumber":"8/2007 DM","sectionType":"part","heading":"8/2007 DM","content":"## 8/2007 DM","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is an amendment to an existing Airworthiness Directive. The original directive (effective February 2001) required only the tape installation. This Amendment 1 adds repeat inspections and the terminating replacement action. This represents a natural evolution of the safety response (interim fix → permanent fix) rather than scope creep beyond the original purpose of addressing false fire alarms from fluid contamination."},"complexity_factors":["Multiple compliance pathways with 'whichever occurs first/later' conditional logic","Four distinct requirements with interdependent deadlines (Requirement 4 terminates the others)","Cross-references to four external Bombardier service bulletins with specific revision dates","Reference to Canadian aviation authority (Transport Canada) for approval of later revisions","Specific part numbers and serial number ranges creating narrow applicability","Technical aviation terminology (TIS, 'C' check, terminating action) requiring domain knowledge"],"plain_english_summary":"This AD applies to Bombardier Regional Jets (s/n 7003–7067 and 7069–7545) and addresses false engine/APU fire warnings caused by liquid contamination of the fire warning control unit. Operators must seal the unit (protective tape), inspect and maintain that seal, and ultimately replace the unit with an improved part as the permanent fix. It prevents distracting or unnecessary emergency responses and restores confidence in fire warnings."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The Amendment expands the original Directive. The original issue required installation of protective tape; this Amendment adds repeat inspections and re‑application of the tape and introduces a terminating action requiring replacement of P/N 472597‑01 with P/N 472597‑02 (Background; Requirements). It also sets specific compliance timeframes and permits later service bulletin revisions only with Transport Canada approval."},"complexity_factors":["Limited applicability to a specific model and serial-number range (CL‑600‑2B19 serials 7003–7067, 7069–7545) reduces scale complexity.","Multiple discrete actions: interim tape installation, periodic inspections/re‑application, and eventual hardware replacement (Requirements 1–4).","Staggered compliance windows with different flight‑hour and calendar triggers (250 hrs/30 days; 5,000 hrs; further 5,000 hrs; 20,000 hrs or date) increase scheduling complexity.","Terminology of 'terminating action' for replacement creates a clear end state but requires tracking until replacement completed (Requirement 4).","Allows use of later service bulletin revisions only if approved by Transport Canada, introducing regulatory discretion and coordination (Requirements notes).","Enforcement and oversight rest with national authority (CASA) and references Transport Canada AD CF‑2000‑35‑R1, creating cross‑jurisdictional compliance links.","Operational costs and downtime are borne by aircraft owners/operators (Compliance/Requirements), with potential substitution of inspection effort for earlier replacement."],"plain_english_summary":"Mandates that operators of Bombardier CL‑600‑2B19 aircraft (serials 7003–7067 and 7069–7545) install protective tape on the flight‑deck fire/overheat control unit P/N 472597‑01, inspect and renew that tape at set intervals, and ultimately replace the unit with P/N 472597‑02 as a terminating action. The measure (Requirements; Compliance) is intended to prevent false engine/APU fire warnings caused by fluid ingress; aircraft owners/operators must perform and fund the work within the specified flight‑hour or calendar windows."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cl-600-41-amdt-1-fire-warning-control-unit","history":"/api/acts/ad-cl-600-41-amdt-1-fire-warning-control-unit/history","analysis":"/api/acts/ad-cl-600-41-amdt-1-fire-warning-control-unit/analysis","conflicts":"/api/acts/ad-cl-600-41-amdt-1-fire-warning-control-unit/conflicts","importantCases":"/api/acts/ad-cl-600-41-amdt-1-fire-warning-control-unit/important-cases","documents":"/api/acts/ad-cl-600-41-amdt-1-fire-warning-control-unit/documents"}}