{"id":"F2007L02124","name":"AD/CL-600/70 - AC Contactors","slug":"ad-cl-600-70-ac-contactors","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":67259,"registerId":"commonwealth-F2007L02124-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-600/70 | AC Contactors | 8/2007 |\n| ------------ | ------------- | ------ |\n\n| Applicability: | Model CL-600-2B19 aeroplanes, serial number 7003 through 7990 inclusive and 8000 through 8070 inclusive.                                                                                                                                                                                                                                                                                                                                                                                                     |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | 1. Unless already accomplished, visually inspect the AC service bus contactors 1K4XD and 2K4XD, part number (P/N) D-18ZZA, and the utility bus contactor K4XA, P/N D-7GRZ, to determine whether the AC contactors have a non-G9 terminal base plate. The above inspection is to be accomplished in accordance with Bombardier Service Bulletin (SB) 601R-24-123, Revision B, dated16 February 2007, or later revision approved by Chief, Continuing Airworthiness, Aircraft Certification, Transport Canada. |\n|                | 2. If the contactors 1K4XD, 2K4XD or K4XA are determined to have a non-G9 terminal base plate, replace the AC service bus contactors 1K4XD and 2K4XD with new P/N D-18ZZC and the utility bus contactor K4XA with new P/ND-7GSZ, in accordance with SB 601R-24-123, Revision B, or later revision approved by Chief, Continuing Airworthiness, Aircraft Certification, Transport Canada.                                                                                                                     |\n|                | 3. AC contactor 1K4XD, 2K4XD or K4XA with a non-G9 terminal base plate may not be installed on any aircraft as a replacement part.                                                                                                                                                                                                                                                                                                                                                                           |\n|                | Note: Transport Canada AD CF-2006-17R1 refers.                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n| Compliance:    | For Requirements 1 and 2 - Within twelve months after the effective date of this Directive.                                                                                                                                                                                                                                                                                                                                                                                                                  |\n|                | For Requirement 3 - As of the effective date of this Directive.                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n|                | This Airworthiness Directive becomes effective on 2 August 2007.                                                                                                                                                                                                                                                                                                                                                                                                                                             |\n| Background:    | Transport Canada has advised that there have been eight incidents of short-circuit failures of Tyco Hartman AC contactors - 1K4XD and K4XA - located in the avionics bay. All of the failed AC contactors had a terminal base plate made from non-G9 melamine material (Ultem 2200 material or black in colour).                                                                                                                                                                                             |\n\n|     | In several cases, the arcing, which was initiated due to the presence of contaminants between the power studs, resulted in a fire that continued until power to the contactor was interrupted, either by burned-through wire or through the generator falling offline.                                     |\n| --- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|     | The original issue of Transport Canada AD CF-2006-17, which was not mandated in Australia, required the sealing of non-G9 terminal base plates with RTV sealant to reduce the risk of arcing and fire. The application of RTV sealant on the non-G9 terminal base plates is now considered interim action. |\n|     | This Directive requires the inspection of the AC contactors and, if necessary, their replacement with contactors that have a terminal base plate made from G9 melamine material. The Directive also prohibits the installation, as replacement spares, of contactors with non-G9 terminal base plates.     |\n\n![](image.001.png)  \nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n14 June 2007","sortOrder":0},{"sectionNumber":"AD/CL-600/70","sectionType":"part","heading":"AD/CL-600/70","content":"## AD/CL-600/70","sortOrder":1},{"sectionNumber":"AC Contactors","sectionType":"part","heading":"AC Contactors","content":"## AC Contactors","sortOrder":2},{"sectionNumber":"8/2007","sectionType":"part","heading":"8/2007","content":"## 8/2007","sortOrder":3}],"analysis":{"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Scope moved from an earlier interim fix to a definitive replacement mandate. The source notes Transport Canada initially required RTV sealing of non‑G9 terminal base plates as interim action; this Directive instead mandates inspection and replacement with G9‑material contactors and prohibits use of non‑G9 contactors as replacements (see Background and Requirements)."},"complexity_factors":["Limited applicability by model and explicit serial number ranges (targets a narrow fleet)","Technical identification of affected parts by part number and terminal base plate material (P/N D-18ZZA, D-18ZZC, D-7GRZ, D-7GSZ; G9 vs non‑G9)","Compliance tied to a specific service bulletin (SB 601R-24-123 Rev B) and any later revision approved by Transport Canada (introduces external approver dependency)","Combination of inspection, mandatory replacement, and a prohibition on installing certain spare parts (operational and supply-chain effects)","Clear compliance timeframe (12 months) and immediate effect for the spare‑part prohibition"],"plain_english_summary":"**What it does:** Requires operators of specified Bombardier CL-600-2B19 aeroplanes (serials 7003–7990 and 8000–8070) to visually inspect three AC contactors and, within 12 months, replace any with a non‑G9 terminal base plate with approved G9‑material contactors; it also bans fitting non‑G9 contactors as spares.  \n**Who it affects and why it matters:** Aircraft owners/operators must carry out and pay for inspections and replacements using Bombardier SB 601R‑24‑123 (or later approved revisions) to address a Transport Canada‑reported risk of arcing and fire from non‑G9 base plates."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope. It targets a specific safety defect in a specific aircraft type with a precise technical remedy. The directive does not expand beyond the original safety purpose of addressing the AC contactor fire risk."},"complexity_factors":["Single, specific aircraft model and narrow serial number range (7003–7990, 8000–8070)","Only three specific part numbers to identify and track (1K4XD, 2K4XD, K4XA)","Clear binary determination required (G9 vs non-G9 terminal base plate)","Straightforward compliance timeline (12 months for inspection/replacement, immediate for installation ban)","Single referenced technical document (Bombardier Service Bulletin 601R-24-123 Rev B)","No nested exceptions, conditional logic, or alternative compliance methods","Minimal defined terms (only standard aviation abbreviations like P/N for part number)"],"plain_english_summary":"This CASA Airworthiness Directive mandates inspection and replacement of certain AC contactors on specified Bombardier Challenger CL-600-2B19 serials after repeated failures of non-G9 terminal base plates that caused short‑circuits, arcing, and avionics-bay fires. It also prohibits fitting non‑G9 contactors as spares.\n\nThe AD affects owners, operators and maintenance organisations servicing those Challengers and aims to eliminate a known fire risk in flight by ensuring contactors use the fire‑resistant G9 base."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cl-600-70-ac-contactors","history":"/api/acts/ad-cl-600-70-ac-contactors/history","analysis":"/api/acts/ad-cl-600-70-ac-contactors/analysis","conflicts":"/api/acts/ad-cl-600-70-ac-contactors/conflicts","importantCases":"/api/acts/ad-cl-600-70-ac-contactors/important-cases","documents":"/api/acts/ad-cl-600-70-ac-contactors/documents"}}