{"id":"F2006B08628","name":"AD/CL-600/8 - Landing Gear Electrical Harnesses - Modification","slug":"ad-cl-600-8-landing-gear-electrical-harnesses-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51609,"registerId":"commonwealth-F2006B08628-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CL-600/8 - Landing Gear Electrical Harnesses - Modification","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Bombardier (Canadair) CL-600 (Challenger) Series Aeroplanes\n\n \n\nAD/CL-600/8 Landing Gear Electrical Harnesses - Modification 3/83\n\nApplicability: All model CL600 aeroplanes as per requirement document. Document: Canadair Challenger SB No. 600-0159.\n\nCompliance: Before issue of Australian Certificate of Airworthiness.\n\n \n\nBackground: To prevent landing gear proximity switches from being affected by electromagnetic interference. This may result in loss of aircraft brakes while landing and taxiing with anti-skid system in use.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The text specifies applicability to all CL-600 aeroplanes as per the requirement document and requires the harness modification before issue of an Australian Certificate of Airworthiness. There is no wording in the provided text indicating an expansion or narrowing of scope from the stated applicability or a change in the required action; the directive remains focused on mandating the specified modification for affected aircraft. (Applicability; Compliance; Document: Canadair Challenger SB No. 600-0159)"},"complexity_factors":["Narrow and specific technical requirement (single modification to landing gear harnesses). (Document: Canadair Challenger SB No. 600-0159)","Universal applicability to all CL-600 models but limited to those seeking Australian Certificate of Airworthiness, which simplifies enforcement scope. (Applicability; Compliance)","Reliance on an external technical document (service bulletin) for the detailed work introduces dependency but does not add procedural complexity in this text. (Document: Canadair Challenger SB No. 600-0159)","No alternative compliance or exemption language in the directive increases procedural clarity but reduces flexibility. (Compliance)","Compliance timing (before Certificate of Airworthiness) creates operational scheduling considerations but is a single clear deadline. (Compliance)"],"plain_english_summary":"What this directive does (mechanically)\n\n- Requires that all Bombardier (Canadair) CL-600 (Challenger) aeroplanes have their landing gear electrical harnesses modified in accordance with the Canadair Challenger Service Bulletin No. 600-0159. (Document: Canadair Challenger SB No. 600-0159)\n- The modification must be completed before the aircraft is issued an Australian Certificate of Airworthiness. (Compliance)\n\nWho this affects\n\n- Aircraft owners, operators, manufacturers and maintenance organisations responsible for CL-600 aeroplanes that are to be certified in Australia. (Applicability)\n\nWhy it matters (stated purpose and the hazard addressed)\n\n- The stated purpose is to prevent landing gear proximity switches being affected by electromagnetic interference. The background notes this interference could result in loss of aircraft brakes while landing and taxiing when the anti-skid system is in use. (Background)\n\nPractical consequences, incentives and costs\n\n- Who pays: The direct cost of procuring parts, labour and any grounding time for the modification falls on the aircraft owner/operator or the party responsible for preparing the aircraft for Australian certification, because compliance is required prior to issuance of the Certificate of Airworthiness. (Compliance)\n- Compliance timing and opportunity cost: The modification is a pre‑certification requirement; completing it can delay issuance of the Certificate of Airworthiness and use of the aircraft until the work is done. (Compliance)\n- Implementation risk and dependence on the service document: The instruction points to a manufacturer service bulletin for the technical work. This creates dependence on the availability and clarity of that bulletin and on parts and qualified labour to install the harness modification correctly. (Document: Canadair Challenger SB No. 600-0159)\n- Administrative discretion and alternatives: The directive states the required action and timing but does not include alternative compliance routes or exemptions in the text provided. That limits administrative flexibility unless other regulatory provisions (not contained here) are invoked. (Compliance)\n- Behavioural effect: Operators seeking an Australian Certificate of Airworthiness for an affected CL-600 must ensure the harness modification is completed; failing to do so prevents certification. (Applicability) \n\nTrade-offs and observable risks\n\n- Concentrated vs diffuse effects: The benefit (reduced risk that proximity switches are disturbed by electromagnetic interference) accrues directly to users of each modified aircraft and their passengers/crew. The costs (parts, labour, downtime) are concentrated on the aircraft owner/operator who must carry out the work. (Background) \n- Substitution and alternatives: The directive specifies a particular modification (per the service bulletin) and does not describe alternative mitigations in the text provided; operators therefore must follow that specified technical solution or seek an alternative through separate approval processes. (Document: Canadair Challenger SB No. 600-0159)\n- Compliance burden: The burden is operational (bookings for maintenance, possible grounding) and financial (parts and labour). The AD does not set out inspection intervals or ongoing maintenance changes in the text provided; it mandates a one-off modification prior to certification. (Compliance)\n\nNet mechanical effect\n\n- After compliance, each affected CL-600 on the Australian register will have modified landing gear electrical harnesses designed to reduce electromagnetic interference with landing gear proximity switches, as implemented per the referenced service bulletin. (Document: Canadair Challenger SB No. 600-0159; Background)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive focused specifically on electromagnetic interference in landing gear systems. It has not expanded beyond its original technical scope. The document appears to be a historical directive (reference '3/83' suggests March 1983 origin) maintaining its original narrow purpose."},"complexity_factors":["Extremely short document (approximately 150 words of substantive content)","Only 1 defined term implicitly referenced (the Service Bulletin)","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Single, unambiguous compliance requirement with no conditional exceptions","No nested logic or alternative compliance pathways","Straightforward applicability test (all CL-600 model aircraft)","Binary compliance trigger (Certificate of Airworthiness issuance)"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific repairs or modifications to aircraft.\n\n**What it does:** It orders owners and operators of **Bombardier (Canadair) CL-600 Challenger series aircraft** to modify the **landing gear electrical wiring (harnesses)**. The fix must be done following the manufacturer's Service Bulletin 600-0159.\n\n**Why it matters:** Without this modification, **electromagnetic interference** (electrical \"noise\" from other aircraft systems) can disrupt the landing gear proximity switches. If these switches malfunction, pilots could **lose braking power during landing and taxiing** — especially dangerous when the anti-skid system is active. This creates a serious safety risk of runway overruns or loss of aircraft control.\n\n**Who must comply:** Anyone seeking an **Australian Certificate of Airworthiness** for a CL-600 aircraft must complete this modification **before** the certificate is issued. In practical terms, this affects aircraft importers, new registrants, and anyone returning a CL-600 to Australian service.\n\n**Key deadline:** The work must be finished **before** the Certificate of Airworthiness is granted — not after."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cl-600-8-landing-gear-electrical-harnesses-modification","history":"/api/acts/ad-cl-600-8-landing-gear-electrical-harnesses-modification/history","analysis":"/api/acts/ad-cl-600-8-landing-gear-electrical-harnesses-modification/analysis","conflicts":"/api/acts/ad-cl-600-8-landing-gear-electrical-harnesses-modification/conflicts","importantCases":"/api/acts/ad-cl-600-8-landing-gear-electrical-harnesses-modification/important-cases","documents":"/api/acts/ad-cl-600-8-landing-gear-electrical-harnesses-modification/documents"}}