{"id":"F2006B08598","name":"AD/CL-600/37 Amdt 1 - Flight Spoiler Centre Hinge Fitting","slug":"ad-cl-600-37-amdt-1-flight-spoiler-centre-hinge-fitting","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51485,"registerId":"commonwealth-F2006B08598-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CL-600/37 Amdt 1 - Flight Spoiler Centre Hinge Fitting","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \n![](image.002.png)  \nBombardier (Canadair) CL-600 (Challenger) Series Aeroplanes\n\nAIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/CL-600/37 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\nAD/CL-600/37\n\nAmdt 1\n\n  \nFlight Spoiler Centre Hinge Fitting 5/2001\n\nApplicability: Model CL-600-2B19 “Regional Jet” aircraft, serial numbers 7003 through 7340\\. Requirement: Inspect in accordance with Transport Canada AD CF-2000-15 R1.\n\nNote 1: Bombardier Alert Service Bulletin (ASB) A601R-57-O27 Revision C refers.\n\nNote 2: Installation of redesigned flight spoilers part number 600-10602-73 and \\-74 provides terminating action to the inspection requirements of Parts A and B of the Requirement document.\n\nCompliance: As specified in the Requirement document for the initial and repeat inspection requirements, and eventual replacement requirement; with a revised effective date of 17 May 2001.\n\nNote: Compliance with previous versions of ASB A601R-57-027 \\- original issue, Revision A, or Revision B - also meet the requirements of paragraph A.1 of the Requirement document.\n\nThis amendment becomes effective on 17 May 2001.\n\nBackground: Transport Canada received reports of four cases of uncommanded deployment of a flight spoiler due to fracture of the actuator lug on one of the centre hinge fittings of the left or right flight spoiler. In each case a status message was posted and the flight crew landed the aircraft safely.\n\nAmendment 1 is issued in response to a revision of the Requirement document which lowers the threshold for inspection of the flight spoiler lug to 3,000 flight cycles.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.003.png)The original issue of this Airworthiness Directive became effective on 5 October 2000.\n\n![](image.004.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 2 April 2001\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 18 April 2001.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment did not broaden the AD’s aircraft applicability or add new types of obligations; it tightened the timing of an existing inspection requirement by lowering the inspection threshold to 3,000 flight cycles. In other words, the AD’s purpose remains the same (preventing uncommanded spoiler deployment due to lug fracture) but the inspection timing was made more conservative. The change is a calibration of enforcement intensity rather than an expansion of scope."},"complexity_factors":["Short, single-aircraft-type AD focused on a discrete hardware item (centre hinge actuator lug).","One external cross-reference: Transport Canada AD CF-2000-15 R1 (major substantive instructions delegated).","One manufacturer document referenced: Bombardier Alert Service Bulletin A601R-57-027 (Revision C noted; earlier revisions accepted for Part A).","Serial-number range applicability (7003–7340) restricts scope but is simple to apply.","Conditional terminating action (install redesigned spoiler parts P/N 600-10602-73 and -74) provides an alternative to repeated inspections.","Single substantive amendment: lowered inspection threshold to 3,000 flight cycles (clear change, not layered exceptions).","Minimal defined terms and no nested exceptions or multiple interlocking Parts.","Compliance section only updates effective date — no complex phase-ins or staggered obligations."],"plain_english_summary":"**What this AD does (mechanics)\n\n- Applies to Bombardier (Canadair) CL-600-2B19 Regional Jet aeroplanes, serial numbers 7003–7340 (\"Applicability\").\n- Requires operators to carry out inspections and follow-up actions exactly as set out in Transport Canada Airworthiness Directive CF-2000-15 R1 (\"Requirement\"). The Australian AD adopts that foreign AD by reference.\n- Allows a permanent fix (so you can stop the repeated inspections) if redesigned flight spoilers, part numbers 600-10602-73 and 600-10602-74, are installed (\"Note 2\").\n- Confirms that following earlier revisions of Bombardier Alert Service Bulletin A601R-57-027 (original, Revision A or B) already satisfies the AD's Part A. It also notes Revision C is referenced by the Transport Canada AD (\"Note 1\").\n- Changes the effective inspection timing by lowering the inspection threshold to 3,000 flight cycles (this is the substance of Amendment 1).\n\nWhy the regulator issued it (stated reason)\n\n- Transport Canada reported four incidents where a flight spoiler deployed unexpectedly because the actuator lug on a centre hinge fitting fractured; each incident generated a cockpit status message and crews landed safely (\"Background\").\n- The AD is intended to detect lug cracking early and require repair/replacement to prevent uncommanded spoiler deployment.\n\nWho is affected and who pays\n\n- Operators of CL-600-2B19 aircraft with serial numbers 7003–7340 must inspect and, if required, replace parts. Operators pay for inspections, labour, parts and aircraft downtime.\n- Bombardier is the likely supplier of the redesigned spoiler parts (P/N 600-10602-73 and -74), so operators who choose the terminating action will purchase parts and installation services.\n\nHow it changes operator behaviour and choices\n\n- Operators must inspect earlier and possibly more frequently because the inspection threshold was lowered to 3,000 flight cycles (Amendment 1).\n- Operators can either keep performing the mandated inspections at the intervals required by the referenced Transport Canada AD or install the redesigned spoiler parts to stop the inspection cycle (the terminating action).\n\nCompliance and implementation notes\n\n- The AD delegates technical instructions to the Transport Canada AD and Bombardier Alert Service Bulletin A601R-57-027 (Revision C is current; earlier revisions also satisfy part requirements) (\"Requirement\", \"Note 1\").\n- The AD sets a revised effective date of 17 May 2001 for the inspection timetable (\"Compliance\").\n\nAnalytical checklist (costs, incentives, trade-offs, risks)\n\n- Costs: inspections (labour, access panels, non-revenue hours), potential replacement parts and installation, recordkeeping. If many aircraft need parts, there may be lead-time and supply costs.\n- Incentives: operators weigh repeated inspection costs and operational disruption against a one-time capital cost to fit redesigned spoilers. The AD creates a clear commercial choice: inspect repeatedly or install the terminating fix.\n- Trade-offs and opportunity cost: choosing inspections delays capital expenditure but increases ongoing maintenance cost and flight-disruption risk; choosing replacement concentrates cost now and reduces future maintenance burden.\n- Implementation risk: reliance on a foreign AD and the manufacturer’s service bulletin means Australian compliance depends on availability of the referenced technical documents and parts; if parts are scarce, operators may face longer inspection programs and potential operational limits.\n- Compliance burden: technical inspections at specified flight-cycle thresholds and recordkeeping; operators must ensure maintenance providers follow the Transport Canada AD/ASB instructions exactly.\n\nKey references inside the AD: Applicability; Requirement (Transport Canada AD CF-2000-15 R1); Note 1 (ASB A601R-57-027 revision references); Note 2 (terminating action parts); Compliance (effective date)."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope — safety inspections for flight spoiler hinge fittings on specific Bombardier aircraft. The amendment narrows the inspection threshold (from higher flight cycles to 3,000 cycles) but does not expand the aircraft types covered, add new systems, or broaden beyond the original safety purpose. It is a technical refinement within the original safety intent."},"complexity_factors":["Short, single-purpose document (approximately 400 words)","Only 4 defined elements: applicability (specific aircraft model/serials), requirement (reference to external Canadian directive), compliance (external reference plus specific date), and background (safety rationale)","Heavy reliance on external documents — the actual inspection instructions are contained in Transport Canada AD CF-2000-15 R1 and Bombardier Alert Service Bulletin A601R-57-O27 Revision C, which are not reproduced here","Simple conditional logic: if aircraft is in serial number range, then inspection required; if redesigned parts installed, then inspection requirement terminates","Clear hierarchical structure with standard AD format (Applicability, Requirement, Compliance, Background)"],"plain_english_summary":"This AD revokes and replaces the earlier directive, accelerating safety action for Bombardier CL-600-2B19 regional jets (S/Ns 7003–7340, ~338 aircraft) by lowering the inspection threshold to 3,000 flight cycles. It responds to uncommanded spoiler deployments caused by a fractured hinge lug, requiring inspection and eventual replacement with redesigned fittings to prevent loss of control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cl-600-37-amdt-1-flight-spoiler-centre-hinge-fitting","history":"/api/acts/ad-cl-600-37-amdt-1-flight-spoiler-centre-hinge-fitting/history","analysis":"/api/acts/ad-cl-600-37-amdt-1-flight-spoiler-centre-hinge-fitting/analysis","conflicts":"/api/acts/ad-cl-600-37-amdt-1-flight-spoiler-centre-hinge-fitting/conflicts","importantCases":"/api/acts/ad-cl-600-37-amdt-1-flight-spoiler-centre-hinge-fitting/important-cases","documents":"/api/acts/ad-cl-600-37-amdt-1-flight-spoiler-centre-hinge-fitting/documents"}}