{"id":"F2006B11136","name":"AD/LEARJET/2 - Spoiler Actuator Attachment Bolts - Replacement","slug":"ad-learjet-2-spoiler-actuator-attachment-bolts-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56820,"registerId":"commonwealth-F2006B11136-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/LEARJET/2 - Spoiler Actuator Attachment Bolts - Replacement","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)  Gates Learjet 24 & 25 Series Aeroplanes\n\n \n\nAD/LEARJET/2 Spoiler Actuator Attachment Bolts - Replacement 6/73\n\nApplicability: All model 24 with S/Nos. 24-178 to 24-268 and model 25 with S/Nos. 25-020 to 25-\n\n114.\n\n \n\nDocument: Gates Learjet SB No. 24/25-237B. Compliance: As detailed in the requirement document.\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\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive focused on a specific mechanical component on specific aircraft serial numbers. It has not expanded beyond its original narrow technical purpose."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 2 defined applicability criteria (serial number ranges for two aircraft models)","Single compliance requirement referencing an external document","No nested conditions, exceptions, or cross-references to other legislation","No interpretative provisions or defined terms section","Straightforward imperative: replace specific bolts on specific aircraft"],"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). Think of it as a \"recall notice\" for aircraft, but legally binding.\n\n**What it requires:** Owners and operators of specific Gates Learjet 24 and 25 series aircraft must **replace the bolts that attach the spoiler actuators** (the mechanical parts that control the spoilers — those panels on the wings that help slow the plane down during landing).\n\n**Who it affects:** \n- **Learjet Model 24** aircraft with serial numbers 24-178 through 24-268\n- **Learjet Model 25** aircraft with serial numbers 25-020 through 25-114\n\n**Why it matters:** Faulty or worn spoiler actuator attachment bolts could cause the spoilers to fail or detach in flight. This would seriously compromise the aircraft's ability to slow down on landing, potentially causing runway overruns or loss of control. The directive references a specific **Service Bulletin (SB No. 24/25-237B)** from the manufacturer that details exactly how to do the replacement.\n\n**Compliance:** Aircraft operators must follow the replacement procedures exactly as specified in that manufacturer bulletin."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD text as provided sets a narrowly targeted replacement requirement for specified serial-numbered Learjet 24 and 25 airframes and refers to a specific service bulletin for the actions. There is no indication in the supplied text that the scope has been expanded or narrowed relative to the directive's plain mechanical purpose; the AD only identifies affected aircraft and delegates the technical work to SB No. 24/25-237B."},"complexity_factors":["Narrow, clearly defined applicability by serial number reduces scope complexity (Applicability).","Substantive technical requirements are delegated to an external service bulletin, so the AD text is short but relies on another document (Document / Compliance).","Absence of procedural detail (no timing, no cost, no alternative compliance text) means understanding full obligations requires consulting the referenced service bulletin.","No mention of exemptions, approvals, or enforcement details in the AD text increases reliance on external regulatory practice for interpretation."],"plain_english_summary":"### What this directive does\n\nThis Airworthiness Directive (AD) orders the replacement of the spoiler actuator attachment bolts on certain Gates Learjet 24 and 25 aeroplanes. It applies only to the aircraft listed by serial number: model 24 with S/Nos. 24-178 to 24-268, and model 25 with S/Nos. 25-020 to 25-114 (see \"Applicability\"). The AD refers operators to Gates Learjet Service Bulletin No. 24/25-237B for the technical instructions and timing (see \"Document\" and \"Compliance\").\n\n### Who it affects\n\n- Owners and operators of the specific Learjet 24 and 25 airframes listed under the Applicability section. The AD creates an obligation for those responsible for the affected aircraft to follow the required actions in the referenced service bulletin (see \"Compliance\").\n\n### How it works, mechanically\n\n- The AD itself identifies the affected fleet (Applicability) and points to a service bulletin for the required work (Document: Gates Learjet SB No. 24/25-237B).\n- The compliance obligation is stated as: \"As detailed in the requirement document.\" That means the AD delegates the specific procedures, parts, and compliance timing to the referenced service bulletin rather than listing them in the AD text.\n\n### Stated purpose and what the AD text does and does not say\n\n- The AD text does not include a description of the safety issue or technical findings; it only prescribes replacement of the spoiler actuator attachment bolts for the specified serial numbers by reference to the service bulletin (Document / Compliance).\n- The AD therefore functions as a mandatory direction to implement the actions detailed in SB No. 24/25-237B; the technical rationale and step-by-step instructions are contained in that external document, not in the AD text itself.\n\n### Practical implications, trade-offs and implementation notes (source-grounded)\n\n- Compliance burden: The AD requires work that will take time and resources, but the AD text does not quantify labour, parts cost, or downtime. Those details will be in the referenced service bulletin (see \"Document\" and \"Compliance\").\n- Who pays: The AD text does not specify who bears costs. The regulatory requirement creates an obligation on those responsible for the affected aircraft to carry out the required actions (see \"Applicability\" and \"Compliance\").\n- Decision authority and discretion: The AD provides no text about exemptions, alternative methods of compliance, or approvals; the AD text itself only points to the service bulletin for required actions. Any administrative discretion or approval process is not described in the AD excerpt provided.\n- Implementation risk and opportunity cost: Because the AD defers technical detail to an external service bulletin, operators must obtain and follow that document to comply. The AD text does not discuss scheduling flexibility, inspection intervals, or follow-up actions; these items will be determined by the service bulletin.\n\n(Referenced source lines: \"Applicability: All model 24 with S/Nos. 24-178 to 24-268 and model 25 with S/Nos. 25-020 to 25-114.\"; \"Document: Gates Learjet SB No. 24/25-237B. Compliance: As detailed in the requirement document.\")"}},"importantCases":[],"_links":{"self":"/api/acts/ad-learjet-2-spoiler-actuator-attachment-bolts-replacement","history":"/api/acts/ad-learjet-2-spoiler-actuator-attachment-bolts-replacement/history","analysis":"/api/acts/ad-learjet-2-spoiler-actuator-attachment-bolts-replacement/analysis","conflicts":"/api/acts/ad-learjet-2-spoiler-actuator-attachment-bolts-replacement/conflicts","importantCases":"/api/acts/ad-learjet-2-spoiler-actuator-attachment-bolts-replacement/important-cases","documents":"/api/acts/ad-learjet-2-spoiler-actuator-attachment-bolts-replacement/documents"}}