{"id":"F2006B11145","name":"AD/LEARJET/28 - Automatic Flight Control Systems - Inspection and Modification","slug":"ad-learjet-28-automatic-flight-control-systems-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56832,"registerId":"commonwealth-F2006B11145-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/LEARJET/28 - Automatic Flight Control Systems - Inspection and 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)  Gates Learjet 24 & 25 Series Aeroplanes\n\n \n\n# AD/LEARJET/28  Automatic Flight Control Systems - Inspection and Modification\n\nApplicability: All models 25, 25A with S/Nos. 25-003 thru 25-066 except 25-061.\n\n \n\nAll models 25B, 25C with S/Nos. 25-061, 25-067 thru 25-205.\n\n# 4/83\n\n \n\nRequirement: 1. Modify the flight control systems in accordance with the following modification kits:\n\n \n\nMODEL MODIFICATION KITS\n\n \n\n25B and 25C AMK 81-9, *AMK 81-8 and AMK 80-13 Change 3.\n\n \n\n25 and 25A AMK 81-10 Change 1, *AMK 81-8 and AMK 80-13 Change 3.\n\n \n\n* Kit AMK 81-8 does not apply unless Kit AAK 76-4 has been installed.\n\n \n\n2. Inspect the stall warning accelerometer in accordance with Gates Learjet Service Bulletin 23, 24, 25-301B.\n\n \n\nNote. FAA AD 82-01-04 Amendment 39-4296 refers.\n\n \n\nCompliance: On or before 30 April 1984.\n\n \n\nBackground:  This action is necessary to reduce the hazard created by a possible malfunction which if not detected could result in a hazardous flight attitude.\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":3,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive focused on a specific technical issue with specific aircraft models. It has not expanded beyond its original purpose of mandating inspection and modification of automatic flight control systems."},"complexity_factors":["Short, single-purpose directive with only 2 main requirements","Limited cross-referencing: references one FAA AD and one manufacturer service bulletin","Moderate conditional logic: applicability depends on specific serial number ranges and model variants","One nested condition: Kit AMK 81-8 applicability depends on prior installation of Kit AAK 76-4","No defined terms section — uses standard aviation terminology","Approximately 200 words total"],"plain_english_summary":"This CASA Airworthiness Directive mandates owners/operators of specified Gates Learjet 25 series (25–003 to 25–066 except 25‑061; and 25‑061, 25‑067 to 25‑205) to modify their automatic flight control systems with manufacturer kits and inspect the stall‑warning accelerometer per the service bulletin. It prevents uncommanded dangerous flight attitudes. Work was required by 30 April 1984; one kit (AMK 81‑8) applies only if AAK 76‑4 is already installed."},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"The text states applicability and requirements for specified models and serial numbers and includes no indication it alters or narrows a prior scope; it sets mandatory modification and inspection obligations for the listed aircraft as presented."},"complexity_factors":["Applicability defined by multiple model types and precise serial number ranges (several inclusive/exclusive ranges).","Multiple specific modification kits required (AMK 81-9, AMK 81-10 Change 1, AMK 81-8, AMK 80-13 Change 3) with a conditional dependency: AMK 81-8 applies only if AAK 76-4 is installed.","Separate inspection requirement referencing Gates Learjet Service Bulletin 23,24,25-301B for the stall warning accelerometer.","Compliance deadline (On or before 30 April 1984) creates a firm scheduling constraint for operators.","Cross-reference to FAA AD 82-01-04 (Amendment 39-4296) introduces reliance on external authority for context.","Technical work likely requires specialised maintenance, parts, and certification of modification/inspection actions by operators or approved maintenance organisations.","The directive specifies actions but leaves implementation details (who performs work, exact certification paperwork) to operators/maintenance organisations, creating administrative and operational discretion."],"plain_english_summary":"This airworthiness directive requires specified Gates Learjet 24/25-series aeroplanes (listed by model and serial number) to have their automatic flight control systems modified with named modification kits and to have the stall‑warning accelerometer inspected per a Gates Learjet service bulletin. The directive, stated as necessary to reduce the hazard from a possible malfunction, was issued by the Civil Aviation safety authority and must be complied with by 30 April 1984. Aircraft owners/operators must arrange and pay for the work."}},"importantCases":[],"_links":{"self":"/api/acts/ad-learjet-28-automatic-flight-control-systems-inspection-and-modification","history":"/api/acts/ad-learjet-28-automatic-flight-control-systems-inspection-and-modification/history","analysis":"/api/acts/ad-learjet-28-automatic-flight-control-systems-inspection-and-modification/analysis","conflicts":"/api/acts/ad-learjet-28-automatic-flight-control-systems-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-learjet-28-automatic-flight-control-systems-inspection-and-modification/important-cases","documents":"/api/acts/ad-learjet-28-automatic-flight-control-systems-inspection-and-modification/documents"}}