{"id":"F2006B11089","name":"AD/LEARJET 35/11 - Elevator Control System - Modification","slug":"ad-learjet-35-11-elevator-control-system-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56749,"registerId":"commonwealth-F2006B11089-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/LEARJET 35/11 - Elevator Control System - 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 35 and 36 Series Aeroplanes\n\n \n\nAD/LEARJET 35/11 Elevator Control System - Modification 1/79\n\nApplicability: All model 35 with S/Nos. 35-002 to 35-041 and all model 36 with S/Nos. 36-002 to 36-016, unless modified in accordance with Kit Nos. AMK 75-10 or AMK 75-10A.\n\n \n\nRequirement: To provide for increased reliability of the elevator control system: Modify the aeroplane by installing Kit No. AMK 75-10A.\n\nCompliance: Within 300 hours time in service after 31 January 1979.\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":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The instrument is a targeted airworthiness directive limited to specified Learjet 35 and 36 serial numbers and prescribes a single retrofit action unless the aircraft already has the listed kit. The text contains no indication that the scope was altered from its original stated purpose (to provide increased elevator control system reliability); it sets a clear applicability rule, an explicit required action, and a compliance deadline, with an exclusion for already-modified aircraft. (Applicability; Requirement; Compliance)"},"complexity_factors":["Narrow, specific applicability by model and serial-number ranges (Applicability)","Single required technical action identified (install Kit No. AMK 75-10A) (Requirement)","Explicit compliance deadline measured in hours time-in-service from a fixed date (Compliance)","Simple exemption clause for aircraft already modified by specified kits (Applicability)","Lack of procedural detail in the text about installation steps, approval or enforcement increases practical implementation steps outside the instrument (Requirement; Compliance)"],"plain_english_summary":"Mandates a retrofit for specific Gates Learjet 35 and 36 airframes (listed serial numbers) to install Kit No. AMK 75‑10A—unless that kit is already fitted—to improve elevator‑control reliability. The installation must be completed within 300 hours’ time‑in‑service after 31 January 1979. Affected owners/operators are legally responsible for sourcing the kit, paying labour and downtime, and scheduling the modification within the compliance window."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-purpose airworthiness directive from 1979. It has not expanded beyond its original scope — it addresses one specific safety modification for specific aircraft serial numbers. The document represents the complete directive with no evidence of scope creep."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 defined applicability criteria (serial number ranges for two models)","Single, unambiguous requirement (install specific kit)","Simple compliance deadline (300 hours time in service after fixed date)","One exemption clause (already modified aircraft)","No cross-references to other legislation or regulations","No conditional logic or nested exceptions"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nOrders owners/operators of certain Gates Learjet 35 and 36 series aircraft to modify the elevator control system (the part of the plane that controls up/down movement). The modification involves installing a specific kit (AMK 75-10A) to make the system more reliable.\n\n**Who it affects:**\n- **Model 35 aircraft** with serial numbers 35-002 through 35-041\n- **Model 36 aircraft** with serial numbers 36-002 through 36-016\n- **Unless** the aircraft was already modified using Kit AMK 75-10 or AMK 75-10A (in which case, you're already compliant)\n\n**Why it matters:**\nElevator control system failures can cause loss of aircraft control. This directive addresses a known reliability issue before it causes accidents. Compliance is mandatory — operators must complete the modification within 300 flight hours after 31 January 1979.\n\n**Key deadline:**\nThe work had to be done within 300 hours of flight time after 31 January 1979 (this is a historical directive from 1979)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-learjet-35-11-elevator-control-system-modification","history":"/api/acts/ad-learjet-35-11-elevator-control-system-modification/history","analysis":"/api/acts/ad-learjet-35-11-elevator-control-system-modification/analysis","conflicts":"/api/acts/ad-learjet-35-11-elevator-control-system-modification/conflicts","importantCases":"/api/acts/ad-learjet-35-11-elevator-control-system-modification/important-cases","documents":"/api/acts/ad-learjet-35-11-elevator-control-system-modification/documents"}}