{"id":"F2006B03661","name":"AD/BEECH 1900/42 - Ventilation Blower Assemblies","slug":"ad-beech-1900-42-ventilation-blower-assemblies","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43251,"registerId":"commonwealth-F2006B03661-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)  \n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 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\n![](image.001.png)  \n\nBeechcraft 1900 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/BEECH 1900/42 Ventilation Blower Asse","sectionType":"part","heading":"AD/BEECH 1900/42 Ventilation Blower Assemblies 3/2004","content":"# AD/BEECH 1900/42 Ventilation Blower Assemblies 3/2004\n\nApplicability: Beech 1900 model aeroplanes, as listed below.","sortOrder":1},{"sectionNumber":"Model","sectionType":"part","heading":"Model","content":"## Model\n\n1900\n\n1900C\n\n1900 (C-12J)\n\n1900D","sortOrder":2},{"sectionNumber":"Serial Number","sectionType":"part","heading":"Serial Number","content":"##   \nSerial Number\n\nUA-3\n\nUB-1 through UB-74 and UC-1 through UC-174 UD-1 through UD-6\n\nUE-1 through UE-427","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":false,"description":"The supplied text shows the AD applies to listed Beech 1900 models and serial numbers and requires corrective action under subregulation 39.1(1) of CASR 1998. The excerpt contains no information indicating a change from the original scope or intent."},"complexity_factors":["Delegated regulatory power: issued under subregulation 39.1(1) of CASR 1998 (creates administrative discretion and legal force).","Reference-dependence: the AD points to a separate 'requirement section' and 'compliance section' for the operative measures and timing (those operative details are not included in the supplied excerpt).","Narrow, serial-numbered applicability: specific models and a detailed list of serial numbers (UA-3; UB-1–UB-74; UC-1–UC-174; UD-1–UD-6; UE-1–UE-427) increases administrative and compliance checking for operators.","Multiple model variants: several closely related model designations (1900, 1900C, 1900 C-12J, 1900D) require cross-referencing fleet records to determine applicability.","Compliance burden allocation: the AD structure makes owners/operators responsible for implementing corrective actions 'in accordance with the instructions' and by the times in the compliance section (imposes operational and likely financial obligations on those parties).","Implementation uncertainty in excerpt: absence of the specific corrective steps and deadlines in the provided text means stakeholders must consult the full AD to determine precise actions, parts, inspections, or engineering instructions."],"plain_english_summary":"This Airworthiness Directive, issued under subregulation 39.1(1) of CASR 1998, requires corrective action for ventilation blower assemblies on specified Beech 1900 series aeroplanes. It applies to the models and serial numbers listed in the applicability section and must be done in accordance with the AD’s requirement and compliance instructions. The CASA delegate issues the AD; owners/operators of the affected aircraft are required to carry out the specified corrective work to address the unsafe condition identified."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This appears to be the original scope of the AD as issued. Airworthiness Directives are typically narrow, targeted instruments addressing specific unsafe conditions in specific aircraft types. There is no indication this has expanded beyond its original purpose of addressing ventilation blower assembly issues in Beech 1900 aircraft."},"complexity_factors":["Short, single-purpose instrument focused on one aircraft type and one system","Limited conditional logic — applicability determined by simple model/serial number lookup","No nested definitions or extensive cross-referencing to other legislation","Standardised AD format with predictable structure (Applicability/Requirement/Compliance)","Technical aviation terminology used but in standard regulatory context","Serial number ranges create some parsing complexity but are straightforward"],"plain_english_summary":"This CASA Airworthiness Directive (AD 3/2004) mandates safety action on ventilation blower assemblies for specific Beechcraft 1900 series aeroplanes (including 1900, 1900C, C‑12J, and certain 1900D serials).  \n\nIt affects owners, operators, maintenance organisations and pilots: compliance is legally required because CASA identified an unsafe condition that must be corrected before the aircraft may be lawfully flown."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-1900-42-ventilation-blower-assemblies","history":"/api/acts/ad-beech-1900-42-ventilation-blower-assemblies/history","analysis":"/api/acts/ad-beech-1900-42-ventilation-blower-assemblies/analysis","conflicts":"/api/acts/ad-beech-1900-42-ventilation-blower-assemblies/conflicts","importantCases":"/api/acts/ad-beech-1900-42-ventilation-blower-assemblies/important-cases","documents":"/api/acts/ad-beech-1900-42-ventilation-blower-assemblies/documents"}}