{"id":"F2006B04677","name":"AD/BELL 412/43 - Tail Rotor Counterweight Bellcrank Retention Nut","slug":"ad-bell-412-43-tail-rotor-counterweight-bellcrank-retention-nut","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44429,"registerId":"commonwealth-F2006B04677-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS 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 issues the following Airworthiness Directive (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.","sortOrder":0},{"sectionNumber":"AD/BELL 412/43 Tail Rotor Counterweight ","sectionType":"part","heading":"AD/BELL 412/43 Tail Rotor Counterweight Bellcrank Retention Nut","content":"# AD/BELL 412/43 Tail Rotor Counterweight Bellcrank Retention Nut\n\nApplicability: Model 412, 412EP, and 412CF helicopters. Requirement: 1. For Model 412 or 412EP helicopters:","sortOrder":1},{"sectionNumber":"9/2001","sectionType":"part","heading":"9/2001","content":"#   \n9/2001\n\nDM","sortOrder":2}],"analysis":{"kimi_summary":{"content_quality":"rejected","complexity_score":3,"rejection_reason":"The provided content is clearly incomplete — it cuts off mid-document with fragmentary text (\"9/2001 9/2001\", \"DM\") and missing sections (the actual requirements and compliance instructions are referenced but not included). The formatting is also corrupted with duplicate headers and broken image references. This appears to be a stub, navigation page, or corrupted extract rather than complete legislation suitable for analysis.","scope_assessment":{"changed":false,"description":"This appears to be a standard, narrow Airworthiness Directive targeting a specific safety issue with a specific aircraft component. No evidence of scope creep beyond original aviation safety purpose."},"complexity_factors":["Short, single-purpose instrument focused on one specific mechanical component","Minimal defined terms (relies on standard aviation terminology)","Simple conditional structure: applicability → requirement → compliance","No nested exceptions or complex cross-referencing to other legislation","Truncated/incomplete content in the provided extract limits assessment of full complexity"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by the Civil Aviation Safety Authority (CASA) that requires specific maintenance action on certain Bell helicopters.\n\n**What it does:**\n- Requires owners and operators of **Bell 412, 412EP, and 412CF helicopters** to take corrective action on the **tail rotor counterweight bellcrank retention nut** — a component in the helicopter's tail rotor system.\n- The exact nature of the required action (inspection, replacement, or modification) would be detailed in the \"requirement section\" and \"compliance section\" referenced in the text, though these specific instructions appear truncated or incomplete in this extract.\n\n**Who it affects:**\n- Operators and maintainers of the specified Bell helicopter models\n- CASA-authorized maintenance organizations servicing these aircraft\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety instructions. Failure to comply can render an aircraft unairworthy (illegal to fly). This particular AD addresses a potential unsafe condition in the tail rotor system — a critical flight control component. Problems with tail rotor components can lead to loss of directional control and catastrophic accidents."},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"Based solely on the supplied excerpt, the AD applies to Bell Model 412, 412EP and 412CF helicopters and requires actions the CASA delegate considers necessary under CAR 1998 subreg 39.1(1). The excerpt does not provide prior or original-intent text to compare against, so there is no evidence in the supplied material that the scope has changed from any original intent."},"complexity_factors":["Cross-reference to CAR 1998 subregulation 39.1(1) which delegates regulatory power to issue mandatory corrective actions","Applicability across three helicopter models (412, 412EP, 412CF) with potentially different serials/configurations","Requirement and compliance details are split into separate sections; exact remedial actions and timing are not present in the supplied excerpt","Regulatory discretion concentrated in a CASA delegate to determine necessary corrective action","Practical compliance complexity (potential inspections, parts, labour, and grounding) depends on omitted technical instructions or referenced service documents"],"plain_english_summary":"This Airworthiness Directive, issued under CAR 1998 by a CASA delegate, mandates corrective action to address an identified unsafe condition on Bell Model 412, 412EP and 412CF helicopters. It requires affected owners/operators to carry out the specified work at the times set out in the AD, with compliance costs borne by them.\n\nThe excerpt omits the specific remedial steps and compliance deadlines; operators must obtain the full AD and any referenced service information to determine exact actions, timing, parts and downtime."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-412-43-tail-rotor-counterweight-bellcrank-retention-nut","history":"/api/acts/ad-bell-412-43-tail-rotor-counterweight-bellcrank-retention-nut/history","analysis":"/api/acts/ad-bell-412-43-tail-rotor-counterweight-bellcrank-retention-nut/analysis","conflicts":"/api/acts/ad-bell-412-43-tail-rotor-counterweight-bellcrank-retention-nut/conflicts","importantCases":"/api/acts/ad-bell-412-43-tail-rotor-counterweight-bellcrank-retention-nut/important-cases","documents":"/api/acts/ad-bell-412-43-tail-rotor-counterweight-bellcrank-retention-nut/documents"}}