{"id":"F2006B04337","name":"AD/BELL 204/34 - Tail Rotor Hub","slug":"ad-bell-204-34-tail-rotor-hub","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44152,"registerId":"commonwealth-F2006B04337-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 204/34 Tail Rotor Hub 8/2000","sectionType":"part","heading":"AD/BELL 204/34 Tail Rotor Hub 8/2000","content":"# AD/BELL 204/34 Tail Rotor Hub 8/2000\n\nApplicability: Model 204B.\n\nRequirement: Remove from service tail rotor hub P/N 204-011-801-121 with any serial number IT0001 to and including IT0010.\n\nCompliance: Before further flight after the effective date of this directive.\n\nNote: FAA AD 89-20-12 refers.\n\nThis Airworthiness Directive becomes effective on 10 August 2000.\n\nBackground: This directive is issued to prevent failure of certain tail rotor hubs. It also follows the re-introduction of the AD Series after sixteen years.\n\n![](image.003.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 6 July 2000\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 12 July 2000.","sortOrder":1}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"N/A - This is a standalone safety directive with no legislative evolution to assess."},"complexity_factors":["Extremely short document (under 200 words)","Only 1 defined term (the part number)","Single, unambiguous requirement with no exceptions or conditions","No cross-references to other legislation (only a non-binding note about a US FAA directive)","Clear compliance deadline with no alternative methods or phased compliance","Plain language throughout with minimal aviation jargon"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a safety order issued by Australia's aviation regulator (CASA) requiring specific action to fix a dangerous problem with aircraft equipment.\n\n**What it does:**\n- **Orders the immediate removal** of a specific tail rotor hub part (part number 204-011-801-121, serial numbers IT0001 through IT0010) from Bell 204B helicopters.\n- **Why:** To prevent the tail rotor hub from failing, which could cause a crash.\n\n**Who it affects:**\n- Owners and operators of **Bell 204B model helicopters** that have this specific tail rotor hub installed.\n\n**What must happen:**\n- The faulty part must be removed **before the helicopter flies again** after 10 August 2000.\n\n**Context:**\n- This directive references a similar US safety order (FAA AD 89-20-12).\n- Notably, this marked the **return of the Airworthiness Directive system** in Australia after a 16-year pause."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive's scope is limited to removing tail rotor hubs P/N 204-011-801-121 with serial numbers IT0001–IT0010 from service (Applicability; Requirement). The Background states the purpose is to prevent hub failure and notes the AD Series re-introduction, but the text does not expand or narrow the technical or fleet scope beyond the listed part and serial numbers (Background)."},"complexity_factors":["Narrow, specific applicability (Model 204B) — reduces breadth of affected fleet (Applicability).","Single clear mandatory action: remove specified P/N and serial-numbered hubs from service — straightforward compliance step (Requirement).","Immediate timing: compliance required before further flight after effective date — operational disruption risk (Compliance; Effective date: 10 August 2000).","Administrative burden to identify affected serial numbers in maintenance records and on parts (Requirement).","Cost and logistics fall on operators/owners: removal and replacement or repair are operator-paid actions (Requirement; Compliance).","Regulatory authority delegated under subregulation 39.1(1) of CAR 1998 — shows source of decision-making power (opening paragraph).","Cross-reference to FAA AD 89-20-12 may affect sourcing of technical instructions or parts history checks (Note).","Background notes risk and procedural history (prevents failure; re-introduction of AD Series) but provides no additional compliance mechanisms (Background)."],"plain_english_summary":"This Airworthiness Directive requires operators of Model 204B helicopters to remove from service tail rotor hubs, part number 204-011-801-121, with serial numbers IT0001–IT0010 before the next flight. It is issued to prevent hub failure and cross-references FAA AD 89-20-12.\n\nOwners/operators must identify and replace the listed hubs immediately, bearing the cost and operational downtime; the directive was issued under subregulation 39.1(1) of CAR 1998 and became effective 10 August 2000."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-204-34-tail-rotor-hub","history":"/api/acts/ad-bell-204-34-tail-rotor-hub/history","analysis":"/api/acts/ad-bell-204-34-tail-rotor-hub/analysis","conflicts":"/api/acts/ad-bell-204-34-tail-rotor-hub/conflicts","importantCases":"/api/acts/ad-bell-204-34-tail-rotor-hub/important-cases","documents":"/api/acts/ad-bell-204-34-tail-rotor-hub/documents"}}