{"id":"F2006B04343","name":"AD/BELL 204/4 Amdt 1 - Tail Rotor Assembly Inspection","slug":"ad-bell-204-4-amdt-1-tail-rotor-assembly-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44158,"registerId":"commonwealth-F2006B04343-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 204/4 Amdt 1 - Tail Rotor Assembly Inspection","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \n![](image.002.png)  \nBell Helicopter Textron 204 Series Helicopters\n\nAIRWORTHINESS 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 revokes Airworthiness Directive (AD) AD/BELL 204/4 issues the following 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.\n\nAD/BELL 204/4\n\nAmdt 1\n\nTail Rotor Assembly Inspection 8/2000\n\nApplicability: Model 204B Series equipped with TR hub and TR Blade assembly P/N 204-011-701- 9 or 204-011-701-15.\n\nRequirement: Action in accordance with Bell SB 204B-1.\n\nNote: FAA AD 67-06-01 refers.\n\nCompliance: 1. Tail rotor blades to be tracked at intervals not exceeding 100 hours time in service after 15 May 1967.\n\n2. Tail Rotor hub and blade assembly are to be balanced at intervals not exceeding 300 hours time in service after 15 May 1967.\n\nThis Amendment becomes effective on 10 August 2000.\n\nBackground: This Directive was issued initially to ensure correct track and balance of the tail rotor assembly.\n\nAmendment 1 includes the country of manufacture AD for reference. 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":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Amendment 1 does not alter the core safety requirements: blade tracking every 100 hours and hub/blade balancing every 300 hours remain unchanged. The amendment adds a reference to the country-of-manufacture AD and notes the AD series was reintroduced after sixteen years (Background)."},"complexity_factors":["Technical maintenance requirements (blade tracking and hub/blade balancing) require qualified maintenance personnel and equipment.","Specific compliance intervals: tracking at 100 hours TIS and balancing at 300 hours TIS (Compliance section).","Direct reliance on an external document: 'Action in accordance with Bell SB 204B-1' (Requirement) — access to and interpretation of the service bulletin is necessary.","Narrow applicability: limited to Model 204B Series with TR Blade assembly P/N 204-011-701-9 or 204-011-701-15 (Applicability).","References other regulator material: Note cites FAA AD 67-06-01, creating cross-jurisdictional documentary links (Note).","Administrative actions: revocation of previous AD/BELL 204/4 and re-introduction of the AD series (Background) — procedural history relevant for operators tracking regulatory status.","Fixed effective and notification dates (Effective date, Gazette notification) that determine operator compliance timing."],"plain_english_summary":"This Airworthiness Directive requires Bell Model 204B helicopters fitted with the specified tail rotor parts to have tail rotor blades tracked every 100 hours and the tail rotor hub and blade assembly balanced every 300 hours, performed in accordance with Bell SB 204B-1. CASA states the directive exists to ensure correct track and balance of the tail rotor assembly; Amendment 1 adds a reference to the country-of-manufacture AD and reintroduces the AD series after sixteen years."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment makes no substantive changes to the original 1967 directive. It merely adds a reference to the US Federal Aviation Administration's equivalent directive for informational purposes and reissues the AD after a 16-year administrative gap in the AD series. The maintenance requirements, applicability, and compliance timeframes remain identical to the original."},"complexity_factors":["Very short document (under 300 words)","Only 2 defined part numbers in applicability section","Simple conditional structure: if helicopter has X parts, do Y maintenance","No nested exceptions or cross-references to other legislation beyond a single note referencing FAA directive","Clear, unambiguous compliance deadlines (100 hours / 300 hours time in service)","Single purpose: mandating specific maintenance intervals"],"plain_english_summary":"Owners/operators of Bell 204B helicopters with tail rotor hub/blade assemblies P/N 204-011-701-9 or -15 must track tail rotor blades every 100 flight hours and balance the hub/blade assembly every 300 hours. This mandatory CASA Airworthiness Directive restates the original 1967 requirements (now referencing FAA AD 67-06-01) and reissues the AD after a lapse—no new obligations are introduced."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-204-4-amdt-1-tail-rotor-assembly-inspection","history":"/api/acts/ad-bell-204-4-amdt-1-tail-rotor-assembly-inspection/history","analysis":"/api/acts/ad-bell-204-4-amdt-1-tail-rotor-assembly-inspection/analysis","conflicts":"/api/acts/ad-bell-204-4-amdt-1-tail-rotor-assembly-inspection/conflicts","importantCases":"/api/acts/ad-bell-204-4-amdt-1-tail-rotor-assembly-inspection/important-cases","documents":"/api/acts/ad-bell-204-4-amdt-1-tail-rotor-assembly-inspection/documents"}}