{"id":"F2006B04654","name":"AD/BELL 412/2 Amdt 1 - Retirement Lives - Fatigue Critical Components","slug":"ad-bell-412-2-amdt-1-retirement-lives-fatigue-critical-components","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44406,"registerId":"commonwealth-F2006B04654-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 412/2 Amdt 1 - Retirement Lives - Fatigue Critical Components","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)  Bell Helicopter Textron 412 Series Helicopters\n\n \n\nAD/BELL 412/2\n\nAmdt 1\n\n\nRetirement Lives - Fatigue Critical Components 11/87\n\n \n\nApplicability: All models.\n\n \n\nRequirement: All components listed in the Mandatory Airworthiness Limitations Schedule, Section 4-10-3 of the Bell Model 412 Maintenance Manual dated 15 January 1981 and incorporating Revision 17 dated 15 April 1986, shall be retired from service at or before the times quoted therein.\n\n \n\nEffective: Forthwith.\n\n \n\nBackground:  This Directive has been revised to reflect the amendment status of the Model 412 series Maintenance Manuals.\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":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1408},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment (Amdt 1) updates the directive to reflect the current amendment status of the Bell maintenance manuals, but does not alter the fundamental scope or purpose of requiring retirement of fatigue critical components."},"complexity_factors":["Single, straightforward requirement with no exceptions or conditions","Very short length (under 150 words)","No defined terms within the instrument itself","Relies entirely on external technical manual for specific component lists and life limits"],"plain_english_summary":"This directive sets mandatory replacement deadlines for high-risk helicopter parts to prevent mechanical failures.\n\n**What it does**\nIt requires operators of Bell 412 series helicopters to permanently remove from service (retire) specific \"fatigue critical components\" once they reach their usage limits. These limits are listed in Section 4-10-3 of the Bell 412 Maintenance Manual (specifically the version dated 15 January 1981 with Revision 17 from April 1986).\n\n**Who it affects**\nAnyone operating Bell 412 helicopters in Australia.\n\n**Why it matters**\nFatigue critical components are parts that could fail catastrophically due to metal fatigue (wear from repeated stress), potentially causing crashes. This rule ensures parts are replaced *before* they become unsafe, rather than after they fail."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-412-2-amdt-1-retirement-lives-fatigue-critical-components","history":"/api/acts/ad-bell-412-2-amdt-1-retirement-lives-fatigue-critical-components/history","analysis":"/api/acts/ad-bell-412-2-amdt-1-retirement-lives-fatigue-critical-components/analysis","conflicts":"/api/acts/ad-bell-412-2-amdt-1-retirement-lives-fatigue-critical-components/conflicts","importantCases":"/api/acts/ad-bell-412-2-amdt-1-retirement-lives-fatigue-critical-components/important-cases","documents":"/api/acts/ad-bell-412-2-amdt-1-retirement-lives-fatigue-critical-components/documents"}}