{"id":"F2006B04472","name":"AD/BELL 206/17 Amdt 1 - Transmission Mount Spindle - Inspection","slug":"ad-bell-206-17-amdt-1-transmission-mount-spindle-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44309,"registerId":"commonwealth-F2006B04472-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 206/17 Amdt 1 - Transmission Mount Spindle - Inspection","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 Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters\n\n \n\nAD/BELL 206/17\n\nAmdt 1\n\n\nTransmission Mount Spindle - Inspection 11/74\n\n \n\nApplicability: All model 206 and TH57A fitted with spindles P/Nos 206-031-554-1 or -3. Document:               Bell SB No. 206-01-74-3.\n\nNote: Agusta SB No. BT206-88 refers.\n\n \n\nCompliance: Within 25 hours time in service after 28 October 1974. Background: AD/Agusta 206/13A equivalent.\n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1899},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is Amendment 1 to an existing Airworthiness Directive. The scope remains tightly focused on the original safety issue — inspection of specific transmission mount spindles on Bell 206 helicopters. The amendment likely updates administrative references or clarifies compliance wording without expanding the class of affected aircraft or the nature of the required inspection."},"complexity_factors":["Extremely short instrument (under 200 words)","Single, unambiguous compliance requirement with fixed timeframe","Limited applicability to specific part numbers only","No conditional logic, exceptions, or legislative cross-references","References external technical documents (Service Bulletins) rather than complex statutory provisions"],"plain_english_summary":"**What this does:**\nThis is a mandatory safety order requiring inspection of the transmission mount spindle — a critical component that supports the helicopter's engine and rotor system — on specific Bell 206 helicopters.\n\n**Who it affects:**\nOwners and operators of:\n- Bell 206 model helicopters\n- TH57A helicopters  \n*Only if fitted with spindle part numbers 206-031-554-1 or 206-031-554-3*\n\n**What you must do:**\nHave the transmission mount spindle inspected according to Bell Service Bulletin 206-01-74-3 (or Agusta Service Bulletin BT206-88 for Agusta-built models) within 25 hours of flight time after 28 October 1974.\n\n**Why it matters:**\nCracks or failures in the transmission mount spindle could cause the rotor system to separate from the airframe, resulting in catastrophic loss of control. This directive ensures potentially defective parts are identified and replaced before they endanger flight safety."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-206-17-amdt-1-transmission-mount-spindle-inspection","history":"/api/acts/ad-bell-206-17-amdt-1-transmission-mount-spindle-inspection/history","analysis":"/api/acts/ad-bell-206-17-amdt-1-transmission-mount-spindle-inspection/analysis","conflicts":"/api/acts/ad-bell-206-17-amdt-1-transmission-mount-spindle-inspection/conflicts","importantCases":"/api/acts/ad-bell-206-17-amdt-1-transmission-mount-spindle-inspection/important-cases","documents":"/api/acts/ad-bell-206-17-amdt-1-transmission-mount-spindle-inspection/documents"}}