{"id":"F2006B04496","name":"AD/BELL 206/40 - Tail Rotor Control Tube Tunnel - Modification","slug":"ad-bell-206-40-tail-rotor-control-tube-tunnel-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114190,"registerId":"commonwealth-F2006B04496-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 206/40 - Tail Rotor Control Tube Tunnel - Modification","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 206/40 Tail Rotor Control Tube Tunnel - Modification 1/73\n\nApplicability: All models. Document: Bell SL No. 206-202.\n\nCompliance: Within 100 hours time in service after 31 January 1973.\n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1310},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This maintains its original narrow scope: mandating a specific mechanical modification for a defined aircraft type based on manufacturer service instructions."},"complexity_factors":["Single, unambiguous requirement","No defined terms section","No cross-references to other legislative provisions","Clear applicability (all models of specific helicopter types)","Simple compliance deadline (time-in-service after fixed date)"],"plain_english_summary":"**What this does:** This directive requires owners and operators of Bell 206 series helicopters (including models made by Bell Helicopter Textron Canada and Agusta Bell) to modify the tail rotor control tube tunnel.\n\n**Who it affects:** Anyone operating these specific helicopter models.\n\n**What must be done:** The modification must be carried out according to Bell Service Letter No. 206-202. This is a manufacturer's instruction that changes how the tail rotor control tube is housed or protected.\n\n**When:** The work must be completed within 100 hours of flight time after 31 January 1973.\n\n**Why it matters:** This is a safety requirement to ensure the tail rotor (which controls the helicopter's direction) operates properly. Problems with the control tube tunnel could affect flight safety."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-206-40-tail-rotor-control-tube-tunnel-modification","history":"/api/acts/ad-bell-206-40-tail-rotor-control-tube-tunnel-modification/history","analysis":"/api/acts/ad-bell-206-40-tail-rotor-control-tube-tunnel-modification/analysis","conflicts":"/api/acts/ad-bell-206-40-tail-rotor-control-tube-tunnel-modification/conflicts","importantCases":"/api/acts/ad-bell-206-40-tail-rotor-control-tube-tunnel-modification/important-cases","documents":"/api/acts/ad-bell-206-40-tail-rotor-control-tube-tunnel-modification/documents"}}