{"id":"F2006B04481","name":"AD/BELL 206/25 - Tail Rotor Balance Check and Tail Rotor Gearbox Casing and Mounting Inspection","slug":"ad-bell-206-25-tail-rotor-balance-check-and-tail-rotor-gearbox-casing-and-mounting-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44318,"registerId":"commonwealth-F2006B04481-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 206/25 - Tail Rotor Balance Check and Tail Rotor Gearbox Casing and Mounting 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 206/25 Tail Rotor Balance Check and Tail Rotor\n\nGearbox Casing and Mounting Inspection\n\n\n7/70\n\n \n\nApplicability: All model 206A and AB-206A with S/Nos. referenced in requirement documents. Document:               Bell SB No. 206A-15, or Agusta SB No. BT206-38.\n\nCompliance: Within 100 hours time in service after 31 July 1970. Background: AD/Agusta 206/17 equivalent.\n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2042},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This airworthiness directive maintains its original narrow technical scope, addressing specific safety concerns regarding tail rotor balance and gearbox mounting integrity on identified Bell helicopter models."},"complexity_factors":["Incorporates technical procedures by reference to external service bulletins (Bell SB 206A-15, Agusta SB BT206-38)","Single operative requirement with no exceptions or conditional clauses","Narrow applicability limited to specific aircraft models and serial numbers","No interpretation section or defined terms"],"plain_english_summary":"**What this does**\n\nThis directive orders mandatory safety checks for specific Bell helicopters. If you own or operate a **Model 206A or AB-206A** helicopter (with serial numbers listed in Bell Service Bulletin 206A-15 or Agusta Service Bulletin BT206-38), you must have a qualified mechanic:\n\n*   **Check the balance** of the tail rotor (the smaller rotor that stops the helicopter from spinning uncontrollably); and\n*   **Inspect** the tail rotor gearbox casing and its mounting to the aircraft structure.\n\n**Who it affects**\n\nOwners and operators of the specific Bell and Agusta-Bell helicopter models listed above.\n\n**Why it matters**\n\nThe tail rotor is essential for controlling the helicopter's direction. If the rotor is unbalanced or the gearbox mounting is cracked or loose, the tail rotor could fail in flight, causing the helicopter to spin and potentially crash.\n\n**Compliance**\n\nThe check must be completed within 100 hours of flight time after 31 July 1970."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-206-25-tail-rotor-balance-check-and-tail-rotor-gearbox-casing-and-mounting-inspection","history":"/api/acts/ad-bell-206-25-tail-rotor-balance-check-and-tail-rotor-gearbox-casing-and-mounting-inspection/history","analysis":"/api/acts/ad-bell-206-25-tail-rotor-balance-check-and-tail-rotor-gearbox-casing-and-mounting-inspection/analysis","conflicts":"/api/acts/ad-bell-206-25-tail-rotor-balance-check-and-tail-rotor-gearbox-casing-and-mounting-inspection/conflicts","importantCases":"/api/acts/ad-bell-206-25-tail-rotor-balance-check-and-tail-rotor-gearbox-casing-and-mounting-inspection/important-cases","documents":"/api/acts/ad-bell-206-25-tail-rotor-balance-check-and-tail-rotor-gearbox-casing-and-mounting-inspection/documents"}}