{"id":"F2006B04509","name":"AD/BELL 206/54 - Tail Rotor Gearbox Assembly - Inspection","slug":"ad-bell-206-54-tail-rotor-gearbox-assembly-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114211,"registerId":"commonwealth-F2006B04509-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 206/54 - Tail Rotor Gearbox Assembly - 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 206/54 Tail Rotor Gearbox Assembly - Inspection 10/73\n\nApplicability: Model 206 Series S/No. 498 to 1055, 1057 to 1077, 1079, 1080, 1082, 1083, 1085 to\n\n1087, 1090, 1091, 1097, 1100 and 1101 fitted with tail rotor gearbox P/N\n\n206.040.400-5 and -11.\n\n \n\nDocument: Bell SB No. 206-04-73-1.\n\n \n\nCompliance: Within 100 hours time in service after 31 October 1973.\n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1323},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standalone directive establishing initial inspection requirements for specific helicopter gearboxes. It has not expanded beyond its original purpose of addressing a specific airworthiness safety concern."},"complexity_factors":["Specific applicability limited to 14 discrete serial number ranges and individual aircraft","Single, clear compliance requirement based on accumulated flight hours","Reference to one external technical document (Bell Service Bulletin) for inspection procedures","No conditional exceptions, nested provisions, or cross-references to other legislation"],"plain_english_summary":"**What this is:** An Airworthiness Directive (AD) — a mandatory safety order issued by the Civil Aviation Safety Authority (CASA) requiring specific helicopter owners to conduct a mechanical inspection.\n\n**What it requires:** Owners must inspect the **tail rotor gearbox assembly** on affected Bell 206 helicopters. The inspection must follow the technical procedure outlined in Bell Service Bulletin No. 206-04-73-1.\n\n**Who it affects:** Operators of Bell 206 helicopters with specific serial numbers (ranging from S/No. 498 to 1101, with several gaps) that are fitted with tail rotor gearbox part numbers 206.040.400-5 or 206.040.400-11.\n\n**When:** The inspection must be completed within **100 hours of flight time** after 31 October 1973.\n\n**Why it matters:** The tail rotor controls the helicopter's direction and stability. This directive addresses potential safety defects in the gearbox that could lead to loss of control if not detected."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-206-54-tail-rotor-gearbox-assembly-inspection","history":"/api/acts/ad-bell-206-54-tail-rotor-gearbox-assembly-inspection/history","analysis":"/api/acts/ad-bell-206-54-tail-rotor-gearbox-assembly-inspection/analysis","conflicts":"/api/acts/ad-bell-206-54-tail-rotor-gearbox-assembly-inspection/conflicts","importantCases":"/api/acts/ad-bell-206-54-tail-rotor-gearbox-assembly-inspection/important-cases","documents":"/api/acts/ad-bell-206-54-tail-rotor-gearbox-assembly-inspection/documents"}}