{"id":"F2006B04694","name":"AD/BELL 47/66 Amdt 4 - Stabilizer Bar Tubes and Assembly","slug":"ad-bell-47-66-amdt-4-stabilizer-bar-tubes-and-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44454,"registerId":"commonwealth-F2006B04694-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 47/66 Amdt 4 - Stabilizer Bar Tubes and Assembly","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 47 (All Variants) Series Helicopters\n\n \n\n# AD/BELL 47/66\n\nAmdt 4\n\nApplicability: All models.\n\n# Stabilizer Bar Tubes and Assembly 10/86\n\n \n\nDocument: Bell SB No. 47-(04-2)-73-1, Rev. A. Kawasaki-Bell S.B. KSB-Bell 338. Compliance:              As per Requirement Document.\n\nNote: This inspection may be accomplished by the pilot-in-command, in which case the precise A.D. reference shall be entered in a certification made on the maintenance release coincident with that for the daily inspection. This inspection may also be performed and certified by any Licensed Aircraft Maintenance Engineer.\n\n \n\nBackground:  To detect cracked stabilizer bar tubes and/or tie rods that are in tension. This Directive has been amended to include Kawasaki-Bell Helicopters.\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\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The Directive was amended to include Kawasaki‑Bell helicopters (Background statement). Mechanically, applicability was broadened to cover additional manufacturer variations; other requirements remain to be read and followed in the cited service bulletin (compliance per Requirement Document)."},"complexity_factors":["Reference to an external Requirement Document (Bell SB and Kawasaki‑Bell SB) for inspection procedures and compliance details — requires operators to obtain and follow another document.","Permits inspection and certification by the pilot‑in‑command as an alternative to a Licensed Aircraft Maintenance Engineer — adds a compliance/recording step (AD reference entry on the maintenance release).","Applicability to \"All models\" increases the population of affected aircraft and requires fleet managers to track applicability across variants.","Amendment to explicitly include Kawasaki‑Bell helicopters expands scope from the prior text and requires operators to reassess covered airframes.","Lack of explicit inspection interval or remedial action in the AD text itself — timing and corrective measures are defined in the Requirement Document, creating dependence on that external source."],"plain_english_summary":"This airworthiness directive requires inspections of the stabilizer bar tubes and tie rods on all Bell 47 series helicopters to detect cracks, following the procedures in the cited Bell/Kawasaki-Bell service bulletins. It applies to all models and may be carried out and certified either by the pilot‑in‑command (with the AD reference entered on the maintenance release) or by a licensed aircraft maintenance engineer. It matters because it creates a mandatory inspection and record‑keeping obligation for operators and maintainers."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":true,"description":"The original AD (issued 10/86) applied only to Bell Textron-manufactured helicopters. Amendment 4 expanded the scope to include Kawasaki-Bell helicopters, which are licensed-built variants of the same design. This is a modest expansion to cover equivalent aircraft from a different manufacturer, rather than a fundamental change in the AD's purpose."},"complexity_factors":["Very short document (approximately 200 words)","Only 1 defined term implicitly referenced (the Service Bulletin)","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Simple conditional logic: inspect as per the referenced document, with two alternative methods of compliance (pilot or engineer)","Single amendment purpose clearly stated (adding Kawasaki-Bell coverage)","No nested exceptions or complex procedural requirements"],"plain_english_summary":"This CASA Airworthiness Directive mandates regular inspections of stabilizer bar tubes and tie rods on all Bell 47 series helicopters (including Kawasaki‑Bell versions) to detect cracks that could cause loss of control. It applies to every operator in Australia — private, commercial, and training.\n\nCompliance must follow Bell Service Bulletin 47-(04-2)-73-1 Rev A (or Kawasaki‑Bell KSB-Bell 338) and may be done by the pilot‑in‑command (with maintenance release notation) or a Licensed Aircraft Maintenance Engineer."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-47-66-amdt-4-stabilizer-bar-tubes-and-assembly","history":"/api/acts/ad-bell-47-66-amdt-4-stabilizer-bar-tubes-and-assembly/history","analysis":"/api/acts/ad-bell-47-66-amdt-4-stabilizer-bar-tubes-and-assembly/analysis","conflicts":"/api/acts/ad-bell-47-66-amdt-4-stabilizer-bar-tubes-and-assembly/conflicts","importantCases":"/api/acts/ad-bell-47-66-amdt-4-stabilizer-bar-tubes-and-assembly/important-cases","documents":"/api/acts/ad-bell-47-66-amdt-4-stabilizer-bar-tubes-and-assembly/documents"}}