{"id":"F2006B04707","name":"AD/BELL 47/85 - Engine Mount Strut Rod Ends - Replacement","slug":"ad-bell-47-85-engine-mount-strut-rod-ends-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44471,"registerId":"commonwealth-F2006B04707-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 47/85 - Engine Mount Strut Rod Ends - Replacement","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\nAD/BELL 47/85 Engine Mount Strut Rod Ends - Replacement 3/81\n\nApplicability: All models 47 equipped with Soloy turbine conversion. Document:  Soloy Conversions Ltd. SB 03-660.\n\nCompliance: Within 100 hours time in service after 31 March 1981.\n\n \n\nBackground: Replacement of stainless steel rod ends is necessary to assure the continued airworthiness of engine mount struts.\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\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive defines its own scope within the text: it applies to all Bell 47 models equipped with the Soloy turbine conversion and requires replacement of the stainless-steel rod ends within 100 hours after 31 March 1981. There is no statement in the AD that narrows or expands that applicability beyond what is set out, so the scope as specified in the document stands unchanged."},"complexity_factors":["Narrow applicability: applies only to Bell 47 models fitted with the Soloy turbine conversion (Applicability).","Single required action: mandates replacement of rod ends rather than multiple or conditional measures (Background; Compliance).","Clear, short compliance window: one fixed deadline — within 100 hours time in service after 31 March 1981 (Compliance).","Reference to external technical document: relies on Soloy Conversions Ltd. SB 03-660 for the procedures, creating dependence on that bulletin for implementation (Document).","Limited technical detail in the AD itself: the AD does not describe replacement steps or parts within the text, increasing reliance on the service bulletin (Document).","Operational impact concentrated on a small group: only operators of the affected conversion are impacted, simplifying regulatory reach but concentrating costs (Applicability; Compliance)."],"plain_english_summary":"CASA requires replacement of the rod-end bearings on engine mount struts of Bell 47 helicopters fitted with the Soloy turbine conversion, done per Soloy Conversions Ltd. SB 03-660 within 100 hours TIS after 31 March 1981. Owners/operators and maintenance providers must comply; the measure preserves engine-mount airworthiness but imposes parts, labour and downtime costs and ties the technical method of compliance to the Soloy service bulletin."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive issued in 1981 (as indicated by the '3/81' suffix). It addresses a specific mechanical defect in a specific aircraft modification. There is no evidence of scope creep; the directive remains precisely targeted at the identified safety issue."},"complexity_factors":["Extremely short document (under 150 words)","Only 4 defined elements: applicability, document reference, compliance deadline, and background","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Single, unambiguous action required with clear deadline","No conditional logic, exceptions, or nested provisions","Technical content limited to specific aircraft model and part number"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations.\n\n**What it requires:** Owners and operators of **Bell 47 helicopters** (all variants) that have been fitted with a **Soloy turbine engine conversion** must replace the **stainless steel rod ends** on their engine mount struts. These rod ends are critical connection points that hold the engine in place.\n\n**When to do it:** The replacement must be completed within **100 hours of flight time** after 31 March 1981.\n\n**Why it matters:** The stainless steel rod ends were found to be unsafe and could fail, potentially causing the engine to detach from the helicopter in flight. This directive forces operators to swap them for safer components to prevent catastrophic accidents.\n\n**Who needs to act:** Anyone operating a Bell 47 helicopter with a Soloy turbine conversion in Australia."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-47-85-engine-mount-strut-rod-ends-replacement","history":"/api/acts/ad-bell-47-85-engine-mount-strut-rod-ends-replacement/history","analysis":"/api/acts/ad-bell-47-85-engine-mount-strut-rod-ends-replacement/analysis","conflicts":"/api/acts/ad-bell-47-85-engine-mount-strut-rod-ends-replacement/conflicts","importantCases":"/api/acts/ad-bell-47-85-engine-mount-strut-rod-ends-replacement/important-cases","documents":"/api/acts/ad-bell-47-85-engine-mount-strut-rod-ends-replacement/documents"}}