{"id":"F2006B02466","name":"AD/ARTOUSTE/5 - Reduction Gear Driving Pinion Bearings Replacement","slug":"ad-artouste-5-reduction-gear-driving-pinion-bearings-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41722,"registerId":"commonwealth-F2006B02466-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/ARTOUSTE/5 - Reduction Gear Driving Pinion Bearings 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 - 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Turbomeca Turbine Engines - Artouste Series\n\n \n\nAD/ARTOUSTE/5 Reduction Gear Driving Pinion NK\n\nBearings Replacement\n\n \n\nApplicability: All Artouste 111B.\n\n \n\nDocument: 1. Turbomeca Service No. 73.218.0022; or\n\n \n\n2. AD/TURB-T/3.\n\n \n\nCompliance: As detailed in the Requirement Document.\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\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The text sets a clear, narrow scope: it applies to all Turbomeca Artouste 111B engines and requires replacement of the reduction gear driving pinion bearings per the referenced service documents (Applicability; Document; Compliance). The instrument itself does not indicate any expansion or narrowing of that scope compared with what it states here; no change from an earlier or different scope is indicated within this document."},"complexity_factors":["Narrow technical scope (single component on a single engine model) reduces conceptual complexity (Applicability: All Artouste 111B).","Dependence on external technical documents (Turbomeca Service No. 73.218.0022 or AD/TURB-T/3) increases practical complexity because the AD does not contain the step-by-step actions (Document: ...; Compliance: As detailed in the Requirement Document).","Regulatory enforcement context (an Airworthiness Directive under Part 39) requires operators to demonstrate compliance and record-keeping, creating administrative burden beyond the physical replacement.","Potential operational complexity from logistics: parts availability, authorised maintenance facilities and aircraft downtime are not addressed in the AD text but are required to implement the action (implied by the replacement requirement).","Limited explanatory material in the AD text (no stated failure mode or detailed rationale) forces reliance on the referenced service documents or regulator guidance to understand urgency and technical detail."],"plain_english_summary":"What this instrument does (mechanical effect)\n\n- The Airworthiness Directive (AD/ARTOUSTE/5) requires replacement of the reduction gear driving pinion bearings on Turbomeca Artouste 111B turbine engines. (See: \"AD/ARTOUSTE/5 Reduction Gear Driving Pinion NK Bearings Replacement\" and \"Applicability: All Artouste 111B.\")\n- The replacement work must be carried out in accordance with a referenced Requirement Document: either Turbomeca Service No. 73.218.0022 or AD/TURB-T/3. (See: \"Document: 1. Turbomeca Service No. 73.218.0022; or 2. AD/TURB-T/3.\" and \"Compliance: As detailed in the Requirement Document.\")\n\nWho this affects and who decides\n\n- Applies to operators, owners and maintainers of aircraft powered by Artouste 111B engines. (Applicability: All Artouste 111B.)\n- The Civil Aviation Safety Authority (CASA) issues and enforces the AD under the Civil Aviation Regulations framework; the technical steps to comply are defined in the referenced service document(s). (See: document header identifying this as a Schedule of Airworthiness Directives and the Document/Compliance lines above.)\n\nWhy it matters (stated and practical consequences)\n\n- The AD instructs mandatory maintenance action: replacement of a specific bearing component. The directive does not include an explanatory statement of the operational fault or accident history in this text; ADs are generally issued to address an identified airworthiness/safety issue, and this instrument sets the required remedial step. (The AD text itself contains no separate rationale paragraph.)\n- Practical effects for affected parties include arranging the replacement work according to the referenced documents, obtaining parts and qualified labour, taking the engine/aircraft out of service for the work, and recording compliance in maintenance logs. (These effects follow from the requirement to perform the replacement \"as detailed in the Requirement Document.\")\n\nCosts, incentives and implementation notes (mechanics, not judgements)\n\n- Who pays: aircraft operators/owners pay for parts, maintenance labour, and any operational downtime required to comply, because the AD applies to their engines. (Applicability + Compliance clauses.)\n- Who benefits (mechanically): providers of the replacement bearings, approved maintenance organisations and technicians will be engaged to perform the work; the AD creates demand for those goods and services because compliance requires following the referenced service instructions. (Compliance tied to specific service document references.)\n- Discretion and direction: the AD prescribes compliance to the Requirement Document and does not delegate choice of alternative procedures in this text. Operators must follow the specified service document(s) unless they obtain an alternative method of compliance through the regulator (not described in this text). (Compliance: \"As detailed in the Requirement Document.\" / Document references.)\n- Implementation risks and burdens: availability of specified parts or authorised maintenance slots, the time aircraft are out of service for the replacement, and the need to apply the exact procedures in the referenced documents are likely operational constraints implied by the AD's instructions. (Implied by the requirement to perform the replacement per the referenced documents.)\n\nSummary of mechanism and trade-offs\n\n- Mechanically, the AD converts a technical maintenance instruction (replacement of a bearing) into a mandatory regulatory obligation for all Artouste 111B engines by citing an external service document as the Requirement Document. (Title + Applicability + Document + Compliance lines.)\n- The directive concentrates immediate costs on operators (parts, labour and downtime) while creating demand for maintenance providers and parts suppliers. The AD leaves technical detail and sequencing to the referenced service document(s), so compliance depends on access to and execution of those documents.\n\nKey citations from the instrument\n\n- Title: \"AD/ARTOUSTE/5 Reduction Gear Driving Pinion NK Bearings Replacement.\" \n- Applicability: \"All Artouste 111B.\" \n- Requirement documents: \"Turbomeca Service No. 73.218.0022; or AD/TURB-T/3.\" \n- Compliance direction: \"As detailed in the Requirement Document.\""},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted maintenance directive focused on a specific mechanical component in a specific engine series. It has not expanded beyond its original safety purpose."},"complexity_factors":["Extremely short document (approximately 150 words)","No defined terms section","No conditional logic or nested exceptions","Single, clear applicability criterion ('All Artouste IIIB')","Compliance achieved by reference to external technical documents (service bulletin) rather than detailed procedural text within the directive itself","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998 and one related AD"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** issued by Australia's Civil Aviation Safety Authority (CASA) for specific helicopter engines.\n\n**What it does:**\n- Requires the replacement of bearings in the reduction gear driving pinion (a mechanical component that transfers power from the engine to the rotor) on certain Turbomeca Artouste turbine engines.\n\n**Who it affects:**\n- Owners and operators of helicopters powered by **Artouste IIIB** turbine engines.\n\n**Why it matters:**\n- Airworthiness Directives are legally binding safety orders. If you don't comply, your aircraft cannot legally fly. This particular AD addresses a specific mechanical wear issue that could affect engine reliability and flight safety.\n\n**How to comply:**\n- Follow the instructions in **Turbomeca Service Bulletin No. 73.218.0022** or refer to **AD/TURB-T/3** (an earlier related directive). The exact replacement schedule and procedures are detailed in those documents, not in this short directive itself."}},"importantCases":[],"_links":{"self":"/api/acts/ad-artouste-5-reduction-gear-driving-pinion-bearings-replacement","history":"/api/acts/ad-artouste-5-reduction-gear-driving-pinion-bearings-replacement/history","analysis":"/api/acts/ad-artouste-5-reduction-gear-driving-pinion-bearings-replacement/analysis","conflicts":"/api/acts/ad-artouste-5-reduction-gear-driving-pinion-bearings-replacement/conflicts","importantCases":"/api/acts/ad-artouste-5-reduction-gear-driving-pinion-bearings-replacement/important-cases","documents":"/api/acts/ad-artouste-5-reduction-gear-driving-pinion-bearings-replacement/documents"}}