{"id":"F2005L01077","name":"AD/ARRIUS/7 Amdt 1 - High Pressure Turbine","slug":"ad-arrius-7-amdt-1-high-pressure-turbine","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":34701,"registerId":"commonwealth-F2005L01077-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Turbomeca Turbine Engines - Arrius Serie","sectionType":"division","heading":"Turbomeca Turbine Engines - Arrius Series","content":"### Turbomeca Turbine Engines - Arrius Series\n\n| AD/ARRIUS/7 Amdt 1 | High Pressure Turbine | 7/2005 TX |\n| ------------------ | --------------------- | --------- |\n\n| Applicability: | Turbomeca ARRIUS 2F engines which are fitted to Eurocopter EC120B helicopters.                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | 1. Do not operate engines fitted with number 2 modules as listed in Alert Fax TURBOMECA 057/05/DSO/TM.2. Engines may be returned to service following inspection/rework at a repair centre, or after module 2 replacement on site or in a workshop, or after inspection of the standard of the ferrule by applying deep servicing instructions on site.Note: DGAC AD UF-2005-073R1 EASA approval No 2005-3868 dated 29 April 2005 refers.                                                                                                                    |\n| Compliance:    | From the effective date of this Directive.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n|                | This Amendment becomes effective on 5 May 2005.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n| Background:    | Following an accident involving an EC1 208, the initial investigation of the Arrius 2F engine showed that one HP blade was totally released from the HP disk. This blade was contained inside the containment ring.The preliminary examination of the engine parts showed that the standard of one ferrule initiated a disturbance in the secondary air system used to cool the HP turbine.This amendment includes additional information for the return to service of affected engines.The original issue of this Directive became effective 30 April 2005. |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n3 May 2005","sortOrder":0},{"sectionNumber":"AD/ARRIUS/7 Amdt 1","sectionType":"part","heading":"AD/ARRIUS/7 Amdt 1","content":"## AD/ARRIUS/7 Amdt 1","sortOrder":1},{"sectionNumber":"High Pressure Turbine","sectionType":"part","heading":"High Pressure Turbine","content":"## High Pressure Turbine","sortOrder":2},{"sectionNumber":"7/2005 TX","sectionType":"part","heading":"7/2005 TX","content":"## 7/2005 TX","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This amendment supplements the original Directive by adding specific return-to-service options and clarifying acceptable on-site and repair-centre remedies (Requirement; Background). It does not broaden the class of affected engines (still ARRIUS 2F on EC120B) but alters operational requirements and compliance steps compared with the original issue."},"complexity_factors":["Narrow technical scope but immediate grounding requirement increases operational disruption (Applicability; Requirement; Compliance).","Multiple compliance paths: inspection/rework at authorised repair centre, on-site/workshop module replacement, or ferrule inspection under deep servicing instructions (Requirement).","Cross-references to external technical documents and foreign AD/EASA approvals require coordination and technical interpretation (Alert Fax TURBOMECA 057/05/DSO/TM.2; Note referencing DGAC AD UF-2005-073R1 / EASA No 2005-3868) (Requirement/Note).","Key terms are technical and potentially ambiguous (e.g. “number 2 modules”, “standard of the ferrule”), requiring specialist judgment to apply (Requirement; Background).","Immediate effective date and safety-driven enforcement create time pressure on operators and maintenance providers, affecting parts/repair capacity and scheduling (Compliance; Background).","Amendment-level document: procedural clarification (return-to-service) rather than a broad regulatory redesign, so legal drafting is concise but depends on technical implementation."],"plain_english_summary":"This directive stops operation of Turbomeca ARRIUS 2F engines fitted with certain “number 2” modules until those modules are inspected, reworked, or replaced as specified in Alert Fax TURBOMECA 057/05/DSO/TM.2 (Requirement; Applicability). It applies to ARRIUS 2F engines on Eurocopter EC120B helicopters. Operators must bear inspection/repair costs and downtime; compliance is immediate from the directive’s effective date (Compliance). The amendment adds return-to-service guidance after an HP turbine blade release investigation (Background)."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment remains tightly scoped to its original safety purpose. It adds return-to-service options (repair centre, module replacement, or ferrule inspection) to the original grounding order, but does not expand the applicability to other engine types, helicopter models, or operational contexts. The scope is precisely the same: Arrius 2F engines on EC120B helicopters with specific module 2 configurations."},"complexity_factors":["Short, single-purpose directive (2 pages)","Only 1 defined applicability criterion (engine model + helicopter type)","3 alternative compliance pathways (repair centre, module replacement, or on-site ferrule inspection)","Cross-reference to external document (Turbomeca Alert Fax 057/05/DSO/TM) for identifying affected parts","Reference to French aviation authority (DGAC) and EASA approval for traceability","No nested exceptions or conditional logic — straightforward prohibition with explicit exemptions for repaired engines"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's aviation regulator (CASA). It applies to specific helicopter engines made by Turbomeca (now Safran Helicopter Engines).\n\n**What it does:**\n- **Grounds certain engines immediately** — you cannot fly helicopters with Arrius 2F engines that have specific \"number 2 modules\" (a section of the engine containing the high-pressure turbine).\n- **Why:** After a crash involving an EC120B helicopter, investigators found that a faulty \"ferrule\" (a small metal ring/collar) in the engine disrupted the cooling airflow to the high-pressure turbine. This caused a turbine blade to break off completely — a catastrophic failure.\n\n**Who it affects:**\n- Operators of **Eurocopter EC120B helicopters** fitted with **Turbomeca Arrius 2F engines**\n- Maintenance organisations and repair centres\n\n**What you must do:**\n- Check if your engine has the affected module (listed in Turbomeca Alert Fax 057/05/DSO/TM)\n- If affected: **stop flying immediately**\n- To return to service, you must either:\n  - Get the engine inspected and repaired at an authorised centre, **or**\n  - Replace the entire module 2, **or**\n  - Inspect the ferrule using special \"deep servicing\" procedures\n\n**Why it matters:** This prevents potentially fatal engine failures. The original directive took effect 30 April 2005; this amendment (effective 5 May 2005) adds more detailed instructions for getting engines back into service safely."}},"importantCases":[],"_links":{"self":"/api/acts/ad-arrius-7-amdt-1-high-pressure-turbine","history":"/api/acts/ad-arrius-7-amdt-1-high-pressure-turbine/history","analysis":"/api/acts/ad-arrius-7-amdt-1-high-pressure-turbine/analysis","conflicts":"/api/acts/ad-arrius-7-amdt-1-high-pressure-turbine/conflicts","importantCases":"/api/acts/ad-arrius-7-amdt-1-high-pressure-turbine/important-cases","documents":"/api/acts/ad-arrius-7-amdt-1-high-pressure-turbine/documents"}}