{"id":"F2006B02534","name":"AD/ASTAZOU/3 - Inspection of Axial Compressor Wheels","slug":"ad-astazou-3-inspection-of-axial-compressor-wheels","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41790,"registerId":"commonwealth-F2006B02534-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/ASTAZOU/3 - Inspection of Axial Compressor Wheels","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 - Astazou Series\n\n \n\nAD/ASTAZOU/3 Inspection of Axial Compressor Wheels NK\n\nApplicability: Astazou 11A, 11AF, 11A2.\n\n \n\nDocument: 1. Turbomeca SL No. 344/73/AST/61; or\n\n \n\n2.    Turbomeca SL No. 349/73/AST/62; or\n\n \n\n3.    Bureau Veritas (SGAC) Airworthiness Directive 73-45; or\n\n \n\n4.    AD/TURB-T/6.\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","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive format consistent with CASA's long-standing Part 39 framework. The scope remains tightly focused on the specific safety issue (compressor wheel inspection) for the specified engine models, which is the intended purpose of ADs."},"complexity_factors":["Extremely short document (under 200 words)","No defined terms section — relies entirely on external technical references","Simple structure: applicability statement, document list, compliance instruction","No conditional logic or nested exceptions","Cross-references are straightforward pointers to four external technical documents rather than internal legislative cross-referencing","Single compliance requirement with no alternative compliance methods or phased implementation"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires specific inspections of **axial compressor wheels** (critical rotating parts in jet engines that compress air before fuel is added) on certain **Turbomeca Astazou** aircraft engines.\n\n**Who it affects:**\n- Owners and operators of aircraft using **Astazou 11A, 11AF, or 11A2** engines\n- Maintenance engineers responsible for keeping these engines airworthy\n\n**What it requires:**\n- Inspections must be carried out exactly as described in one of four referenced technical documents (service bulletins from the engine manufacturer Turbomeca, a French airworthiness directive, or a previous Australian directive)\n- The \"NK\" marking indicates this directive cannot be modified or cancelled without CASA approval\n\n**Why it matters:**\nCompressor wheel failures can cause catastrophic engine damage and potentially fatal accidents. This directive ensures potential defects are caught before they cause in-flight emergencies. Compliance is legally mandatory — flying without completing these inspections violates civil aviation law."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The source text does not indicate any alteration to the AD’s scope from an earlier instrument. The AD sets applicability (Astazou 11A, 11AF, 11A2) and requires compliance with the listed requirement documents; no amendment or scope-expansion language appears in the provided text (Applicability; Document list; Compliance)."},"complexity_factors":["Technical subject matter (axial compressor wheel inspection) requires specialised maintenance knowledge.","Operative detail is delegated to four external requirement documents (Turbomeca SL No. 344/73/AST/61; Turbomeca SL No. 349/73/AST/62; Bureau Veritas AD 73-45; AD/TURB-T/6), requiring operators to obtain and reconcile those sources (Document list; Compliance).","The AD text is concise and does not state inspection intervals, procedures or acceptance criteria, creating dependence on referenced documents (Compliance).","Limited applicability to specific engine models reduces scope but concentrates impact on particular operators/maintainers (Applicability).","Regulatory enforcement is under Civil Aviation Regulations, Part 39, which frames legal effect but is not spelled out in the AD text (header)."],"plain_english_summary":"This AD mandates inspections of axial compressor wheels on Turbomeca Astazou 11A/11AF/11A2 engines and requires operators to comply with one of four specified external requirement documents for the inspection regime.  \n\nIt affects aircraft owners/operators and maintenance organisations, who bear the costs and operational disruption; CASA enforces compliance. The measure aims to reduce in‑service failure risk while delegating technical detail to the referenced documents."}},"importantCases":[],"_links":{"self":"/api/acts/ad-astazou-3-inspection-of-axial-compressor-wheels","history":"/api/acts/ad-astazou-3-inspection-of-axial-compressor-wheels/history","analysis":"/api/acts/ad-astazou-3-inspection-of-axial-compressor-wheels/analysis","conflicts":"/api/acts/ad-astazou-3-inspection-of-axial-compressor-wheels/conflicts","importantCases":"/api/acts/ad-astazou-3-inspection-of-axial-compressor-wheels/important-cases","documents":"/api/acts/ad-astazou-3-inspection-of-axial-compressor-wheels/documents"}}