{"id":"F2006B02239","name":"AD/AL 250/18 - Compressor Bleed Valve Orifice - Installation","slug":"ad-al-250-18-compressor-bleed-valve-orifice-installation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41469,"registerId":"commonwealth-F2006B02239-current","compilationNumber":null,"startDate":"2026-04-01","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AL 250/18 - Compressor Bleed Valve Orifice - Installation","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-description: CASA Airworthiness Directive\nmeta-generator: Aspose.Words for .NET 22.10.0\nmeta-keywords: Issue 7/1973,Turbine engines,Allison Turbine Engines - 250 Series,Compressor Bleed Valve Orifice - Installation,18\ntitle: Airworthiness Directive - AD/AL 250/18 - Compressor Bleed Valve Orifice - Installation\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)  Allison Turbine Engines - 250 Series\n\n \n\nAD/AL 250/18 Compressor Bleed Valve Orifice - Installation 7/73\n\nApplicability: All 250-C18A series fitted with bleed valves. P/N 6854607 or 6870460 installed in Hughes 369H Helicopters.\n\n \n\nDocument: Allison 250 CEB 107.\n\n \n\nCompliance: Before 31 July 1973.\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":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1466},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This is the original 1973 directive (Issue 7/1973) with a narrow technical scope targeting a specific hardware defect in identified engine models. No evidence of amendments or expansion beyond the original safety-critical installation requirement."},"complexity_factors":["Single compliance requirement with explicit deadline","Limited applicability restricted to specific engine model, part numbers, and aircraft type","No exceptions, exemptions, or conditional logic","Only one reference document (Allison 250 CEB 107)","Total operative text under 50 words"],"plain_english_summary":"**What this is:** A safety directive requiring operators of specific helicopter engines to modify the compressor bleed valve orifice (a small opening that releases air pressure from the engine).\n\n**Who it affects:** Owners and operators of Hughes 369H helicopters equipped with Allison 250-C18A series turbine engines that have bleed valves with part numbers 6854607 or 6870460.\n\n**What you must do:** Install or modify the compressor bleed valve orifice according to the manufacturer's instructions in service bulletin **Allison 250 CEB 107**.\n\n**Deadline:** This work must be completed before 31 July 1973.\n\n**Why it matters:** This fixes a potential safety defect in the engine's air pressure regulation system. If not corrected, the bleed valve could malfunction, risking engine damage or failure during flight."}},"importantCases":[],"_links":{"self":"/api/acts/ad-al-250-18-compressor-bleed-valve-orifice-installation","history":"/api/acts/ad-al-250-18-compressor-bleed-valve-orifice-installation/history","analysis":"/api/acts/ad-al-250-18-compressor-bleed-valve-orifice-installation/analysis","conflicts":"/api/acts/ad-al-250-18-compressor-bleed-valve-orifice-installation/conflicts","importantCases":"/api/acts/ad-al-250-18-compressor-bleed-valve-orifice-installation/important-cases","documents":"/api/acts/ad-al-250-18-compressor-bleed-valve-orifice-installation/documents"}}