{"id":"F2006B02246","name":"AD/AL 250/3 - Oil Filter By-Pass Valve Poppet Guide - Replacement","slug":"ad-al-250-3-oil-filter-by-pass-valve-poppet-guide-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41476,"registerId":"commonwealth-F2006B02246-current","compilationNumber":null,"startDate":"2026-04-01","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AL 250/3 - Oil Filter By-Pass Valve Poppet Guide - 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)  Allison Turbine Engines - 250 Series\n\n \n\nAD/AL 250/3 Oil Filter By-Pass Valve Poppet Guide - Replacement\n\n\n6/68\n\n \n\nApplicability: All 250-C18 and 250-C18A engine gearboxes specified in Allison CEB No. 250 CEB-31.\n\n \n\nDocument: Allison CEB No. 250 CEB-31.\n\n \n\nCompliance: Before installation in an aircraft following next overhaul completed after 13 June 1968.\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":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2020},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow technical scope, targeting only the specific valve component in specific engine models as originally intended."},"complexity_factors":["Single operative requirement with minimal text","No definitions section or interpretative provisions","Single external cross-reference to manufacturer service bulletin (Allison CEB No. 250 CEB-31)","Simple compliance trigger based on overhaul timing and specific calendar date"],"plain_english_summary":"This Airworthiness Directive mandates the replacement of a specific mechanical part—the **oil filter by-pass valve poppet guide**—in certain Allison turbine aircraft engines.\n\n**Who it affects**\nOperators and maintenance providers working with Allison 250-C18 or 250-C18A engine gearboxes (specifically those listed in the manufacturer's service bulletin Allison CEB No. 250 CEB-31).\n\n**What it requires**\nBefore installing one of these engines in an aircraft after its next overhaul, you must replace the poppet guide with a new component according to the specifications in the manufacturer's service bulletin mentioned above.\n\n**Why it matters**\nThe poppet guide is a critical component of the oil filtration system. Failure to replace it could compromise oil pressure regulation and filtration, potentially leading to engine damage or failure during flight."}},"importantCases":[],"_links":{"self":"/api/acts/ad-al-250-3-oil-filter-by-pass-valve-poppet-guide-replacement","history":"/api/acts/ad-al-250-3-oil-filter-by-pass-valve-poppet-guide-replacement/history","analysis":"/api/acts/ad-al-250-3-oil-filter-by-pass-valve-poppet-guide-replacement/analysis","conflicts":"/api/acts/ad-al-250-3-oil-filter-by-pass-valve-poppet-guide-replacement/conflicts","importantCases":"/api/acts/ad-al-250-3-oil-filter-by-pass-valve-poppet-guide-replacement/important-cases","documents":"/api/acts/ad-al-250-3-oil-filter-by-pass-valve-poppet-guide-replacement/documents"}}