{"id":"F2006B02241","name":"AD/AL 250/2 - Compressor Front Bearing Thrust Washer and Spring - Replacement","slug":"ad-al-250-2-compressor-front-bearing-thrust-washer-and-spring-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41471,"registerId":"commonwealth-F2006B02241-current","compilationNumber":null,"startDate":"2026-04-01","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AL 250/2 - Compressor Front Bearing Thrust Washer and Spring - Replacement","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 6/1968,Turbine engines,Allison Turbine Engines - 250 Series,Compressor Front Bearing Thrust Washer and Spring - Replacement,2\ntitle: Airworthiness Directive - AD/AL 250/2 - Compressor Front Bearing Thrust Washer and Spring - Replacement\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 250/2  Compressor Front Bearing Thrust Washer and Spring - Replacement\n\n\n6/68\n\n \n\nApplicability: All 250-C18 and 250-C18A engines compressors specified in Allison CEB No. 250 CEB-6.\n\n \n\nDocument: Allison CEB No. 250 CEB-6.\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","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1414},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This directive retains its original narrow technical scope, targeting only the replacement of specific compressor components in designated Allison engine models without expansion into broader operational or airworthiness requirements."},"complexity_factors":["Extremely brief directive (under 100 words of operative text)","Single external document reference (Allison CEB No. 250 CEB-6)","Applicability limited to only two specific engine models","Simple compliance trigger (pre-installation after post-June 1968 overhaul)","No exceptions, exemptions, or nested conditional logic"],"plain_english_summary":"This is a **safety maintenance order** for specific aircraft engines. \n\n**Who it affects**: Owners and operators of aircraft fitted with **Allison 250-C18 or 250-C18A** turbine engines.\n\n**What it requires**: If you overhaul one of these engines **after 13 June 1968**, you must replace the **compressor front bearing thrust washer and spring** before installing the engine back into an aircraft. The replacement must follow the manufacturer's instructions in **Allison Service Bulletin 250 CEB-6**.\n\n**Why it matters**: Worn or faulty thrust washers can cause engine compressor failure. This rule prevents potentially catastrophic engine damage by ensuring critical parts are replaced during overhaul."}},"importantCases":[],"_links":{"self":"/api/acts/ad-al-250-2-compressor-front-bearing-thrust-washer-and-spring-replacement","history":"/api/acts/ad-al-250-2-compressor-front-bearing-thrust-washer-and-spring-replacement/history","analysis":"/api/acts/ad-al-250-2-compressor-front-bearing-thrust-washer-and-spring-replacement/analysis","conflicts":"/api/acts/ad-al-250-2-compressor-front-bearing-thrust-washer-and-spring-replacement/conflicts","importantCases":"/api/acts/ad-al-250-2-compressor-front-bearing-thrust-washer-and-spring-replacement/important-cases","documents":"/api/acts/ad-al-250-2-compressor-front-bearing-thrust-washer-and-spring-replacement/documents"}}