{"id":"F2006B02243","name":"AD/AL 250/21 - Ceco F.C.U. Throttle Shaft and Governor Quadrant and Shaft Assembly - Inspection","slug":"ad-al-250-21-ceco-f-c-u-throttle-shaft-and-governor-quadrant-and-shaft-assembly-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41473,"registerId":"commonwealth-F2006B02243-current","compilationNumber":null,"startDate":"2026-04-01","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AL 250/21 - Ceco F.C.U. Throttle Shaft and Governor Quadrant and Shaft Assembly - Inspection","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 250/21 Ceco F.C.U. Throttle Shaft and Governor\n\nQuadrant and Shaft Assembly - Inspection\n\n\n3/74\n\n \n\nApplicability: All 250-C20 series engines fitted with Ceco FCU assemblies prior to S/N 3AAC2088 and with power turbine governor assemblies prior to S/Nos. 3AAD2364 and 3ACK175.\n\n \n\nDocument: Allison 250-C20 CEB No. 1033.\n\n \n\nCompliance: Within 100 hours’ time in service after 29 March 1974.\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":2067},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is the original 1974 directive. The scope remains tightly confined to the inspection of specific Ceco FCU and governor hardware on Allison 250-C20 engines as originally mandated, with no evidence of expansion into broader operational or airworthiness areas."},"complexity_factors":["Single mandatory action with no exceptions or nested conditions","Limited applicability criteria (one engine series and two specific serial number ranges)","Only one external technical reference (Allison CEB No. 1033)","Clear, unambiguous compliance metric (100 hours time in service)"],"plain_english_summary":"**What this is:** An Airworthiness Directive — a mandatory safety order issued by the aviation regulator requiring specific maintenance actions on aircraft engines.\n\n**Who it affects:** Owners and operators of **Allison 250-C20 series turbine engines** fitted with:\n- Ceco Fuel Control Unit (FCU) assemblies with serial numbers earlier than 3AAC2088\n- Power turbine governor assemblies with serial numbers earlier than 3AAD2364 and 3ACK175\n\n**What must be done:** Inspect the **throttle shaft** on the Ceco FCU and the **quadrant and shaft assembly** on the power turbine governor. The inspection must follow the procedures in Allison Service Bulletin CEB No. 1033.\n\n**When:** Within 100 hours of flight time (time in service) after 29 March 1974.\n\n**Why it matters:** This prevents potential engine failures or loss of power control due to defects in these specific components. Operating an aircraft without completing this inspection violates aviation safety law."}},"importantCases":[],"_links":{"self":"/api/acts/ad-al-250-21-ceco-f-c-u-throttle-shaft-and-governor-quadrant-and-shaft-assembly-inspection","history":"/api/acts/ad-al-250-21-ceco-f-c-u-throttle-shaft-and-governor-quadrant-and-shaft-assembly-inspection/history","analysis":"/api/acts/ad-al-250-21-ceco-f-c-u-throttle-shaft-and-governor-quadrant-and-shaft-assembly-inspection/analysis","conflicts":"/api/acts/ad-al-250-21-ceco-f-c-u-throttle-shaft-and-governor-quadrant-and-shaft-assembly-inspection/conflicts","importantCases":"/api/acts/ad-al-250-21-ceco-f-c-u-throttle-shaft-and-governor-quadrant-and-shaft-assembly-inspection/important-cases","documents":"/api/acts/ad-al-250-21-ceco-f-c-u-throttle-shaft-and-governor-quadrant-and-shaft-assembly-inspection/documents"}}