{"id":"F2006B09333","name":"AD/ECUREUIL/20 - Main Gear Box Oil Filter - Inspection","slug":"ad-ecureuil-20-main-gear-box-oil-filter-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53515,"registerId":"commonwealth-F2006B09333-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/ECUREUIL/20 - Main Gear Box Oil Filter - 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 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Eurocopter AS 350 (Ecureuil) Series Helicopters\n\n \n\nAD/ECUREUIL/20 Main Gear Box Oil Filter - Inspection 2/83\n\nApplicability: All models AS350 fitted with a Tedeco magnetic plug P/N B4439 with electrical indication, and not modified to AMS 07-1211.\n\n \n\nDocument: Aerospatiale AS350 SB 05.12.\n\n \n\nCompliance: At periods not exceeding 100 hours time in service after 31 March, 1983.\n\n \n\nBackground:  The manufacturer advises of the need to reduce the inspection interval for the main gearbox oil filter, on helicopters fitted with the Tedeco magnetic plug installation.\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":1455},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original, tightly constrained scope. It addresses a discrete airworthiness issue—reduced inspection intervals for a specific magnetic plug installation—without expanding into broader operational or maintenance requirements. The instrument remains focused on the original safety concern identified by the manufacturer."},"complexity_factors":["Single, unambiguous compliance requirement (100-hour inspection interval)","Narrow applicability limited to specific aircraft model with specific part number","No conditional logic, exceptions, or nested provisions","Only four operative sections (Applicability, Document, Compliance, Background)","Requires cross-reference to external technical document (Aerospatiale Service Bulletin 05.12)"],"plain_english_summary":"**What this does:** This is a mandatory safety inspection rule for certain Eurocopter AS 350 helicopters (also known as Ecureuil or Squirrel). It requires operators to check the main gearbox oil filter every 100 hours of flight time.\n\n**Who it affects:** Owners and operators of AS350 helicopters fitted with a specific Tedeco magnetic plug (part number B4439) that has electrical indication, unless the helicopter has already been modified according to service bulletin AMS 07-1211.\n\n**Why it matters:** The manufacturer identified that these specific magnetic plugs need more frequent checking than originally planned. The plug collects metal particles from the gearbox oil to warn of mechanical wear. If it malfunctions or becomes blocked, the pilot might not get a warning before the gearbox fails—a potentially catastrophic in-flight emergency. This rule prevents that by mandating regular hands-on inspections."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ecureuil-20-main-gear-box-oil-filter-inspection","history":"/api/acts/ad-ecureuil-20-main-gear-box-oil-filter-inspection/history","analysis":"/api/acts/ad-ecureuil-20-main-gear-box-oil-filter-inspection/analysis","conflicts":"/api/acts/ad-ecureuil-20-main-gear-box-oil-filter-inspection/conflicts","importantCases":"/api/acts/ad-ecureuil-20-main-gear-box-oil-filter-inspection/important-cases","documents":"/api/acts/ad-ecureuil-20-main-gear-box-oil-filter-inspection/documents"}}