{"id":"F2006B02262","name":"AD/AL 250/50 Amdt 1 - N2 Overspeed Control Assembly - Addition of Lockwashers to Ground Jumper Lead","slug":"ad-al-250-50-amdt-1-n2-overspeed-control-assembly-addition-of-lockwashers-to-ground-jumper-lead","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41492,"registerId":"commonwealth-F2006B02262-current","compilationNumber":null,"startDate":"2026-04-01","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AL 250/50 Amdt 1 - N2 Overspeed Control Assembly - Addition of Lockwashers to Ground Jumper Lead","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 250/50\n\nAmdt 1\n\n\nN2 Overspeed Control Assembly - Addition of Lockwashers to Ground Jumper Lead\n\n\n1/83\n\n \n\nApplicability: All model 250-C28C and C30S engines excepting those exempted in the documents.\n\n \n\nDocument: Allison 250-C28C, Alert CEB A73-2024, Rev. 2. Allison 250-C30S, Alert CEB A73- 3015, Rev. 2.\n\n \n\nCompliance: As per the requirement document.\n\n \n\nBackground: This AD has been amended to include all Models 250-C28C, C30 and C30S, excepting the engine Serial Nos. specified in the document.\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":1953},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":true,"description":"Amendment 1 expands the directive's reach from the original scope to include all Model 250-C28C, C30 and C30S engines, while introducing specific serial number exemptions detailed in the referenced Alert Commercial Engine Bulletins."},"complexity_factors":["Heavy reliance on external technical documents (CEBs A73-2024 and A73-3015) for actual compliance procedures","Exemptions defined by serial numbers contained only in external documents, not listed in the directive itself","Specialist aviation terminology (N2 overspeed control, ground jumper leads, lockwashers) requiring technical knowledge","Amendment format requires cross-referencing with original AD/AL 250/50 to determine what changed"],"plain_english_summary":"**What this does:** This is a mandatory safety directive (an Airworthiness Directive) requiring a specific hardware fix on certain aircraft turbine engines.\n\n**Who it affects:** Owners and operators of aircraft powered by **Allison 250-C28C and C30S** model engines (commonly used in helicopters and light aircraft).\n\n**What must happen:** Maintenance crews must install **lockwashers** (special washers that stop bolts vibrating loose) onto the **ground jumper lead** (an electrical earthing wire) attached to the **N2 overspeed control assembly** (the safety system that stops the engine from over-revving).\n\n**Why it matters:** Without this fix, vibration can loosen the electrical connection, potentially causing the overspeed protection to fail or creating dangerous electrical faults.\n\n**What's changed:** This amendment expands the directive to cover more engine models (adding the C30 series and clarifying coverage of C28C and C30S) while excluding specific engine serial numbers listed in the referenced technical bulletins."}},"importantCases":[],"_links":{"self":"/api/acts/ad-al-250-50-amdt-1-n2-overspeed-control-assembly-addition-of-lockwashers-to-ground-jumper-lead","history":"/api/acts/ad-al-250-50-amdt-1-n2-overspeed-control-assembly-addition-of-lockwashers-to-ground-jumper-lead/history","analysis":"/api/acts/ad-al-250-50-amdt-1-n2-overspeed-control-assembly-addition-of-lockwashers-to-ground-jumper-lead/analysis","conflicts":"/api/acts/ad-al-250-50-amdt-1-n2-overspeed-control-assembly-addition-of-lockwashers-to-ground-jumper-lead/conflicts","importantCases":"/api/acts/ad-al-250-50-amdt-1-n2-overspeed-control-assembly-addition-of-lockwashers-to-ground-jumper-lead/important-cases","documents":"/api/acts/ad-al-250-50-amdt-1-n2-overspeed-control-assembly-addition-of-lockwashers-to-ground-jumper-lead/documents"}}