{"id":"F2006B04729","name":"AD/BN-2/18 - Engine Oil Return Pipes - Modification","slug":"ad-bn-2-18-engine-oil-return-pipes-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44493,"registerId":"commonwealth-F2006B04729-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BN-2/18 - Engine Oil Return Pipes - Modification","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)  Pilatus Britten-Norman BN-2 Series Aeroplanes\n\n \n\nAD/BN-2/18 Engine Oil Return Pipes - Modification NK\n\nApplicability: All models.\n\n \n\nDocument: Britten Norman SB BN-2/SB.40 Issue 2.\n\n \n\nCompliance: Within 100 hours time in service after 26 February 1971.\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\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1240},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"The directive remains strictly limited to its original purpose: mandating a specific mechanical modification to engine oil return pipes on BN-2 aircraft."},"complexity_factors":["Single, unambiguous operational requirement","No interpretation section or defined terms","No cross-references to other legislative provisions","Straightforward compliance deadline and method"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order issued by the aviation regulator) for owners and operators of **Pilatus Britten-Norman BN-2 Series aircraft** (twin-engine utility planes commonly known as Islanders).\n\n**What you must do:**\n- Modify the **engine oil return pipes** on your aircraft according to the technical instructions in **Britten Norman Service Bulletin BN-2/SB.40 Issue 2**.\n- Complete this work within **100 hours of flight time** after 26 February 1971.\n\n**Why it matters:**\nThis directive fixes a specific safety defect in the engine oil return system. If not addressed, faulty oil return pipes could cause engine oil starvation, potentially leading to engine failure and loss of the aircraft.\n\n**Who it affects:**\nAnyone who owns, operates, or maintains BN-2 series aircraft in Australia."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bn-2-18-engine-oil-return-pipes-modification","history":"/api/acts/ad-bn-2-18-engine-oil-return-pipes-modification/history","analysis":"/api/acts/ad-bn-2-18-engine-oil-return-pipes-modification/analysis","conflicts":"/api/acts/ad-bn-2-18-engine-oil-return-pipes-modification/conflicts","importantCases":"/api/acts/ad-bn-2-18-engine-oil-return-pipes-modification/important-cases","documents":"/api/acts/ad-bn-2-18-engine-oil-return-pipes-modification/documents"}}