{"id":"F2006B04769","name":"AD/BN-2/58 - 70 Amp DC Generation System","slug":"ad-bn-2-58-70-amp-dc-generation-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44533,"registerId":"commonwealth-F2006B04769-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BN-2/58 - 70 Amp DC Generation System","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-2/58 70 Amp DC Generation System 4/96 DM\n\nApplicability: All BN2 Series aircraft with either Modification NB/M/1148, “70 amp DC Generation System”, incorporated or Modification NB/M/1571, “Introduction of Increased Rated Diode - 70 amp DC Generation System” not incorporated.\n\n \n\nRequirement: Replace diodes on STBD and PORT GEN Switches in accordance with Pilatus Britten-Norman Mandatory Service Bulletin BN 2-228 Issue 1.\n\n \n\nNote: Compliance with this Service Bulletin is classified Mandatory by the UK CAA.\n\n \n\nCompliance: Within 50 hours time in service after 14 February 1996.\n\n \n\nBackground: Incorporation of this Directive will increase the circuit reliability of the 70 amp DC Generation System.\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":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive's scope is limited to replacing diodes on the port and starboard generator switches for BN‑2 aircraft meeting the stated modification conditions. The text gives no indication the scope was altered from its original objective of improving 70‑amp DC generation system reliability."},"complexity_factors":["Narrow technical requirement limited to diode replacement on two generator switches (Requirement).","Applicability condition tied to specific modification status: NB/M/1148 incorporated or NB/M/1571 not incorporated (Applicability).","Reliance on an external manufacturer document for implementation: Pilatus Mandatory Service Bulletin BN 2‑228 Issue 1 (Requirement).","Short compliance window specified: within 50 hours time in service after 14 February 1996 (Compliance).","Regulatory cross-reference: UK CAA classified the service bulletin as mandatory, creating multi‑authority expectation (Note).","Stated objective limited to increasing circuit reliability, rather than introducing broader system changes (Background)."],"plain_english_summary":"This airworthiness directive requires operators of Pilatus Britten‑Norman BN‑2 series aircraft with the listed modification status to replace the diodes on the port and starboard generator switches by following Pilatus Mandatory Service Bulletin BN 2‑228 Issue 1. Compliance must occur within 50 hours’ time in service after 14 February 1996.\n\nThe change is intended to increase reliability of the 70‑amp DC generation system. Operators must arrange and fund the replacements; the Civil Aviation Safety Authority enforces the directive and the UK CAA classified the service bulletin as mandatory."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific technical defect in a specific aircraft type. It has not expanded beyond its original purpose of ensuring electrical system reliability in BN-2 aircraft with the 70 amp generation system."},"complexity_factors":["Single, specific technical requirement (diode replacement)","Limited applicability criteria based on two specific aircraft modifications","No nested exceptions or conditional logic","No defined terms section","Single compliance deadline with straightforward calculation (50 hours after fixed date)","Cross-reference to only one external document (Service Bulletin BN 2-228)","Total length under 200 words"],"plain_english_summary":"This AD requires owners/operators of Pilatus Britten‑Norman BN‑2 series aircraft with the 70‑amp DC system upgrade (Mod NB/M/1148), or without the later diode improvement (Mod NB/M/1571), to replace the diodes on both engine generator switches. \n\nThe replacement prevents possible loss of electrical power generation and must be completed within 50 flight hours after 14 February 1996."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bn-2-58-70-amp-dc-generation-system","history":"/api/acts/ad-bn-2-58-70-amp-dc-generation-system/history","analysis":"/api/acts/ad-bn-2-58-70-amp-dc-generation-system/analysis","conflicts":"/api/acts/ad-bn-2-58-70-amp-dc-generation-system/conflicts","importantCases":"/api/acts/ad-bn-2-58-70-amp-dc-generation-system/important-cases","documents":"/api/acts/ad-bn-2-58-70-amp-dc-generation-system/documents"}}