{"id":"F2006B11362","name":"AD/MU-2/32 - Replacement of Series Relay and Modification to the Two Battery System","slug":"ad-mu-2-32-replacement-of-series-relay-and-modification-to-the-two-battery-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":57261,"registerId":"commonwealth-F2006B11362-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/MU-2/32 - Replacement of Series Relay and Modification to the Two Battery 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)  Mitsubishi MU-2 Series Aeroplanes\n\n \n\n# AD/MU-2/32 Replacement of Series Relay and Modification\n\nto the Two Battery System\n\nApplicability: MU-2B (Airplanes with MU-2 Series Bulletin No. 093 incorporated).\n\n# 2/84\n\n \n\nMU-2B-20 (S/N 124, 165 through 169, 171 through 181, 183 through 222 and 233).\n\n \n\nMU-2B-30 (S/N 502, 505 through 508 and 510 through 547).\n\n \n\nDocument: Mitsubishi SB 156 dated 3 August 1972 and Japan Civil Aviation Bureau AD No.\n\nTCD-859-72 dated 4 September 1972.\n\n \n\nCompliance: Before issue of Australian Certificate of Airworthiness.\n\n \n\nBackground: Advice from manufacturer of possibility that excessive arcing will occur in series relay of the two battery system, resulting in possible damage to the aircraft.\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":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific technical defect in specific aircraft. It has not expanded beyond its original purpose of mandating a particular electrical system repair."},"complexity_factors":["Very short document (approximately 200 words)","Only 2 defined applicability criteria (aircraft models and serial numbers)","Single compliance requirement with clear deadline","No cross-references to other legislation or regulations beyond citation of parent Civil Aviation Regulations 1998","No conditional logic or exceptions","Straightforward factual background with single technical issue"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific Mitsubishi MU-2 aircraft.\n\n**What it does:**\n- Requires owners/operators of certain MU-2B-20 and MU-2B-30 aircraft to replace a faulty \"series relay\" (an electrical switch that controls power flow between two batteries)\n- Also requires modifications to the two-battery electrical system\n\n**Who it affects:**\n- Owners and operators of specific Mitsubishi MU-2B aircraft with particular serial numbers (listed in the document)\n- Only applies to aircraft that have already incorporated Service Bulletin No. 093\n\n**Why it matters:**\n- The manufacturer identified a safety risk where the series relay could produce \"excessive arcing\" (dangerous electrical sparks)\n- This arcing could damage the aircraft's electrical system or potentially cause a fire\n- The directive must be completed **before** the aircraft can receive an Australian Certificate of Airworthiness (meaning it cannot legally fly in Australia until fixed)\n\n**Key point:** This is a **mandatory safety fix**, not optional. The aircraft cannot be certified as airworthy until this work is done."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive implements manufacturer and Japan Civil Aviation Bureau advice for specified MU-2B serial numbers and requires the hardware change before Australian certification. It does not expand applicability or impose requirements beyond those sources; it sets a pre-certification compliance timing tied to the cited documents."},"complexity_factors":["Narrow applicability defined by model and specific serial numbers (MU-2B lists).","Technical electrical modification (relay replacement and two-battery system work) requiring qualified maintenance.","Fixed compliance timing: must be done before issue of Australian Certificate of Airworthiness.","Cross-reference to external documents (Mitsubishi SB 156 and Japan AD TCD-859-72) for implementing details.","Administrative burden: proof of compliance needed for certification.","Potential variation where Bulletin No. 093 already incorporated affects applicability."],"plain_english_summary":"**What it does:** This airworthiness directive requires owners/operators of specified **Mitsubishi MU-2B** aeroplanes to replace the series relay and modify the two‑battery electrical system before an Australian Certificate of Airworthiness is issued. It implements the manufacturer's bulletin (Mitsubishi SB 156) and the Japan Civil Aviation Bureau AD to address possible excessive arcing in the series relay that could damage the aircraft."}},"importantCases":[],"_links":{"self":"/api/acts/ad-mu-2-32-replacement-of-series-relay-and-modification-to-the-two-battery-system","history":"/api/acts/ad-mu-2-32-replacement-of-series-relay-and-modification-to-the-two-battery-system/history","analysis":"/api/acts/ad-mu-2-32-replacement-of-series-relay-and-modification-to-the-two-battery-system/analysis","conflicts":"/api/acts/ad-mu-2-32-replacement-of-series-relay-and-modification-to-the-two-battery-system/conflicts","importantCases":"/api/acts/ad-mu-2-32-replacement-of-series-relay-and-modification-to-the-two-battery-system/important-cases","documents":"/api/acts/ad-mu-2-32-replacement-of-series-relay-and-modification-to-the-two-battery-system/documents"}}