{"id":"F2006B07351","name":"AD/TB20/5 - Battery Tray Installation","slug":"ad-tb20-5-battery-tray-installation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49448,"registerId":"commonwealth-F2006B07351-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TB20/5 - Battery Tray Installation","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)  Aerospatiale (Socata) TB20 (Trinidad) Series Aeroplanes\n\n \n\nAD/TB20/5 Battery Tray Installation 10/85\n\nApplicability: All models TB20 series with S/Nos up to 441 but excluding S/Nos 343, 382, 414, 423, 425 to 429 and 434 to 438.\n\n \n\nRequirement: Inspect and modify the battery tray installation in accordance with the requirements detailed in Socata Service Letter No. 18 under description paragraph 1. Pay particular attention to surrounding fuselage structure for signs of electrolyte spillage and subsequent damage.\n\n \n\nNote: French AD 85-130-(A) refers.\n\n \n\nCompliance: Within 50 hours time in service after 31 October 1985.\n\n \n\nBackground:  The battery tray installation may be such that electrolyte spillage from the battery could cause fuselage structural damage due to corrosion.\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, single-issue airworthiness directive from 1985 addressing a specific battery tray corrosion risk. It has not expanded beyond its original narrow technical scope."},"complexity_factors":["Single, specific technical requirement referencing an external document (Socata Service Letter No. 18)","Narrow applicability: only affects one aircraft model series with specific serial number exclusions","Simple compliance deadline: 50 hours time in service after a fixed date","No defined terms section, no cross-references to other legislation, no conditional logic or nested exceptions","Total length: approximately 250 words","Single operational requirement with one background note"],"plain_english_summary":"This AD requires owners/operators of Socata TB20 Trinidad aeroplanes (serials up to 441, with specified exclusions) to inspect and, if needed, modify the battery tray per Socata Service Letter No. 18 because electrolyte leakage can corrode fuselage structure. \n\nCompliance is mandatory within 50 flight hours after 31 October 1985 — a safety-critical, legally binding action to prevent structural failure from battery-acid corrosion."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive targets a defined subset of TB20 serial numbers and mandates inspection/modification to address a stated corrosion risk. It implements a targeted corrective requirement rather than expanding applicability beyond the listed aircraft."},"complexity_factors":["Dependency on an external document (Socata Service Letter No. 18) for technical detail and corrective steps.","Serial-number applicability with multiple explicit exclusions requires careful applicability checks.","Short compliance window tied to a fixed date (50 hours after 31 October 1985) creates scheduling pressure for operators.","Requires technical inspection for electrolyte spillage and corrosion, relying on maintenance judgement to assess damage and necessary repairs.","Cross-reference to a foreign airworthiness directive (French AD 85-130-(A)) which may require review for consistency."],"plain_english_summary":"This airworthiness directive requires owners/operators of specified Aerospatiale (Socata) TB20 aeroplanes (serial numbers up to 441, with listed exclusions) to inspect and modify the battery tray installation in accordance with Socata Service Letter No. 18, paying particular attention to electrolyte spillage and subsequent fuselage corrosion. Compliance is required within 50 flight hours after 31 October 1985.\n\nThe obligation and any costs rest with aircraft owners/operators; the AD delegates technical detail and remedial action to the manufacturer’s service instructions and maintenance judgement."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tb20-5-battery-tray-installation","history":"/api/acts/ad-tb20-5-battery-tray-installation/history","analysis":"/api/acts/ad-tb20-5-battery-tray-installation/analysis","conflicts":"/api/acts/ad-tb20-5-battery-tray-installation/conflicts","importantCases":"/api/acts/ad-tb20-5-battery-tray-installation/important-cases","documents":"/api/acts/ad-tb20-5-battery-tray-installation/documents"}}