{"id":"F2006B05472","name":"AD/PA-23/46 - Exhaust System - Inspection and Modification","slug":"ad-pa-23-46-exhaust-system-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46260,"registerId":"commonwealth-F2006B05472-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-23/46 - Exhaust System - Inspection and 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)  Piper PA-23 (Apache and Aztec) Series Aeroplanes\n\n \n\nAD/PA-23/46 Exhaust System - Inspection and Modification 7/71\n\nApplicability: Models PA-23-250 and PA-E23-250 with S/Nos. 27-2505 to 27-4653 excepting 27-4560, 27-4576, 27-4620 and 27-4651.\n\n \n\nDocument: Piper SB No. 319.\n\n \n\nCompliance: Within 100 hours time in service after 30 July 1971.\n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2569},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This airworthiness directive maintains its original narrow scope targeting exhaust system safety for specific aircraft models. There is no indication of scope expansion beyond the original technical safety issue identified in the manufacturer's service bulletin."},"complexity_factors":["Narrow applicability limited to specific aircraft serial number ranges with four explicit exclusions","Reference to external technical document (Piper SB No. 319) without reproducing its content, requiring access to manufacturer documentation","Use of aviation-specific compliance metric (hours 'time in service' rather than calendar dates)"],"plain_english_summary":"**What this requires**\nThis safety directive orders owners and operators of specific Piper Apache and Aztec aircraft to inspect and modify their exhaust systems according to manufacturer guidelines.\n\n**Who it applies to**\nOwners of Piper PA-23-250 and PA-E23-250 model aircraft with serial numbers from 27-2505 to 27-4653. Four specific aircraft are excluded from this requirement: serial numbers 27-4560, 27-4576, 27-4620, and 27-4651.\n\n**What must be done**\nAircraft operators must follow the procedures outlined in **Piper Service Bulletin No. 319** (the manufacturer's technical safety instructions) to inspect and modify the exhaust system.\n\n**Compliance deadline**\nThe work must be completed within 100 hours of flight time accumulated after 30 July 1971.\n\n**Why it matters**\nThis ensures the exhaust systems on these specific aircraft remain airworthy, preventing potential failures that could create safety hazards during flight."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-23-46-exhaust-system-inspection-and-modification","history":"/api/acts/ad-pa-23-46-exhaust-system-inspection-and-modification/history","analysis":"/api/acts/ad-pa-23-46-exhaust-system-inspection-and-modification/analysis","conflicts":"/api/acts/ad-pa-23-46-exhaust-system-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-pa-23-46-exhaust-system-inspection-and-modification/important-cases","documents":"/api/acts/ad-pa-23-46-exhaust-system-inspection-and-modification/documents"}}