{"id":"F2006B05707","name":"AD/PA-31/12 - Engine Control System - Inspection and Modification","slug":"ad-pa-31-12-engine-control-system-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135506,"registerId":"commonwealth-F2006B05707-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-31/12 - Engine Control System - Inspection and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-31 Series Aeroplanes\n\n \n\nAD/PA-31/12 Engine Control System - Inspection\n\nand Modification\n\n\n6/70\n\n \n\nApplicability: All models with S/Nos. 31-2, 31-4 to 31-526, 31-528 to 31-536, 31-538 to 31-561,\n\n31-563 to 31-578, 31-580 to 31-584, 31-586 to 31-596, 31-598 to 31-599, 31-602,\n\n31-604 to 31-606, 31-614, 31-619, 31-621, 31-623 to 31-626, 31-629 to 31-632, 31-\n\n637 and 31-641.\n\n \n\nDocument: Piper SL No. 548.\n\n \n\nCompliance: Within 100 hours time in service after 30 June 1970.\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":1613},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This directive maintains its original 1970 scope. It remains narrowly targeted at the specific engine control system modification for the listed Piper PA-31 serial numbers, with no expansion to additional aircraft systems or models."},"complexity_factors":["Fragmented applicability list requiring cross-checking of 30+ separate serial number ranges","External technical reference to Piper Service Letter 548 (not reproduced in the directive)","Technical aviation term 'time in service' used for compliance calculation"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of certain Piper PA‑31 aircraft (specific serial number ranges) to inspect and modify the engine control system per Piper Service Letter No. 548. The work must be completed within 100 flight hours after 30 June 1970. It corrects a known safety defect and compliance is legally mandatory."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-31-12-engine-control-system-inspection-and-modification","history":"/api/acts/ad-pa-31-12-engine-control-system-inspection-and-modification/history","analysis":"/api/acts/ad-pa-31-12-engine-control-system-inspection-and-modification/analysis","conflicts":"/api/acts/ad-pa-31-12-engine-control-system-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-pa-31-12-engine-control-system-inspection-and-modification/important-cases","documents":"/api/acts/ad-pa-31-12-engine-control-system-inspection-and-modification/documents"}}