{"id":"F2006B06376","name":"AD/PT6T/6 - Fuel Pump Coupling - Replacement","slug":"ad-pt6t-6-fuel-pump-coupling-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47645,"registerId":"commonwealth-F2006B06376-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PT6T/6 - Fuel Pump Coupling - Replacement","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 - 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Pratt and Whitney Canada Turbine Engines - PT6T Series\n\n \n\nAD/PT6T/6 Fuel Pump Coupling - Replacement 10/85\n\nApplicability:   PT6T-3, -3B, -6; ST6T-75, -76.\n\n \n\nDocument: 1. Pratt and Whitney Aircraft of Canada SB No. 5184; or\n\n \n\n2. AD/UAC-T/36.\n\nCompliance:  If not already accomplished the new drive coupling is to be fitted by 31 January 1981. Background:   In Australia and overseas, fuel pump decouples have occurred on some models of\n\nPT6 engines with similar fuel pump drive couplings. This Directive is issued in order to preclude pump decouples on twin PT6 engines by replacing the existing fuel pump drive coupling with a new coupling incorporating a flange to restrict axial movement.\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":1521},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow technical scope—addressing a specific mechanical defect in specific engine models through mandatory parts replacement. It has not expanded beyond this targeted safety purpose."},"complexity_factors":["Single, unambiguous mechanical action required (parts replacement)","Narrow applicability limited to 5 specific engine model variants","Single fixed compliance deadline with no conditional extensions","No nested exceptions, provisos, or conditional logic","Minimal cross-referencing (only 2 supporting technical documents referenced)"],"plain_english_summary":"This mandatory airworthiness directive required owners/operators to replace the fuel-pump drive coupling on specific Pratt & Whitney Canada PT6T engine models with an improved coupling that has a flange to stop axial movement and prevent the pump from sliding off the drive shaft. It affects operators of those twin-engine helicopter powerplants and maintenance engineers; the change addresses past pump decoupling incidents that could cause single- or dual-engine failure. The retrofit deadline was 31 January 1981."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pt6t-6-fuel-pump-coupling-replacement","history":"/api/acts/ad-pt6t-6-fuel-pump-coupling-replacement/history","analysis":"/api/acts/ad-pt6t-6-fuel-pump-coupling-replacement/analysis","conflicts":"/api/acts/ad-pt6t-6-fuel-pump-coupling-replacement/conflicts","importantCases":"/api/acts/ad-pt6t-6-fuel-pump-coupling-replacement/important-cases","documents":"/api/acts/ad-pt6t-6-fuel-pump-coupling-replacement/documents"}}