{"id":"F2006B07249","name":"AD/T53/2 - First Stage Power Turbine Rotor Blade Retaining Pins Retirement Life","slug":"ad-t53-2-first-stage-power-turbine-rotor-blade-retaining-pins-retirement-life","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49137,"registerId":"commonwealth-F2006B07249-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/T53/2 - First Stage Power Turbine Rotor Blade Retaining Pins Retirement Life","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)  AlliedSignal (Lycoming) Turbine Engines - T53 Series\n\n \n\nAD/T53/2 First Stage Power Turbine Rotor Blade\n\nRetaining Pins Retirement Life\n\n\n1/86\n\n \n\nApplicability: T5313A, T5313A S/N Suffix \"A\", T5313B S/N LEO7500 to LEO7513 and LEO7528 to LEO7532. T53-L-13, T53-L-13 S/N Suffix \"A\" T53-L-13A and T53-L-13B S/N\n\nprior to LE22568.\n\n \n\nDocument: 1. Lycoming Product Support Service Bulletin No. 0003, Rev. 5; or\n\n \n\n2. AD/LYC-T/5B. Compliance: 30 November 1973.\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":2532},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow scope focused solely on the retirement of specific retaining pins in identified T53 engine models. Despite bearing a 1986 publication date with a 1973 compliance deadline (suggesting republication or consolidation), there is no indication of scope expansion beyond the original pin retirement requirement."},"complexity_factors":["Extremely brief instrument incorporating external technical standard by reference (Lycoming Service Bulletin)","Applicability limited to specific engine models and discrete serial number ranges","Single, unambiguous compliance action (retirement/replacement of parts) with absolute deadline","No defined terms, nested exceptions, or conditional logic within the instrument itself"],"plain_english_summary":"This AD mandates permanent removal of first-stage power turbine rotor blade retaining pins from certain AlliedSignal (Lycoming) T53-series engines, requiring compliance with Lycoming Service Bulletin No. 0003 (Rev. 5) or earlier AD/LYC-T/5B. It affects owners/operators of specified T53 engine serial ranges and had a compliance deadline of 30 November 1973. Retiring these pins prevents catastrophic blade loss and engine failure, protecting aircraft control and safety."}},"importantCases":[],"_links":{"self":"/api/acts/ad-t53-2-first-stage-power-turbine-rotor-blade-retaining-pins-retirement-life","history":"/api/acts/ad-t53-2-first-stage-power-turbine-rotor-blade-retaining-pins-retirement-life/history","analysis":"/api/acts/ad-t53-2-first-stage-power-turbine-rotor-blade-retaining-pins-retirement-life/analysis","conflicts":"/api/acts/ad-t53-2-first-stage-power-turbine-rotor-blade-retaining-pins-retirement-life/conflicts","importantCases":"/api/acts/ad-t53-2-first-stage-power-turbine-rotor-blade-retaining-pins-retirement-life/important-cases","documents":"/api/acts/ad-t53-2-first-stage-power-turbine-rotor-blade-retaining-pins-retirement-life/documents"}}