{"id":"F2006B07245","name":"AD/T53/16 - Power Turbine Clamping Plate - Inspection","slug":"ad-t53-16-power-turbine-clamping-plate-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49126,"registerId":"commonwealth-F2006B07245-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/T53/16 - Power Turbine Clamping Plate - Inspection","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/T53/16 Power Turbine Clamping Plate - Inspection 1/86\n\nApplicability: All T5313A, T5313B, T53-L-13A and T53-L-13B Series engines, and power turbine rotor assemblies listed by S/No. in Lycoming SB No. 0041; and all spare clamping plates P/N 1-140-144-2.\n\n \n\nDocument: 1. Lycoming SB No. 0041; or\n\n \n\n2. AD/LYC-T/17.\n\n \n\nCompliance: As per paragraph 1Da and 1Db of Lycoming SB 0041.\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":1319},"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow, technical scope. It was always intended as a targeted safety intervention for specific engine models and remains limited to clamping plate inspections. No expansion of subject matter or affected parties has occurred."},"complexity_factors":["Relies entirely on external technical document (Lycoming SB No. 0041) for actual inspection procedures","Contains specific aviation part numbers (P/N 1-140-144-2) and serial number lists requiring cross-referencing","Assumes technical knowledge of turbine engine architecture (power turbine rotor assemblies)","References superseded or parallel directives (AD/LYC-T/17) without explanation"],"plain_english_summary":"**What this does:**\nThis is a mandatory safety instruction (called an **Airworthiness Directive**) requiring inspections of **power turbine clamping plates** on specific Lycoming T53 aircraft engines.\n\n**Who it affects:**\n*   Operators of aircraft fitted with T5313A, T5313B, T53-L-13A or T53-L-13B engines (commonly used in helicopters like the Bell UH-1 Iroquois)\n*   Anyone holding spare clamping plates part number 1-140-144-2\n*   Owners of specific power turbine rotor assemblies listed by serial number in Lycoming Service Bulletin No. 0041\n\n**What must be done:**\nAircraft owners must inspect the clamping plates according to the procedures in **Lycoming Service Bulletin No. 0041** (paragraphs 1Da and 1Db). This is to detect cracks or defects that could cause the power turbine to fail in flight.\n\n**Why it matters:**\nA failed clamping plate can cause catastrophic engine failure. This rule makes the inspection legally mandatory rather than just a manufacturer recommendation."}},"importantCases":[],"_links":{"self":"/api/acts/ad-t53-16-power-turbine-clamping-plate-inspection","history":"/api/acts/ad-t53-16-power-turbine-clamping-plate-inspection/history","analysis":"/api/acts/ad-t53-16-power-turbine-clamping-plate-inspection/analysis","conflicts":"/api/acts/ad-t53-16-power-turbine-clamping-plate-inspection/conflicts","importantCases":"/api/acts/ad-t53-16-power-turbine-clamping-plate-inspection/important-cases","documents":"/api/acts/ad-t53-16-power-turbine-clamping-plate-inspection/documents"}}