{"id":"F2006B07450","name":"AD/TPE 331/4 - Propeller Pitch Control - Modification","slug":"ad-tpe-331-4-propeller-pitch-control-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49779,"registerId":"commonwealth-F2006B07450-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TPE 331/4 - Propeller Pitch Control - 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 - 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  AlliedSignal (Garrett/AiResearch) Turbine Engines - TPE 331 Series\n\n \n\nAD/TPE 331/4 Propeller Pitch Control - Modification 3/86\n\nApplicability: TPE-331 series with S/Nos. 61001 to 61117, 61201 to 61223, 61403 to 61409 and\n\n61802 to 61809.\n\n \n\nRequirement: AiResearch TPE-331 SB No. 7; or\n\n \n\nAD/AIR-T/1.\n\n \n\nCompliance: Forthwith.\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\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2317},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive with a narrow scope limited to specific engine serial numbers and a single technical modification. There is no evidence of scope expansion beyond the original safety issue."},"complexity_factors":["Extremely brief text (under 150 words)","Only two alternative compliance pathways","External cross-references to technical documents (Service Bulletin No. 7 and AD/AIR-T/1)","No interpretation section or defined terms","Simple applicability criteria limited to specific serial number ranges","Immediate compliance deadline without conditional triggers or exceptions"],"plain_english_summary":"This AD requires an immediate modification to the propeller pitch control system on AlliedSignal (Garrett/AiResearch) TPE-331 turbine engines of the specified serial-number ranges, affecting owners and operators of those aircraft. Compliance must be carried out forthwith using AiResearch Service Bulletin No. 7 or the alternative AD/AIR‑T/1 because the defect could compromise propeller control and flight safety."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tpe-331-4-propeller-pitch-control-modification","history":"/api/acts/ad-tpe-331-4-propeller-pitch-control-modification/history","analysis":"/api/acts/ad-tpe-331-4-propeller-pitch-control-modification/analysis","conflicts":"/api/acts/ad-tpe-331-4-propeller-pitch-control-modification/conflicts","importantCases":"/api/acts/ad-tpe-331-4-propeller-pitch-control-modification/important-cases","documents":"/api/acts/ad-tpe-331-4-propeller-pitch-control-modification/documents"}}