{"id":"F2006B07469","name":"AD/TPE 331/6 - Anti-Icing Shield - Modification","slug":"ad-tpe-331-6-anti-icing-shield-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49854,"registerId":"commonwealth-F2006B07469-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TPE 331/6 - Anti-Icing Shield - 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 331/6 Anti-Icing Shield - Modification 3/86\n\nApplicability: TPE-331-25A, -25D and -25F engines. Document:  AiResearch TPE-331 SB No. 10; or\n\nAD/AIR-T/3.\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\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2056},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This is a narrow, technical safety mandate targeting a single mechanical component on specific engine models. It remains strictly limited to its original purpose of requiring an anti-icing shield modification and has not expanded to cover broader operational or maintenance requirements."},"complexity_factors":["Single, unambiguous compliance requirement","No exceptions, exemptions, or conditional logic","Clear, immediate compliance timeframe ('forthwith')","Only three specific engine models affected","References external technical standard (Service Bulletin) rather than detailing steps within the text itself"],"plain_english_summary":"This is a mandatory safety order (called an Airworthiness Directive) that requires immediate action from aircraft owners and operators.\n\n**What it requires**\nIf you operate an aircraft with AlliedSignal TPE-331 turboprop engines (specifically models -25A, -25D, or -25F), you must modify the **anti-icing shield** — a component that prevents ice from building up on the engine intake.\n\n**How to comply**\nCarry out the modification exactly as described in the manufacturer's Service Bulletin No. 10 (or follow alternative directive AD/AIR-T/3). This must be done **immediately** (the legal term used is \"forthwith,\" meaning without delay).\n\n**Why it matters**\nIce buildup can choke the engine or damage internal components, potentially causing engine failure during flight. This directive ensures a specific safety fix is applied to prevent that risk."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tpe-331-6-anti-icing-shield-modification","history":"/api/acts/ad-tpe-331-6-anti-icing-shield-modification/history","analysis":"/api/acts/ad-tpe-331-6-anti-icing-shield-modification/analysis","conflicts":"/api/acts/ad-tpe-331-6-anti-icing-shield-modification/conflicts","importantCases":"/api/acts/ad-tpe-331-6-anti-icing-shield-modification/important-cases","documents":"/api/acts/ad-tpe-331-6-anti-icing-shield-modification/documents"}}