{"id":"F2006B09065","name":"AD/DHC-3/17 - Engine Cooling","slug":"ad-dhc-3-17-engine-cooling","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52821,"registerId":"commonwealth-F2006B09065-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-3/17 - Engine Cooling","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 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  DHC-3 (Otter) Series Aeroplanes\n\n \n\nAD/DHC-3/17 Engine Cooling NK\n\nApplicability: All models.\n\n \n\nRequirement: 1. Unless it can be demonstrated, by flight test or otherwise, that adequate engine cooling is already provided, modify the augmentor tubes and intercylinder baffles to ensure that the maximum permissible engine cylinder head temperatures will not be exceeded in flight under Intercontinental Maximum Standard ambient temperature conditions.\n\n \n\nNote: De Havilland Australia, TNS DHC-3 Aust. No 1 provides a satisfactory augmentor tube modification.\n\n \n\n2. Tests conducted to justify engine cooling shall be carried out in accordance with a Flight Test Schedule approved by the Secretary.\n\n \n\nCompliance: Forthwith.\n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1565},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a targeted airworthiness directive addressing a specific technical safety issue (engine cooling) for a single aircraft type. The scope remains precisely focused on the original mechanical safety concern without expansion into broader operational or certification areas."},"complexity_factors":["Single technical requirement with one clear exception clause","Limited to specific aircraft model (DHC-3 Otter)","No nested legislative cross-references beyond the enabling Regulations","Straightforward compliance obligation (immediate action required)"],"plain_english_summary":"This safety order requires owners/operators of De Havilland DHC‑3 Otter aircraft in Australia to immediately modify the engine cooling system—upgrading augmentor tubes and intercylinder baffles—or, alternatively, demonstrate by flight testing or other means (with the test plan approved by the Secretary) that the engine remains within safe temperatures at Intercontinental Maximum Standard conditions. It’s aimed at preventing catastrophic engine overheating in Australia’s hot climate."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-3-17-engine-cooling","history":"/api/acts/ad-dhc-3-17-engine-cooling/history","analysis":"/api/acts/ad-dhc-3-17-engine-cooling/analysis","conflicts":"/api/acts/ad-dhc-3-17-engine-cooling/conflicts","importantCases":"/api/acts/ad-dhc-3-17-engine-cooling/important-cases","documents":"/api/acts/ad-dhc-3-17-engine-cooling/documents"}}