{"id":"F2006B06163","name":"AD/PDH/4 - Model 4/4000/6 Blade - Modification","slug":"ad-pdh-4-model-4-4000-6-blade-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46983,"registerId":"commonwealth-F2006B06163-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PDH/4 - Model 4/4000/6 Blade - 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 - 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Propellers - Variable Pitch - De Havilland\n\n \n\nAD/PDH/4 Model 4/4000/6 Blade - Modification NK\n\nApplicability: All blades fitted to types PD66/446/2 and PD96/446/1 propellers. Document:  1. DH MHS Series 4HF No. 118; or\n\n2. ANO 107.1.4.9.5.1.\n\n \n\nCompliance: Before installation in an aircraft.\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":1439},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"Standard Airworthiness Directive limited to specific De Havilland propeller models. The scope is precisely targeted at the identified blade models and does not appear to have expanded beyond the original technical safety issue."},"complexity_factors":["Very short single requirement with no exceptions or conditional logic","Technical aviation terminology requires specialized knowledge to identify affected parts","Substantive content depends on external technical documents not included in the legislative text","No defined terms section or interpretive provisions"],"plain_english_summary":"**What this is:** A mandatory safety instruction (called an Airworthiness Directive) issued by the Civil Aviation Safety Authority (CASA) for specific aircraft propeller blades.\n\n**Who it affects:** Anyone who owns, maintains, or operates aircraft using **De Havilland variable pitch propellers** (specifically models PD66/446/2 and PD96/446/1) fitted with **Model 4/4000/6 blades**.\n\n**What it requires:** Before installing any of these blades on an aircraft, you must carry out a specific modification to the blade. The exact steps for the modification are found in two technical documents:\n- De Havilland Maintenance Handbook Series 4HF No. 118, or\n- Airworthiness Notice 107.1.4.9.5.1\n\n**Why it matters:** This ensures the propeller blades meet current safety standards and are airworthy (safe to fly) before being put into service. Ignoring this directive would violate aviation safety regulations."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pdh-4-model-4-4000-6-blade-modification","history":"/api/acts/ad-pdh-4-model-4-4000-6-blade-modification/history","analysis":"/api/acts/ad-pdh-4-model-4-4000-6-blade-modification/analysis","conflicts":"/api/acts/ad-pdh-4-model-4-4000-6-blade-modification/conflicts","importantCases":"/api/acts/ad-pdh-4-model-4-4000-6-blade-modification/important-cases","documents":"/api/acts/ad-pdh-4-model-4-4000-6-blade-modification/documents"}}