{"id":"F2006B08847","name":"AD/DC4/4 - Goodyear 20DHBM Type Wheels - Flange Replacement","slug":"ad-dc4-4-goodyear-20dhbm-type-wheels-flange-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52334,"registerId":"commonwealth-F2006B08847-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DC4/4 - Goodyear 20DHBM Type Wheels - Flange Replacement","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)  Douglas DC4 Series Aeroplanes\n\n \n\nAD/DC4/4  Goodyear 20DHBM Type NK Wheels - Flange Replacement\n\nDocument: 1. Goodyear SB (DC4) No. 1; or\n\n \n\n2. FAA AD 48-1-1; or 3. ANO 105.1.16.2.5.3.\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":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive focused specifically on wheel flange replacement for one aircraft type. It has not expanded beyond its original safety purpose."},"complexity_factors":["Extremely short document (approximately 150 words)","No defined terms section","No conditional logic or exceptions","Simple directive structure: identify affected aircraft, specify the part, cite technical references","Single operational requirement (flange replacement) with three alternative compliance paths","No cross-references to other legislation beyond the cited technical documents"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** issued by Australia's Civil Aviation Safety Authority (CASA) for **Douglas DC-4 aircraft**. Specifically, it mandates the replacement of wheel flanges on **Goodyear 20DHBM type wheels** (marked with \"NK\").\n\n**What it does:**\n- Requires aircraft operators to replace specific wheel flanges on the main landing gear wheels of DC-4 aeroplanes\n- References three alternative technical documents that provide the detailed instructions for this replacement:\n  - Goodyear Service Bulletin (SB) No. 1 for DC-4s\n  - US Federal Aviation Administration (FAA) AD 48-1-1\n  - Australian National Operations (ANO) 105.1.16.2.5.3\n\n**Who it affects:**\n- Owners and operators of Douglas DC-4 series aircraft in Australia\n- Maintenance organisations servicing these aircraft\n\n**Why it matters:**\n- Airworthiness Directives are legally binding safety orders. Compliance is mandatory.\n- Wheel flange failures can cause catastrophic accidents during takeoff or landing.\n- This AD ensures Australian DC-4 operators maintain their aircraft to the same safety standard as required in the US (via the FAA reference) and by the manufacturer (Goodyear)."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The text supplied sets a specific requirement: flange replacement for Goodyear 20DHBM type NK wheels on Douglas DC4 series aircraft and directs compliance to one of three listed documents. The excerpt contains no indication that the scope has been altered from an earlier or original intent; it defines the action and the acceptable sources for the procedure (Document: Goodyear SB (DC4) No. 1; FAA AD 48-1-1; ANO 105.1.16.2.5.3)."},"complexity_factors":["Directive text is short and targeted (single corrective action specified).","Compliance depends on three externally referenced documents rather than contained procedures, increasing practical complexity.","The AD excerpt does not include timing, enforcement, or exemption detail, leaving operational questions unresolved.","Potential for differences between referenced documents to create ambiguity for implementers."],"plain_english_summary":"This airworthiness directive (AD/DC4/4) mandates replacement of the flanges on Goodyear 20DHBM type NK wheels fitted to Douglas DC4 series aircraft. Compliance is achieved by following one of three referenced documents (Goodyear SB (DC4) No. 1; FAA AD 48-1-1; or ANO 105.1.16.2.5.3). \n\nIt affects DC4 owners/operators and maintenance organisations, who must carry out and fund the specified work to meet the AD."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dc4-4-goodyear-20dhbm-type-wheels-flange-replacement","history":"/api/acts/ad-dc4-4-goodyear-20dhbm-type-wheels-flange-replacement/history","analysis":"/api/acts/ad-dc4-4-goodyear-20dhbm-type-wheels-flange-replacement/analysis","conflicts":"/api/acts/ad-dc4-4-goodyear-20dhbm-type-wheels-flange-replacement/conflicts","importantCases":"/api/acts/ad-dc4-4-goodyear-20dhbm-type-wheels-flange-replacement/important-cases","documents":"/api/acts/ad-dc4-4-goodyear-20dhbm-type-wheels-flange-replacement/documents"}}