{"id":"F2006B08851","name":"AD/DC4/8 - Oxygen Regulator - Relocation","slug":"ad-dc4-8-oxygen-regulator-relocation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52345,"registerId":"commonwealth-F2006B08851-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DC4/8 - Oxygen Regulator - Relocation","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/DC4/8 Oxygen Regulator - Relocation NK\n\nDocument: 1. Douglas SB (C54) No. 247 dated 16 November 1945; or\n\n \n\n2. FAA AD 46-11-2; or\n\n \n\n3. ANO 105.1.16.2.5.7.\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\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This appears to be a historical airworthiness directive from the 1940s-1950s era (referencing documents from 1945-1946). It has not grown beyond its original narrow purpose of addressing a specific safety modification to oxygen regulators on a single aircraft type."},"complexity_factors":["Extremely short document — only a few lines of substantive content","No defined terms section","No conditional logic or nested exceptions","Simple directive structure: identifies aircraft type, describes required action, lists reference documents","Minimal cross-referencing (only three external technical documents cited)","No procedural steps or compliance timelines specified in the excerpt provided"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** for **Douglas DC-4 series aircraft** — a type of four-engine propeller plane that was common in the 1940s and 1950s.\n\n**What it does:**\nThe directive requires owners or operators of these aircraft to **relocate the oxygen regulator** — the device that controls the flow of oxygen to the crew and passengers at high altitudes. The directive references three technical documents that provide the specific instructions for how to do this:\n- A Douglas service bulletin from November 1945\n- An FAA (American aviation regulator) directive from 1946\n- An old Australian aviation order\n\n**Who it affects:**\nAnyone who still operates a Douglas DC-4 aircraft in Australia. These are mostly vintage or heritage aircraft now, as the type was largely retired from commercial service decades ago.\n\n**Why it matters:**\nOxygen systems are critical safety equipment. If the regulator is in the wrong location, it could fail to deliver oxygen properly during an emergency decompression at altitude, potentially endangering crew and passengers. This directive ensures the aircraft meets minimum safety standards to remain airworthy."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"There is no indication in the supplied text that the scope of the requirement has been changed from the original instrument. The AD is limited to Douglas DC‑4 series aeroplanes and requires relocation of an oxygen regulator by following one of the three listed documents (AD/DC4/8 Documents 1–3)."},"complexity_factors":["Single, narrowly focused requirement (relocate oxygen regulator) reduces substantive complexity.","Cross‑references to three external technical documents (Douglas SB C54 No.247 (1945); FAA AD 46‑11‑2; ANO 105.1.16.2.5.7) require operators/maintainers to obtain and apply external material.","One referenced document is a vintage 1945 service bulletin, which may complicate sourcing and interpretation.","The legal force derives from the AD listing in Part 39 – 105, so procedural and enforcement clarity is high (low regulatory complexity).","Lack of explanatory material in the AD text supplied means practical intent and scope must be inferred from the title and references rather than from an explicit statement in the instrument."],"plain_english_summary":"This airworthiness directive requires owners/operators of Douglas DC‑4 series aeroplanes to relocate an oxygen regulator, with compliance mandated by one of three referenced technical authorities (a Douglas service bulletin, an FAA AD, or an ANO reference). It matters because the modification is legally compulsory for continued airworthiness, placing planning, parts, labour and documentation costs on the small group of operators still flying DC‑4s and potentially raising practical issues from relying on vintage technical material."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dc4-8-oxygen-regulator-relocation","history":"/api/acts/ad-dc4-8-oxygen-regulator-relocation/history","analysis":"/api/acts/ad-dc4-8-oxygen-regulator-relocation/analysis","conflicts":"/api/acts/ad-dc4-8-oxygen-regulator-relocation/conflicts","importantCases":"/api/acts/ad-dc4-8-oxygen-regulator-relocation/important-cases","documents":"/api/acts/ad-dc4-8-oxygen-regulator-relocation/documents"}}