{"id":"F2006B08850","name":"AD/DC4/7 - Tail Pipe Shroud Deflector - Installation","slug":"ad-dc4-7-tail-pipe-shroud-deflector-installation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52342,"registerId":"commonwealth-F2006B08850-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DC4/7 - Tail Pipe Shroud Deflector - Installation","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/DC4/7 Tail Pipe Shroud Deflector - Installation NK\n\nDocument: 1. Douglas SB (C54) No. 289 Addendum; or 2. FAA AD 48-14-4; or\n\n3. ANO 105.1.16.2.5.6.\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 the original scope of the AD — a targeted safety modification for a specific aircraft type. There is no evidence of scope creep; it remains focused on the single technical issue of exhaust deflector installation for DC-4 series aircraft."},"complexity_factors":["Extremely short document — essentially a reference pointer to other technical documents rather than standalone instructions","Only one substantive requirement (install the deflector)","No defined terms section — relies entirely on external technical references","No conditional logic or exceptions — simple mandatory compliance","Cross-references to 3 external documents, but these are listed rather than integrated","Minimal legislative machinery — this is an administrative safety order, not a statute with interpretive sections"],"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-1960s.\n\n**What it does:**\nThe directive requires owners and operators of these aircraft to install a **tail pipe shroud deflector** — a metal shield or guard fitted around the exhaust tail pipe. This prevents exhaust flames or hot gases from damaging nearby parts of the aircraft or causing fire hazards.\n\n**Who it affects:**\n- Anyone who owns or operates a Douglas DC-4, C-54, or related variants (military or civilian versions)\n- Maintenance organisations servicing these aircraft\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety orders. If you don't comply, you cannot legally fly the aircraft. This particular AD addresses a fire risk from engine exhaust — a serious safety issue in piston-engine aircraft.\n\n**How to comply:**\nOperators must follow one of three referenced documents:\n1. **Douglas Service Bulletin (SB) No. 289 Addendum** — manufacturer's official repair instruction\n2. **FAA AD 48-14-4** — the original US safety order this is based on\n3. **ANO 105.1.16.2.5.6** — an older Australian airworthiness notice\n\nThe \"NK\" marking indicates this applies to aircraft with **NK** (likely a specific engine or configuration variant — though the exact meaning would require checking the full AD register)."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The provided AD text sets out a specific technical requirement (installation of a tail pipe shroud deflector) and lists three documents as acceptable means of compliance. There is no indication in the text supplied that the AD's scope has been changed from an earlier stated intent; the instrument confines its requirement to Douglas DC4 series aeroplanes and points to the listed documents for implementation, so the scope appears unchanged based on the material given."},"complexity_factors":["Single, narrowly framed requirement (installation of one item) reduces legal complexity","Multiple acceptable compliance documents (three different references) increases practical complexity because operators choose among methods","Affected fleet consists of an older aircraft type (Douglas DC4/C54), raising parts availability and maintenance-resource complexity","Regulatory embedding: enforcement and record-keeping rely on the broader CASA/Part 39 airworthiness framework, which requires cross-referencing to other regulatory material","Sparse textual detail in the AD itself (no procedural steps or timelines in the provided text) shifts complexity to the referenced documents"],"plain_english_summary":"This AD requires owners/operators and their maintenance organisations to fit a tail‑pipe shroud deflector on Douglas DC4 series aircraft, with compliance achieved by following one of three specified technical documents.  \n\nIssued by CASA and enforced as an airworthiness directive, it’s a mandatory configuration change affecting operators’ costs, downtime and parts/labour arrangements while providing a prescribed safety modification."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dc4-7-tail-pipe-shroud-deflector-installation","history":"/api/acts/ad-dc4-7-tail-pipe-shroud-deflector-installation/history","analysis":"/api/acts/ad-dc4-7-tail-pipe-shroud-deflector-installation/analysis","conflicts":"/api/acts/ad-dc4-7-tail-pipe-shroud-deflector-installation/conflicts","importantCases":"/api/acts/ad-dc4-7-tail-pipe-shroud-deflector-installation/important-cases","documents":"/api/acts/ad-dc4-7-tail-pipe-shroud-deflector-installation/documents"}}