{"id":"F2006B08835","name":"AD/DC4/29 - Fire Detector Guard - Installation","slug":"ad-dc4-29-fire-detector-guard-installation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52288,"registerId":"commonwealth-F2006B08835-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DC4/29 - Fire Detector Guard - 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/DC4/29 Fire Detector Guard - Installation NK\n\nApplicability: All models.\n\n \n\nRequirement:  Install a guard over each Wilcolator fire detector in the baggage compartment which will adequately protect the unit from vertical and horizontal damage, but which will not impair the effectiveness of its heat detection.\n\n \n\nNote: Figure 1 of this Order provides details of an approved type of guard.\n\n \n\nor ANO 105.1.16.2.5.28.\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":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The Order applies to all Douglas DC-4 series aeroplanes and mandates installation of a guard over each Wilcolator fire detector in the baggage compartment. The text supplied sets that scope directly (Applicability; Requirement) and does not indicate any change from that stated intent within this instrument."},"complexity_factors":["Single, clearly stated technical requirement (install a guard over each Wilcolator fire detector in baggage compartment). (Requirement)","Applicability is simple and broad (all models). (Applicability)","Key technical constraint requires balancing protection vs. detector effectiveness, which requires engineering judgement or testing. (Requirement)","Reference to an approved design (Figure 1) reduces ambiguity about acceptable solution but introduces dependency on that document for detailed specification. (Note)","No compliance timeframe, penalty, or detailed approval procedure is contained in the text excerpt, which shifts complexity to the broader regulatory framework. (Header; Order text)","Potential supplier/approval effects from naming an approved design (Note) — practical complexity in procurement, but not legal complexity in the Order itself."],"plain_english_summary":"This Order requires owners/operators of Douglas DC‑4 series aeroplanes to fit an approved physical guard over every Wilcolator fire detector in the baggage compartment to protect against vertical and horizontal damage without impairing heat sensing. It points to an approved design (Figure 1) and references ANO 105.1.16.2.5.28.\n\nThe rule mainly affects aircraft operators, maintenance organisations, engineers and parts suppliers, imposing parts, labour and technical checks to demonstrate compliance; the Order sets performance expectations but gives no enforcement timing or test procedures."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive focused specifically on fire detector protection for one aircraft type. It has not expanded beyond its original technical purpose."},"complexity_factors":["Extremely short — single substantive requirement","Only one defined term implicitly referenced ('Wilcolator' — a proprietary fire detector brand)","No cross-references to other legislation except a single alternative compliance path (ANO reference)","No conditional logic, exceptions, or nested provisions","Single applicability criterion ('All models') with no exclusions","Visual reference to Figure 1 (diagram) not reproduced in text"],"plain_english_summary":"**What this is:** An Airworthiness Directive (AD) for Douglas DC-4 aircraft — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA).\n\n**What it requires:** Owners and operators of all DC-4 models must install protective guards over the Wilcolator fire detectors located in the baggage compartment. These guards must:\n- **Protect the detectors** from damage coming from above (vertical) and from the sides (horizontal)\n- **Not block heat detection** — the guards can't interfere with the detector's ability to sense fire\n\n**Who it affects:** Anyone who owns, operates, or maintains Douglas DC-4 series aeroplanes (a vintage four-engine propeller aircraft from the 1940s).\n\n**Why it matters:** Fire detectors in baggage compartments are critical safety equipment. Without protection, they could be physically damaged by luggage or cargo, potentially leaving the aircraft without early fire warning. This directive prevents that failure mode while ensuring the detectors still work properly.\n\n**Compliance path:** The directive references an approved design (Figure 1 in the Order) and an alternative regulatory reference (ANO 105.1.16.2.5.28 — an old Air Navigation Order for those following earlier compliance standards)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dc4-29-fire-detector-guard-installation","history":"/api/acts/ad-dc4-29-fire-detector-guard-installation/history","analysis":"/api/acts/ad-dc4-29-fire-detector-guard-installation/analysis","conflicts":"/api/acts/ad-dc4-29-fire-detector-guard-installation/conflicts","importantCases":"/api/acts/ad-dc4-29-fire-detector-guard-installation/important-cases","documents":"/api/acts/ad-dc4-29-fire-detector-guard-installation/documents"}}