{"id":"F2006B10482","name":"AD/HS 125/43 - Emergency Brake Valve Knife Edges - Inspection and Replacement","slug":"ad-hs-125-43-emergency-brake-valve-knife-edges-inspection-and-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116227,"registerId":"commonwealth-F2006B10482-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 125/43 - Emergency Brake Valve Knife Edges - Inspection and 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)  British Aerospace BAe 125 Series Aeroplanes\n\n \n\nAD/HS 125/43  Emergency Brake Valve Knife Edges - Inspection and Replacement\n\n\n4/76\n\n \n\nThis AD contents has been removed from the listing because the aircraft model is not currently on the register.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\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 standard administrative deactivation of a safety directive when the affected aircraft fleet no longer operates in Australian airspace. The scope remains precisely targeted at the original aircraft type and component; it has not expanded or morphed into broader regulatory territory."},"complexity_factors":["Extremely short document (under 200 words)","No defined terms section","No cross-references to other legislation","No conditional logic or nested exceptions","Simple binary status (active/removed based on aircraft registration)","Technical content limited to a single mechanical component reference"],"plain_english_summary":"This document is an **Airworthiness Directive (AD)** — a mandatory safety notice issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific maintenance actions on aircraft.\n\n**What it covers:**\n- **Aircraft type:** British Aerospace BAe 125 series business jets\n- **Issue:** Emergency brake valve \"knife edges\" — these are precision-machined sealing surfaces in the aircraft's emergency braking system\n- **Required action:** Inspection and replacement of these components\n\n**Current status:**\nThis directive has been **removed from active listings** because no BAe 125 aircraft are currently registered in Australia. The directive still exists in the regulations but is effectively dormant — it would only become relevant again if an aircraft of this type were added to the Australian register.\n\n**Why this matters:**\nAirworthiness Directives are legally binding safety instructions. Even though this one is currently inactive, it illustrates how aviation safety regulators maintain detailed technical oversight of aircraft systems — right down to specific mechanical components like brake valve edges — and how they manage regulatory burden by shelving requirements when no affected aircraft operate in their jurisdiction."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The document as presented no longer has active scope for Australian-registered aircraft because it states: \"This AD contents has been removed from the listing because the aircraft model is not currently on the register.\" The original scope implied by the AD title would have applied to British Aerospace BAe 125 series aeroplanes; the removal note indicates the listing no longer applies to any Australian-registered examples, so current practical scope in the Australian register is nil (see removal note)."},"complexity_factors":["Very brief source text: title and a short removal note only, no procedural detail or compliance schedule present (see AD title and removal note).","Technical specificity implied: component-level work (\"emergency brake valve knife edges\") requires specialised maintenance knowledge, but instructions are not included.","Regulatory context: appears in a formal schedule under the Civil Aviation Safety Authority header, creating jurisdictional implications without the full AD wording.","Historical/administrative status: the entry is marked removed from the listing because the model is not on the register, which changes practical scope but leaves open whether the AD exists elsewhere in a full form.","Unspecified enforcement and cost data: absence of explicit compliance times, inspection methods, or cost estimates increases uncertainty for operators and maintainers."],"plain_english_summary":"This AD requires inspection—and replacement if needed—of the emergency brake valve knife edges on British Aerospace BAe 125 series aeroplanes to address a safety concern with that component. It affects operators, owners and maintenance organisations responsible for BAe 125s and imposes inspection, parts and downtime costs. The listing notes the entry was removed because no BAe 125s are currently on the Australian register."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-125-43-emergency-brake-valve-knife-edges-inspection-and-replacement","history":"/api/acts/ad-hs-125-43-emergency-brake-valve-knife-edges-inspection-and-replacement/history","analysis":"/api/acts/ad-hs-125-43-emergency-brake-valve-knife-edges-inspection-and-replacement/analysis","conflicts":"/api/acts/ad-hs-125-43-emergency-brake-valve-knife-edges-inspection-and-replacement/conflicts","importantCases":"/api/acts/ad-hs-125-43-emergency-brake-valve-knife-edges-inspection-and-replacement/important-cases","documents":"/api/acts/ad-hs-125-43-emergency-brake-valve-knife-edges-inspection-and-replacement/documents"}}