{"id":"F2006B10489","name":"AD/HS 125/50 - Oxygen Supply Valve - Inspection and Modification","slug":"ad-hs-125-50-oxygen-supply-valve-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116241,"registerId":"commonwealth-F2006B10489-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 125/50 - Oxygen Supply Valve - Inspection and Modification","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 125/50 Oxygen Supply Valve - Inspection\n\nand Modification\n\nApplicability: As detailed in the requirement documents. Document: Hawker Siddeley SB 35,A25; or\n\nFAA AD 77-26-01.\n\n \n\nCompliance: As detailed in the requirement document.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n\n2/78\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 oxygen supply valve inspection and modification for one aircraft series. It has not expanded beyond its original safety purpose."},"complexity_factors":["Extremely short document (approximately 150 words)","No defined terms section — relies entirely on external referenced documents","No conditional logic or exceptions within the text itself","Simple structure: applicability, document reference, compliance requirement","All technical complexity is outsourced to referenced documents (Hawker Siddeley SB 35,A25 and FAA AD 77-26-01)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order — issued by Australia's Civil Aviation Safety Authority (CASA) for a specific type of aircraft.\n\n**What it does:**\n- Requires owners and operators of **British Aerospace BAe 125 series aeroplanes** (business jets) to inspect and modify the **oxygen supply valve** on these aircraft.\n- The directive references technical documents that spell out exactly what needs to be done: either Hawker Siddeley Service Bulletin 35,A25 or an equivalent American Federal Aviation Administration (FAA) directive (AD 77-26-01).\n\n**Who it affects:**\n- Anyone who owns, operates, or maintains BAe 125 aircraft in Australia.\n- This includes charter companies, private owners, and maintenance organisations.\n\n**Why it matters:**\n- Oxygen systems are critical for passenger safety at high altitudes. A faulty valve could mean passengers and crew don't get oxygen if cabin pressure is lost — potentially causing unconsciousness or death.\n- This directive ensures a known defect gets fixed before it causes an accident.\n\n**Key point:** The directive itself doesn't contain the detailed instructions — it simply says \"follow this technical bulletin or the FAA directive.\" This is common in aviation law, where Australia adopts safety standards developed overseas."},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"The AD text makes no indication that its substantive scope has changed from its stated intent: it requires inspection and modification of the oxygen supply valve by reference to the named requirement documents. There is no material in the supplied text suggesting an expansion or narrowing of scope beyond what those referenced documents prescribe."},"complexity_factors":["The AD delegates all procedural detail to external documents (Hawker Siddeley SB 35,A25; FAA AD 77-26-01), requiring operators to obtain and interpret those texts.","Applicability is stated only as \"As detailed in the requirement documents\", producing potential ambiguity about which individual aeroplanes are in scope without consulting the referenced documents.","Compliance is similarly delegated (\"As detailed in the requirement document\"), so legal compliance depends on external technical material and its correct edition/version.","Cross-reference to an FAA airworthiness directive introduces a cross-jurisdictional reference that may require reconciling differences between documents.","Operational complexity for operators includes scheduling maintenance, sourcing parts and qualified technicians, and managing aircraft downtime, but none of these are quantified in the AD.","Enforcement and record-keeping depend on regulators and maintenance organisations applying the external documents consistently, creating potential implementation variability."],"plain_english_summary":"This AD legally requires operators of specified BAe 125 series aeroplanes to inspect and, if necessary, modify the oxygen supply valve by following the actions in the referenced Hawker Siddeley SB 35,A25 or FAA AD 77-26-01. It affects aircraft owners/operators and maintenance organisations, who bear the cost, scheduling and compliance risk of obtaining and following those external documents. Practically, the AD sets the obligation and safety standard while delegating procedural detail and timing to the named requirement documents."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-125-50-oxygen-supply-valve-inspection-and-modification","history":"/api/acts/ad-hs-125-50-oxygen-supply-valve-inspection-and-modification/history","analysis":"/api/acts/ad-hs-125-50-oxygen-supply-valve-inspection-and-modification/analysis","conflicts":"/api/acts/ad-hs-125-50-oxygen-supply-valve-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-hs-125-50-oxygen-supply-valve-inspection-and-modification/important-cases","documents":"/api/acts/ad-hs-125-50-oxygen-supply-valve-inspection-and-modification/documents"}}