{"id":"F2006B10504","name":"AD/HS 125/64 - Audio Integrating System Wiring - Modification","slug":"ad-hs-125-64-audio-integrating-system-wiring-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116271,"registerId":"commonwealth-F2006B10504-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 125/64 - Audio Integrating System Wiring - 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 125/64 Audio Integrating System Wiring - Modification 4/84\n\nApplicability: All Hawker Siddeley HS-125 series listed in requirement document.\n\n \n\nDocument: Hawker Siddeley HS-125 Service Bulletin No. 23-21-(8765) November 1983 (Revision 2).\n\n \n\nCAA AD No. 046-04-83 refers.\n\n \n\nCompliance: Before 31 May, 1984.\n\n \n\nBackground:  A single failure in the electrical supply to the ESB31 and EA76 Audio integrating systems, can produce a complete failure of all aircraft audio systems. Modification involves segregation of power supplies.\n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive issued for a specific aircraft type and specific technical issue. It has not expanded beyond its original narrow scope of mandating a wiring modification to prevent audio system failure."},"complexity_factors":["Very short document (under 200 words)","Only one defined term (the applicability reference to 'requirement document')","No cross-references to other legislation or regulations beyond a single related AD number","Single, unambiguous compliance requirement with fixed deadline","No conditional logic, exceptions, or nested provisions","Technical content refers to external engineering document rather than being contained within the directive itself"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires owners or operators of specific aircraft to make a specific repair or modification.\n\n**What it does:** It orders operators of **British Aerospace BAe 125 series aircraft** (also known as Hawker Siddeley HS-125) to modify the wiring of their **audio integrating systems** — the equipment that handles all radio and intercom communications in the cockpit.\n\n**Why it matters:** A single electrical fault could knock out **all audio systems at once** — meaning pilots couldn't hear air traffic control, communicate with each other, or receive critical warnings. The fix involves **separating the power supplies** so that one failure doesn't cascade into total communication blackout.\n\n**Who must comply:** Anyone operating these specific aircraft must complete the modification **before 31 May 1984** (the deadline has long passed, so this is now historical).\n\n**How to comply:** Follow the technical instructions in **Hawker Siddeley Service Bulletin No. 23-21-(8765) Revision 2** (November 1983)."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive does not change scope from what is stated in the source. It applies to the HS-125 series listed in the requirement document, mandates the wiring modification described in the referenced Hawker Siddeley service bulletin, and requires compliance before 31 May 1984. There is no indication in the text that the applicability, required modification, or compliance deadline were altered from the original intent. (Applicability; Document; Compliance; Background)"},"complexity_factors":["Single, well-defined technical action required (wiring modification to segregate power supplies) reduces procedural complexity","Clear applicability (all HS-125 series listed in requirement document) simplifies identification of affected aircraft","Firm compliance deadline creates scheduling pressure but not ongoing regulatory complexity","Dependence on a specific manufacturer service bulletin for the technical method introduces technical precision and potential parts/specialist requirements","Potential operational complexity from scheduling aircraft downtime and ensuring workmanship quality","Reference to an external CAA AD (046-04-83) adds a minor layer of regulatory cross-reference"],"plain_english_summary":"This directive requires a wiring modification per Hawker Siddeley Service Bulletin to segregate power supplies to the ESB31 and EA76 audio integrating systems on specified HS‑125 aeroplanes, preventing a single electrical failure from disabling all aircraft audio. Affected owners/operators must fund and complete the work by 31 May 1984, risking downtime and enforcement if not timely."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-125-64-audio-integrating-system-wiring-modification","history":"/api/acts/ad-hs-125-64-audio-integrating-system-wiring-modification/history","analysis":"/api/acts/ad-hs-125-64-audio-integrating-system-wiring-modification/analysis","conflicts":"/api/acts/ad-hs-125-64-audio-integrating-system-wiring-modification/conflicts","importantCases":"/api/acts/ad-hs-125-64-audio-integrating-system-wiring-modification/important-cases","documents":"/api/acts/ad-hs-125-64-audio-integrating-system-wiring-modification/documents"}}