{"id":"F2006B10525","name":"AD/HS 125/83 Amdt 1 - Chafing of Wiring Loom","slug":"ad-hs-125-83-amdt-1-chafing-of-wiring-loom","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116313,"registerId":"commonwealth-F2006B10525-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 125/83 Amdt 1 - Chafing of Wiring Loom","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nBritish Aerospace BAe 125 Series Aeroplanes\n\nAD/HS 125/83\n\nAmdt 1\n\n  \nChafing of Wiring Loom 5/87\n\nApplicability: As detailed in relevant Requirement Documents.\n\nRequirement: 1. Action in accordance with British Aerospace Alert Bulletin 24-A258 as follows:\n\nIsolate all electrical power and with the aid of a torch and mirror, inspect wiring loom behind bottom RH corner of panel ZK (Rear Equipment Bay, RH side) for clearance between cables and terminals of circuit breaker B7. Pay particular attention to heavy duty (size 10) EFIS supply cables from circuit breakers B5 and B6.\n\n2. Action in accordance with British Aerospace Service Bulletin 24-259-(3171B). Compliance: For Para 1: Prior to further flight after 4 September 1986.\n\nFor Para 2: Prior to 30 June 1987.\n\nBackground: 1. Chafing of wiring loom has occurred resulting in loss of EFIS, No 2 Air Data, Fuel Computers (Auto) and No 1 Windscreen Alternator.\n\n2. This amendment introduces Service Bulletin 24-259-(3171B) which details modifications to further enhance electrical integrity within panel ZK.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is an Airworthiness Directive (AD) — a standard safety instrument in aviation regulation. It maintains its original narrow scope: addressing a specific wiring defect in a specific aircraft type. The amendment (Amdt 1) adds a second compliance action (the Service Bulletin) to enhance the original directive, but this is a natural evolution within the original safety purpose rather than scope creep."},"complexity_factors":["Single, specific aircraft type (British Aerospace BAe 125 series)","Only two discrete compliance actions required","Clear deadlines with calendar dates","Minimal cross-referencing (only to specific manufacturer bulletins: Alert Bulletin 24-A258 and Service Bulletin 24-259-(3171B))","No defined terms section","No conditional logic or nested exceptions","Short document (approximately 200 words)","Straightforward applicability clause referencing external Requirement Documents"],"plain_english_summary":"This CASA safety directive requires owners, operators and maintenance engineers of British Aerospace BAe 125 aircraft to inspect and repair wiring behind panel ZK in the rear equipment bay to prevent heavy cables from chafing against circuit breaker B7 and damaging EFIS power feeds. It mandates immediate inspection before further flight and installation of the Service Bulletin modification by the specified deadline to prevent in‑flight loss of critical flight instruments and systems."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment expands the AD beyond an immediate inspection requirement (British Aerospace Alert Bulletin 24‑A258) by adding a mandated modification per Service Bulletin 24‑259‑(3171B) to 'further enhance electrical integrity within panel ZK' (Background 2). Practically, scope shifts from inspection/rectification to a required design/installation change with a later compliance date (Requirement Para 2; compliance prior to 30 June 1987), increasing implementation burden on operators."},"complexity_factors":["Multiple external documents required: Alert Bulletin 24‑A258 (inspection procedure) and Service Bulletin 24‑259‑(3171B) (modification) — operators must obtain and follow both.","Applicability is specified only as 'As detailed in relevant Requirement Documents', requiring cross‑reference to other records to identify affected serials/aircraft.","Two distinct compliance timelines: immediate inspection 'prior to further flight after 4 September 1986' (Para 1) and a later modification deadline 'prior to 30 June 1987' (Para 2).","Inspection requires isolating all electrical power and use of torch/mirror to reach a confined location (behind bottom RH corner of panel ZK), increasing labour/time and access difficulty.","Focus on specific heavy duty (size 10) EFIS supply cables from breakers B5 and B6 and clearance to circuit breaker B7 — technical specificity raises need for qualified personnel.","Non‑prescriptive costs and effects on operations: potential aircraft downtime, parts/labour for modification, and recordkeeping to demonstrate compliance.","Regulatory source: Civil Aviation Safety Authority AD enforcing manufacturer documents — discretion limited but reliant on correct execution of prescribed service instructions."],"plain_english_summary":"This directive requires BAe 125 operators to isolate electrical power, inspect the wiring loom behind the lower‑right of panel ZK for clearance between cables and circuit breaker B7 (with particular attention to size‑10 EFIS supply cables), and to carry out a modification per British Aerospace Service Bulletin 24‑259‑(3171B). Inspection must be done before the next flight after 4 September 1986; the modification must be completed by 30 June 1987. The actions respond to recorded chafing that led to loss of EFIS, air‑data, fuel computers and a windscreen alternator."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-125-83-amdt-1-chafing-of-wiring-loom","history":"/api/acts/ad-hs-125-83-amdt-1-chafing-of-wiring-loom/history","analysis":"/api/acts/ad-hs-125-83-amdt-1-chafing-of-wiring-loom/analysis","conflicts":"/api/acts/ad-hs-125-83-amdt-1-chafing-of-wiring-loom/conflicts","importantCases":"/api/acts/ad-hs-125-83-amdt-1-chafing-of-wiring-loom/important-cases","documents":"/api/acts/ad-hs-125-83-amdt-1-chafing-of-wiring-loom/documents"}}