{"id":"F2006B10425","name":"AD/HS 125/145 - Electrical Wiring Chafing","slug":"ad-hs-125-145-electrical-wiring-chafing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116113,"registerId":"commonwealth-F2006B10425-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 125/145 - Electrical Wiring Chafing","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 125/145 Electrical Wiring Chafing 11/94\n\nApplicability: Hawker 1000 and BAe 125 Series 1000A and B aircraft identified in Hawker Raytheon Corporate Jets Mandatory Service Bulletin SB A29-92 Revision 1 dated 1 August 1994.\n\nRequirement: If not previously accomplished, action in accordance with Hawker Raytheon Corporate Jets Mandatory Service Bulletin SB A29-92 Revision 1 dated 1 August 1994.\n\nNote: This Service Bulletin has been classified as mandatory by the CAA(UK).\n\nCompliance: Prior to 30 October 1994.\n\nBackground: The aircraft manufacturer has received reports of chafing of an electrical cable/loom on a hydraulic pipe, this caused an insulation breakdown and electrical short circuit which produced a pin-hole failure of the hydraulic pipe. Action required by this Directive is designed to decrease the likelihood of a loss of hydraulic pressure, electrical malfunction or an in-flight fire.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive targeting a specific mechanical defect in specific aircraft models. It has not expanded beyond its original purpose of addressing the wiring chafing/hydraulic pipe failure risk."},"complexity_factors":["Very short document (under 200 words)","Only one substantive requirement: comply with an external manufacturer bulletin","No defined terms section — relies entirely on the referenced service bulletin for technical details","Single, unambiguous compliance deadline","No nested conditions, exceptions, or cross-references to other legislation beyond the named aircraft models and service bulletin"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:** It requires owners or operators of certain British Aerospace BAe 125 series business jets (specifically the Hawker 1000 and BAe 125 Series 1000A and B models) to carry out a specific safety inspection or repair. The work must follow instructions set out in a manufacturer bulletin called \"SB A29-92 Revision 1\" dated 1 August 1994.\n\n**Why it matters:** The manufacturer discovered that electrical wiring was rubbing against (\"chafing\" on) a hydraulic pipe. This friction wore through the wire insulation, causing an electrical short circuit. That short circuit then burned a tiny hole (\"pin-hole failure\") in the hydraulic pipe. The risks here are serious: loss of hydraulic pressure (making the aircraft harder to control), electrical system failures, or even an in-flight fire.\n\n**Who must comply:** Anyone operating the affected aircraft models who hasn't already done this work.\n\n**Deadline:** The work had to be completed before 30 October 1994.\n\n**Key point:** This directive makes mandatory a service bulletin that was originally issued by the UK aviation authority (CAA(UK)), showing how Australia adopts international safety standards for aircraft registered here."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive implements the manufacturer’s remedial action for a specific chafing hazard on identified BAe 125/Hawker 1000 aeroplanes and sets a compliance deadline. It does not broaden the universe of affected aircraft beyond those listed in the cited service bulletin, nor does it expand remedial measures beyond the actions specified in that bulletin. The stated scope therefore aligns with the original safety‑remedy intent described in the Background."},"complexity_factors":["Narrow applicability: applies only to aircraft identified in a single manufacturer service bulletin (Applicability).","Single, well-defined corrective action tied to a specific service bulletin revision (Requirement).","Firm compliance deadline reduces scheduling flexibility but simplifies enforcement (Compliance).","Technical execution requires qualified maintenance personnel and parts, creating procedural complexity in execution but not in legal terms (Requirement).","Regulatory reliance on a manufacturer document (SB A29-92 Rev 1) creates a dependency on that document’s clarity and any subsequent revisions (Requirement; Note)."],"plain_english_summary":"### What this instrument does (mechanically)\n\nThis airworthiness directive requires operators of certain British Aerospace BAe 125/Hawker 1000 aeroplanes to carry out the work described in a specific manufacturer service bulletin. It names the exact aircraft covered (those identified in Hawker Raytheon Corporate Jets Mandatory Service Bulletin SB A29-92 Revision 1 dated 1 August 1994) and makes compliance mandatory by a set deadline (Prior to 30 October 1994). (Applicability; Requirement; Compliance)\n\nThe directive references and requires action “in accordance with” the manufacturer’s Mandatory Service Bulletin SB A29-92 Rev 1 dated 1 August 1994. The UK CAA has classified that Service Bulletin as mandatory, a fact noted in the directive. (Requirement; Note)\n\n### Why the regulator required this action (official rationale)\n\nThe manufacturer reported incidents where an electrical cable/loom chafed against a hydraulic pipe. The chafing led to an electrical short that punctured the hydraulic pipe, creating a pin‑hole failure. The stated purpose of the required work is to reduce the chance of hydraulic pressure loss, electrical malfunction or an in‑flight fire. (Background)\n\n### Who this affects and who pays\n\n- Aircraft operators and owners of the specific BAe 125/Hawker 1000 aeroplanes identified in the service bulletin must ensure the work is done. (Applicability; Requirement)\n- The direct costs (labour, parts, aircraft downtime) fall on those operators or their insurers. Maintenance organisations that carry out the work will invoice operators; operators may choose approved or qualified providers. (Requirement)\n\n### Who decides and what the directive changes about behaviour\n\n- The Civil Aviation Safety Authority (as issuer of this Airworthiness Directive) requires operators to follow the manufacturer’s service bulletin by the stated compliance date. (Header; Requirement; Compliance)\n- Operators must inspect and modify/repair the electrical loom/hydraulic routing as specified in SB A29-92 Rev 1, or otherwise accomplish the prescribed actions. This changes operator behaviour by converting the manufacturer’s bulletin into a mandatory regulatory action and imposing a hard deadline. (Requirement; Compliance)\n\n### Costs, compliance burden and implementation risks\n\n- Compliance imposes direct costs: parts, qualified technician labour, and aircraft out‑of‑service time. These are borne by the aircraft operator. (Requirement; Compliance)\n- The action is technical and safety‑critical; it requires qualified maintenance personnel and access to the specific service bulletin. Operators without internal capability will need to engage external providers, creating transaction costs and scheduling risk. (Requirement)\n- The directive ties compliance to a specific revision of the manufacturer’s bulletin. If that bulletin lacks detail or if later technical refinements exist, operators face ambiguity about whether additional steps are needed; the AD does not itself reconcile later changes. (Requirement; Note)\n- The AD does not set inspection or record‑keeping procedures in the text provided; verifying and documenting compliance will fall to operators and maintenance organisations under ordinary airworthiness record rules. (Requirement)\n\n### Effects on private enterprise, competition and choices\n\n- Maintenance demand is concentrated on providers capable of performing the manufacturer‑specified work. That can increase workload and revenues for qualified maintenance organisations and may disadvantage operators who lack access to those providers. (Requirement)\n- The AD channels choice toward following the manufacturer’s remediation method (the cited service bulletin). Operators retain freedom to select providers and pay costs, but not to decline the corrective action without regulatory relief. (Requirement; Compliance)\n\n### Trade‑offs, opportunity costs and implementation uncertainty\n\n- The regulator’s trade‑off: impose a mandatory, time‑limited fix to reduce an identified safety risk, at the expense of immediate operator costs and aircraft downtime. (Background; Compliance)\n- Opportunity costs to operators include delayed flights, diverted maintenance capacity, and expenditure that could otherwise be used for other upgrades or operations. (Compliance)\n- Implementation risks include incomplete fixes, variations in workmanship between providers, and the potential need for follow‑up if the service bulletin is later revised; the AD locks the compliance requirement to the cited revision. (Requirement; Note)\n\n### Bottom line (mechanical effect)\n\nThe AD converts a manufacturer’s mandatory service bulletin into a regulator‑enforced obligation for identified BAe 125/Hawker 1000 aeroplanes to eliminate a wiring‑to‑hydraulic‑pipe chafing risk, with the compliance responsibility and costs borne by aircraft operators and the deadline set by the regulator. (Applicability; Requirement; Compliance; Background)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-125-145-electrical-wiring-chafing","history":"/api/acts/ad-hs-125-145-electrical-wiring-chafing/history","analysis":"/api/acts/ad-hs-125-145-electrical-wiring-chafing/analysis","conflicts":"/api/acts/ad-hs-125-145-electrical-wiring-chafing/conflicts","importantCases":"/api/acts/ad-hs-125-145-electrical-wiring-chafing/important-cases","documents":"/api/acts/ad-hs-125-145-electrical-wiring-chafing/documents"}}