{"id":"F2006B09525","name":"AD/EMB-120/8 - Electrical Power Wiring","slug":"ad-emb-120-8-electrical-power-wiring","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54124,"registerId":"commonwealth-F2006B09525-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/EMB-120/8 - Electrical Power Wiring","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)  \nEmbraer EMB-120 (Brasilia) Series Aeroplanes\n\nAD/EMB-120/8 Electrical Power Wiring 8/93\n\nApplicability: All Embraer EMB-120 aircraft prior to serial number 120280. Requirement: Action in accordance with Embraer Service Bulletin No 120-24-0047 dated\n\n26 February 1993.\n\nNote: CTA (Brazil) AD 93-05-02 Amdt 39-717 refers.\n\nCompliance: At the next scheduled Type “A” maintenance inspection after 22 July 1993.\n\nBackground: Embraer has reported the failure of the “Bus 3 Contactor” relay which was caused by a fault in the connection of a “DC Bus 1” feed wire. This failure caused smoke in the cockpit and overheating of the wiring. Compliance with this Directive will ensure that the bus is wired correctly, thus decreasing the possibility of wiring overheating and the resultant smoke and/or fire in the cockpit.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive, as written, confines action to EMB-120 aircraft with serial numbers prior to 120280 and requires corrective wiring work per the specified Embraer Service Bulletin at the next Type “A” inspection after 22 July 1993. The text shows no indication that the directive’s scope was changed from that stated purpose: it targets a specific wiring fault on a defined set of aircraft and prescribes a single remedial pathway (Applicability; Requirement; Compliance; Background)."},"complexity_factors":["Serial-number-based applicability limits scope and requires checking aircraft serials (Applicability).","Mandate delegates technical detail to an external document (Embraer Service Bulletin No. 120-24-0047), requiring operators to obtain and follow that bulletin (Requirement).","Compliance timing is tied to maintenance scheduling (next Type “A” inspection after 22 July 1993), which affects operational planning (Compliance).","Technical nature of the corrective work (electrical bus wiring and contactor relay) requires trained maintenance personnel and access to parts/documentation (Background; Requirement).","Cross-reference to a foreign authority (CTA (Brazil) AD 93-05-02 Amdt 39-717) introduces alignment with external regulatory findings (Note)."],"plain_english_summary":"This AD requires operators of Embraer EMB‑120 aeroplanes with serial numbers before 120280 to correct a DC Bus wiring fault per Embraer Service Bulletin No. 120‑24‑0047 (26 Feb 1993), to be done at the next scheduled Type “A” inspection after 22 July 1993.  \n\nThe fix, paid for and arranged by owners/operators, addresses a faulty DC Bus 1 feed that can cause Bus 3 contactor failure, smoke and wiring overheating in the cockpit."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific wiring defect in a specific aircraft model. It has not expanded beyond its original purpose of mandating a single technical fix."},"complexity_factors":["Single, specific technical requirement (follow one service bulletin)","No defined terms section — all terminology is standard aviation maintenance language","No cross-references to other legislation or complex conditional logic","Clear applicability criteria (serial number cutoff)","Single compliance deadline tied to existing maintenance schedule","Background explanation provided in plain language"],"plain_english_summary":"This is an **Airworthiness Directive** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nOrders owners and operators of certain Embraer EMB-120 \"Brasilia\" aircraft to fix a dangerous electrical wiring fault. The problem involves a relay called the \"Bus 3 Contactor\" that can fail due to a faulty connection in a power feed wire. When this fails, it causes smoke in the cockpit and overheating — creating a fire risk.\n\n**Who must act:**\nAnyone operating an Embraer EMB-120 aircraft with a serial number **below 120280** (older aircraft in this series).\n\n**What they must do:**\nFollow the repair instructions in **Embraer Service Bulletin No 120-24-0047** (dated 26 February 1993). This bulletin contains the technical steps to rewire the connection properly.\n\n**When they must do it:**\nBy the next scheduled \"Type A\" maintenance inspection after **22 July 1993**.\n\n**Why it matters:**\nThis is a fire-prevention measure. The faulty wiring had already caused at least one incident with smoke in the cockpit. The directive forces operators to fix the problem before it causes an in-flight fire."}},"importantCases":[],"_links":{"self":"/api/acts/ad-emb-120-8-electrical-power-wiring","history":"/api/acts/ad-emb-120-8-electrical-power-wiring/history","analysis":"/api/acts/ad-emb-120-8-electrical-power-wiring/analysis","conflicts":"/api/acts/ad-emb-120-8-electrical-power-wiring/conflicts","importantCases":"/api/acts/ad-emb-120-8-electrical-power-wiring/important-cases","documents":"/api/acts/ad-emb-120-8-electrical-power-wiring/documents"}}