{"id":"F2006B10422","name":"AD/HS 125/142 - Flightdeck Six Volt Lighting Electrical Power","slug":"ad-hs-125-142-flightdeck-six-volt-lighting-electrical-power","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116107,"registerId":"commonwealth-F2006B10422-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 125/142 - Flightdeck Six Volt Lighting Electrical Power","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 125/142 Flightdeck Six Volt Lighting Electrical Power 5/94\n\nApplicability: All series 600A, 600B, 700A and 700B aircraft, without Modification 253544A&B incorporated.\n\nRequirement: Incorporate Modification No 253544A&B in accordance with Hawker Raytheon Corporate Jets Service Bulletin (Modification) SB.24-310-3544A&B dated\n\n14 February 1994.\n\nNote: This Service Bulletin has been classified as Mandatory by the CAA(UK).\n\nCompliance: Prior to 31 January 1995.\n\nBackground: Hawker Raytheon Corporate Jets have advised of an incident, where a wire from the 6V output of the flightdeck lighting transformer on electrical panel \\`RY’, short circuited to ground causing a small amount of smoke on the flightdeck. Investigation revealed that the 6V output from the transformer was inadequately protected. This directive requires the installation of two circuit breakers to protect the 6V lighting circuits.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Scope remains as specified: it applies only to BAe 125 series 600A/600B/700A/700B aircraft that have not incorporated Modification 253544A&B and requires incorporation of that modification by the stated date (Applicability; Requirement; Compliance). The directive’s purpose—to add two circuit breakers to protect the 6V flightdeck lighting after an identified short-circuit incident—matches the explicit Background and Requirement and does not broaden the set of affected aircraft or regulatory obligations beyond those stated."},"complexity_factors":["Limited applicability to specific BAe 125 series without Modification 253544A&B (Applicability).","Mandated technical change: incorporation of Modification No 253544A&B per a specified Service Bulletin (Requirement; Service Bulletin).","Fixed compliance deadline creates scheduling and operational impact for operators (Compliance: prior to 31 January 1995).","Technical work involves installation of two circuit breakers protecting the 6V lighting circuits (Background/Requirement).","Implementation cost and aircraft downtime borne by aircraft owners/operators and maintenance organisations (implied by Requirement/Compliance).","Fleet status must be checked to identify which aircraft lack the modification (Applicability).","Cross-jurisdictional reference: the Service Bulletin is classified Mandatory by CAA(UK), reinforcing regulatory intent (Note).","Enforcement implication: non-compliance risks operational restrictions until modification is completed (implied by Compliance)."],"plain_english_summary":"This airworthiness directive requires operators of British Aerospace BAe 125 series 600A, 600B, 700A and 700B aeroplanes (that have not already done so) to install Modification No. 253544A&B in accordance with Hawker Raytheon Service Bulletin SB.24-310-3544A&B by 31 January 1995. It responds to an incident where a 6‑volt flightdeck lighting output shorted to ground and mandates installation of two circuit breakers to protect the 6V lighting circuits, shifting the cost and scheduling burden to affected operators and their maintenance providers."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete airworthiness directive addressing a specific safety defect in specific aircraft models. It remains tightly scoped to its original purpose of mandating a single electrical safety modification."},"complexity_factors":["Very short document (under 200 words)","Only 4 defined applicability criteria (specific aircraft models)","Single, unambiguous requirement with clear reference to external technical document","No nested conditions or exceptions","No cross-references to other legislation beyond basic citation of Civil Aviation Regulations 1998 Part 39","Clear compliance deadline with no alternative methods of compliance stated"],"plain_english_summary":"This is a **mandatory safety fix** for specific British Aerospace BAe 125 business jets (models 600A, 600B, 700A, and 700B). \n\n**What it does:**\n- Requires owners/operators to install two circuit breakers on the flight deck lighting system\n- This protects against electrical short circuits in the 6-volt lighting transformer\n\n**Why it matters:**\n- A wire short-circuited on one aircraft, causing smoke in the cockpit — a serious fire risk during flight\n- The original design didn't have adequate protection for this electrical circuit\n- The fix comes from the manufacturer (Hawker Raytheon) via a mandatory service bulletin\n\n**Who must comply:**\n- Anyone operating the affected aircraft models that haven't already had this modification done\n- Deadline: before 31 January 1995\n\n**In simple terms:** If you own one of these specific jets, you must get this electrical safety upgrade done by the deadline to prevent potential cockpit fires."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-125-142-flightdeck-six-volt-lighting-electrical-power","history":"/api/acts/ad-hs-125-142-flightdeck-six-volt-lighting-electrical-power/history","analysis":"/api/acts/ad-hs-125-142-flightdeck-six-volt-lighting-electrical-power/analysis","conflicts":"/api/acts/ad-hs-125-142-flightdeck-six-volt-lighting-electrical-power/conflicts","importantCases":"/api/acts/ad-hs-125-142-flightdeck-six-volt-lighting-electrical-power/important-cases","documents":"/api/acts/ad-hs-125-142-flightdeck-six-volt-lighting-electrical-power/documents"}}