{"id":"F2006B10898","name":"AD/JETSTREAM/30 - Electrical Power - Static Inverters","slug":"ad-jetstream-30-electrical-power-static-inverters","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56434,"registerId":"commonwealth-F2006B10898-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/JETSTREAM/30 - Electrical Power - Static Inverters","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 3100 (Jetstream) Series Aeroplanes\n\nAD/JETSTREAM/30 Electrical Power \\- Static Inverters 1/89\n\nApplicability: Jetstream 3100 series aircraft constructor numbers 601-695 inclusive fitted with Leland model ASH 674-3 and 674-33 static inverters, but excluding constructor numbers 647, 656, 659 and 667.\n\nRequirement: Action in accordance with BAe Jetstream ASB 24-A-JA880640.\n\nCompliance: Inverters that have exceeded 5000 hrs TIS but less than 10,000 hrs TIS are to be replaced before 26 May 1989;\n\nInverters that have exceeded 10,000 hrs TIS are to be replaced before 26 February 1989.\n\nNote: Refer also to Requirement document para D for amplification of compliance details.\n\nBackground: Operators have reported in-flight incidents of inverter failure due to overheat and smoking of components.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD text establishes a confined, equipment-specific corrective requirement: replace specified Leland static inverters on identified Jetstream 3100 aeroplanes by set dates tied to hours TIS, and to perform the work per a BAe service bulletin. The Background explains the safety incidents prompting the measure. The document itself contains no language indicating a change from an earlier or different intended scope; the Applicability, Requirement and Compliance provisions are consistent with the stated safety rationale. (Applicability; Requirement; Compliance; Background)"},"complexity_factors":["Specificity of applicability: identifies a narrow set of aircraft constructor numbers and excludes four constructor numbers (Applicability).","Two-tier compliance deadlines based on a continuous metric (hours TIS): different dates for >5,000 but <10,000 hrs and for >10,000 hrs (Compliance).","Dependence on an external technical document (BAe Jetstream ASB 24-A-JA880640) for the exact corrective actions (Requirement).","Reference to an additional amplification paragraph (para D) outside the AD text for compliance detail (Note).","Technical identification of parts by model numbers (Leland ASH 674-3 and 674-33) requiring correct parts identification by operators (Applicability)."],"plain_english_summary":"What this directive does mechanically\n\n- Requires replacement of specified static inverters on certain British Aerospace Jetstream 3100 aeroplanes. (Applicability; Requirement)\n- The parts targeted are Leland model ASH 674-3 and 674-33 static inverters fitted to constructor numbers 601–695, except 647, 656, 659 and 667. (Applicability)\n- Work must be carried out in accordance with BAe Jetstream ASB 24-A-JA880640. (Requirement)\n- Deadlines depend on the inverter’s hours time-in-service (TIS): inverters with more than 5,000 but less than 10,000 hrs TIS must be replaced by 26 May 1989; inverters with more than 10,000 hrs TIS must be replaced by 26 February 1989. (Compliance)\n\nWho is affected and who decides\n\n- Aircraft operators of the identified Jetstream 3100 series are the parties required to take action: they must replace the listed inverters by the stated dates. (Applicability; Compliance)\n- The AD directs operators to follow a manufacturer service bulletin (BAe Jetstream ASB 24-A-JA880640), so the exact technical steps and parts specification are set by that document. (Requirement)\n\nWhy it matters (official rationale and practicable implications)\n\n- The AD is prompted by reported in-flight incidents of inverter failure involving overheating and smoking components. The background identifies those safety incidents as the reason for the corrective action. (Background)\n- Practically, complying operators will incur direct costs to replace inverters, need to schedule maintenance within the specified windows, and must rely on the BAe service bulletin for technical execution. (Requirement; Compliance)\n\nTesting the stated purpose against practical trade-offs and implementation points\n\n- Who pays: The operator that owns/controls the affected aeroplane must arrange and therefore bear the replacement work called for by the AD. This follows from the Applicability and Compliance instructions requiring replacement. (Applicability; Compliance)\n- Incentives created: Operators have an incentive to monitor inverter TIS closely because the deadline depends on recorded hours. Failure to track TIS could force near-term compliance costs or unscheduled removals. (Compliance)\n- Trade-offs and opportunity costs: Replacing inverters imposes parts and labour costs and maintenance downtime; operators choose between scheduling work in normal maintenance windows or arranging out-of-cycle work to meet the AD deadlines. (Compliance)\n- Implementation dependency and discretion: The AD requires action “in accordance with” a BAe service bulletin, so the exact tasks and acceptance criteria are delegated to that manufacturer document. The AD’s Note refers to paragraph D for additional compliance detail, indicating that further procedural amplification exists outside the AD itself. Those references create dependence on external documents for full compliance detail. (Requirement; Note)\n- Compliance burden: The burden is concrete and narrow—identifying affected aeroplanes and inverters, checking recorded hours TIS, arranging replacements by the stated dates, and following the BAe ASB. (Applicability; Compliance; Requirement)\n- Effects on private choice and operations: The measure constrains operators’ maintenance choices with respect to the specified inverters and forces a change in maintenance timing; otherwise it does not alter ownership, wider contractual freedoms, or market structure in ways specified by the AD text. (Applicability; Requirement)\n\nKey procedural references in the AD\n\n- Applicability lists which aeroplanes and which inverter models are covered. (Applicability)\n- The Requirement directs operators to perform the corrective action per BAe Jetstream ASB 24-A-JA880640. (Requirement)\n- Compliance sets the replacement deadlines tied to inverter TIS. (Compliance)\n- A Note points to further amplification of compliance details in paragraph D. (Note)\n- Background explains the trigger for the AD: reported in-flight inverter failures due to overheating and smoking components. (Background)\n\nSummary statement\n\nThe AD mandates replacement of specific Leland static inverters on a defined subset of Jetstream 3100 aeroplanes within set deadlines based on recorded hours in service, following a BAe service bulletin. It is triggered by reported in-flight failures (overheat/smoke). The direct consequences for operators are the cost and scheduling of replacements, reliance on the manufacturer’s service bulletin for technical steps, and the need to track inverter hours to meet the mandated deadlines. (Applicability; Requirement; Compliance; Note; Background)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in specific aircraft. It has not expanded beyond its original purpose of mandating inverter replacement."},"complexity_factors":["Very short document (under 200 words)","Only 4 defined elements: specific aircraft model, serial number range, excluded serial numbers, and inverter models","Simple conditional structure: two compliance deadlines based solely on flight hours (TIS = Time In Service)","Single cross-reference to manufacturer service bulletin (BAe Jetstream ASB 24-A-JA880640)","No nested exceptions or complex legal definitions"],"plain_english_summary":"This is a **safety order** (called an \"Airworthiness Directive\") issued by Australia's aviation safety regulator (CASA) for a specific type of aircraft: the British Aerospace Jetstream 3100 series.\n\n**What it does:**\nIt requires airlines and aircraft owners to **replace certain electrical components** (called \"static inverters\" — devices that convert DC power to AC power for aircraft systems) before specific deadlines.\n\n**Who it affects:**\n- Owners and operators of Jetstream 3100 aircraft with serial numbers 601-695 (except four specific aircraft: 647, 656, 659, and 667)\n- Only applies if the aircraft uses Leland model ASH 674-3 or 674-33 inverters\n\n**The deadlines:**\n- **Before 26 February 1989:** Replace inverters with more than 10,000 flight hours\n- **Before 26 May 1989:** Replace inverters with 5,000-10,000 flight hours\n\n**Why it matters:**\nThese inverters were overheating and smoking during flight — a serious fire risk. This order forces operators to swap out the faulty equipment before it fails dangerously in the air."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jetstream-30-electrical-power-static-inverters","history":"/api/acts/ad-jetstream-30-electrical-power-static-inverters/history","analysis":"/api/acts/ad-jetstream-30-electrical-power-static-inverters/analysis","conflicts":"/api/acts/ad-jetstream-30-electrical-power-static-inverters/conflicts","importantCases":"/api/acts/ad-jetstream-30-electrical-power-static-inverters/important-cases","documents":"/api/acts/ad-jetstream-30-electrical-power-static-inverters/documents"}}