{"id":"F2006B06967","name":"AD/SF340/38 - Electrical Power AC Generator Control Relays","slug":"ad-sf340-38-electrical-power-ac-generator-control-relays","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114875,"registerId":"commonwealth-F2006B06967-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SF340/38 - Electrical Power AC Generator Control Relays","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)  \nSAAB SF340 Series Aeroplanes\n\nAD/SF340/38 Electrical Power AC Generator Control Relays 2/93\n\nApplicability: All SAAB model SF340A aeroplanes with serial numbers 004 to 159 inclusive and model 340B aeroplanes with serial numbers 160 to 325 inclusive.\n\nRequirement: Action in accordance with the technical requirements of SAAB Service Bulletin 340- 24-022 dated 21 October 1992.\n\nNote: Swedish (LFV) SAD Number 1-057 refers.\n\nCompliance: Prior to 1 November 1993.\n\nBackground: A number of failures have occurred in AC generator control relays where the main contacts have arced. This arcing may cause melted metal to drip on electrical wires routed below the relays resulting in further electrical failures, as well as the possibility of smoke in the cockpit.\n\nThis Directive requires that the offending relays be replaced to prevent further arcing of the contacts.","sortOrder":0}],"analysis":{"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 a defined aircraft fleet. It has not expanded beyond its original purpose of mandating relay replacement to prevent electrical arcing hazards."},"complexity_factors":["Single, specific mechanical action required (relay replacement)","Only 2 applicability criteria (aircraft model and serial number ranges)","References only one external technical document (SAAB Service Bulletin)","No conditional logic, exceptions, or alternative compliance methods","Fixed compliance deadline with no extensions or phased implementation","No defined terms section — uses plain technical language"],"plain_english_summary":"**What this is:** An Airworthiness Directive (AD) — essentially a mandatory safety order for aircraft.\n\n**What it does:** Requires owners and operators of specific SAAB SF340 aircraft to replace faulty AC generator control relays. These relays were experiencing dangerous electrical arcing (sparking) that could melt metal, drip onto wires below, cause more electrical failures, and potentially create smoke in the cockpit.\n\n**Who it affects:**\n- All SAAB SF340A aircraft with serial numbers 004–159\n- All SAAB SF340B aircraft with serial numbers 160–325\n\n**What must be done:** Follow the technical instructions in SAAB Service Bulletin 340-24-022 (dated 21 October 1992) to replace the defective relays.\n\n**When:** Before 1 November 1993.\n\n**Why it matters:** This prevents in-flight electrical fires and smoke emergencies. The arcing problem had already caused multiple failures, creating serious safety risks including potential loss of electrical systems and cockpit smoke."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive addresses the original, stated objective: removing AC generator control relays that have exhibited arcing to prevent further electrical failures and possible cockpit smoke. It applies to the specific serial-numbered SF340A and 340B aeroplanes listed and prescribes compliance through the referenced SAAB service bulletin by the stated deadline (Applicability; Requirement; Compliance; Background). There is no indication in the text that the scope departs from that original mechanical objective."},"complexity_factors":["Narrow applicability limited to specific serial-number ranges (Applicability)","Prescriptive technical remedy referenced externally via a service bulletin rather than detailed in the directive (Requirement)","Fixed compliance deadline creating scheduling pressure for affected operators (Compliance)","Safety-critical electrical failure mode requiring competent maintenance actions (Background)","Minimal regulatory discretion in remedy selection because the directive points to a specific service bulletin (Requirement)"],"plain_english_summary":"### What this directive does\n\n- The Civil Aviation Safety Authority requires certain SAAB SF340 aeroplanes to have specific AC generator control relays replaced. (Header; Requirement)\n- The replacement must be performed in accordance with SAAB Service Bulletin 340-24-022 dated 21 October 1992. (Requirement)\n- The work must be completed before 1 November 1993. (Compliance)\n\n### Who this affects\n\n- Owners and operators of SAAB SF340A aeroplanes with serial numbers 004–159 and SAAB 340B aeroplanes with serial numbers 160–325. (Applicability)\n- Maintenance organisations and technicians who perform aircraft electrical component replacement under the service bulletin. (Requirement)\n\n### Why it matters (mechanics and risks addressed)\n\n- The directive responds to repeated failures of AC generator control relays in which the main contacts have arced. Arcing has caused melted metal to fall onto wires routed beneath the relays, producing further electrical failures and the possibility of smoke in the cockpit. (Background)\n- By mandating replacement of the offending relays, the measure aims to stop further arcing and remove the immediate source of those failure modes. (Requirement; Background)\n\n### Who pays, who decides, and what changes\n\n- The regulator issuing the rule is the Civil Aviation Safety Authority. (Header)\n- Aircraft owners/operators must arrange and fund the replacement work and ensure compliance with the service bulletin by the deadline. (Applicability; Requirement; Compliance)\n- Maintenance personnel must follow the technical steps set out in SAAB Service Bulletin 340-24-022 when replacing the relays. (Requirement)\n\n### Implementation trade-offs, incentives and compliance burden\n\n- Direct cost and downtime: Operators incur the cost of parts, labour and aircraft out-of-service time to carry out the replacements before the deadline. (Applicability; Requirement; Compliance)\n- Certainty of method: The directive prescribes a single technical solution (the SAAB service bulletin). That limits operator discretion about how to fix the identified fault but provides a specific approved procedure to follow. (Requirement)\n- Safety focus vs. operational impact: The action removes an identified source of electrical arcing and potential cockpit smoke, while imposing a one-off compliance obligation on the specified fleet segment. (Background; Requirement)\n- Reference to another authority: The note records a corresponding Swedish airworthiness directive (LFV SAD 1-057), which can be used as a related source of information. (Note)\n\n### Practical effect summary\n\n- A defined subset of the SAAB SF340 fleet must have the AC generator control relays replaced according to the specified SAAB service bulletin, and this must be done by the stated deadline. The directive assigns the procedural details to the service bulletin and places the logistical, financial and scheduling burden on operators and their maintenance providers. (Applicability; Requirement; Compliance; Background)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-sf340-38-electrical-power-ac-generator-control-relays","history":"/api/acts/ad-sf340-38-electrical-power-ac-generator-control-relays/history","analysis":"/api/acts/ad-sf340-38-electrical-power-ac-generator-control-relays/analysis","conflicts":"/api/acts/ad-sf340-38-electrical-power-ac-generator-control-relays/conflicts","importantCases":"/api/acts/ad-sf340-38-electrical-power-ac-generator-control-relays/important-cases","documents":"/api/acts/ad-sf340-38-electrical-power-ac-generator-control-relays/documents"}}