{"id":"F2006B06949","name":"AD/SF340/20 - Autopilot Wiring","slug":"ad-sf340-20-autopilot-wiring","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114847,"registerId":"commonwealth-F2006B06949-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SF340/20 - Autopilot Wiring","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  SAAB SF340 Series Aeroplanes\n\n \n\nAD/SF340/20 Autopilot Wiring 2/91\n\nApplicability: SAAB SF340A S/No’s 079 thru 159. SAAB SF 340B S/No’s 160 thru 199. Requirement:               Modify as appropriate in accordance with LFV (Swedish) AD 1-041.\n\nNote: SAAB-SCANIA SB SAAB 340-34-068 also refers.\n\n \n\nCompliance: Prior to 1st June 1991.\n\n \n\nBackground: Wire FD 574-24 must be replaced with a 20 AWG sized wire to ensure correct circuit co-ordination is maintained.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument itself sets out a narrow, specific scope: it applies to SAAB SF340A S/No’s 079–159 and SF340B S/No’s 160–199 and requires replacement of wire FD 574-24 with 20 AWG in accordance with LFV AD 1-041 and the SAAB-SCANIA service bulletin, to be completed prior to 1 June 1991 (Applicability; Requirement; Note; Compliance; Background). The text contains no indication that the scope has been broadened or otherwise altered from this stated content."},"complexity_factors":["Narrow applicability limited to specific SAAB SF340 serial numbers (Applicability)","Single, specific technical action required (replace wire FD 574-24 with 20 AWG) (Background)","Dependence on external technical documents (LFV AD 1-041 and SAAB-SCANIA SB SAAB 340-34-068) for implementation details (Requirement; Note)","A fixed statutory compliance deadline imposes scheduling and operational constraints (Compliance)","Regulatory enforcement and recordkeeping obligations borne by operators and maintenance organisations (implicit in Compliance and Requirement)"],"plain_english_summary":"### What this instrument requires\n\n- This is an Airworthiness Directive that applies to specific SAAB SF340 aeroplanes: SF340A serial numbers 079–159 and SF340B serial numbers 160–199 (Applicability).\n- It requires the replacement of a particular wire (identified as FD 574-24) with a 20 AWG sized wire. The replacement must be carried out in accordance with the Swedish aviation authority's AD (LFV AD 1-041) and related SAAB-SCANIA service information (Requirement; Note; Background).\n- The work must be completed before 1 June 1991 (Compliance).\n\n### Who it affects\n\n- Aircraft owners and operators of the listed SAAB SF340 aircraft are directly affected because they must arrange and pay for the wiring change (Applicability; Requirement).\n- Maintenance organisations and licensed engineers will be responsible for performing the wiring replacement and for using the referenced LFV AD and SAAB-SCANIA service bulletin as the technical instructions (Requirement; Note).\n- The Civil Aviation Safety Authority issues and enforces the directive by prescribing the modification and the deadline (document heading and Compliance).\n\n### Why it matters (mechanical effect)\n\n- The stated technical reason is to ensure correct circuit co-ordination by replacing wire FD 574-24 with a larger (20 AWG) conductor (Background). Correct circuit coordination affects how electrical circuits interact and can be relevant to the safe operation of avionics and autopilot systems.\n\n### Practical consequences, incentives and costs\n\n- Who pays: aircraft owners/operators pay for parts, labour and any associated downtime required to carry out the modification (Applicability; Requirement).\n- Who decides/how it is done: the directive requires the action to follow LFV AD 1-041 and refers to SAAB-SCANIA SB SAAB 340-34-068 for technical details; this channels the required method to those external documents rather than leaving it to ad hoc judgement by maintainers (Requirement; Note).\n- Compliance burden: the operator must arrange a maintenance action before the stated date and keep records demonstrating compliance (Compliance). The action is a single, specified wiring replacement rather than an open-ended inspection regime.\n- Implementation risk and incentives: if the replacement is not done correctly, the stated purpose (maintain correct circuit coordination) will not be achieved; maintenance providers are therefore incentivised to follow the referenced AD/SB precisely (Background; Requirement).\n- Market effects: the directive creates demand for maintenance labour and the particular wire part on the affected serial-number aircraft; owners incur the cost and maintenance providers obtain the work (Applicability; Requirement).\n\n### How it operates mechanically\n\n- The directive identifies affected aircraft by serial number (Applicability).\n- It prescribes the required action (replace FD 574-24 with 20 AWG) and points to the LFV AD and a SAAB-SCANIA service bulletin for technical instructions (Requirement; Note).\n- It sets a firm compliance deadline (Prior to 1st June 1991) (Compliance).\n\n(Quoted section references: Applicability; Requirement; Note; Compliance; Background.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive targeting a specific technical defect in a specific aircraft type. It has not expanded beyond its original purpose of mandating a wiring modification."},"complexity_factors":["Extremely short document (under 150 words)","Only 2 defined applicability criteria (serial number ranges)","Single technical requirement with external reference to Swedish directive","No nested conditions, exceptions, or cross-references within the instrument itself","Clear compliance date with no conditional extensions"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific repairs or modifications to aircraft.\n\n**What it does:**\nOrders owners and operators of certain **SAAB SF340 aircraft** (a Swedish-made regional turboprop plane) to replace a specific electrical wire in the autopilot system. The old wire (labelled \"FD 574-24\") must be swapped for a thicker 20 AWG wire to prevent electrical problems.\n\n**Who it affects:**\n- Owners and operators of SAAB SF340A planes with serial numbers 079 through 159\n- Owners and operators of SAAB SF340B planes with serial numbers 160 through 199\n\n**Why it matters:**\nThe wrong wire size could cause the autopilot system to malfunction — a serious safety risk during flight. The directive ensures the aircraft's electrical \"circuit coordination\" (the way protective devices like fuses work together) functions correctly.\n\n**Key details:**\n- **Deadline:** Must be done before 1 June 1991\n- **How to comply:** Follow the instructions in Swedish aviation authority directive LFV AD 1-041\n- **Extra reference:** SAAB's own service bulletin SB SAAB 340-34-068 provides additional guidance"}},"importantCases":[],"_links":{"self":"/api/acts/ad-sf340-20-autopilot-wiring","history":"/api/acts/ad-sf340-20-autopilot-wiring/history","analysis":"/api/acts/ad-sf340-20-autopilot-wiring/analysis","conflicts":"/api/acts/ad-sf340-20-autopilot-wiring/conflicts","importantCases":"/api/acts/ad-sf340-20-autopilot-wiring/important-cases","documents":"/api/acts/ad-sf340-20-autopilot-wiring/documents"}}