{"id":"F2006B06956","name":"AD/SF340/27 - Lavatory Circuit Breaker Replacement","slug":"ad-sf340-27-lavatory-circuit-breaker-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114854,"registerId":"commonwealth-F2006B06956-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SF340/27 - Lavatory Circuit Breaker Replacement","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/SF340/27 Lavatory Circuit Breaker Replacement 7/91\n\nApplicability: As specified in the Requirement Document.\n\n \n\nRequirement: Action in accordance with the technical requirements Swedish AD 1-045.\n\n \n\nNote: SAAB-SCANIA SB 340-25-181 also refers.\n\n \n\nCompliance: Prior to 8 December 1991.\n\n \n\nBackground:  Action in accordance with this AD is necessary in order to prevent possible wire overload if a failure occurs in the forward or aft lavatory electrical system.\n\n \n\nNote: The compliance date specified in the Requirement document has been extended from 8 September 1991 to 8 December 1991.\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 does not change the substantive technical requirement; it mandates replacement per Swedish AD 1-045 and refers to SAAB‑SCANIA SB 340‑25‑181 (Requirement; Note). The only recorded change is an extension of the compliance date from 8 September 1991 to 8 December 1991 (Note), which alters timing but not the scope of work required."},"complexity_factors":["Cross-reference to external technical documents (Swedish AD 1-045 and SAAB‑SCANIA SB 340‑25‑181) rather than containing full technical steps within the AD (Requirement; Note).","Applicability is delegated to a separate \"Requirement Document\" rather than being stated directly in the text (Applicability).","Compliance deadline with a recorded extension (from 8 September 1991 to 8 December 1991) introduces a time-bound enforcement element (Compliance; Note).","Limited procedural detail in the AD itself: parts, labour hours, and acceptance/inspection criteria are not specified in this instrument (Requirement; Note).","Regulatory context indicated by the Civil Aviation Regulations heading, implying oversight and enforcement mechanisms external to the AD text (heading)."],"plain_english_summary":"What this instrument requires and how it works\n\n- This airworthiness directive applies to SAAB SF340 aeroplanes; the exact aircraft or serials covered are set out \"as specified in the Requirement Document\" (Applicability).\n- It directs operators to perform a replacement of the lavatory circuit breaker(s) by following the technical instructions in Swedish AD 1-045 (Requirement). SAAB‑SCANIA Service Bulletin SB 340‑25‑181 is also referenced (Note).\n- The replacement must be completed before 8 December 1991; the document records that the earlier compliance date of 8 September 1991 was extended to 8 December 1991 (Compliance; Note).\n- The stated technical aim is to prevent possible wire overload if a failure occurs in the forward or aft lavatory electrical system (Background).\n\nWho is affected and who decides\n\n- The directive is addressed to operators/owners of the SAAB SF340 aircraft covered by the Requirement Document (Applicability; Requirement). The directive sets the mandatory action and the compliance date (Requirement; Compliance).\n- The issuing authority is the Civil Aviation Safety Authority framework under the Civil Aviation Regulations 1998 (PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY) as shown in the heading.\n\nCosts, incentives and practical effects (mechanical, not normative)\n\n- Direct cost and work: Operators must obtain the technical instructions (Swedish AD 1-045 and the SAAB service bulletin where relevant), source replacement parts or breakers if required, and have maintenance personnel carry out the replacement before the compliance date (Requirement; Note; Compliance).\n- Operational impact: Aircraft covered by the AD will need to be taken out of service for the work until the replacement is completed, which imposes scheduling and availability costs (Compliance).\n- Distribution of costs and benefits: The benefit is reduced risk of wire overload in the specified lavatory electrical systems (Background). The AD does not state funding, compensation or cost-sharing mechanisms; therefore, the practical effect is that the operators who must comply will bear the direct costs and operational downtime (Applicability; Requirement).\n\nImplementation and compliance considerations\n\n- The AD relies on external technical documents (Swedish AD 1-045 and SAAB‑SCANIA SB 340‑25‑181) to define the detailed technical steps; the AD itself does not set out step‑by‑step procedures (Requirement; Note).\n- Because the AD references other documents for technical content, operators must obtain and follow those documents to achieve compliance (Requirement; Note).\n- The only change recorded in this instrument is an extension of the compliance date from 8 September 1991 to 8 December 1991 (Note). The AD does not amend the technical requirement itself.\n\nHow compliance will change behaviour\n\n- Operators will schedule and perform the specified lavatory circuit breaker replacement on the applicable SAAB SF340 aeroplanes in line with the Swedish AD and the SAAB service bulletin before the compliance date (Requirement; Note; Compliance). This requires maintenance planning, parts procurement (if parts are required by the referenced documents) and record-keeping to show compliance."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-limited safety directive with a single specific purpose. It has not expanded beyond its original intent of mandating a specific hardware replacement to prevent electrical overload in lavatory systems."},"complexity_factors":["Extremely short document — only 8 substantive lines of regulatory text","No defined terms section — relies entirely on external technical documents","Single, unambiguous compliance action (replace circuit breakers)","No nested conditions, exceptions, or cross-references to other legislation","Defers all technical detail to referenced Swedish AD and manufacturer service bulletin"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) requiring specific repairs or modifications to aircraft.\n\n**What it does:** It orders owners and operators of **SAAB SF340 series aircraft** to replace certain circuit breakers in the forward and aft (front and back) lavatory (toilet) electrical systems.\n\n**Why it matters:** Faulty circuit breakers in the lavatory electrical system could cause **wire overload** — meaning wires could overheat, potentially leading to fire or electrical failure. This is a safety-critical fix to prevent that risk.\n\n**Who must comply:** Anyone operating SAAB SF340 aircraft in Australia. The directive references a Swedish aviation directive (AD 1-045) and a SAAB service bulletin (SB 340-25-181) for the exact technical steps.\n\n**Key deadline:** The work had to be completed before **8 December 1991** (extended from an earlier September deadline)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sf340-27-lavatory-circuit-breaker-replacement","history":"/api/acts/ad-sf340-27-lavatory-circuit-breaker-replacement/history","analysis":"/api/acts/ad-sf340-27-lavatory-circuit-breaker-replacement/analysis","conflicts":"/api/acts/ad-sf340-27-lavatory-circuit-breaker-replacement/conflicts","importantCases":"/api/acts/ad-sf340-27-lavatory-circuit-breaker-replacement/important-cases","documents":"/api/acts/ad-sf340-27-lavatory-circuit-breaker-replacement/documents"}}