{"id":"F2006B06981","name":"AD/SF340/51 - Engine Nacelle Fire Extinguisher Wiring","slug":"ad-sf340-51-engine-nacelle-fire-extinguisher-wiring","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114898,"registerId":"commonwealth-F2006B06981-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SF340/51 - Engine Nacelle Fire Extinguisher Wiring","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/SF340/51 Engine Nacelle Fire Extinguisher Wiring 3/96\n\nApplicability: This Directive is applicable to Model SF 340A aeroplanes serial numbers SF340-004 through \\-159 inclusive and Model 340B aeroplanes serial numbers 340B-160 through\n\n\\-345 inclusive.\n\nRequirement: Inspect and modify the engine nacelle fire extinguisher wiring in accordance with SAAB Aircraft AB Service Bulletin SAAB 340-26-015 dated 23 November 1995.\n\nNote: Swedish (LFV) SAD 1-079 refers.\n\nCompliance: No later than the next 4000 flight hour inspection (C check) after 29 February 1996.\n\nBackground: This Directive supersedes AD/SF340/39. SAAB Aircraft AB have advised that the possibility still exists for incorrect connection of the nacelle fire extinguishers despite incorporation of the modification required by AD/SF340/39. The actions required by this Directive are designed to ensure that the possibility of incorrect installation of fire extinguisher electrical wiring connections is minimised.","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 wiring issue in specific aircraft. It supersedes a previous directive on the same issue but does not represent scope creep beyond its original aviation safety purpose."},"complexity_factors":["Single, specific technical requirement referencing an external service bulletin","Clear applicability limited to specific aircraft models and serial number ranges","Simple compliance deadline tied to existing maintenance schedule (C check)","No defined terms section, no nested exceptions, no conditional logic","Short document (approximately 150 words) with straightforward structure"],"plain_english_summary":"CASA mandates inspection and correction of engine fire‑extinguisher wiring on specified Saab SF340A (s/n 004–159) and SF340B (s/n 160–345) aircraft. Operators must follow SAAB Service Bulletin 340‑26‑015 and complete repairs by the next C‑check (4,000 flight hours) after 29 Feb 1996. The AD closes a prior fix gap to ensure extinguishers operate in an emergency."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"This Directive supersedes AD/SF340/39 but maintains the same fleet applicability and continues to address incorrect nacelle fire‑extinguisher wiring; it updates the required inspection/modification method by referencing SAAB Service Bulletin 340-26-015 rather than expanding the set of affected aircraft."},"complexity_factors":["Narrow applicability by specific serial-number ranges (Applicability)","Prescriptive mandate to follow a manufacturer's service bulletin (Requirement)","Compliance deadline tied to routine heavy maintenance (next 4,000‑flight‑hour C check) (Compliance)","Supersedes an earlier AD and tightens/clarifies required action (Background)","Low regulatory discretion — operators must implement the specified inspection/modification","Operational scheduling and direct cost burden fall on aircraft owners/operators","Dependency on availability and clarity of the referenced service bulletin for technical compliance"],"plain_english_summary":"Requires operators of specified SAAB SF340A and 340B aeroplanes (listed serial ranges) to inspect and modify engine nacelle fire extinguisher wiring following SAAB Service Bulletin 340-26-015. Compliance is required by the next 4,000‑flight‑hour C‑check after 29 February 1996.\n\nThis imposes a compliance cost and scheduling obligation on aircraft owners/operators, who must organise and pay for work specified by the manufacturer to reduce the risk of incorrect extinguisher electrical connections."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sf340-51-engine-nacelle-fire-extinguisher-wiring","history":"/api/acts/ad-sf340-51-engine-nacelle-fire-extinguisher-wiring/history","analysis":"/api/acts/ad-sf340-51-engine-nacelle-fire-extinguisher-wiring/analysis","conflicts":"/api/acts/ad-sf340-51-engine-nacelle-fire-extinguisher-wiring/conflicts","importantCases":"/api/acts/ad-sf340-51-engine-nacelle-fire-extinguisher-wiring/important-cases","documents":"/api/acts/ad-sf340-51-engine-nacelle-fire-extinguisher-wiring/documents"}}