{"id":"F2006B02958","name":"AD/B737/59 - Engine Fire Extinguishing System","slug":"ad-b737-59-engine-fire-extinguishing-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42300,"registerId":"commonwealth-F2006B02958-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B737/59 - Engine Fire Extinguishing System","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)  Boeing 737 Series Aeroplanes\n\n \n\nAD/B737/59 Engine Fire Extinguishing System 7/91\n\nApplicability:   As detailed in the Requirement Document.\n\n \n\nRequirement:  Action in accordance with the Technical Requirements of FAA AD 91-09-12. Compliance:  Prior to 28 May 1994.\n\nBackground:  This AD requires modification of the engine fire extinguishing system wiring and plumbing to preclude improper connection during maintenance. Compliance with this AD constitutes terminating action for the repetitive inspections and functional checks required by AD/B737/19.\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":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive with a single purpose: correcting a specific maintenance error risk in fire suppression systems. It has not expanded beyond its original technical scope."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","No defined terms section — relies entirely on external references","Single operative requirement: comply with FAA AD 91-09-12","No conditional logic, exceptions, or nested provisions","Simple structure: Applicability → Requirement → Compliance date → Background","Cross-references only to external documents (FAA AD and earlier CASA AD), not to internal sections"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific Boeing 737 aircraft.\n\n**What it does:** The directive requires airlines and aircraft operators to modify the **engine fire extinguishing system** on affected Boeing 737 planes. Specifically, they must change the wiring and plumbing to prevent maintenance crews from accidentally connecting parts incorrectly. Think of it like redesigning fuel and electrical lines so they physically cannot be plugged into the wrong sockets.\n\n**Who it affects:** Operators of Boeing 737 series aircraft registered in Australia (or operating under Australian regulations). The exact models covered are listed in a separate technical document referenced as \"the Requirement Document.\"\n\n**Why it matters:** Engine fires are obviously catastrophic. If the fire extinguishing system is wired or plumbed incorrectly during maintenance, it might fail to deploy when needed — or deploy in the wrong engine. This AD fixes a design flaw that could allow such dangerous misconnections.\n\n**Key deadline:** The modifications had to be completed before **28 May 1994**.\n\n**Bonus effect:** Once operators complied with this AD, they could stop doing repetitive inspections and functional checks that were previously required under an earlier directive (AD/B737/19). This is called \"terminating action\" — the fix is permanent, so the ongoing checks are no longer needed."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This AD changes the compliance approach set by the earlier AD/B737/19 by mandating a one-off modification to engine fire extinguishing system wiring and plumbing that, when done, constitutes terminating action for the repetitive inspections and functional checks previously required (Background). The new scope requires following FAA AD 91-09-12 technical steps (Requirement) and applies to the aircraft identified in the separate Requirement Document (Applicability)."},"complexity_factors":["Cross-reference to an external FAA AD (FAA AD 91-09-12) for technical requirements (Requirement).","Applicability is not listed in full in the text; it points to a separate Requirement Document for which aircraft are covered (Applicability).","Interplay with a prior AD (AD/B737/19): this AD acts as terminating action for those repetitive inspections (Background).","Technical nature of required work (wiring and plumbing modification) requires qualified maintenance, parts, and aircraft downtime (Requirement/Background).","Fixed compliance deadline (28 May 1994) creates scheduling pressure for operators (Requirement).","The AD text itself lacks detailed verification procedures, meaning compliance depends on external documents and normal regulatory record-keeping (Requirement/Background)."],"plain_english_summary":"This AD requires owners/operators of the Boeing 737 series named in the Requirement Document to complete a one‑off wiring and plumbing modification to engine fire‑extinguishing systems, following FAA AD 91‑09‑12, by 28 May 1994. The change prevents improper maintenance connections that could defeat the extinguishing system and serves as terminating action for the prior recurring inspections under AD/B737/19. Operators bear the modification costs and must consult the referenced documents for technical steps and compliance evidence."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-59-engine-fire-extinguishing-system","history":"/api/acts/ad-b737-59-engine-fire-extinguishing-system/history","analysis":"/api/acts/ad-b737-59-engine-fire-extinguishing-system/analysis","conflicts":"/api/acts/ad-b737-59-engine-fire-extinguishing-system/conflicts","importantCases":"/api/acts/ad-b737-59-engine-fire-extinguishing-system/important-cases","documents":"/api/acts/ad-b737-59-engine-fire-extinguishing-system/documents"}}