{"id":"F2006B05986","name":"AD/PA-42/2 - Nacelle Fuel Tank Check Valve - Installation","slug":"ad-pa-42-2-nacelle-fuel-tank-check-valve-installation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":136197,"registerId":"commonwealth-F2006B05986-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-42/2 - Nacelle Fuel Tank Check Valve - Installation","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)  Piper PA-42 (Cheyenne III) Series Aeroplanes\n\n \n\nAD/PA-42/2 Nacelle Fuel Tank Check Valve - Installation 4/83\n\nApplicability: All model PA-42 with S/Nos. 42-7800002 to 42-8001070. Document:  Piper SB No. 736.\n\nCompliance: Within 100 hours time in service after 30 June 1983.\n\n \n\nBackground: Should an engine fire occur, a broken fuel scavenge pump return line assembly could become a source of flame propagation.\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\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1226},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive maintains its original narrow scope: a specific airframe modification for a defined aircraft type and serial number range to address a specific fire safety hazard. No evidence of scope expansion beyond the original technical intent."},"complexity_factors":["Document contains only 5 substantive paragraphs","Single compliance action required (installation of one component)","Simple applicability test based solely on aircraft serial number range","Only one external reference (Piper Service Bulletin No. 736)","No defined terms, exceptions, or conditional clauses"],"plain_english_summary":"This is a **safety directive** for owners of specific Piper PA-42 Cheyenne III aircraft. It mandates the installation of a check valve in the engine nacelle fuel tank to prevent fire spread.\n\n**The problem:** If an engine catches fire, a broken fuel scavenge pump return line could act like a fuse, allowing flames to travel along the fuel line and spread the fire.\n\n**Who is affected:** Owners of PA-42 aircraft with serial numbers from 42-7800002 to 42-8001070.\n\n**What must be done:** Install a check valve following the instructions in Piper Service Bulletin No. 736.\n\n**Deadline:** Within 100 hours of flight time after 30 June 1983.\n\n**Why this matters:** The check valve acts as a safety barrier to stop flames from propagating through the fuel system during an engine fire, reducing the risk of catastrophic aircraft damage or loss of life."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-42-2-nacelle-fuel-tank-check-valve-installation","history":"/api/acts/ad-pa-42-2-nacelle-fuel-tank-check-valve-installation/history","analysis":"/api/acts/ad-pa-42-2-nacelle-fuel-tank-check-valve-installation/analysis","conflicts":"/api/acts/ad-pa-42-2-nacelle-fuel-tank-check-valve-installation/conflicts","importantCases":"/api/acts/ad-pa-42-2-nacelle-fuel-tank-check-valve-installation/important-cases","documents":"/api/acts/ad-pa-42-2-nacelle-fuel-tank-check-valve-installation/documents"}}