{"id":"F2006B04434","name":"AD/BELL 206/12 - Transmission Magnetic Drain Plug B-734 Replacement","slug":"ad-bell-206-12-transmission-magnetic-drain-plug-b-734-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44265,"registerId":"commonwealth-F2006B04434-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 206/12 - Transmission Magnetic Drain Plug B-734 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)  Bell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters\n\n \n\nAD/BELL 206/12 Transmission Magnetic Drain Plug B-734 Replacement\n\nApplicability: All models fitted with transmission magnetic drain plug B-734. Document: Bell SL No. 206A-58.\n\nCompliance: Within 100 hours time in service after 15 April 1969. Background: AD/Agusta 206/6 equivalent.\n\n\n4/69\n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2406},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive remains tightly focused on its original purpose: mandating replacement of a specific wear-item component in helicopter transmissions. There is no evidence of scope expansion into broader operational requirements or additional aircraft systems."},"complexity_factors":["Single, unambiguous compliance action (replace one part)","No definitions section or interpretation clauses","External reference to manufacturer service letter (Bell SL 206A-58) for technical procedures","Simple time-based trigger (100 hours time in service)","Minimal conditional logic (applicability determined by presence of specific part number only)"],"plain_english_summary":"This is a straightforward maintenance order for Bell 206 helicopter operators.\n\n**What it does**\nThe directive requires owners to replace a specific transmission magnetic drain plug (part number B-734) within 100 hours of flying time after 15 April 1969.\n\n**Why this matters**\nThe magnetic drain plug sits in the transmission (the gearbox that drives the rotor) and acts like a magnetised sieve, catching tiny metal fragments from wear and tear. If the plug fails or becomes saturated, mechanics lose their early warning system for internal damage. Replacing it ensures metal debris is detected before it causes catastrophic transmission failure and a potential crash.\n\n**Who is affected**\nAnyone operating Bell 206 or Agusta-Bell 206 helicopters fitted with this specific drain plug part. Compliance requires checking the aircraft's flight logs against the 100-hour deadline."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-206-12-transmission-magnetic-drain-plug-b-734-replacement","history":"/api/acts/ad-bell-206-12-transmission-magnetic-drain-plug-b-734-replacement/history","analysis":"/api/acts/ad-bell-206-12-transmission-magnetic-drain-plug-b-734-replacement/analysis","conflicts":"/api/acts/ad-bell-206-12-transmission-magnetic-drain-plug-b-734-replacement/conflicts","importantCases":"/api/acts/ad-bell-206-12-transmission-magnetic-drain-plug-b-734-replacement/important-cases","documents":"/api/acts/ad-bell-206-12-transmission-magnetic-drain-plug-b-734-replacement/documents"}}