{"id":"F2006B04656","name":"AD/BELL 412/21 - Fuel Cell Interconnect Tube","slug":"ad-bell-412-21-fuel-cell-interconnect-tube","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44408,"registerId":"commonwealth-F2006B04656-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 412/21 - Fuel Cell Interconnect Tube","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)  \nBell Helicopter Textron 412 Series Helicopters\n\nAD/BELL 412/21 Fuel Cell Interconnect Tube 5/89\n\nDM\n\nApplicability: All model 412 or 412 NB within the S/No range as detailed in the Requirement Document.\n\nRequirement: Action in accordance with Bell Alert Service Bulletin No 412-88-40, latest revision.\n\nCompliance: 1. For aircraft fitted or were previously fitted with P/N 204-072-915-103 external cargo suspension assembly. Inspect daily for leakage. If leakage evident replace tube before further flight. If no leakage is evident replace tube at next maintenance release inspection or by 30 April 1989, whichever occurs first.\n\n    2. For aircraft which have never had the cargo suspension assembly fitted. Replace tube at next maintenance release inspection or by 31 July 1989 whichever occurs first.\n\n    3. For aircraft having the cargo suspension assembly installed for the first time. If not already carried out ensure the interconnect tube P/N 412-061-673-101 is fitted during cargo suspension assembly installation.\n\nBackground: To reduce possible fuel interconnect tube damage from the cargo suspension assembly during slung load operation. The manufacturer requires a redesigned tube to be fitted. Also, two rubber fuel hoses are inspected for correct clamping during the tube installation.","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2085},"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive maintains its original narrow technical scope focused solely on fuel system integrity in Bell 412 helicopters equipped for external load operations. It does not expand beyond the stated purpose of preventing fuel tube damage from cargo suspension assemblies."},"complexity_factors":["Three distinct compliance pathways contingent on aircraft modification history (cargo suspension assembly installation status)","Hard compliance deadlines (30 April 1989 and 31 July 1989) creating time-barred obligations","Cross-reference to external technical document (Bell Alert Service Bulletin 412-88-40) for full procedural requirements","Multiple specific part numbers (P/N 204-072-915-103, P/N 412-061-673-101) requiring verification against aircraft maintenance records","Conditional logic: immediate grounding requirement if leakage detected vs. deferred replacement if no leakage","Daily inspection burden for high-risk aircraft (those with cargo hooks)","Applicability limited to specific serial number ranges detailed in a separate 'Requirement Document' not included in the text"],"plain_english_summary":"A safety order requiring owners/operators of Bell 412/412NB helicopters in specified serial ranges to replace a fuel cell interconnect tube that can be damaged by external cargo suspension gear, causing dangerous fuel leaks. Timelines and inspection rules vary by cargo‑hook history; installing the cargo hook now requires the redesigned tube and accompanying rubber‑hose clamp checks. The rule prevents in‑flight fire and engine‑loss risks from known interference damage."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-412-21-fuel-cell-interconnect-tube","history":"/api/acts/ad-bell-412-21-fuel-cell-interconnect-tube/history","analysis":"/api/acts/ad-bell-412-21-fuel-cell-interconnect-tube/analysis","conflicts":"/api/acts/ad-bell-412-21-fuel-cell-interconnect-tube/conflicts","importantCases":"/api/acts/ad-bell-412-21-fuel-cell-interconnect-tube/important-cases","documents":"/api/acts/ad-bell-412-21-fuel-cell-interconnect-tube/documents"}}