{"id":"F2006B04759","name":"AD/BN-2/48 - Wing Tip Tank Fuel Contents Transmitter Floats - Inspection","slug":"ad-bn-2-48-wing-tip-tank-fuel-contents-transmitter-floats-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44523,"registerId":"commonwealth-F2006B04759-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BN-2/48 - Wing Tip Tank Fuel Contents Transmitter Floats - Inspection","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)  Pilatus Britten-Norman BN-2 Series Aeroplanes\n\n \n\n# AD/BN-2/48  Wing Tip Tank Fuel Contents Transmitter Floats - Inspection\n\nApplicability: All models BN-2 Islander with wing tip fuel tanks. Document:  Britten Norman SB BN-2/SB 154.\n\n# 6/83\n\nCompliance: As per requirement document within 100 hours time in service after 31 August 1983.\n\n \n\nBackground: Wing tip fuel tank contents transmitter floats are prone to erosion and require repetitive inspections to prevent fuel system contamination which could result in loss of engine power.\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, targeted safety directive addressing a specific mechanical defect in a specific aircraft type. It has not expanded beyond its original purpose of preventing fuel system contamination through float erosion."},"complexity_factors":["Very short document (under 200 words)","Only one defined term (Applicability refers to specific aircraft models)","Single cross-reference to external technical document (Service Bulletin BN-2/SB 154)","Simple conditional logic: if you have this aircraft type with this equipment, you must comply","No nested exceptions or complex procedural branching","Clear, unambiguous compliance deadline (100 hours after fixed date)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nRequires owners and operators of **Pilatus Britten-Norman BN-2 Islander aircraft** (all models fitted with wing tip fuel tanks) to inspect the fuel gauge floats inside those wing tip tanks.\n\n**Why it matters:**\nThe floats that measure fuel levels can **erode and break apart**. If pieces break off, they can contaminate the fuel system and cause **engine failure** — obviously catastrophic when you're flying.\n\n**What must happen:**\n- Follow the inspection procedure in **Britten-Norman Service Bulletin BN-2/SB 154**\n- Complete the first inspection within **100 flight hours** after 31 August 1983\n- This is a **repetitive inspection** (ongoing maintenance, not a one-off fix)\n\n**Who it affects:**\nAnyone operating or maintaining BN-2 Islander aircraft with wing tip tanks in Australia — typically used for regional transport, sightseeing, or utility work in remote areas."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive applies to all BN‑2 Islander models that have wing tip fuel tanks and requires inspections per the referenced Britten Norman service bulletin. The text does not indicate any alteration or expansion of that scope beyond the stated applicability and compliance window."},"complexity_factors":["Reliance on an external requirement document (Britten Norman SB BN‑2/SB 154) for procedural detail rather than including steps in the directive itself (Document).","Initial compliance deadline tied to a specific date and a 100 hours time‑in‑service window, which is precise but historic (Compliance).","Applicability limited to BN‑2 Islanders with wing tip tanks, requiring operators to determine model configuration before applying the directive (Applicability).","Repetitive inspection schedule is not specified in the directive text and must be read from the service bulletin, adding an extra step to determine ongoing obligations (Compliance; Document).","Technical subject matter (erosion of transmitter floats and fuel system contamination) requires maintenance competence and possible parts replacement, imposing operational and cost burdens on operators (Background)."],"plain_english_summary":"Requires BN‑2 Islander aeroplanes with wing‑tip fuel tanks to inspect the fuel contents transmitter floats per Britten Norman SB BN‑2/SB 154, with the first inspection within 100 hours TIS after 31 Aug 1983. Operators/owners must obtain and follow the service bulletin (and pay for work); inspections address float erosion that could contaminate fuel and risk engine power loss."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bn-2-48-wing-tip-tank-fuel-contents-transmitter-floats-inspection","history":"/api/acts/ad-bn-2-48-wing-tip-tank-fuel-contents-transmitter-floats-inspection/history","analysis":"/api/acts/ad-bn-2-48-wing-tip-tank-fuel-contents-transmitter-floats-inspection/analysis","conflicts":"/api/acts/ad-bn-2-48-wing-tip-tank-fuel-contents-transmitter-floats-inspection/conflicts","importantCases":"/api/acts/ad-bn-2-48-wing-tip-tank-fuel-contents-transmitter-floats-inspection/important-cases","documents":"/api/acts/ad-bn-2-48-wing-tip-tank-fuel-contents-transmitter-floats-inspection/documents"}}