{"id":"F2006B04771","name":"AD/BN-2/6 - Main Fuel Pipe - Modification","slug":"ad-bn-2-6-main-fuel-pipe-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44536,"registerId":"commonwealth-F2006B04771-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BN-2/6 - Main Fuel Pipe - Modification","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\nAD/BN-2/6 Main Fuel Pipe - Modification NK\n\nApplicability: All model BN-2A fitted with main fuel pipes P/N NB-57-439. Document:  Britten-Norman SB BN-2/1SB11 Issue 2.\n\nCompliance: Within 100 hours time in service after 12 May 1969.\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\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive issued in 1969 for a specific mechanical defect. It has not expanded beyond its original narrow scope of requiring a fuel pipe modification on affected BN-2A aircraft."},"complexity_factors":["Single, specific aircraft model and part number identified","Clear, unambiguous compliance deadline (100 hours time in service after fixed date)","No defined terms section","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Single mandatory action with no exceptions or conditional logic","Extremely short document (approximately 100 words of substantive content)"],"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:**\nOrders owners and operators of certain **Pilatus Britten-Norman BN-2 Islander aircraft** to modify the main fuel pipe on their planes.\n\n**Who it affects:**\nAnyone who owns or operates a **BN-2A model aircraft** that has main fuel pipes with the part number **P/N NB-57-439**.\n\n**What must be done:**\nThe aircraft must be modified according to the manufacturer's Service Bulletin **Britten-Norman SB BN-2/1SB11 Issue 2**.\n\n**When it must be done:**\nWithin **100 hours of flying time** after **12 May 1969**.\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety instructions. If you don't comply, you cannot legally fly the aircraft. This particular directive addresses a specific fuel pipe design that was apparently unsafe or prone to failure — ignoring it could lead to fuel leaks, engine failure, or worse."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive’s scope is explicitly limited to 'All model BN-2A fitted with main fuel pipes P/N NB-57-439' and requires the modification specified in Britten-Norman SB BN-2/1SB11 Issue 2 to be completed within 100 hours time in service after 12 May 1969 (Applicability; Document; Compliance). The text contains no indication that the applicability or required action was broadened or narrowed from an earlier version within this excerpt."},"complexity_factors":["Narrow applicability — only BN-2A aircraft fitted with main fuel pipe P/N NB-57-439 (Applicability)","Single mandated action — modify main fuel pipe per manufacturer service bulletin (Document)","Clear, short compliance window — 100 hours time in service after a specified date (Compliance)","Dependence on an external technical document (Britten-Norman SB BN-2/1SB11 Issue 2) for procedural detail (Document)","Operational dependencies — need for parts, qualified maintenance personnel and scheduling/downtime","Regulatory enforcement under Part 39 creates mandatory legal requirement with limited discretion (header)"],"plain_english_summary":"This airworthiness directive mandates that Pilatus Britten‑Norman BN‑2A aircraft fitted with main fuel pipe P/N NB‑57‑439 be modified per Britten‑Norman SB BN‑2/1SB11 Issue 2. Owners/operators and maintenance organisations must complete the work within 100 hours time‑in‑service after 12 May 1969. Compliance is mandatory and costs (parts, labour, downtime) fall to operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bn-2-6-main-fuel-pipe-modification","history":"/api/acts/ad-bn-2-6-main-fuel-pipe-modification/history","analysis":"/api/acts/ad-bn-2-6-main-fuel-pipe-modification/analysis","conflicts":"/api/acts/ad-bn-2-6-main-fuel-pipe-modification/conflicts","importantCases":"/api/acts/ad-bn-2-6-main-fuel-pipe-modification/important-cases","documents":"/api/acts/ad-bn-2-6-main-fuel-pipe-modification/documents"}}