{"id":"F2006B10494","name":"AD/HS 125/55 - Fuel Filler Neck Flap Valve - Installation","slug":"ad-hs-125-55-fuel-filler-neck-flap-valve-installation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116251,"registerId":"commonwealth-F2006B10494-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 125/55 - Fuel Filler Neck Flap 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)  British Aerospace BAe 125 Series Aeroplanes\n\n \n\nAD/HS 125/55 Fuel Filler Neck Flap Valve - Installation 7/81\n\nApplicability: As detailed in the requirement document.\n\n \n\nDocument:  British Aerospace 125 SB No. 28-60-(2465), Rev. No. 2. Compliance: Before 31 January 1982.\n\nBackground: A rubber flap valve is fitted to each of the fuel tank filler necks to minimise the inflight effects of an improperly closed fuel filler cap.\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":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The text requires installation of flap valves per the named service bulletin and sets a compliance deadline. The directive refers to a separate requirement document for exact applicability but does not indicate any amendment or expansion of scope within this text. Therefore, based on the supplied instrument, the scope is the installation requirement as stated and has not been changed within this document. (See: \"Applicability\", \"Document\", \"Compliance\", \"Background\".)"},"complexity_factors":["Clear, single technical action required (installation of flap valves). (Background)","Definite compliance deadline provided (before 31 January 1982). (Compliance)","Applicability is not fully specified in the directive text; requires consulting a separate requirement document, adding a small procedural step. (Applicability)","Technical method is delegated to an external service bulletin rather than set out in full here, requiring operators to obtain and follow that document. (Document)","No multiple compliance options, exemptions, or phased timelines included in the text supplied."],"plain_english_summary":"This directive requires operators of specified British Aerospace BAe 125 series aeroplanes to install a rubber flap valve on each fuel tank filler neck, following the named British Aerospace service bulletin, by 31 January 1982. It affects owners/operators of the listed aircraft and is intended to reduce in‑flight consequences from a fuel filler cap that is not properly closed."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive focused specifically on fuel filler neck flap valve installation. It has not expanded beyond its original narrow safety purpose."},"complexity_factors":["Extremely short document (under 200 words)","Only 1 defined term implicitly referenced (the service bulletin)","No conditional logic or nested exceptions","Single, unambiguous compliance action required","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Clear applicability and deadline"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for **British Aerospace BAe 125 series aircraft**.\n\n**What it does:**\n- Requires owners/operators to install a **rubber flap valve** on each fuel tank filler neck\n- This valve acts as a backup safety device to reduce fuel leakage risks if a fuel cap isn't properly secured during flight\n\n**Who it affects:**\n- Operators of British Aerospace BAe 125 series aeroplanes\n- Maintenance organisations servicing these aircraft\n\n**Why it matters:**\n- Prevents potentially catastrophic fuel leaks caused by human error (improperly closed fuel caps)\n- The directive references a specific British Aerospace service bulletin (SB 28-60-2465 Rev 2) that contains the detailed installation instructions\n- **Compliance deadline:** Before 31 January 1982 (now historical, but would have been mandatory when active)\n\n**Key point:** This is a **retrofit requirement** — aircraft needed modification to meet this safety standard, not just an inspection."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-125-55-fuel-filler-neck-flap-valve-installation","history":"/api/acts/ad-hs-125-55-fuel-filler-neck-flap-valve-installation/history","analysis":"/api/acts/ad-hs-125-55-fuel-filler-neck-flap-valve-installation/analysis","conflicts":"/api/acts/ad-hs-125-55-fuel-filler-neck-flap-valve-installation/conflicts","importantCases":"/api/acts/ad-hs-125-55-fuel-filler-neck-flap-valve-installation/important-cases","documents":"/api/acts/ad-hs-125-55-fuel-filler-neck-flap-valve-installation/documents"}}