{"id":"F2006B05581","name":"AD/PA-25/9 - Sealing of Rear Fuel Tank Bay","slug":"ad-pa-25-9-sealing-of-rear-fuel-tank-bay","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46607,"registerId":"commonwealth-F2006B05581-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-25/9 - Sealing of Rear Fuel Tank Bay","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)  Piper PA-25 (Pawnee) Series Aeroplanes\n\n \n\nAD/PA-25/9 Sealing of Rear Fuel Tank Bay 10/62\n\nApplicability: Model PA-25-235 and variants of that model.\n\n \n\nRequirement: All openings between the fuselage fuel tank bay and the hopper bay shall be sealed with plates of 2024ST material not less than 24 gauge or other material having at least equivalent fire resistant properties.\n\n \n\nCompliance: Before 1 September 1971.\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":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1712},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"The directive remains tightly focused on its original purpose: requiring a specific fire-safety modification for a single aircraft model series. There is no indication of scope expansion beyond the PA-25-235 and its direct variants."},"complexity_factors":["Single sentence requirement with no conditional clauses","No defined terms or interpretation section","Zero cross-references to other legislation","Single applicability criterion (specific aircraft model)","One fixed compliance date with no exceptions or extensions"],"plain_english_summary":"**What this is:** An Airworthiness Directive (a mandatory safety order) requiring a specific fire-prevention modification to certain Piper Pawnee agricultural aircraft.\n\n**Who it affects:** Owners and operators of **Piper PA-25-235** model aircraft (and its variants) — these are single-engine crop-dusting planes commonly used in agriculture.\n\n**What it requires:** All gaps between the **fuselage fuel tank bay** (where the fuel is stored) and the **hopper bay** (where agricultural chemicals/fertiliser are carried) must be sealed with metal plates. The plates must be made of **2024ST aluminium alloy** at least 24 gauge thick (about 0.5mm), or another material with equivalent fire-resistant properties.\n\n**Why it matters:** This prevents fire from spreading between the fuel tank and the chemical hopper, reducing the risk of catastrophic in-flight fires during agricultural operations.\n\n**Compliance:** This modification should have been completed before **1 September 1971**."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-25-9-sealing-of-rear-fuel-tank-bay","history":"/api/acts/ad-pa-25-9-sealing-of-rear-fuel-tank-bay/history","analysis":"/api/acts/ad-pa-25-9-sealing-of-rear-fuel-tank-bay/analysis","conflicts":"/api/acts/ad-pa-25-9-sealing-of-rear-fuel-tank-bay/conflicts","importantCases":"/api/acts/ad-pa-25-9-sealing-of-rear-fuel-tank-bay/important-cases","documents":"/api/acts/ad-pa-25-9-sealing-of-rear-fuel-tank-bay/documents"}}