{"id":"F2006B09980","name":"AD/FU24/19 - Engine Mounts and Firewalls","slug":"ad-fu24-19-engine-mounts-and-firewalls","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55282,"registerId":"commonwealth-F2006B09980-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/FU24/19 - Engine Mounts and Firewalls","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)  Airparts (NZ) Ltd. FU 24 Series Aeroplanes\n\n \n\nAD/FU24/19 Engine Mounts and Firewalls 6/68\n\nApplicability: All models except those fitted with Lycoming IO-720 engines.\n\n \n\nRequirement: 1. Inspect the engine mounts for loose rivets and elongated rivet holes between the engine bearer frames P/N 243076 and 243077, and the engine mount casings P/N 244100 and 244101.\n\n \n\n2.    Inspect the firewall P/N 243140 for cracking particularly in the following locations:\n\n \n\n(a)     Adjacent to the nose leg lower attachment fitting P/N 243038;\n\n \n\n(b)     Adjacent to the doubler plates P/N 243128;\n\n \n\n(c)     Near the top of the two vertical reinforcing angles. Compliance: At intervals not exceeding 100 hours time in service.\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":1345},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow scope focused solely on mandatory repetitive inspections of engine mount structures and firewalls for the FU-24 aircraft series. It has not expanded beyond this specific mechanical safety concern."},"complexity_factors":["Specific aircraft part numbers (P/N 243076, 243077, etc.) require technical familiarity","Single conditional exclusion (Lycoming IO-720 engines)","Straightforward repetitive compliance interval (100 hours) with no nested exceptions or cross-references to other legislation"],"plain_english_summary":"This rule requires owners/operators of New Zealand-made Airparts FU-24 (“Fletcher”) aircraft—except those fitted with Lycoming IO-720 engines—to perform mandatory safety inspections every 100 flight hours.  \n\nInspectors must check engine mounts and the firewall for loose rivets, stretched or cracked holes, and cracks that could lead to engine separation or fire propagation. The directive is legally enforceable to prevent catastrophic in-flight failures."}},"importantCases":[],"_links":{"self":"/api/acts/ad-fu24-19-engine-mounts-and-firewalls","history":"/api/acts/ad-fu24-19-engine-mounts-and-firewalls/history","analysis":"/api/acts/ad-fu24-19-engine-mounts-and-firewalls/analysis","conflicts":"/api/acts/ad-fu24-19-engine-mounts-and-firewalls/conflicts","importantCases":"/api/acts/ad-fu24-19-engine-mounts-and-firewalls/important-cases","documents":"/api/acts/ad-fu24-19-engine-mounts-and-firewalls/documents"}}