{"id":"F2006B09975","name":"AD/FU24/11 - Fin Rib and Skin Cracking - Inspection","slug":"ad-fu24-11-fin-rib-and-skin-cracking-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55263,"registerId":"commonwealth-F2006B09975-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/FU24/11 - Fin Rib and Skin Cracking - 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)  Airparts (NZ) Ltd. FU 24 Series Aeroplanes\n\n \n\nAD/FU24/11 Fin Rib and Skin Cracking - Inspection 6/68\n\nApplicability: All models prior to S/Nos. 120 not modified in accordance with FAC SB 12 September 58-1.\n\n \n\nDocument: Fletcher SB 12 September 58-1.\n\n \n\nCompliance: At intervals not exceeding 200 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\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":1489},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This airworthiness directive maintains its original narrow scope targeting specific structural integrity issues in early-model Fletcher FU-24 aircraft. There is no evidence of scope creep beyond the original safety purpose of preventing fin structure failures."},"complexity_factors":["Single, unambiguous compliance requirement (200-hour inspection interval)","Limited applicability criteria (specific serial number range and modification status)","No defined terms, nested exceptions, or conditional logic","References only one external technical document"],"plain_english_summary":"This directive requires owners and operators of specific Fletcher FU-24 agricultural aircraft to regularly inspect the tail section for dangerous cracks.\n\n**Who it affects:** Anyone operating Fletcher FU-24 series planes with serial numbers below 120 that haven't been modified according to the manufacturer's Service Bulletin 58-1 (issued 12 September 1958).\n\n**What it requires:** You must check the vertical fin (the upright tail section) ribs and skin for cracking at least every 200 hours of flight time.\n\n**Why it matters:** Cracks in the tail structure can lead to structural failure and potentially cause the aircraft to crash. This is a safety-critical maintenance requirement to prevent accidents in these older aircraft models."}},"importantCases":[],"_links":{"self":"/api/acts/ad-fu24-11-fin-rib-and-skin-cracking-inspection","history":"/api/acts/ad-fu24-11-fin-rib-and-skin-cracking-inspection/history","analysis":"/api/acts/ad-fu24-11-fin-rib-and-skin-cracking-inspection/analysis","conflicts":"/api/acts/ad-fu24-11-fin-rib-and-skin-cracking-inspection/conflicts","importantCases":"/api/acts/ad-fu24-11-fin-rib-and-skin-cracking-inspection/important-cases","documents":"/api/acts/ad-fu24-11-fin-rib-and-skin-cracking-inspection/documents"}}