{"id":"F2006B09096","name":"AD/DHC-6/1 - Upper Rudder Fairing - Modification","slug":"ad-dhc-6-1-upper-rudder-fairing-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115649,"registerId":"commonwealth-F2006B09096-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-6/1 - Upper Rudder Fairing - 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)  DHC-6 (Twin Otter) Series Aeroplanes\n\n \n\nAD/DHC-6/1 Upper Rudder Fairing - Modification 5/67\n\nApplicability: All models with S/Nos. 1 to 6, 8 and 9. Document:  De Havilland of Canada Mod. Bulletin 6/1013. Compliance:               Before 1 September 1971.\n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1187},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This directive remains tightly focused on its original purpose: requiring a specific structural modification to specific aircraft serial numbers. There is no evidence of scope creep or expansion beyond the original technical safety requirement."},"complexity_factors":["Extremely short text (under 100 words)","No defined terms section","Single, clear applicability criteria (specific serial numbers)","Single compliance action with clear deadline","No conditional logic or exceptions"],"plain_english_summary":"**What this does:** This is a mandatory safety directive (called an Airworthiness Directive) that requires owners of specific De Havilland DHC-6 Twin Otter aircraft to modify the upper rudder fairing.\n\n**Who it affects:** Owners and operators of DHC-6 Twin Otter aircraft with serial numbers 1 through 6, 8, and 9.\n\n**What must be done:** The aircraft's upper rudder fairing must be modified according to the specifications in De Havilland of Canada Modification Bulletin 6/1013.\n\n**Why it matters:** This ensures the aircraft meets safety standards. The modification must be completed before 1 September 1971.\n\n**In simple terms:** If you own one of these specific old Twin Otter planes, you must get this particular fix done to the tail section by the deadline."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-6-1-upper-rudder-fairing-modification","history":"/api/acts/ad-dhc-6-1-upper-rudder-fairing-modification/history","analysis":"/api/acts/ad-dhc-6-1-upper-rudder-fairing-modification/analysis","conflicts":"/api/acts/ad-dhc-6-1-upper-rudder-fairing-modification/conflicts","importantCases":"/api/acts/ad-dhc-6-1-upper-rudder-fairing-modification/important-cases","documents":"/api/acts/ad-dhc-6-1-upper-rudder-fairing-modification/documents"}}