{"id":"F2006B09128","name":"AD/DHC-6/4 - Nose Landing Gear - Modification","slug":"ad-dhc-6-4-nose-landing-gear-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115681,"registerId":"commonwealth-F2006B09128-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-6/4 - Nose Landing Gear - 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-6/4 Nose Landing Gear - Modification 7/67\n\nApplicability: All models with S/Nos. 4 to 24, 26 to 29 and 31 to 37. Document:  De Havilland of Canada Mod. Bulletin 6/1040.\n\nCompliance: Before 1 September 1971.\n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1022},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This is a narrow, technical safety directive targeting a specific mechanical issue in specific aircraft. There is no indication the scope has expanded beyond the original safety modification requirement."},"complexity_factors":["Single operative requirement with no conditional logic","No defined terms section","Limited applicability restricted to specific aircraft serial numbers","Straightforward compliance deadline with no exceptions or extensions mentioned"],"plain_english_summary":"**What this is:** An Airworthiness Directive — essentially a mandatory safety order issued by the Civil Aviation Safety Authority (CASA) requiring specific aircraft owners to make mechanical changes to their planes.\n\n**Who it affects:** Owners or operators of DHC-6 \"Twin Otter\" aircraft with specific serial numbers: 4 through 24, 26 through 29, and 31 through 37.\n\n**What it requires:** These aircraft must have their nose landing gear (the front wheel assembly used for takeoff, landing, and taxiing) modified according to technical instructions in De Havilland of Canada Modification Bulletin 6/1040.\n\n**Deadline:** The modification had to be completed before 1 September 1971.\n\n**Why it matters:** Airworthiness directives are legally binding safety requirements. Failure to comply means the aircraft cannot legally fly in Australian airspace."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-6-4-nose-landing-gear-modification","history":"/api/acts/ad-dhc-6-4-nose-landing-gear-modification/history","analysis":"/api/acts/ad-dhc-6-4-nose-landing-gear-modification/analysis","conflicts":"/api/acts/ad-dhc-6-4-nose-landing-gear-modification/conflicts","importantCases":"/api/acts/ad-dhc-6-4-nose-landing-gear-modification/important-cases","documents":"/api/acts/ad-dhc-6-4-nose-landing-gear-modification/documents"}}