{"id":"F2006B09053","name":"AD/DHC-2/4 - Undercarriage Legs - Anti-Corrosion Treatment","slug":"ad-dhc-2-4-undercarriage-legs-anti-corrosion-treatment","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52780,"registerId":"commonwealth-F2006B09053-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-2/4 - Undercarriage Legs - Anti-Corrosion Treatment","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-2 (Beaver) Series Aeroplanes\n\n \n\nAD/DHC-2/4 Undercarriage Legs - Anti-Corrosion Treatment NK\n\nApplicability: All models with S/Nos. 1 to 943 and 946. Document:  DH (Canada) TNS Series “B” No. 90, Issue 2. Compliance:               Forthwith.\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":1337},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This airworthiness directive maintains its original narrow scope—requiring anti-corrosion treatment for specific aircraft undercarriage components. There is no evidence of scope creep or expansion beyond the original safety purpose."},"complexity_factors":["Extremely short instrument (approximately 50 words of substantive content)","No defined terms or interpretation section","Single unconditional compliance requirement ('forthwith')","Simple applicability criteria based solely on aircraft serial numbers","No cross-references to other legislation beyond citing the source Canadian technical document"],"plain_english_summary":"**What this means:** This is a mandatory safety order (called an Airworthiness Directive) issued by Australia's aviation safety regulator for a specific type of aircraft.\n\n**Who it affects:** Owners and operators of De Havilland Canada DHC-2 \"Beaver\" aeroplanes with serial numbers 1 through 943, and serial number 946.\n\n**What must be done:** The aircraft's undercarriage legs (the struts that hold the wheels) must receive anti-corrosion treatment immediately.\n\n**Why it matters:** Corrosion in the undercarriage can weaken the structure that supports the aircraft during landing and taxiing. This directive requires immediate action to prevent potential failure of the landing gear, which could cause accidents during takeoff or landing."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-2-4-undercarriage-legs-anti-corrosion-treatment","history":"/api/acts/ad-dhc-2-4-undercarriage-legs-anti-corrosion-treatment/history","analysis":"/api/acts/ad-dhc-2-4-undercarriage-legs-anti-corrosion-treatment/analysis","conflicts":"/api/acts/ad-dhc-2-4-undercarriage-legs-anti-corrosion-treatment/conflicts","importantCases":"/api/acts/ad-dhc-2-4-undercarriage-legs-anti-corrosion-treatment/important-cases","documents":"/api/acts/ad-dhc-2-4-undercarriage-legs-anti-corrosion-treatment/documents"}}