{"id":"F2006B08860","name":"AD/DH 104/16 - Flap System Modification to Prevent Crossing of Pneumatic Lines","slug":"ad-dh-104-16-flap-system-modification-to-prevent-crossing-of-pneumatic-lines","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52059,"registerId":"commonwealth-F2006B08860-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DH 104/16 - Flap System Modification to Prevent Crossing of Pneumatic Lines","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)  DH 104 (Dove) Series Aeroplanes\n\n \n\nAD/DH 104/16 Flap System Modification to Prevent\n\nCrossing of Pneumatic Lines\n\n\n8/71\n\n \n\nApplicability: All models.\n\n \n\nDocument:  De Havilland Mod. No. 607. Compliance: Before 1 September 1971.\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":2094},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This directive maintains a narrow, targeted scope focused solely on a specific mechanical modification for the DH 104 aircraft type. There is no evidence of expansion into unrelated operational areas or broader regulatory reach."},"complexity_factors":["Extremely short length (only 3 substantive regulatory lines)","No defined terms or interpretation section","Single, unconditional applicability criterion ('All models')","No nested exceptions, cross-references to other legislation, or conditional logic","Clear reference to external technical standard (De Havilland Mod. No. 607)"],"plain_english_summary":"**What it does**\nThis is a mandatory safety order (called an Airworthiness Directive) requiring owners of De Havilland DH 104 Dove aircraft to modify the flap system. Specifically, it mandates a design change to prevent pneumatic (air pressure) lines from crossing each other inside the aircraft's flap mechanism.\n\n**Who it affects**\nAnyone who owns or operates any model of the DH 104 Dove series aircraft—a twin-engine propeller aircraft commonly used in the mid-20th century.\n\n**What must be done**\nOperators must implement \"De Havilland Modification No. 607\" to the flap system. This was a physical hardware change to be completed before 1 September 1971.\n\n**Why it matters**\nCrossing pneumatic lines could potentially cause the flaps to malfunction or fail during flight. This directive ensures these vintage aircraft were retrofitted to eliminate that specific safety risk."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dh-104-16-flap-system-modification-to-prevent-crossing-of-pneumatic-lines","history":"/api/acts/ad-dh-104-16-flap-system-modification-to-prevent-crossing-of-pneumatic-lines/history","analysis":"/api/acts/ad-dh-104-16-flap-system-modification-to-prevent-crossing-of-pneumatic-lines/analysis","conflicts":"/api/acts/ad-dh-104-16-flap-system-modification-to-prevent-crossing-of-pneumatic-lines/conflicts","importantCases":"/api/acts/ad-dh-104-16-flap-system-modification-to-prevent-crossing-of-pneumatic-lines/important-cases","documents":"/api/acts/ad-dh-104-16-flap-system-modification-to-prevent-crossing-of-pneumatic-lines/documents"}}