{"id":"F2006B08856","name":"AD/DH 104/12 Amdt 2 - Outer Mainplane - Inspection","slug":"ad-dh-104-12-amdt-2-outer-mainplane-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52055,"registerId":"commonwealth-F2006B08856-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DH 104/12 Amdt 2 - Outer Mainplane - 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)  DH 104 (Dove) Series Aeroplanes\n\n \n\nAD/DH 104/12\n\nAmdt 2\n\n\nOuter Mainplane - Inspection 4/75\n\n \n\nApplicability: All models not incorporating Mod. 870. Document: De Havilland TNS CT(104) No. 134, Issue 5. Compliance:               As detailed in the requirements document.\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":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This instrument is labelled as Amendment 2 to AD/DH 104/12 (Amdt 2), indicating it modifies an earlier airworthiness directive. The supplied text does not set out how the scope was altered from the original AD; it only states the current applicability (all models not incorporating Mod. 870) and references De Havilland TNS CT(104) No. 134, Issue 5 for compliance details."},"complexity_factors":["Short AD text delegates all technical detail to an external document (De Havilland TNS CT(104) No. 134, Issue 5), requiring users to obtain that document to understand concrete obligations.","Applicability carve-out (aircraft with Mod. 870) requires operators to determine modification status for each aircraft.","Regulatory outcome depends on external technical content (inspection intervals, criteria, corrective actions), creating dependency on a non-statutory document.","Operational burden (scheduling, downtime, parts, repair) depends on variables not stated in the AD, adding implementation uncertainty.","Enforcement is straightforward (inspection required) but technicians and certificating staff must interpret and apply the referenced technical standard correctly."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of De Havilland DH 104 (Dove) aircraft that do not incorporate Mod. 870 to have the outer mainplane inspected in accordance with De Havilland TNS CT(104) No. 134, Issue 5. The Civil Aviation Safety Authority enforces the requirement; inspection costs and downtime fall to operators, creating a potential incentive to install Mod. 870 to remove the AD’s applicability."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive focused on a specific structural inspection for a specific aircraft type. The amendment appears to maintain the original scope (outer mainplane inspection) without expanding to other systems or aircraft types. The reference to \"Amdt 2\" suggests iterative refinement of inspection requirements rather than scope creep."},"complexity_factors":["Extremely short document (approximately 150 words of substantive content)","Only one defined applicability criterion (Mod. 870)","Single cross-reference to external technical document (De Havilland TNS CT(104) No. 134)","No conditional logic, exceptions, or nested provisions within the directive itself","Compliance delegated entirely to external technical document","No interpretation section or defined terms within the directive text"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**Which aircraft:** De Havilland DH 104 \"Dove\" series aeroplanes (a twin-engine propeller aircraft from the 1940s-60s), specifically those that have **not** been modified with \"Mod. 870\".\n\n**What it requires:** A mandatory **inspection of the outer mainplane** (the outer section of the wing, from roughly mid-span to the wingtip). The exact inspection procedures, intervals, and methods are found in a separate technical document: De Havilland Technical News Sheet CT(104) No. 134, Issue 5.\n\n**Why it matters:** Airworthiness Directives are legally binding safety instructions. If you own or operate one of these aircraft, you **must** complete this inspection to keep the aircraft legally airworthy. The directive likely addresses potential structural fatigue, corrosion, or cracking in the wing structure — critical for flight safety.\n\n**Key point:** This is **Amendment 2** (Amdt 2), meaning the inspection requirements have been updated at least twice since the original directive was issued."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dh-104-12-amdt-2-outer-mainplane-inspection","history":"/api/acts/ad-dh-104-12-amdt-2-outer-mainplane-inspection/history","analysis":"/api/acts/ad-dh-104-12-amdt-2-outer-mainplane-inspection/analysis","conflicts":"/api/acts/ad-dh-104-12-amdt-2-outer-mainplane-inspection/conflicts","importantCases":"/api/acts/ad-dh-104-12-amdt-2-outer-mainplane-inspection/important-cases","documents":"/api/acts/ad-dh-104-12-amdt-2-outer-mainplane-inspection/documents"}}