{"id":"F2006B08863","name":"AD/DH 104/19 Amdt 1 - Engine Mounting Frames - Inspection","slug":"ad-dh-104-19-amdt-1-engine-mounting-frames-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52063,"registerId":"commonwealth-F2006B08863-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DH 104/19 Amdt 1 - Engine Mounting Frames - 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 104/19\n\nAmdt 1\n\n\nEngine Mounting Frames - Inspection 8/71\n\n \n\nApplicability: All models fitted with engine mount frames No. 4EM201A and 4EM203A.\n\n \n\nRequirement: Inspect the engine mounting frames for evidence of internal corrosion by visual and radiographic means.\n\n \n\nNote: The inspections shall be carried out in accordance with Hawker Siddeley TNS CT(104) No. 190 Issue 2. Radiographs and any associated reports shall be submitted to the Secretary for examination.\n\n \n\nCompliance: At intervals not exceeding 4 years.\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":3,"scope_assessment":{"changed":false,"description":"The supplied text is an amendment instrument (Amdt 1) but does not include the original AD text for comparison. The document as provided states current applicability (frames 4EM201A and 4EM203A), mandatory visual and radiographic inspection procedures (Requirement), reliance on Hawker Siddeley TNS CT(104) No. 190 Issue 2 (Note), submission of radiographs/reports to the Secretary (Note) and a four‑year maximum interval (Compliance). The supplied material does not by itself show how those elements differ from the original AD, so no change of scope can be determined from this text alone."},"complexity_factors":["Narrow technical applicability to two specific engine mount frame part numbers (Applicability).","Mandated radiographic (NDT) inspection in addition to visual inspection — requires specialised equipment and qualified personnel (Requirement; Note).","Reference to an external technical standard (Hawker Siddeley TNS CT(104) No. 190 Issue 2) which operators must follow (Note).","Administrative requirement to submit radiographs and reports to the Secretary for examination, adding regulatory interaction beyond on‑aircraft work (Note).","Fixed compliance interval (every 4 years) that imposes recurring scheduling and cost obligations (Compliance)."],"plain_english_summary":"This directive requires operators of DH 104 (Dove) aeroplanes fitted with engine mount frames 4EM201A or 4EM203A to carry out visual and radiographic inspections for internal corrosion, following Hawker Siddeley TNS CT(104) No. 190 Issue 2, at intervals not exceeding four years. Radiographs and reports must be submitted to the Secretary. It affects owners/operators who must fund and schedule specialised NDT work and any resulting repairs."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive focused on a specific technical inspection for a specific aircraft type. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 defined technical references (engine mount frame numbers)","Single, clear compliance requirement with straightforward frequency (4-year intervals)","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","No conditional logic, exceptions, or nested provisions","Simple structure: applicability → requirement → compliance"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety instruction issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:** It requires owners and operators of certain **de Havilland DH 104 \"Dove\" aircraft** to inspect their **engine mounting frames** (the metal structures that hold the engines to the wings) for **internal corrosion** — rust or deterioration you can't see from the outside.\n\n**Who must follow it:** Anyone operating a DH 104 Dove fitted with specific engine mount frame models (No. 4EM201A and 4EM203A).\n\n**What must be done:**\n- **Visual inspection** — looking at the frames\n- **Radiographic inspection** — using X-rays or similar technology to see inside the metal\n- **How often:** Every 4 years maximum\n- **Technical standard:** Inspections must follow a specific Hawker Siddeley technical document (TNS CT(104) No. 190 Issue 2)\n- **Reporting:** X-ray images and reports must be sent to the Secretary (of CASA) for review\n\n**Why it matters:** Internal corrosion in engine mounts can weaken the structure without visible warning signs. If an engine mount fails in flight, the engine could detach — a catastrophic safety risk. This directive prevents accidents by catching hidden damage before it becomes dangerous."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dh-104-19-amdt-1-engine-mounting-frames-inspection","history":"/api/acts/ad-dh-104-19-amdt-1-engine-mounting-frames-inspection/history","analysis":"/api/acts/ad-dh-104-19-amdt-1-engine-mounting-frames-inspection/analysis","conflicts":"/api/acts/ad-dh-104-19-amdt-1-engine-mounting-frames-inspection/conflicts","importantCases":"/api/acts/ad-dh-104-19-amdt-1-engine-mounting-frames-inspection/important-cases","documents":"/api/acts/ad-dh-104-19-amdt-1-engine-mounting-frames-inspection/documents"}}