{"id":"F2006B08871","name":"AD/DH 104/29 - Engine Mounting Frame - Inspection","slug":"ad-dh-104-29-engine-mounting-frame-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52292,"registerId":"commonwealth-F2006B08871-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DH 104/29 - Engine Mounting Frame - 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 104/29 Engine Mounting Frame - Inspection 5/72\n\nApplicability: All models.\n\n \n\nDocument: Hawker Siddeley TNS CT(104) No. 228 Issue 1.\n\n \n\nCompliance: Within 50 hours time in service after 22 May 1972 and thereafter at intervals not exceeding 75 hours time in service.\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":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-limited safety directive from 1972 concerning a specific airframe component on a specific aircraft type. It has not expanded beyond its original narrow technical scope."},"complexity_factors":["Extremely short document — only 6 substantive lines of regulatory text","No defined terms section — all language is plain operational English","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Single, unambiguous compliance requirement with clear time intervals","No conditional logic, exceptions, or alternative compliance methods","Single applicability criterion ('All models') with no carve-outs or exemptions"],"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) under the Civil Aviation Regulations 1998.\n\n**What it does:** It requires owners and operators of **DH 104 (Dove) series aeroplanes** — a British twin-engine aircraft from the 1940s-60s — to inspect the **engine mounting frame** (the structural component that attaches the engine to the aircraft wing or fuselage).\n\n**Who must comply:** Anyone operating any model of the DH 104 Dove aircraft.\n\n**What must be done:**\n- **First inspection:** Must be completed within **50 hours of flying time** after 22 May 1972\n- **Ongoing inspections:** Must be repeated every **75 hours of flying time** thereafter\n\n**Why it matters:** Engine mounting frames carry heavy loads and vibration. Cracks or failures here could cause an engine to detach in flight — catastrophic for safety. This AD mandates regular checks to catch problems before they become dangerous.\n\n**Technical reference:** The inspection must follow the procedure in **Hawker Siddeley Technical Note TNS CT(104) No. 228 Issue 1** — the manufacturer's official guidance for this specific check."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive's scope is stated in the instrument: it applies to all DH 104 (Dove) models and mandates inspections per the cited Hawker Siddeley document on the specified schedule (Applicability; Document; Compliance). The text provided contains no indication that the scope has been expanded or narrowed compared with an earlier version, so there is no evident change of scope within this extract."},"complexity_factors":["Narrow technical scope limited to engine mounting frame on a single aircraft series (Applicability).","Simple, fixed inspection timing: initial inspection within 50 hours after a specified date, then every 75 hours (Compliance).","Dependence on an external technical document (Hawker Siddeley TNS CT(104) No. 228 Issue 1) for inspection procedure (Document).","Requirement applies to all models of the series, so no model-by-model differentiation (Applicability).","Does not specify reporting, remedial standards, or enforcement steps in the text provided, which may require reference to broader regulatory material (header)."],"plain_english_summary":"This airworthiness directive requires DH 104 (Dove) operators to carry out recurring inspections of the engine mounting frame per Hawker Siddeley TNS CT(104) No. 228 Issue 1, with an initial check within 50 hours after 22 May 1972 and thereafter every 75 hours. Owners/operators must arrange and fund inspections and any repairs, maintenance organisations perform them, and the Civil Aviation Safety Authority enforces the requirement under the Civil Aviation Regulations."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dh-104-29-engine-mounting-frame-inspection","history":"/api/acts/ad-dh-104-29-engine-mounting-frame-inspection/history","analysis":"/api/acts/ad-dh-104-29-engine-mounting-frame-inspection/analysis","conflicts":"/api/acts/ad-dh-104-29-engine-mounting-frame-inspection/conflicts","importantCases":"/api/acts/ad-dh-104-29-engine-mounting-frame-inspection/important-cases","documents":"/api/acts/ad-dh-104-29-engine-mounting-frame-inspection/documents"}}