{"id":"F2006B08935","name":"AD/DH114/25 - Mainplanes and Flaps - Inspection and Modification","slug":"ad-dh114-25-mainplanes-and-flaps-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52526,"registerId":"commonwealth-F2006B08935-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DH114/25 - Mainplanes and Flaps - Inspection and Modification","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)  DH114 (Heron) Series Aeroplanes\n\n \n\nAD/DH114/25 Mainplanes and Flaps - Inspection NK\n\nand Modification\n\n \n\nApplicability: All models.\n\n \n\nDocument: Hawker Siddeley TNS Heron (114) No. W.16, Issue 1. Compliance:  As detailed in the requirement 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":false,"description":"The provided AD text does not indicate any change in scope from an earlier instrument or from an original intent. It plainly applies to \"All models\" of the DH114 (Heron) and directs compliance to the separate requirement document (W.16 Issue 1). No amendment history or comparison to a prior scope is present in the supplied text."},"complexity_factors":["References an external requirement document (W.16 Issue 1) for all procedural detail, shifting crucial information outside the AD text.","Applicability covers all DH114 (Heron) models, meaning the directive affects every operator of the type.","Technical nature of required work (mainplanes and flaps inspection/modification) — requires specialised maintenance skills and possibly parts.","AD text does not specify timing, deadlines, or enforcement mechanics; those elements are in the referenced document, creating implementation uncertainty.","Potential operational disruption (aircraft downtime) and coordination with maintenance providers increase practical complexity even though the AD text is short."],"plain_english_summary":"# What this instrument does\n\nThis is an Airworthiness Directive (AD) titled \"AD/DH114/25 Mainplanes and Flaps - Inspection NK and Modification\" issued under the Civil Aviation Regulations, Part 39. It requires inspections and a modification relating to the mainplanes (wings) and flaps on DH114 (Heron) series aeroplanes. (See title and heading lines.)\n\n# Who it affects\n\n- Owners and operators of DH114 (Heron) aeroplanes (the AD states \"Applicability: All models\").\n- Maintenance organisations and technicians who carry out the inspection and modification work, and any suppliers of parts or services needed to comply. (See \"Applicability: All models\" and the referenced document.)\n\n# How it works mechanically\n\n- The AD makes compliance conditional on a separate requirement document: \"Hawker Siddeley TNS Heron (114) No. W.16, Issue 1.\" The AD says: \"Compliance: As detailed in the requirement document.\" That document sets out the precise inspection tasks, modification steps, and (presumably) any timing or repeat intervals.\n- This AD is issued under the Schedule of Airworthiness Directives within the Civil Aviation Safety Authority framework (Part 39). The AD itself points operators to the W.16 Issue 1 document for the mandatory actions.\n\n# Why it matters (stated purpose and mechanical implications)\n\n- The AD’s title and required actions indicate it is addressing an issue related to mainplanes and flaps by mandating inspection and modification. The AD text provided does not include an explicit statement of the underlying safety finding or incident that prompted the directive; it only identifies the required document and the aircraft affected (see title, \"Document\" and \"Compliance\" lines).\n\n# Costs, incentives, and compliance burden (mechanics, not judgments)\n\n- Who pays: The immediate financial burden falls on aircraft owners/operators who must implement the inspections and modifications described in the referenced document (see \"Compliance: As detailed in the requirement document\").\n- Time and opportunity cost: Compliance will likely require downtime for affected aeroplanes while inspections and modifications are carried out; the AD text itself does not specify timing or downtime, those details are in W.16 Issue 1.\n- Technical and supply effects: The modification may require specialised maintenance skills, tooling or parts. If supply or capability is limited, that may delay compliance or raise costs; the AD text does not specify parts lists or availability.\n- Administrative and enforcement discretion: The AD refers operators to an external requirement document (W.16 Issue 1). That structure concentrates decision-making about the exact remedial steps, intervals and acceptability criteria in that document rather than in the short AD text, creating implementation dependence on the contents of W.16 and on how the regulator enforces the AD under Part 39.\n\n# Trade-offs, implementation risk and unintended consequences (mechanisms to watch)\n\n- The AD centralises the mandatory steps in a separate technical document. This reduces the length of the AD but transfers critical implementation detail and any associated discretion to the requirement document (see \"Document: Hawker Siddeley TNS Heron (114) No. W.16, Issue 1\" and \"Compliance\").\n- Because the AD applies to \"All models,\" the cost and operational impact is broadly distributed across all operators of the type; any benefits from the actions (not stated in this text) would accrue to users of those aeroplanes and to third parties affected by their operation. The AD text itself does not quantify benefits, costs, timing or exemptions.\n- The AD does not, in the excerpt provided, specify compliance deadlines, inspection intervals, or criteria for acceptable modification results. Those procedural and enforcement details are in the referenced W.16 document; until that document is consulted, affected parties cannot determine exact obligations or plan resource allocation.\n\n# What to do next if you are affected\n\n- Obtain and review \"Hawker Siddeley TNS Heron (114) No. W.16, Issue 1\" to see the detailed inspection and modification requirements and any timing or reporting obligations (see \"Document\" and \"Compliance\" lines).\n- Plan for the direct costs, downtime and technical capability needed to carry out the tasks specified in W.16, and coordinate with qualified maintenance organisations.\n\n(References in this summary are to the lines in the AD text provided: title/heading, \"Applicability: All models.\", \"Document: Hawker Siddeley TNS Heron (114) No. W.16, Issue 1.\" and \"Compliance: As detailed in the requirement document.\")"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive focused on a specific airframe (DH114 Heron) and specific components (mainplanes and flaps). It does not expand beyond its original safety purpose."},"complexity_factors":["Extremely short document — only 4 substantive lines of regulatory text","No defined terms section; relies entirely on external technical reference document","No conditional logic or nested exceptions within the directive itself","Single, straightforward compliance requirement: follow the external document","All technical complexity is offloaded to the referenced Hawker Siddeley technical service bulletin (TNS No. W.16)"],"plain_english_summary":"This is an **Airworthiness Directive** (AD) — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It applies to all models of the **de Havilland DH114 Heron** aircraft, a British-designed twin-engine propeller plane from the 1950s.\n\n**What it requires:**\n- Owners and operators must inspect and modify the **mainplanes** (the main wings) and **flaps** (the movable surfaces on the wings that help with takeoff and landing) according to a specific technical document: *Hawker Siddeley TNS Heron (114) No. W.16, Issue 1*.\n\n**Who must comply:**\n- Anyone who owns, operates, or maintains a DH114 Heron aircraft in Australia.\n\n**Why it matters:**\n- Airworthiness Directives are legally binding safety instructions. They are issued when CASA identifies a condition or defect that could make an aircraft unsafe. Failing to comply means the aircraft cannot legally fly in Australian airspace. This particular AD addresses potential structural issues with the wings and flaps that could affect flight safety if left unaddressed."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dh114-25-mainplanes-and-flaps-inspection-and-modification","history":"/api/acts/ad-dh114-25-mainplanes-and-flaps-inspection-and-modification/history","analysis":"/api/acts/ad-dh114-25-mainplanes-and-flaps-inspection-and-modification/analysis","conflicts":"/api/acts/ad-dh114-25-mainplanes-and-flaps-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-dh114-25-mainplanes-and-flaps-inspection-and-modification/important-cases","documents":"/api/acts/ad-dh114-25-mainplanes-and-flaps-inspection-and-modification/documents"}}