{"id":"F2006B08982","name":"AD/DHA-3/25 Amdt 2 - Centre Section and Wing Spar - Life Limitations","slug":"ad-dha-3-25-amdt-2-centre-section-and-wing-spar-life-limitations","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52600,"registerId":"commonwealth-F2006B08982-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHA-3/25 Amdt 2 - Centre Section and Wing Spar - Life Limitations","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)  DHA-3 (Drover) Series Aeroplanes\n\n \n\nAD/DHA-3/25\n\nAmdt 2\n\n\nCentre Section and Wing Spar - Life Limitations 3/68\n\n \n\nApplicability: All models.\n\n \n\nDocument: Hawker de Havilland Australia TNS CT (A3) No. 129 Issue 4. 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 AD text provided does not indicate a narrowing or widening of applicability; it explicitly states applicability to \"All models.\" The instrument delegates the substantive life‑limitation requirements to the referenced Hawker de Havilland Requirement Document (TNS CT (A3) No. 129 Issue 4). The AD amends existing material (Amdt 2), but the excerpt does not identify any change in scope from the original AD beyond the incorporation of the referenced document."},"complexity_factors":["The AD text is short and delegates detailed requirements to an external Requirement Document (Hawker de Havilland TNS CT (A3) No. 129 Issue 4), creating dependence on that technical document for substantive compliance details.","Technical subject matter (centre section and wing spar life limitations) requires specialised engineering and maintenance judgement found in the referenced document.","Applicability is broad (\"All models\"), which can increase administrative complexity for diverse operators and maintenance providers.","Amendment status (Amdt 2) indicates prior iterations exist, so tracing changes and their operational impact requires review of earlier versions and the referenced Issue 4.","Enforcement under the Civil Aviation Regulations Part 39 implies regulatory oversight and possible certification/recordkeeping requirements not detailed in the AD text."],"plain_english_summary":"# What this instrument does\n\nThis document is an Airworthiness Directive (AD) titled \"AD/DHA-3/25 Amdt 2 — Centre Section and Wing Spar - Life Limitations\" that appears in the Civil Aviation Safety Authority schedule of airworthiness directives under the Civil Aviation Regulations 1998, Part 39. Mechanically, the AD requires operators to follow the life‑limitation requirements set out in a separate technical Requirement Document: Hawker de Havilland Australia TNS CT (A3) No. 129 Issue 4. (See: \"Document: Hawker de Havilland Australia TNS CT (A3) No. 129 Issue 4\" and \"Compliance: As detailed in the Requirement Document.\")\n\nApplicable aircraft: the AD states it applies to all models of the DHA‑3 (Drover) series aeroplanes. (See: \"Applicability: All models.\")\n\n# Who it affects and who decides\n\n- Who must act: registered owners and operators of DHA‑3 (Drover) series aeroplanes that fall within the stated applicability. (Applicability.)\n- Who issues/enforces: the AD is issued under the Commonwealth Civil Aviation framework (Part 39) and is listed in the Civil Aviation Safety Authority schedule of ADs. The AD points to a Hawker de Havilland technical document as the source of the specific required actions. (Heading and Document reference.)\n\n# How it works in practice\n\n- The AD does not itself list detailed inspection, retirement, or replacement actions in the text provided here. Instead, it makes compliance contingent on the separate Requirement Document (Hawker de Havilland TNS CT (A3) No. 129 Issue 4). (See: \"Compliance: As detailed in the Requirement Document.\" and \"Document: ... Issue 4.\")\n- Operators must obtain and follow that Requirement Document to determine what must be done, when, and by whom.\n\n# Practical implications, trade-offs and implementation points (source‑grounded)\n\n- Compliance burden and who pays: Because the AD requires following an external technical Requirement Document, the direct compliance burden (inspections, component removals, replacements, record keeping) falls on aircraft owners/operators who must carry out or pay for the work specified in the referenced document. (Compliance and Document references.)\n- Certainty and information dependence: The AD’s text is brief and delegates the operational detail to the referenced Requirement Document; this creates a dependence on that external document for specifics of timing, scope and cost. (Compliance and Document references.)\n- Administrative discretion and enforcement: Enforcement follows the AD framework under Part 39 and the Civil Aviation Safety Authority schedule; the AD itself does not list discretionary exemptions or alternative methods of compliance in the excerpt provided. (Instrument heading and schedule context.)\n- Effects on markets and private choice: By imposing life‑limitation requirements (as stated in the title and by reference), the AD can change how long affected structural parts may remain in service. That change is likely to affect operators’ maintenance planning, asset utilisation and replacement timing; maintenance organisations will be engaged to perform the required work under the Requirement Document. The AD text delegates the detailed mechanics of those effects to the referenced document. (Title and Compliance reference.)\n- Implementation risk and opportunity cost: Because the AD incorporates external, technical requirements by reference, delays or ambiguity in accessing or interpreting the Requirement Document create implementation risk for operators and maintenance providers. The AD text here does not state transitional arrangements, cost offsets, or alternative compliance pathways. (Compliance and Document references.)\n\n# Summary of source citations\n\n- Applicability declared as \"All models.\" (Applicability)\n- Required technical source: Hawker de Havilland Australia TNS CT (A3) No. 129 Issue 4. (Document)\n- Compliance: actions and timing are those \"detailed in the Requirement Document.\" (Compliance)\n\nThis summary describes the instrument’s mechanical effect (delegation of mandatory life‑limit requirements to a specified technical document), who bears the compliance obligations (owners/operators), who enforces (regulatory AD framework under Part 39), and the main operational trade‑offs (dependence on the external Requirement Document for detail and costs)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive maintaining its original purpose: imposing structural life limits on a specific aircraft type. Amendment 2 suggests routine updating based on operational experience or manufacturer data, not scope creep."},"complexity_factors":["Extremely short document (approximately 150 words)","No defined terms section — relies entirely on external technical reference","Single, straightforward requirement: comply with referenced technical document","No conditional logic, exceptions, or nested provisions","Cross-reference limited to one external technical standard (TNS CT (A3) No. 129 Issue 4)","Applies universally to 'All models' with no carve-outs or exemptions"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order — issued by Australia's Civil Aviation Safety Authority (CASA) for a specific type of aircraft called the **DHA-3 Drover**.\n\n**What it does:**\n- Sets **life limitations** (maximum flying hours or cycles) for the **centre section and wing spar** of these planes. These are critical structural components that hold the wings to the fuselage.\n- Requires operators to follow a specific technical document (Hawker de Havilland Australia TNS CT (A3) No. 129 Issue 4) to ensure these parts are inspected, tracked, and retired before they become unsafe.\n\n**Who it affects:**\n- Anyone who owns or operates a DHA-3 Drover aircraft (all models).\n\n**Why it matters:**\n- Metal fatigue in wing spars can lead to catastrophic structural failure. This AD prevents accidents by forcing operators to monitor how much stress these parts have endured and replace them before they reach dangerous limits.\n- \"Amendment 2\" (Amdt 2) means this is an updated version of an earlier directive, likely reflecting new data about how these aircraft age.\n\n**In short:** If you fly a Drover, you must track how hard you've worked the wings and follow the manufacturer's instructions to keep them airworthy."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dha-3-25-amdt-2-centre-section-and-wing-spar-life-limitations","history":"/api/acts/ad-dha-3-25-amdt-2-centre-section-and-wing-spar-life-limitations/history","analysis":"/api/acts/ad-dha-3-25-amdt-2-centre-section-and-wing-spar-life-limitations/analysis","conflicts":"/api/acts/ad-dha-3-25-amdt-2-centre-section-and-wing-spar-life-limitations/conflicts","importantCases":"/api/acts/ad-dha-3-25-amdt-2-centre-section-and-wing-spar-life-limitations/important-cases","documents":"/api/acts/ad-dha-3-25-amdt-2-centre-section-and-wing-spar-life-limitations/documents"}}