{"id":"F2007L00123","name":"AD/AT/20 Amdt 4 - Wing Lower Spar Cap Safe Life - CANCELLED","slug":"ad-at-20-amdt-4-wing-lower-spar-cap-safe-life-cancelled","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":68227,"registerId":"commonwealth-F2007L00123-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AT/20 Amdt 4 - Wing Lower Spar Cap Safe Life - CANCELLED","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 20.2\ntitle: AIRCRAFT\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\n \n\nAIRWORTHINESS DIRECTIVE\n\nOn the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive AD/AT/20 Amdt 4.\n\n### Airtractor AT-300, 400 and 500 Series Aeroplanes\n\n| AD/AT/20 Amdt 4 | Wing Lower Spar Cap Safe Life | 2/2007 |\n| --- | --- | --- |\n\n\n \n\n| Requirement: | CANCELLED. |\n| --- | --- |\n|  | This AD is cancelled on 15 February 2007. |\n| Background: | The requirements of this Directive are now contained in AD/AT/21 Amdt 3. |\n\n\n![](image.001.png)\n\nDavid Villiers  Delegate of the Civil Aviation Safety Authority\n\n4 January 2007\n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1711},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This instrument performs a straightforward revocation without expanding regulatory scope. It is an administrative consolidation, transferring existing requirements to a different airworthiness directive rather than creating new obligations."},"complexity_factors":["Single operative provision (cancellation)","No defined terms or interpretation section","Only one cross-reference to the replacement instrument","Extremely short length (less than one page)","No conditional logic or exceptions"],"plain_english_summary":"**What this document does**\n\nThis is a cancellation notice for a previous aviation safety rule. Specifically, it revokes Airworthiness Directive (AD) AD/AT/20 Amdt 4, which previously set safety limits for wing lower spar caps on Airtractor AT-300, 400 and 500 series aircraft (agricultural aeroplanes).\n\n**Who it affects**\nOwners and operators of these specific Airtractor aircraft models.\n\n**Why it matters**\nThe safety requirements haven't disappeared—they've simply been moved to a different directive (AD/AT/21 Amdt 3). This cancellation avoids duplication and consolidates the rules in one place. The cancellation took effect on 15 February 2007.\n\n**In simple terms**: The old safety rule about wing spar caps is no longer in force because those same rules now live in a different document."}},"importantCases":[],"_links":{"self":"/api/acts/ad-at-20-amdt-4-wing-lower-spar-cap-safe-life-cancelled","history":"/api/acts/ad-at-20-amdt-4-wing-lower-spar-cap-safe-life-cancelled/history","analysis":"/api/acts/ad-at-20-amdt-4-wing-lower-spar-cap-safe-life-cancelled/analysis","conflicts":"/api/acts/ad-at-20-amdt-4-wing-lower-spar-cap-safe-life-cancelled/conflicts","importantCases":"/api/acts/ad-at-20-amdt-4-wing-lower-spar-cap-safe-life-cancelled/important-cases","documents":"/api/acts/ad-at-20-amdt-4-wing-lower-spar-cap-safe-life-cancelled/documents"}}