{"id":"F2009L02242","name":"AD/TB20/1 - Engine Mount - Inspection/Replacement - CANCELLED","slug":"ad-tb20-1-engine-mount-inspection-replacement-cancelled","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":162062,"registerId":"commonwealth-F2009L02242-current","compilationNumber":null,"startDate":"2026-04-04","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Aerospatiale (Socata) TB20 (Trinidad) Se","sectionType":"division","heading":"Aerospatiale (Socata) TB20 (Trinidad) Series Aeroplanes","content":"### Aerospatiale (Socata) TB20 (Trinidad) Series Aeroplanes\n\n| AD/TB20/1 | Engine Mount - Inspection/Replacement | 7/2009 |\n| --------- | ------------------------------------- | ------ |\n\n| Requirement: | CANCELLED.                                                                                                                                                                 |\n| ------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|              | This AD is cancelled on 2 July 2009.                                                                                                                                       |\n| Background:  | This Australian AD specified replacement of engine mounts with serial numbers nominated in SB No. 20 GR 71-09 before further flight in 1984. The AD is no longer required. |\n\n![](image.001.png)\n\nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n19 May 2009","sortOrder":0},{"sectionNumber":"AD/TB20/1","sectionType":"part","heading":"AD/TB20/1","content":"## AD/TB20/1","sortOrder":1},{"sectionNumber":"Engine Mount - Inspection/Replacement","sectionType":"part","heading":"Engine Mount - Inspection/Replacement","content":"## Engine Mount - Inspection/Replacement","sortOrder":2},{"sectionNumber":"7/2009","sectionType":"part","heading":"7/2009","content":"## 7/2009","sortOrder":3}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1887},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This instrument terminates the regulatory requirement entirely rather than expanding its scope. The original AD mandated specific engine mount replacements for safety reasons; this cancellation simply removes that obligation without adding new requirements, extending coverage to new aircraft types, or modifying the original intent."},"complexity_factors":["Single operative provision (cancellation only)","No defined terms or interpretation sections","No conditional logic, exceptions, or procedural requirements","Minimal cross-referencing (only historical reference to superseded service bulletin SB No. 20 GR 71-09)","Extremely brief instrument (cancellation notice format)"],"plain_english_summary":"**What this does:** This document cancels an old air safety rule (Airworthiness Directive AD/TB20/1) that previously required owners of specific aircraft to replace certain engine mounts.\n\n**Who it affects:** Owners and operators of **Aerospatiale (Socata) TB20 (Trinidad) series aeroplanes**.\n\n**What changed:** The original rule (issued in 1984) required replacing engine mounts with specific serial numbers—referenced in Service Bulletin No. 20 GR 71-09—before the aircraft could fly again. As of **2 July 2009**, this requirement is completely removed because it is \"no longer required.\"\n\n**Why it matters:** Aircraft owners and maintenance providers no longer need to comply with this specific directive. This eliminates a mandatory inspection or replacement task, potentially saving time and maintenance costs for affected aircraft."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tb20-1-engine-mount-inspection-replacement-cancelled","history":"/api/acts/ad-tb20-1-engine-mount-inspection-replacement-cancelled/history","analysis":"/api/acts/ad-tb20-1-engine-mount-inspection-replacement-cancelled/analysis","conflicts":"/api/acts/ad-tb20-1-engine-mount-inspection-replacement-cancelled/conflicts","importantCases":"/api/acts/ad-tb20-1-engine-mount-inspection-replacement-cancelled/important-cases","documents":"/api/acts/ad-tb20-1-engine-mount-inspection-replacement-cancelled/documents"}}