{"id":"F2006B02080","name":"AD/AC/20 - Rudder Trim Tab Hinge Mount - Inspection","slug":"ad-ac-20-rudder-trim-tab-hinge-mount-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41310,"registerId":"commonwealth-F2006B02080-current","compilationNumber":null,"startDate":"2026-04-01","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AC/20 - Rudder Trim Tab Hinge Mount - Inspection","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-description: CASA Airworthiness Directive\nmeta-generator: Aspose.Words for .NET 22.10.0\nmeta-keywords: Issue 7/1962,Aircraft below 5700 kg,Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes,Rudder Trim Tab Hinge Mount - Inspection,20\ntitle: Airworthiness Directive - AD/AC/20 - Rudder Trim Tab Hinge Mount - Inspection\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)  Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes\n\n \n\nAD/AC/20 Rudder Trim Tab Hinge Mount - Inspection 7/62\n\nApplicability: All models: S/Nos. 151 to 892, except 871 and 875. Document:  Aero Commander SL No. 114A.\n\nCompliance: At intervals not exceeding 500 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","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1801},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow scope of mandating periodic inspection of a specific aircraft component. It has not expanded beyond its initial safety purpose."},"complexity_factors":["Single unambiguous compliance requirement (inspect every 500 hours)","Minimal conditional logic (only two serial number exclusions: 871 and 875)","No cross-references to other legislation","Only one external technical reference (Service Letter No. 114A)","Extremely short length with plain language"],"plain_english_summary":"**The bottom line:** If you own a specific vintage Twin Commander aircraft, you must check the rudder trim tab hinge for cracks every 500 flying hours.\n\n**The details:** This Airworthiness Directive (a compulsory safety rule) applies to Aero Commander 500, 600 and 700 series aircraft with serial numbers 151–892 (but not 871 or 875). You need to inspect the hinge mount that attaches the rudder trim tab — that's the small adjustable flap on the rudder that helps keep the plane flying straight without constant foot pressure on the pedals. The inspection follows the manufacturer's Service Letter No. 114A.\n\n**Why bother:** A failed hinge could mean losing control of the trim tab, making the aircraft harder to handle and potentially dangerous."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ac-20-rudder-trim-tab-hinge-mount-inspection","history":"/api/acts/ad-ac-20-rudder-trim-tab-hinge-mount-inspection/history","analysis":"/api/acts/ad-ac-20-rudder-trim-tab-hinge-mount-inspection/analysis","conflicts":"/api/acts/ad-ac-20-rudder-trim-tab-hinge-mount-inspection/conflicts","importantCases":"/api/acts/ad-ac-20-rudder-trim-tab-hinge-mount-inspection/important-cases","documents":"/api/acts/ad-ac-20-rudder-trim-tab-hinge-mount-inspection/documents"}}