{"id":"F2006B02102","name":"AD/AC/43 - Elevator Servo Cable Guard Plate - Installation","slug":"ad-ac-43-elevator-servo-cable-guard-plate-installation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41332,"registerId":"commonwealth-F2006B02102-current","compilationNumber":null,"startDate":"2026-04-01","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AC/43 - Elevator Servo Cable Guard Plate - Installation","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 9/1970,Aircraft below 5700 kg,Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes,Elevator Servo Cable Guard Plate - Installation,43\ntitle: Airworthiness Directive - AD/AC/43 - Elevator Servo Cable Guard Plate - Installation\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/43 Elevator Servo Cable Guard Plate - Installation 9/70\n\nApplicability: Models 500S and 500U S/Nos. 1531 to 3085 and 3087 equipped with Mitchell Century III Autopilot System.\n\n \n\nDocument: Aero Commander SL 223.\n\n \n\nCompliance: Within 300 hours’ time in service after 30 September 1970.\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":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1571},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This 1970 directive remains strictly limited to its original purpose: mandating a specific physical modification to elevator servo cable systems on specific Twin Commander aircraft models. It has not expanded beyond this technical safety fix."},"complexity_factors":["Single, specific compliance action (install guard plate)","Narrow applicability limited to specific aircraft models, serial numbers, and autopilot equipment","No defined terms or interpretation section","Minimal cross-referencing (only to one external technical document)","No exceptions, exemptions, or conditional logic"],"plain_english_summary":"**What this is:** A safety order (called an *Airworthiness Directive*) issued by the Civil Aviation Safety Authority requiring a specific mechanical fix on certain aircraft.\n\n**Who it affects:** Owners and operators of **Twin Commander 500S and 500U** aeroplanes with serial numbers between 1531–3085 and 3087, but **only if** the aircraft is fitted with a Mitchell Century III Autopilot System.\n\n**What it requires:** You must install a **guard plate** to protect the elevator servo cables (the control cables that help move the tail elevators). The exact instructions for how to install it are contained in **Aero Commander Service Letter 223** (a manufacturer technical bulletin).\n\n**Deadline:** The work had to be completed within **300 hours of flight time** after 30 September 1970.\n\n**Why it matters:** The guard plate prevents the servo cables from being damaged or interfered with, which could otherwise compromise the pilot's ability to control the aircraft's pitch."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ac-43-elevator-servo-cable-guard-plate-installation","history":"/api/acts/ad-ac-43-elevator-servo-cable-guard-plate-installation/history","analysis":"/api/acts/ad-ac-43-elevator-servo-cable-guard-plate-installation/analysis","conflicts":"/api/acts/ad-ac-43-elevator-servo-cable-guard-plate-installation/conflicts","importantCases":"/api/acts/ad-ac-43-elevator-servo-cable-guard-plate-installation/important-cases","documents":"/api/acts/ad-ac-43-elevator-servo-cable-guard-plate-installation/documents"}}