{"id":"F2006B08732","name":"AD/DAUPHIN/21 - Tail Rotor Pitch Change Spider and Blade Horn Foot","slug":"ad-dauphin-21-tail-rotor-pitch-change-spider-and-blade-horn-foot","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51965,"registerId":"commonwealth-F2006B08732-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DAUPHIN/21 - Tail Rotor Pitch Change Spider and Blade Horn Foot","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)  Eurocopter SA 360 and SA 365 (Dauphin) Series Helicopters\n\n \n\n# AD/DAUPHIN/21 Tail Rotor Pitch Change Spider\n\nand Blade Horn Foot\n\nApplicability: All model SA 360, SA 361, SA 365C, C1, C2, C3, N and FS helicopters.\n\n \n\nRequirement: Action in accordance with Aerospatiale Service Telex No 05-12 and 05-16 as applicable.\n\n \n\nNote: Aerospatiale Telex N 12853 refers.\n\n \n\nCompliance: 1. Unless already accomplished, prior to further flight.\n\n# 13/87\n\n \n\n2.    On completion of 10 flying hours or at each `after last flight’ inspection of the day, whichever occurs first.\n\n \n\n3.    Immediately following any reports of high vibration levels from the tail rotor assy.\n\n \n\nBackground: The manufacturer has advised of two pitch change lugs and one blade horn foot within the fenestron, failing due to fatigue.\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":2161},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive remains tightly focused on its original purpose of addressing specific fatigue failures in tail rotor components. It has not expanded beyond the original safety issue identified by the manufacturer."},"complexity_factors":["Reliance on external technical documents (Aerospatiale Service Telex 05-12 and 05-16) without reproducing their content","Multiple compliance triggers (time-based, flight-hour-based, and condition-based)","Technical aviation terminology requiring specialized engineering knowledge (fenestron, pitch change spider, blade horn foot, fatigue failure)"],"plain_english_summary":"This mandatory Airworthiness Directive orders operators of Eurocopter Dauphin helicopters (SA 360, SA 361, SA 365C/C1/C2/C3, SA 365N, SA 365FS) to inspect and maintain tail-rotor fenestron parts (pitch change spider, blade horn foot) after discovery of fatigue cracks and some in-service failures that could cause loss of directional control.\n\nOperators must verify repairs before the next flight, inspect every 10 flight hours or each flying day (or immediately after high tail-rotor vibration), and follow Aerospatiale Service Telex 05-12 and 05-16."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dauphin-21-tail-rotor-pitch-change-spider-and-blade-horn-foot","history":"/api/acts/ad-dauphin-21-tail-rotor-pitch-change-spider-and-blade-horn-foot/history","analysis":"/api/acts/ad-dauphin-21-tail-rotor-pitch-change-spider-and-blade-horn-foot/analysis","conflicts":"/api/acts/ad-dauphin-21-tail-rotor-pitch-change-spider-and-blade-horn-foot/conflicts","importantCases":"/api/acts/ad-dauphin-21-tail-rotor-pitch-change-spider-and-blade-horn-foot/important-cases","documents":"/api/acts/ad-dauphin-21-tail-rotor-pitch-change-spider-and-blade-horn-foot/documents"}}