{"id":"F2006B04659","name":"AD/BELL 412/24 - Main Rotor Pitch Link to Pitch Horn Bolt","slug":"ad-bell-412-24-main-rotor-pitch-link-to-pitch-horn-bolt","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44411,"registerId":"commonwealth-F2006B04659-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 412/24 - Main Rotor Pitch Link to Pitch Horn Bolt","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)  Bell Helicopter Textron 412 Series Helicopters\n\n \n\nAD/BELL 412/24 Main Rotor Pitch Link to Pitch Horn Bolt 7/89\n\nTX\n\n \n\nApplicability: All model 412 series.\n\n \n\nRequirement: Action in accordance with Bell Alert Service Bulletin 412-89-44. Compliance: Within 5 hours time in service after receipt of this Directive.\n\nBackground: A main rotor pitch link to pitch horn bolt was found broken during an accident investigation. An inspection of the subject bolt is required pending final investigation results.\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":951},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This directive remains tightly focused on its original purpose: addressing an immediate airworthiness concern regarding a specific mechanical component. It represents a standard reactive safety measure typical of Airworthiness Directives, with no expansion beyond the technical scope of the identified defect."},"complexity_factors":["Extremely short document (approximately 100 words of substantive content)","No definitions or interpretation section","Simple, unqualified applicability statement ('All model 412 series')","Single, unambiguous compliance requirement referencing an external technical standard","No conditional logic, exceptions, or nested provisions"],"plain_english_summary":"**What this is:** An urgent safety directive (called an Airworthiness Directive) issued by the Civil Aviation Safety Authority for Bell 412 helicopters.\n\n**Who it affects:** Anyone who operates or maintains Bell 412 series helicopters.\n\n**What it requires:**\n*   **Action:** Operators must follow the instructions in \"Bell Alert Service Bulletin 412-89-44\" regarding the bolt that connects the main rotor pitch link to the pitch horn (a critical component in the rotor system that controls the helicopter's lift and movement).\n*   **Deadline:** This must be done within 5 hours of flying time after receiving this directive.\n\n**Why it matters:** During an accident investigation, investigators found that one of these specific bolts had broken. Because this bolt is essential for controlling the main rotor, a failure could be catastrophic. This directive requires immediate inspection (and likely replacement) of this bolt on all affected helicopters while the full investigation is still underway."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-412-24-main-rotor-pitch-link-to-pitch-horn-bolt","history":"/api/acts/ad-bell-412-24-main-rotor-pitch-link-to-pitch-horn-bolt/history","analysis":"/api/acts/ad-bell-412-24-main-rotor-pitch-link-to-pitch-horn-bolt/analysis","conflicts":"/api/acts/ad-bell-412-24-main-rotor-pitch-link-to-pitch-horn-bolt/conflicts","importantCases":"/api/acts/ad-bell-412-24-main-rotor-pitch-link-to-pitch-horn-bolt/important-cases","documents":"/api/acts/ad-bell-412-24-main-rotor-pitch-link-to-pitch-horn-bolt/documents"}}