{"id":"F2006B04619","name":"AD/BELL 222/4 - Tail Rotor Servo Control Linkage","slug":"ad-bell-222-4-tail-rotor-servo-control-linkage","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44371,"registerId":"commonwealth-F2006B04619-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 222/4 - Tail Rotor Servo Control Linkage","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 Canada (BHTC) 222 Series Helicopters\n\n \n\nAD/BELL 222/4 Tail Rotor Servo Control Linkage 9/85\n\nTX\n\n \n\nApplicability: All model 222 and 222U Helicopters.\n\n \n\nRequirement: Action in accordance with Bell Helicopter Textron Alert Service Bulletins 222-85-33 and 222U-85-8.\n\n \n\nNote: Copies of the requirement documents may be obtained from Department of Aviation Regional Offices.\n\n \n\nCompliance: Before further flight after 19 July 1985.\n\n \n\nBackground: A 222 overseas while hovering experienced an uncontrollable right turn. The cause was found to be a disconnect of the control linkage on the tail rotor servo. A linkage rivet was missing which allowed the pivot pin to fall out.\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":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive’s scope aligns with its stated purpose: to require the manufacturer-prescribed inspections/repairs for all Bell 222 and 222U helicopters to address a tail-rotor servo control linkage failure (see \"Applicability\", \"Requirement\", and \"Background\"). The instrument specifies who must act, how (by following the two Alert Service Bulletins), and when (before further flight after 19 July 1985), which matches the operational objective described in the background incident."},"complexity_factors":["Narrow applicability limited to specific aircraft models (\"Applicability: All model 222 and 222U Helicopters\").","Mandatory, time-critical compliance: must be completed before further flight after a specific date (\"Compliance: Before further flight after 19 July 1985\").","Dependence on external manufacturer documents (Alert Service Bulletins 222-85-33 and 222U-85-8) to define the exact actions (\"Requirement\").","Need to obtain the service bulletins from a government office (\"Note: Copies ... may be obtained from Department of Aviation Regional Offices\").","Safety-critical technical work (tail rotor servo control linkage) requiring qualified maintenance and parts (implied by the technical nature of the \"Background\" failure)."],"plain_english_summary":"This mandatory directive requires owners/operators of Bell Helicopter Textron model 222 and 222U helicopters to perform inspections and corrective work exactly as set out in Bell Alert Service Bulletins 222-85-33 and 222U-85-8, to be completed before any further flight after 19 July 1985. It responds to an in‑service tail‑rotor control linkage failure that caused an uncontrollable hover turn and shifts compliance costs and potential grounding risk onto operators until the specified work is done."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete safety directive addressing a specific mechanical defect. It has not expanded beyond its original purpose of mandating a fix for the tail rotor servo control linkage fault."},"complexity_factors":["Very short document (under 200 words)","Only 2 defined applicability criteria (model 222 and 222U)","Single straightforward requirement referencing external technical documents","No nested conditions, exceptions, or cross-references to other legislation","Clear compliance deadline with no alternative methods or conditional extensions"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific helicopters.\n\n**What it does:**\nOrders owners and operators of **Bell 222 and 222U helicopters** to inspect and fix a dangerous fault in the **tail rotor servo control linkage** (the mechanical connection that controls the tail rotor, which keeps the helicopter stable and prevents it from spinning).\n\n**Why it matters:**\nA helicopter overseas suffered an **uncontrollable right turn while hovering** because a rivet fell out of this linkage, causing the pivot pin to drop out and disconnect the controls. This could cause a crash.\n\n**What must be done:**\n- Follow two specific Bell Helicopter service bulletins: **222-85-33** and **222U-85-8**\n- Complete the work **before flying again after 19 July 1985**\n\n**Who it affects:**\nAnyone operating Bell 222 or 222U helicopters in Australia — typically emergency services, charter operators, or private owners."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-222-4-tail-rotor-servo-control-linkage","history":"/api/acts/ad-bell-222-4-tail-rotor-servo-control-linkage/history","analysis":"/api/acts/ad-bell-222-4-tail-rotor-servo-control-linkage/analysis","conflicts":"/api/acts/ad-bell-222-4-tail-rotor-servo-control-linkage/conflicts","importantCases":"/api/acts/ad-bell-222-4-tail-rotor-servo-control-linkage/important-cases","documents":"/api/acts/ad-bell-222-4-tail-rotor-servo-control-linkage/documents"}}