{"id":"F2006B09486","name":"AD/EMB-110/46 - Rudder Trim Tab Actuator System","slug":"ad-emb-110-46-rudder-trim-tab-actuator-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54003,"registerId":"commonwealth-F2006B09486-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/EMB-110/46 - Rudder Trim Tab Actuator System","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)  Embraer EMB-110 (Bandeirante) Series Aeroplanes\n\n \n\nAD/EMB-110/46 Rudder Trim Tab Actuator System 2/92 TX\n\nApplicability: All models.\n\n \n\nRequirement: Action in accordance with the technical requirements of Brazilian Airworthiness Directive T91-11-01.\n\n \n\nNote: Embraer SB 110-27-0091 refers.\n\n \n\nCompliance: Within 10 hours time in service after 11 December 1991.\n\n \n\nBackground:  This Directive requires visual inspection of the tab system. Incorrect installation of rudder trim tab system has caused failure of tab rods on at least two occasions. This condition may cause severe vibration and control difficulties.\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\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive remains focused on inspecting the rudder trim tab actuator system for all EMB-110 models to address incorrect installation and tab-rod failures. It achieves this by mandating compliance with the Brazilian AD and referencing an Embraer service bulletin. There is no indication in the text that the scope deviates from that stated purpose (Applicability; Requirement; Note; Background)."},"complexity_factors":["Cross-reference to an external airworthiness directive (Brazilian AD T91-11-01) rather than full procedural text in this instrument (Requirement)","Reference to a manufacturer service bulletin (Embraer SB 110-27-0091) requiring operators to obtain and apply additional documents (Note)","Short compliance window (10 hours time in service) that creates scheduling and operational constraints (Compliance)","Technical inspection requiring qualified maintenance personnel and possible unspecified corrective actions if defects are found (Background; Requirement)","Applicability to all models of EMB-110 increases the population of affected operators but does not differentiate by configuration (Applicability)"],"plain_english_summary":"What this directive does\n\n- This Airworthiness Directive (AD) applies to all models of the Embraer EMB-110 (Bandeirante) aeroplane. (Applicability)\n- It requires operators to carry out the actions specified in Brazilian Airworthiness Directive T91-11-01. The Embraer Service Bulletin SB 110-27-0091 is referenced for related work. (Requirement; Note)\n- The required inspection must be done within 10 hours time in service after 11 December 1991. (Compliance)\n\nWhy the directive was issued\n\n- The directive directs a visual inspection of the rudder trim tab actuator system because incorrect installation of the rudder trim tab system has caused failure of tab rods on at least two occasions. The stated safety concern is that such failures may cause severe vibration and control difficulties. (Background)\n\nWho pays, who decides, and what changes\n\n- Who pays: Aircraft operators (owners or operators of EMB-110 aircraft) bear the cost of performing the inspection and any corrective work required by the referenced AD or service bulletin. (Requirement; Note; Compliance)\n- Who decides: The Civil Aviation Safety Authority issued this AD and requires compliance with the Brazilian AD and the referenced Embraer service bulletin. Maintenance personnel must follow those documents when performing the work. (Requirement; Note)\n- What behaviour changes: Operators must schedule and perform a visual inspection of the rudder trim tab actuator system within the 10-hour window and take any corrective action specified by the referenced documents. This may change maintenance scheduling and resource allocation for affected aircraft. (Requirement; Compliance)\n\nMechanics and trade-offs to be aware of\n\n- The AD is implemented by cross-reference: it obliges operators to follow another authority’s (Brazilian) AD and a manufacturer’s service bulletin rather than specifying all steps in this instrument. That requires operators and maintenance providers to obtain and apply those external documents. (Requirement; Note)\n- Time constraint: The 10-hour time-in-service compliance window is short and may require operators to interrupt planned flying or reallocate maintenance slots. (Compliance)\n- Technical competence and potential additional work: The directive mandates a visual inspection; if the inspection reveals incorrect installation or damage, further corrective work may be needed. That corrective work is not spelled out in this AD itself but is expected to follow the referenced AD/service bulletin, so costs and downtime could be larger than the inspection alone. (Requirement; Note; Background)\n- Concentration of benefits and diffusion of costs: The safety benefit from preventing tab-rod failure accrues to aircraft occupants and operators; the immediate monetary and scheduling costs fall directly on the aircraft operators who must carry out inspections and repairs. (Background; Compliance)\n\nImplementation risk and compliance burden\n\n- Implementation depends on maintenance personnel obtaining and correctly applying the Brazilian AD T91-11-01 and Embraer SB 110-27-0091. Any ambiguity or variation between those documents and local practice creates execution risk. (Requirement; Note)\n- The AD does not itself provide a tolerances table or step-by-step corrective measures; it relies on the referenced documents to define technical work, which concentrates technical discretion with the documents’ authors and the maintenance organisation following them. (Requirement; Note)\n\nReference sections: Applicability; Requirement; Note; Compliance; Background."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive addressing a specific mechanical defect. It has not expanded beyond its original purpose of mandating inspection of the rudder trim tab actuator system."},"complexity_factors":["Extremely short document (under 200 words)","Only 1 substantive requirement (visual inspection)","Single cross-reference to foreign directive (Brazilian AD T91-11-01) — technical details outsourced","Single cross-reference to manufacturer service bulletin (Embraer SB 110-27-0091)","Simple compliance deadline (10 hours time in service after fixed date)","No defined terms section, no conditional logic, no exceptions","Clear applicability (all models)"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for **Embraer EMB-110 Bandeirante aircraft**.\n\n**What it does:**\n- Requires owners and operators of these Brazilian-made twin-turboprop planes to **visually inspect the rudder trim tab actuator system** — the mechanical parts that help fine-tune the plane's yaw (side-to-side movement) to keep it flying straight.\n\n**Why it matters:**\n- Incorrect installation of this system has already caused **tab rod failures on at least two occasions**. If this happens in flight, it can cause **severe vibration and control difficulties** — potentially dangerous situations for pilots and passengers.\n\n**Who must comply:**\n- Anyone operating any model of the Embraer EMB-110 series.\n\n**What they must do:**\n- Follow the technical instructions in **Brazilian Airworthiness Directive T91-11-01** (referenced document from the country of manufacture).\n- Complete the inspection **within 10 flight hours after 11 December 1991**.\n- **Service Bulletin 110-27-0091** from Embraer provides additional guidance.\n\nThis is essentially Australia adopting a safety fix developed in Brazil to prevent mechanical failures that could compromise aircraft control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-emb-110-46-rudder-trim-tab-actuator-system","history":"/api/acts/ad-emb-110-46-rudder-trim-tab-actuator-system/history","analysis":"/api/acts/ad-emb-110-46-rudder-trim-tab-actuator-system/analysis","conflicts":"/api/acts/ad-emb-110-46-rudder-trim-tab-actuator-system/conflicts","importantCases":"/api/acts/ad-emb-110-46-rudder-trim-tab-actuator-system/important-cases","documents":"/api/acts/ad-emb-110-46-rudder-trim-tab-actuator-system/documents"}}