{"id":"F2006B03584","name":"AD/BEA 121/2 - Rudder Control Torque Tubes","slug":"ad-bea-121-2-rudder-control-torque-tubes","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43154,"registerId":"commonwealth-F2006B03584-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEA 121/2 - Rudder Control Torque Tubes","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)  Beagle B121 (Pup) Series Aeroplanes\n\n \n\nAD/BEA 121/2 Rudder Control Torque Tubes 8/69\n\nApplicability: All models with S/Nos. 001 to 092.\n\n \n\nRequirement: Action in accordance with Beagle SB No. B121/8.\n\n \n\nCompliance: Within 100 hours time in service after 29 September 1969 and thereafter at intervals not exceeding 100 hours time in service.\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\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in a specific aircraft type. It has not expanded beyond its original purpose of ensuring rudder control integrity in early Beagle B121 aircraft."},"complexity_factors":["Extremely short document (under 200 words)","Only 4 operative provisions: applicability, requirement, compliance, and reference to external technical document","No defined terms section — uses plain aviation terminology","Single cross-reference to manufacturer service bulletin (Beagle SB No. B121/8)","Simple temporal trigger (100 hours time in service) with straightforward recurring interval","No nested conditions, exceptions, or conditional logic"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:** It requires owners and operators of specific **Beagle B121 (Pup) aircraft** (serial numbers 001 to 092) to inspect or repair the **rudder control torque tubes** — the mechanical components that transfer pilot pedal movements to the rudder at the tail of the plane.\n\n**Who must comply:** Anyone operating or maintaining these specific Beagle Pup aircraft models.\n\n**What action is required:** Follow the instructions in **Beagle Service Bulletin B121/8** (a manufacturer-issued technical notice). The directive doesn't spell out the exact repair steps — it simply makes the manufacturer's bulletin legally binding.\n\n**When it must be done:**\n- **First time:** Within 100 hours of flying time after 29 September 1969\n- **Ongoing:** Repeated every 100 hours of flying time thereafter\n\n**Why it matters:** Rudder control failures can cause loss of directional control during flight, potentially leading to accidents. This AD ensures a known defect in early-production Beagle Pup aircraft is caught before it becomes dangerous."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The instrument itself states a specific applicability (serial numbers 001–092), a specific referenced action (Beagle SB No. B121/8), and a fixed compliance interval (within 100 hours after 29 September 1969 and every 100 hours thereafter). There is no text in the instrument indicating an expansion or narrowing of that scope from an earlier version; therefore the scope as stated appears unchanged within the four corners of this document."},"complexity_factors":["Narrow, clearly stated applicability limited to Beagle B121 serial numbers 001–092 (\"Applicability\").","Single, externally referenced technical action rather than multiple in‑text procedures — operators must obtain and follow Beagle SB No. B121/8 (\"Requirement\").","A simple, fixed recurring compliance interval (first within 100 hours after 29 September 1969, then at intervals not exceeding 100 hours) creates an ongoing obligation but is mechanically straightforward (\"Compliance\").","Regulatory placement under Part 39 — the AD formality requires administrative tracking, but the directive itself is administratively simple (heading)."],"plain_english_summary":"This airworthiness directive (AD) directs owners/operators of Beagle B121 (Pup) series aeroplanes with serial numbers 001–092 to carry out a specific maintenance action and to repeat that action on a regular schedule.\n\n- What the instrument does mechanically: It requires the action described in Beagle Service Bulletin No. B121/8 to be carried out on every affected aeroplane, first within 100 hours time in service after 29 September 1969 and then repeatedly at intervals not exceeding 100 hours time in service (see \"Requirement\" and \"Compliance\").\n\n- Who issues and who decides the required action: The directive is issued under the Civil Aviation Regulations framework (Part 39 — Schedule of Airworthiness Directives). The substantive maintenance action to be performed is defined by Beagle SB No. B121/8; the AD makes following that service bulletin mandatory for the listed aircraft (see heading and \"Requirement\").\n\n- Who is affected and who pays: Owners and operators of Beagle B121 series aeroplanes with serial numbers 001–092 are directly affected (see \"Applicability\"). They are responsible for arranging and paying for whatever inspections, repairs, or replacements are specified by Beagle SB No. B121/8 and for ensuring the work is repeated at the 100‑hour intervals set by the AD (see \"Compliance\").\n\n- Compliance mechanics and enforcement: The AD sets a clear schedule: first compliance within 100 hours time in service after 29 September 1969, then at intervals not exceeding 100 hours thereafter. Compliance consists of performing the actions specified in the referenced service bulletin; the AD makes those actions mandatory for the listed serial numbers (see \"Requirement\" and \"Compliance\").\n\n- Costs, incentives and trade‑offs implied by the text: The directive creates a recurring maintenance cost and associated aircraft downtime for the affected fleet because it mandates an action at fixed 100‑hour intervals (see \"Compliance\"). It centralises the technical specification of that action in an externally published document (Beagle SB No. B121/8), which operators must obtain and follow (see \"Requirement\"). The AD imposes procedural certainty (what must be done and when) but reduces operator discretion about how to meet the AD beyond what the service bulletin allows. The document does not itself allocate funds, mandate who performs the work, or state penalties for non‑compliance; those matters are handled through the regulatory enforcement framework under which the AD is issued (see heading and Part reference). \n\n- Practical implementation points and risks signalled by the AD text: Operators must (a) confirm whether their aeroplane falls within the serial number range (see \"Applicability\"), (b) obtain and follow the procedures in Beagle SB No. B121/8 (see \"Requirement\"), and (c) schedule recurring work at no greater than 100‑hour intervals (see \"Compliance\"). The AD creates an ongoing administrative and maintenance obligation for each affected aircraft. The text does not describe alternative compliance paths, variance procedures, or the content of the service bulletin; those details must be obtained from Beagle SB No. B121/8 (see \"Requirement\")."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bea-121-2-rudder-control-torque-tubes","history":"/api/acts/ad-bea-121-2-rudder-control-torque-tubes/history","analysis":"/api/acts/ad-bea-121-2-rudder-control-torque-tubes/analysis","conflicts":"/api/acts/ad-bea-121-2-rudder-control-torque-tubes/conflicts","importantCases":"/api/acts/ad-bea-121-2-rudder-control-torque-tubes/important-cases","documents":"/api/acts/ad-bea-121-2-rudder-control-torque-tubes/documents"}}