{"id":"F2006B03590","name":"AD/BEA 121/25 - Control Rod End Fittings","slug":"ad-bea-121-25-control-rod-end-fittings","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43180,"registerId":"commonwealth-F2006B03590-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEA 121/25 - Control Rod End Fittings","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 121/25 Control Rod End Fittings 7/87\n\nApplicability: All models.\n\n \n\nRequirement: Action in accordance with British Aerospace SB B121/91.\n\n \n\nCompliance: Within 100 hours time in service after 30 June 1987 or prior to the issue of the next Maintenance Release after 30 June 1987 whichever is later.\n\n \n\nBackground: There has been an incident where the forward elevator control tube fork end became detached from the control tube assembly with consequent loss of elevator control.\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, single-issue airworthiness directive from 1987 addressing a specific mechanical failure. It has not expanded beyond its original purpose of mandating inspection/repair of control rod end fittings on Beagle B121 aircraft."},"complexity_factors":["Single, specific aircraft type (Beagle B121 Pup series)","One clear requirement referencing an external technical document (British Aerospace SB B121/91)","Simple compliance deadline with two alternative triggers (100 hours time-in-service OR next Maintenance Release)","No defined terms section, no cross-references to other legislation, no conditional exceptions","Background provided in plain language explaining the safety risk"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft.\n\n**What it does:** It requires owners and operators of **Beagle B121 (Pup) series aeroplanes** to inspect and fix a dangerous problem with the **control rod end fittings** — the metal joints that connect the elevator control tubes (the parts that make the plane go up and down).\n\n**Why it matters:** A control rod end fitting had already failed once, causing a pilot to lose control of the elevator. This directive prevents crashes by forcing operators to follow a specific British Aerospace service bulletin (SB B121/91) to fix the problem.\n\n**Who must comply:** Anyone operating a Beagle B121 Pup aircraft.\n\n**When:** The fix must be done within 100 hours of flying time after 30 June 1987, or before the next Maintenance Release (a legal document saying the aircraft is safe to fly) is issued after that date — whichever comes later."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD as presented applies to all Beagle B121 models and mandates compliance with British Aerospace SB B121/91 within a specific time window. The text does not indicate any expansion or narrowing of scope beyond that original requirement: it directs all applicable aircraft to undertake the actions in the referenced service bulletin within the stated timeframe to address the incident described."},"complexity_factors":["Delegation to external document (British Aerospace SB B121/91) for technical steps rather than specifying them in the AD","Time-limited compliance window tied to both hours-in-service and the administrative milestone of a Maintenance Release","Applicability to all models of the Beagle B121 series (broad applicability but narrow technical scope)","Safety-critical system (elevator control) increases procedural and verification attention despite simple AD text","AD specifies obligation and timeframe but provides no cost, parts list, or work descriptions within the directive itself"],"plain_english_summary":"This AD requires owners/operators and maintenance organisations of Beagle B121 (Pup) series aeroplanes to carry out inspections and/or modifications as specified in British Aerospace Service Bulletin B121/91. It responds to an incident where a forward elevator control tube fork end detached, risking loss of elevator control. Work must be completed within 100 hours TIS after 30 June 1987 or before the next Maintenance Release; costs and scheduling are the responsibility of the owner/operator."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bea-121-25-control-rod-end-fittings","history":"/api/acts/ad-bea-121-25-control-rod-end-fittings/history","analysis":"/api/acts/ad-bea-121-25-control-rod-end-fittings/analysis","conflicts":"/api/acts/ad-bea-121-25-control-rod-end-fittings/conflicts","importantCases":"/api/acts/ad-bea-121-25-control-rod-end-fittings/important-cases","documents":"/api/acts/ad-bea-121-25-control-rod-end-fittings/documents"}}