{"id":"F2006B02573","name":"AD/AUS/3 - Tailplane Bracing","slug":"ad-aus-3-tailplane-bracing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41829,"registerId":"commonwealth-F2006B02573-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AUS/3 - Tailplane Bracing","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)  Auster/Beagle A.61 Series Aeroplanes\n\n \n\nAD/AUS/3 Tailplane Bracing 2/50\n\nApplicability: All models manufactured before July 1947.\n\n \n\nRequirement: Action in accordance with Auster SB Issue 10, or Auster Mod. No. 1381. Compliance:              Forthwith.\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":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The instrument applies to a specific, time‑bound population of aircraft (those manufactured before July 1947) and prescribes a specific corrective action via a manufacturer service bulletin or modification number. Nothing in the text indicates an expansion or narrowing of that population or a change from the directive’s apparent original corrective aim; the scope appears consistent with the stated applicability and requirement."},"complexity_factors":["Narrow and well-defined applicability (all models manufactured before July 1947).","Prescriptive remedy referenced by external documents (Auster SB Issue 10 or Auster Mod. No. 1381) rather than detailed in the text.","Immediate compliance requirement (\"Forthwith\") increases operational urgency but does not add legal complexity.","Lack of in-text enforcement, exemption, or timing detail — implementation relies on regulator processes and the referenced technical documents.","Practical complexity due to aircraft vintage: potential scarcity of parts and specialised labour increases logistical complexity for implementers."],"plain_english_summary":"### What this directive does\n\nThis airworthiness directive orders a specific change to the tailplane bracing on Auster/Beagle A.61 series aeroplanes that were manufactured before July 1947. It requires operators to carry out the technical work described in either \"Auster SB Issue 10\" or \"Auster Mod. No. 1381\" (Requirement). The work must be done immediately — the directive says \"Forthwith\" (Compliance). The directive is issued under the Civil Aviation Regulations schedule of airworthiness directives (header).\n\n### Who this affects\n\n- Aircraft owners and operators of Auster/Beagle A.61 series aeroplanes built before July 1947 (Applicability).  \n- Maintenance organisations or certificated mechanics who perform the modification or service‑bulletin work specified (Requirement).\n\n### How it works, mechanically\n\n- The regulator identifies a safety or airworthiness concern affecting a defined group of aircraft and prescribes a corrective technical action by reference to an aircraft manufacturer service bulletin or modification number (Requirement).  \n- The owner/operator must obtain the specified service bulletin or modification instructions and implement that work on each affected aircraft (Requirement).  \n- The regulator expects compliance without delay (Compliance: \"Forthwith\").\n\n### Who pays, who decides, and what changes\n\n- Owners/operators pay for the parts, labour and any associated downtime required to carry out the service bulletin or modification (Requirement).  \n- The Civil Aviation Safety Authority (via the airworthiness directives schedule under the Civil Aviation Regulations) is the issuing authority that decides the mandatory action (header).  \n- The behaviour change required is: aircraft that fall within the Applicability must be modified in accordance with the referenced technical document before continuing ordinary operation, and this must be done immediately (Applicability; Requirement; Compliance).\n\n### Practical costs, incentives and implementation considerations\n\n- The directive is prescriptive about the remedial action but does not set out technical steps in the text; implementers must obtain the specified Auster service bulletin or modification instructions to know the exact work (Requirement). This imposes a documentary/administrative step.  \n- Direct costs: parts, skilled maintenance labour, and aircraft downtime are borne by owners/operators (Requirement).  \n- Implementation risk and opportunity cost: affected aircraft are older (manufactured before July 1947), so parts or approved materials and suitable maintenance expertise may be scarce; owners may need to source replacement components or approved equivalents (Applicability; Requirement).  \n- Compliance burden: the directive requires immediate action (Compliance: \"Forthwith\"), which may force short notice grounding and reallocating maintenance resources.  \n- Bureaucratic discretion: the directive prescribes which technical document to follow but does not describe enforcement steps, extensions, or alternatives in this text; any discretion about exemptions or compliance scheduling would rest with the regulator or its delegated processes (Requirement; Compliance).  \n- Effects on market/private choice: until the specified modification is completed, affected aircraft will likely be restricted from normal operation, which can reduce availability, generate maintenance demand for specialised services, and potentially affect resale or operating value (Applicability; Requirement).\n\nSources cited from the instrument: Applicability; Requirement (Auster SB Issue 10 or Auster Mod. No. 1381); Compliance (Forthwith)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive for a specific vintage aircraft type. It has not expanded beyond its original purpose of addressing tailplane bracing issues in pre-1947 Auster aircraft."},"complexity_factors":["Extremely short document (under 150 words)","Only 2 defined applicability criteria (aircraft model and manufacture date)","Single requirement with two alternative compliance methods","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","No conditional logic, exceptions, or nested provisions","Simple imperative language ('Forthwith') with no temporal complexity"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order for aircraft. Specifically, **AD/AUS/3** applies to **Auster/Beagle A.61 Series Aeroplanes** (a type of light aircraft) that were **manufactured before July 1947**.\n\n**What it requires:**\nOwners or operators of these aircraft must immediately inspect or modify the **tailplane bracing** (the structural supports for the horizontal tail section at the rear of the plane). They must follow either:\n- **Auster Service Bulletin Issue 10**, or\n- **Auster Modification No. 1381**\n\n**When:** **Forthwith** — meaning immediately, without delay.\n\n**Why it matters:**\nThis directive addresses a potential structural weakness in the tail section of these vintage aircraft. If the tailplane bracing fails, the pilot could lose control of the aircraft. Because these planes are over 75 years old, the Civil Aviation Safety Authority (CASA) has issued this mandatory directive to prevent accidents."}},"importantCases":[],"_links":{"self":"/api/acts/ad-aus-3-tailplane-bracing","history":"/api/acts/ad-aus-3-tailplane-bracing/history","analysis":"/api/acts/ad-aus-3-tailplane-bracing/analysis","conflicts":"/api/acts/ad-aus-3-tailplane-bracing/conflicts","importantCases":"/api/acts/ad-aus-3-tailplane-bracing/important-cases","documents":"/api/acts/ad-aus-3-tailplane-bracing/documents"}}