{"id":"F2006B06343","name":"AD/PROCTOR/4(Re-Issue) - Control Cable Pulley - Modification","slug":"ad-proctor-4-re-issue-control-cable-pulley-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47539,"registerId":"commonwealth-F2006B06343-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PROCTOR/4(Re-Issue) - Control Cable Pulley - Modification","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)  Percival Proctor Series Aeroplanes\n\n \n\nAD/PROCTOR/4\n\n(Re-Issue)\n\n\nControl Cable Pulley - Modification 6/50\n\n \n\nApplicability: All Mk. IV and Mk. V.\n\n \n\nRequirement: 1. Percival Proctor Mod. No. C1206, or\n\n \n\n2. DCA/PROCTOR/4, or 3. A.N.O. 105.1.26.2.5.2.\n\nCompliance: 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","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This document is a re-issue of AD/PROCTOR/4 but, based on the text provided, it retains the same operative elements: it applies to all Mk. IV and Mk. V aircraft, requires modification of the control cable pulley by one of three specified references (Percival Proctor Mod. No. C1206; DCA/PROCTOR/4; A.N.O. 105.1.26.2.5.2), and sets compliance as \"Forthwith.\" The re-issue text gives no indication that the scope or substantive requirements have been broadened or narrowed compared with the earlier version."},"complexity_factors":["Narrow and clearly defined applicability (only Percival Proctor Mk. IV and Mk. V).","Single substantive action required (modify control cable pulley) reduces procedural complexity.","Three alternative modification references create minor decision-making (which modification to apply).","Immediate compliance requirement (\"Forthwith\") increases implementation urgency and logistical complexity.","Absence of technical detail in the AD text requires operators to obtain and follow external modification documents, adding practical complexity.","Lack of specification about who must perform the work (owner, licensed maintenance organisation) creates interpretive uncertainty.","Short text with no stated enforcement or approval steps limits administrative complexity in the instrument itself but shifts complexity to the broader regulatory regime."],"plain_english_summary":"This directive requires an immediate modification to the control‑cable pulley on all Percival Proctor Mk. IV and Mk. V aircraft. Compliance is \"forthwith\" and is satisfied by carrying out any one of three specified modification references (Percival Proctor Mod. No. C1206; DCA/PROCTOR/4; or A.N.O. 105.1.26.2.5.2).\n\nIt affects aircraft owners/operators, who must arrange and pay for the chosen modification and any downtime or maintenance costs; technical details must be obtained from the cited modification instructions."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive focused on a specific mechanical modification for a specific vintage aircraft type. It has not expanded beyond its original safety purpose."},"complexity_factors":["Extremely short document (under 200 words)","Only 3 defined compliance pathways (the three modification references)","No nested exceptions or conditional logic","Single applicability criterion (aircraft model)","Single requirement with three alternative methods","No cross-references to other legislation beyond the three named standards","Straightforward imperative language ('Forthwith') with no temporal calculations"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for **Percival Proctor Series Aeroplanes**.\n\n**What it does:**\n- Requires owners/operators of all Mark IV and Mark V Percival Proctor aircraft to modify the **control cable pulley** system\n- The modification must be done using one of three approved methods:\n  - **Percival Proctor Modification No. C1206** (the manufacturer's official modification), OR\n  - **DCA/PROCTOR/4** (an alternative approved by the Department of Civil Aviation), OR\n  - **A.N.O. 105.1.26.2.5.2** (an Air Navigation Order specification)\n\n**Who it affects:**\n- Anyone who owns, operates, or maintains Percival Proctor Mk. IV or Mk. V aircraft\n\n**Why it matters:**\n- Control cable pulleys are critical to flight safety — they guide the cables that move the aircraft's control surfaces (ailerons, elevator, rudder)\n- A faulty or worn pulley could cause control system failure, potentially leading to loss of control of the aircraft\n- The directive uses \"**Forthwith**\" for compliance, meaning it must be done **immediately** — not at the next scheduled maintenance\n\n**In short:** If you fly or maintain one of these specific vintage British aircraft in Australia, you must immediately upgrade the control cable pulleys using one of the three approved methods."}},"importantCases":[],"_links":{"self":"/api/acts/ad-proctor-4-re-issue-control-cable-pulley-modification","history":"/api/acts/ad-proctor-4-re-issue-control-cable-pulley-modification/history","analysis":"/api/acts/ad-proctor-4-re-issue-control-cable-pulley-modification/analysis","conflicts":"/api/acts/ad-proctor-4-re-issue-control-cable-pulley-modification/conflicts","importantCases":"/api/acts/ad-proctor-4-re-issue-control-cable-pulley-modification/important-cases","documents":"/api/acts/ad-proctor-4-re-issue-control-cable-pulley-modification/documents"}}