{"id":"F2006B06342","name":"AD/PROCTOR/3(Re-Issue) - Centre Section Spar - Modification","slug":"ad-proctor-3-re-issue-centre-section-spar-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47536,"registerId":"commonwealth-F2006B06342-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PROCTOR/3(Re-Issue) - Centre Section Spar - 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/3\n\n(Re-Issue)\n\n\nCentre Section Spar - Modification 6/50\n\n \n\nApplicability: All Mk. IV and Mk. V.\n\n \n\nRequirement: 1. Percival Civil Mod. No. C1225, or\n\n \n\n2. DCA/PROCTOR/3, or 3. A.N.O. 105.1.26.2.5.1.\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":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with a narrow, specific scope: mandating a single structural modification for a specific aircraft type. There is no evidence of scope creep; it remains tightly focused on the centre section spar modification for Percival Proctor Mk. IV and V aircraft, which appears to be its original and sole purpose."},"complexity_factors":["Extremely short document (under 200 words)","Only 3 substantive paragraphs: applicability, requirement, and compliance","No defined terms section — all terms are either common aviation knowledge or reference external documents","Simple conditional structure: comply with option 1 OR option 2 OR option 3","No cross-references to other legislation beyond the enabling regulation (Civil Aviation Regulations 1998, Part 39)","No exceptions, exemptions, or nested conditions","References to external technical documents (modification numbers) but these are standard aviation practice rather than legislative complexity"],"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 **Percival Proctor Mk. IV and Mk. V aircraft** to modify the **centre section spar** (a critical structural component that runs through the middle of the wing and fuselage, essentially the backbone of the aircraft's wing structure).\n\n**Specific requirements:** Aircraft owners must comply with **one** of three approved modification methods:\n- **Percival Civil Modification No. C1225** (the manufacturer's official modification), **or**\n- **DCA/PROCTOR/3** (an earlier Department of Civil Aviation directive), **or**  \n- **A.N.O. 105.1.26.2.5.1** (an old Air Navigation Order — essentially a predecessor regulation)\n\n**Who it affects:** Anyone who owns, operates, or maintains Percival Proctor Mk. IV or Mk. V aeroplanes.\n\n**When:** **Forthwith** — meaning immediately, without delay. This is urgent.\n\n**Why it matters:** This directive addresses a structural safety issue with the centre section spar. If left unmodified, the spar could fail in flight, with potentially catastrophic consequences. The \"Re-Issue\" suggests this is an updated version of a previous directive, possibly consolidating earlier requirements or clarifying compliance methods."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The document is labelled as a \"Re-Issue,\" but the text on this page sets out the same applicability (all Mk. IV and Mk. V) and the same compliance requirement (perform one of the three listed modifications forthwith). The AD text does not on its face indicate an expansion or narrowing of applicability or a different technical requirement compared with an earlier issuance, so no change of scope is identifiable from the supplied text."},"complexity_factors":["Narrow technical scope: applies only to Percival Proctor Mk. IV and Mk. V (low subject-matter breadth). (Applicability)","Immediate compliance requirement increases operational scheduling pressure but does not add legal complexity: \"Forthwith.\" (Compliance)","Dependence on external technical documents (Percival Civil Mod. No. C1225; DCA/PROCTOR/3; A.N.O. 105.1.26.2.5.1) adds practical complexity in obtaining and interpreting the required procedures. (Requirement)","No technical detail included in the AD text itself — implementers must consult the referenced documents for procedure and parts, which concentrates substantive complexity outside the AD.","Limited discretion: AD prescribes specific acceptable modifications rather than permitting open-ended alternatives, simplifying legal choice but requiring exact adherence to referenced documents. (Requirement)"],"plain_english_summary":"What this instrument does (mechanically)\n\n- Requires a physical modification to the centre section spar on Percival Proctor aeroplanes of Marks IV and V. The modification must be carried out by following one of three specified documents: Percival Civil Mod. No. C1225; or DCA/PROCTOR/3; or A.N.O. 105.1.26.2.5.1. (See \"Applicability\" and \"Requirement\".)\n- The required action is to be carried out immediately: the AD states compliance \"Forthwith.\" (See \"Compliance\".)\n\nWho it affects and who pays\n\n- Affected parties: owners, operators and maintenance organisations responsible for Percival Proctor Mk. IV and Mk. V aircraft. (See \"Applicability\".)\n- Who pays: the operator or owner pays the direct costs (parts, labour, hangar time) and bears any operational disruption while the modification is performed. The AD itself does not allocate funding.\n\nWho decides and what discretion remains\n\n- The issuing authority is the Civil Aviation Safety Authority (this appears in the document header). The AD prescribes compliance by reference to one of the three named modification documents; it does not describe alternate technical procedures within the AD text. That constrains discretion to the listed options. (See \"Requirement\".)\n\nWhy the AD exists (as an airworthiness directive) and how that interacts with costs and incentives\n\n- The instrument is issued as an Airworthiness Directive, which by form and placement in the Schedule of Airworthiness Directives is intended to mandate corrective or preventive work on aircraft to address an airworthiness concern. The text itself requires a centre section spar modification but does not include the technical or causal detail in this page.\n- Trade-offs and incentives: because compliance is required \"forthwith\" (Compliance), operators have an incentive to schedule and fund the modification promptly to remain compliant. That creates immediate, concentrated costs for owners/operators of the affected types; any safety or airworthiness benefit from the modification would be concentrated on operators and passengers of those specific aeroplanes. The AD provides three specified technical paths, which limits operators to those documented methods rather than allowing independently derived alternatives unless those are separately authorised.\n\nPractical implementation notes and risks\n\n- Compliance burden: operators must obtain the referenced modification document (Percival Civil Mod. No. C1225, DCA/PROCTOR/3, or A.N.O. 105.1.26.2.5.1), schedule maintenance, source parts and record the work. (See \"Requirement\".)\n- Administrative and access risk: the AD depends on external documents. If those documents are old, unavailable, or require interpretation, that can delay compliance or create additional administrative cost.\n- Operational risk: immediate compliance may require aircraft to be taken out of service until the modification is done, affecting availability and revenue for operators.\n\nConcrete citations to the instrument\n\n- Applicability: \"All Mk. IV and Mk. V.\" (Applicability)\n- Requirement: \"1. Percival Civil Mod. No. C1225, or 2. DCA/PROCTOR/3, or 3. A.N.O. 105.1.26.2.5.1.\" (Requirement)\n- Compliance timing: \"Forthwith.\" (Compliance)\n\nNet mechanical effect in one sentence\n\n- All Percival Proctor Mk. IV and V aircraft must have their centre section spar modified immediately by following one of the three specified modification documents; the operator bears the cost and scheduling burden, and the AD limits the acceptable modification methods to those specified."}},"importantCases":[],"_links":{"self":"/api/acts/ad-proctor-3-re-issue-centre-section-spar-modification","history":"/api/acts/ad-proctor-3-re-issue-centre-section-spar-modification/history","analysis":"/api/acts/ad-proctor-3-re-issue-centre-section-spar-modification/analysis","conflicts":"/api/acts/ad-proctor-3-re-issue-centre-section-spar-modification/conflicts","importantCases":"/api/acts/ad-proctor-3-re-issue-centre-section-spar-modification/important-cases","documents":"/api/acts/ad-proctor-3-re-issue-centre-section-spar-modification/documents"}}