{"id":"F2006B06344","name":"AD/PROCTOR/5 (Re-Issue) - Fuel Tank Vent - Modification","slug":"ad-proctor-5-re-issue-fuel-tank-vent-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47543,"registerId":"commonwealth-F2006B06344-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PROCTOR/5 (Re-Issue) - Fuel Tank Vent - 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/5\n\n(Re-Issue)\n\n\nFuel Tank Vent - Modification 6/50\n\n \n\nApplicability: All Mk. IV and Mk. V.\n\n \n\nRequirement: 1. Percival Civil Mod. No. C1175, or\n\n \n\n2. DCA/PROCTOR/5, or 3. A.N.O. 105.1.26.2.5.3.\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 appears to be a straightforward re-issue of a specific airworthiness directive targeting a known safety issue with fuel tank vents on particular aircraft models. The scope remains tightly focused on the original technical safety purpose with no evidence of scope creep."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 2 defined applicability criteria (Mk. IV and Mk. V models)","Simple alternative structure for compliance (3 options connected by 'or')","No cross-references to other legislation beyond the three named standards","No conditional logic, exceptions, or nested provisions","Single, unambiguous compliance deadline ('Forthwith')","No interpretation section or defined terms"],"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** — specifically the Mk. IV and Mk. V models.\n\n**What it does:**\n- Requires owners/operators to modify the **fuel tank vent system** on these aircraft\n- The modification must follow one of three approved methods:\n  1. Percival Civil Modification No. C1175 (the manufacturer's official modification), OR\n  2. DCA/PROCTOR/5 (an earlier Department of Civil Aviation directive), OR\n  3. A.N.O. 105.1.26.2.5.3 (an Air Navigation Order reference)\n\n**Who it affects:**\n- Anyone who owns, operates, or maintains Percival Proctor Mk. IV or Mk. V aircraft in Australia\n\n**Why it matters:**\n- Fuel tank venting is critical for safe aircraft operation — proper ventilation prevents fuel starvation, pressure build-up, and potential fire hazards\n- The directive uses \"**Forthwith**\" (immediately) as the compliance deadline, meaning this is an urgent safety fix with no grace period\n- This is a \"**Re-Issue**\" of a previous directive, suggesting it replaces or consolidates earlier versions\n\n**In short:** If you fly or maintain one of these specific vintage British aircraft, you must immediately ensure the fuel tank vent has been modified using one of the three approved methods."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The instrument is presented as a re-issue but the text specifies applicability to all Mk. IV and Mk. V and mandates one of three named modifications to the fuel tank vent. The document itself does not state an expansion or narrowing of the class of affected aircraft or the set of acceptable modifications, so there is no evidence within this text that the scope of who must comply has changed."},"complexity_factors":["Short, narrowly targeted directive applying to a specific aircraft type and two marks (Applicability).","Only three explicit compliance options are listed, limiting procedural complexity (Requirement).","Immediate compliance requirement increases operational urgency but does not add procedural layers (Compliance).","Technical detail is externalised to three referenced documents/mods, which requires locating and interpreting those sources.","No procedural or enforcement detail in the text (e.g. verification steps, deadlines beyond 'forthwith'), reducing internal complexity but shifting work to implementers."],"plain_english_summary":"This AD requires all Percival Proctor Mk. IV and Mk. V aeroplanes to have the fuel-tank vent system modified forthwith, by implementing one of three specified modification standards (Percival Civil Mod. No. C1175, DCA/PROCTOR/5, or A.N.O. 105.1.26.2.5.3.). \n\nOwners/operators must arrange and pay for the work, choose which authorised modification to use, and may need to ground aircraft until compliance; no alternative measures are permitted in the AD."}},"importantCases":[],"_links":{"self":"/api/acts/ad-proctor-5-re-issue-fuel-tank-vent-modification","history":"/api/acts/ad-proctor-5-re-issue-fuel-tank-vent-modification/history","analysis":"/api/acts/ad-proctor-5-re-issue-fuel-tank-vent-modification/analysis","conflicts":"/api/acts/ad-proctor-5-re-issue-fuel-tank-vent-modification/conflicts","importantCases":"/api/acts/ad-proctor-5-re-issue-fuel-tank-vent-modification/important-cases","documents":"/api/acts/ad-proctor-5-re-issue-fuel-tank-vent-modification/documents"}}