{"id":"F2006B06134","name":"AD/PC-6/30 - Anti-Reverse System - Modification","slug":"ad-pc-6-30-anti-reverse-system-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46915,"registerId":"commonwealth-F2006B06134-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PC-6/30 - Anti-Reverse System - 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)  Pilatus Porter PC-6 Series Aeroplanes\n\n \n\nAD/PC-6/30 Anti-Reverse System - Modification 11/70\n\nApplicability: All model PC-6/B1-H2 with S/Nos prior to 726.\n\n \n\nRequirement: 1. Modify anti-reversing circuit as per para 2.21 of Pilatus SB No. 101.\n\n \n\n2.    Test anti-reversing valve as per para 2.1 of Pilatus SN No. 101.\n\n \n\n3.    Function test anti-reversing system as per para 2.22 of Pilatus SB No. 101. Compliance:              For Para. 1 - within 100 hours time in service after 31 December 1970.\n\nFor Paras. 2 and 3 - Within 100 hours time in service after 31 December 1970 and thereafter at intervals not exceeding 100 hours time in service.\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 source text sets specific applicability, required actions and compliance timing. It does not indicate any amendment to or change from a prior scope within the document itself. Therefore there is no evidence in the supplied text that the directive's scope has changed from an earlier intent."},"complexity_factors":["Narrow and clearly stated applicability by model and serial number (low scope complexity).","Direct, limited set of actions: one modification and two types of tests (low procedural complexity).","Mandatory reliance on external document (Pilatus SB No. 101 paras 2.21, 2.1, 2.22) increases practical complexity because compliance requires obtaining and following that bulletin.","Calendar- and hours-based compliance deadlines (100 hours after 31 December 1970) create scheduling requirements for operators.","Recurring inspection interval (every 100 hours) imposes an ongoing compliance/maintenance cycle."],"plain_english_summary":"This AD mandates a one‑off modification and recurring functional checks of the anti‑reversing system on Pilatus PC‑6/B1‑H2 aeroplanes with serial numbers before 726. Owners/operators must arrange and pay for the work, follow Pilatus Service Bulletin No. 101 procedures, and perform initial and repeat tests at 100‑hour intervals—creating an ongoing maintenance and scheduling cost."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive from 1970 addressing a specific mechanical defect in a specific aircraft model. It has not expanded beyond its original purpose of mandating a modification and recurring inspection of the anti-reverse system."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 3 operative requirements with clear cross-references to external technical documents (Pilatus Service Bulletin No. 101)","Simple conditional logic: two compliance deadlines based on paragraph numbers","No defined terms section — uses plain technical language","Single applicability criterion (model and serial number range)","No nested exceptions or conditional carve-outs"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific Pilatus Porter aircraft to fix a problem with the **anti-reverse system** (a safety mechanism that prevents the propeller from spinning backwards).\n\n**Who it affects:**\n- Owners and operators of **Pilatus PC-6/B1-H2 aircraft** with **serial numbers before 726**\n\n**What must be done:**\n1. **Modify the anti-reversing circuit** — following instructions in Pilatus Service Bulletin No. 101, paragraph 2.21\n2. **Test the anti-reversing valve** — following paragraph 2.1 of the same bulletin\n3. **Function test the entire system** — following paragraph 2.22 of the bulletin\n\n**When it must be done:**\n- The modification (step 1) must happen **within 100 flight hours after 31 December 1970**\n- The testing (steps 2 and 3) must happen **within 100 flight hours after 31 December 1970**, and then **repeated every 100 flight hours** ongoing\n\n**Why it matters:**\nAnti-reverse systems stop the propeller from reversing direction unexpectedly, which could cause loss of control during landing or ground operations. This directive ensures a critical safety fix is applied and regularly checked to prevent accidents."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pc-6-30-anti-reverse-system-modification","history":"/api/acts/ad-pc-6-30-anti-reverse-system-modification/history","analysis":"/api/acts/ad-pc-6-30-anti-reverse-system-modification/analysis","conflicts":"/api/acts/ad-pc-6-30-anti-reverse-system-modification/conflicts","importantCases":"/api/acts/ad-pc-6-30-anti-reverse-system-modification/important-cases","documents":"/api/acts/ad-pc-6-30-anti-reverse-system-modification/documents"}}