{"id":"F2006B06126","name":"AD/PC-6/23 - Rudder Bottom Nose Rib - Inspection and Modification","slug":"ad-pc-6-23-rudder-bottom-nose-rib-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46898,"registerId":"commonwealth-F2006B06126-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PC-6/23 - Rudder Bottom Nose Rib - Inspection and 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\n# AD/PC-6/23 Rudder Bottom Nose Rib - Inspection\n\nand Modification\n\nApplicability: All models prior to S/No. 685. Document: Pilatus SB No. 80.\n\n# 7/68\n\nCompliance: Inspect within 100 hours time in service after 11 July 1968 and thereafter at intervals not exceeding 100 hours time in service until modified. Modify before 1 January 1969.\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":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive targeting a specific structural component on a specific aircraft model range. It has not expanded beyond its original purpose of addressing the rudder bottom nose rib integrity issue."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 operative requirements (inspect and modify)","Single applicability criterion (serial number threshold)","No defined terms section","No cross-references to other legislation beyond the enabling regulation (CAR 1998 Part 39)","Simple temporal logic (single deadline, single recurring interval)","Clear reference to external technical document (Pilatus SB) for implementation details"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nRequires owners and operators of **Pilatus Porter PC-6 series aeroplanes** (specifically those built before serial number 685) to:\n- **Inspect** the rudder bottom nose rib within 100 hours of flying time after 11 July 1968, and then re-inspect it every 100 hours of flying time until a modification is done\n- **Modify** the aircraft before 1 January 1969 to fix the problem permanently\n\n**Who it affects:**\n- Owners and operators of older Pilatus Porter PC-6 aircraft (serial numbers below 685)\n- Maintenance engineers working on these aircraft\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety instructions. If you don't comply, you cannot legally fly the aircraft. This particular AD addresses a structural issue with the rudder (the part that steers the aircraft left and right) that could potentially cause a safety problem if left unaddressed. The directive references a manufacturer's Service Bulletin (SB No. 80/7/68) which contains the technical details of what needs to be checked and fixed.\n\n**Key takeaway:** If you own one of these specific Pilatus Porter aircraft, you had a deadline (1 January 1969) to permanently fix this rudder issue, with regular inspections required until that fix was done."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The text sets out the directive’s applicability, inspection intervals and a modification deadline. It does not indicate any amendment or change of scope from an earlier instrument within the provided text; therefore no change of scope is evident from this document."},"complexity_factors":["Narrow applicability (specific aircraft series and serial-number cut-off)","Single, short recurring inspection interval (100 hours) until modification","Fixed calendar deadline for modification (before 1 January 1969)","Dependence on an external technical document (Pilatus SB No. 80) for procedure","Operational scheduling and downtime implications for affected operators"],"plain_english_summary":"Owners/operators of Pilatus PC‑6 (Pilatus Porter) aeroplanes with serial numbers before 685 must carry out recurring inspections of the rudder bottom nose rib and complete a mandated modification (per Pilatus SB No. 80).  \n\nInspections start within 100 hours TIS after 11 July 1968 and repeat every 100 hours until the modification is done, which must be completed before 1 January 1969—imposing maintenance, downtime and cost burdens on owners/operators and their maintenance providers."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pc-6-23-rudder-bottom-nose-rib-inspection-and-modification","history":"/api/acts/ad-pc-6-23-rudder-bottom-nose-rib-inspection-and-modification/history","analysis":"/api/acts/ad-pc-6-23-rudder-bottom-nose-rib-inspection-and-modification/analysis","conflicts":"/api/acts/ad-pc-6-23-rudder-bottom-nose-rib-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-pc-6-23-rudder-bottom-nose-rib-inspection-and-modification/important-cases","documents":"/api/acts/ad-pc-6-23-rudder-bottom-nose-rib-inspection-and-modification/documents"}}