{"id":"F2006B06141","name":"AD/PC-6/37 - Flat End Rib - Inspection","slug":"ad-pc-6-37-flat-end-rib-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46930,"registerId":"commonwealth-F2006B06141-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PC-6/37 - Flat End Rib - Inspection","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-6/37 Flat End Rib - Inspection 6/76\n\nApplicability: All models prior to S/No. 744. Document: Pilatus SB No. 124.\n\nCompliance: Within 10 hours time in service after 19 May 1976 and thereafter at intervals not exceeding 100 hours time in service until modified.\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\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive focused on a specific structural inspection for a specific aircraft model. It has not expanded beyond its original purpose of ensuring the airworthiness of early-model Pilatus Porter PC-6 aircraft regarding the flat end rib component."},"complexity_factors":["Very short document — approximately 100 words of substantive content","Only 4 defined elements: applicability (aircraft models), reference document (Pilatus SB No. 124), compliance deadline, and recurring interval","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Simple conditional logic: inspect once, then repeat every 100 hours until modified","Single exception/exit condition: compliance obligation ceases upon modification per manufacturer bulletin"],"plain_english_summary":"**What this is:** 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:** It requires owners and operators of **Pilatus Porter PC-6 series aeroplanes** (specifically those built before serial number 744) to inspect a particular aircraft part called the **\"flat end rib\"** — a structural component of the wing or fuselage.\n\n**Who must comply:** Anyone operating these specific Pilatus Porter aircraft in Australia.\n\n**The requirements:**\n- **First inspection:** Must be done within 10 hours of flying time after 19 May 1976\n- **Ongoing inspections:** Must be repeated every 100 hours of flying time\n- **When it stops:** These repeated inspections can stop once the aircraft is modified according to Pilatus Service Bulletin No. 124 (the manufacturer's official fix)\n\n**Why it matters:** This directive addresses a potential structural defect that could compromise flight safety. The repetitive inspection requirement ensures the aircraft remains safe to fly until a permanent repair is installed. Ignoring this directive would make the aircraft unairworthy and illegal to operate."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The text provides a single-date directive with applicability, a referenced service bulletin, and fixed inspection intervals. It does not indicate any alteration of scope from an earlier or original instrument; no change is recorded in the supplied text."},"complexity_factors":["Narrow applicability (only PC-6 serial numbers prior to S/No. 744) reduces scope complexity.","Time-based compliance schedule with a short initial deadline (10 hours TIS) and recurring 100-hour interval requires operational scheduling and record-keeping.","Key technical details and the modification procedure are delegated to an external document (Pilatus SB No. 124), creating a dependency on that bulletin for precise actions.","The directive leaves unspecified what constitutes the terminating \"modification,\" so interpretation/confirmation against the service bulletin is required.","Regulatory enforceability under Part 39 imposes mandatory compliance and potential administrative oversight."],"plain_english_summary":"Owners and operators of Pilatus PC‑6 aeroplanes with serial numbers before 744 must inspect the \"flat end rib\" per Pilatus Service Bulletin No. 124. \n\nThe first inspection was required within 10 hours TIS after 19 May 1976 and thereafter at intervals not exceeding 100 hours TIS until the aeroplane is modified; this mandatory CASA Part 39 airworthiness directive delegates technical detail to SB No. 124."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pc-6-37-flat-end-rib-inspection","history":"/api/acts/ad-pc-6-37-flat-end-rib-inspection/history","analysis":"/api/acts/ad-pc-6-37-flat-end-rib-inspection/analysis","conflicts":"/api/acts/ad-pc-6-37-flat-end-rib-inspection/conflicts","importantCases":"/api/acts/ad-pc-6-37-flat-end-rib-inspection/important-cases","documents":"/api/acts/ad-pc-6-37-flat-end-rib-inspection/documents"}}