{"id":"F2006B10676","name":"AD/HU 369/13 - Main Rotor Blade - Inspection","slug":"ad-hu-369-13-main-rotor-blade-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116616,"registerId":"commonwealth-F2006B10676-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HU 369/13 - Main Rotor Blade - 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)  McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters\n\n \n\nAD/HU 369/13 Main Rotor Blade - Inspection 10/74\n\nApplicability: All 500 model 369H series. Document: Hughes SIN No. HN-73.\n\nCompliance: Within 25 hours time in service after 7 October 1974 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\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 focused specifically on main rotor blade inspections for one helicopter series. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 4 defined elements: Applicability, Document reference, Compliance deadline, and recurring interval","No cross-references to other legislation sections","No conditional logic or exceptions — straightforward mandatory requirement","Single technical reference to manufacturer service information (Hughes SIN HN-73)","Simple temporal structure: one initial deadline + recurring interval"],"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 specific Hughes/Kawasaki helicopters to inspect the main rotor blades for safety issues.\n\n**Who it affects:**\n- **Aircraft affected:** All McDonnell Douglas (Hughes) and Kawasaki 369 series helicopters, specifically the \"500 model 369H series\"\n- **People affected:** Helicopter operators, maintenance engineers, and owners of these aircraft\n\n**What must be done:**\n- **First inspection:** Must be completed within 25 hours of flying time after 7 October 1974\n- **Ongoing inspections:** Must be repeated every 100 hours of flying time thereafter\n\n**Why it matters:** Main rotor blades are critical components — if they fail, the helicopter crashes. This AD mandates regular inspections to catch potential defects before they cause accidents. The reference to \"Hughes SIN No. HN-73\" suggests this responds to a specific safety issue or incident identified by the manufacturer.\n\n**Key point:** This is not optional. \"Compliance\" means you must do it or the aircraft cannot legally fly."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Based solely on the supplied text, the directive's scope is limited to \"All 500 model 369H series\" and prescribes inspection timing and a referenced manufacturer document. The document itself contains no indication that the scope has been altered from its original terms; there is no language within this text that expands or narrows applicability beyond the stated model series."},"complexity_factors":["Narrow and clearly defined applicability (single model family) reduces complexity (Applicability: All 500 model 369H series).","Simple, fixed compliance timing with an initial and recurring interval reduces procedural complexity (Compliance: within 25 hours after 7 Oct 1974, then ≤100-hour intervals).","Reliance on an external technical document (Hughes SIN No. HN-73) increases operational complexity because the directive does not itself specify inspection steps.","Absence of remedial action details in the supplied text creates ambiguity for maintenance decision-making (directive mandates inspection but not corrective measures).","Reference to regulatory framework (Part 39) without embedded enforcement or alternative compliance provisions requires operators to consult broader regulations, adding a modest administrative layer."],"plain_english_summary":"This Airworthiness Directive (AD/HU 369/13) requires operators of all 500 model 369H series helicopters to perform main rotor blade inspections per Hughes Service Information Notice HN‑73. Inspections are due within 25 hours TIS after 7 Oct 1974 and thereafter every 100 hours TIS.  \n\nIssued by the Civil Aviation Safety Authority under Part 39, it affects owners/operators who must schedule, fund, and act on inspections per the referenced procedure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hu-369-13-main-rotor-blade-inspection","history":"/api/acts/ad-hu-369-13-main-rotor-blade-inspection/history","analysis":"/api/acts/ad-hu-369-13-main-rotor-blade-inspection/analysis","conflicts":"/api/acts/ad-hu-369-13-main-rotor-blade-inspection/conflicts","importantCases":"/api/acts/ad-hu-369-13-main-rotor-blade-inspection/important-cases","documents":"/api/acts/ad-hu-369-13-main-rotor-blade-inspection/documents"}}