{"id":"F2006B10696","name":"AD/HU 369/34 Amdt 1 - Tail Rotor Hub - Inspection and Modification","slug":"ad-hu-369-34-amdt-1-tail-rotor-hub-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116656,"registerId":"commonwealth-F2006B10696-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HU 369/34 Amdt 1 - Tail Rotor Hub - 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)  McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters\n\n \n\nAD/HU 369/34\n\nAmdt 1\n\n\nTail Rotor Hub - Inspection and Modification 4/79\n\n \n\nApplicability: All 500 model 369H Series with tail rotor hub assemblies and tail rotor blade attachment bolts as listed in Hughes SIN No. HN-128.1.\n\n \n\nDocument: Hughes SIN No. HN-128.1. Compliance:  As per requirement document.\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":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The instrument is labelled \"Amdt 1,\" but the supplied text contains no comparison to earlier wording or any explicit indication that the scope (the set of affected aircraft or the nature of the mandatory actions) has been altered from the original AD. Based on the supplied material, there is no demonstrated change in scope; the AD simply applies the Hughes SIN HN-128.1 requirements to the listed 369H Series aircraft (see \"Amdt 1\", \"Applicability\" and \"Document\")."},"complexity_factors":["The AD text is short and procedural, but it delegates all technical detail to an external manufacturer document (Hughes SIN HN-128.1), which increases practical complexity.","Applicability is narrowly defined (specific model and parts) which simplifies scope determination but requires cross-referencing the SIN to identify affected serials/parts.","The AD is an amendment (Amdt 1) but the supplied text does not include or describe prior text or the nature of the amendment, creating interpretive uncertainty.","Technical subject matter (tail rotor hub inspection/modification) is specialised and will require qualified maintenance personnel and possibly specialised parts.","The AD refers to regulatory authority (Part 39 schedule) but does not include enforcement detail or allowed alternative compliance procedures in the excerpt supplied."],"plain_english_summary":"This Airworthiness Directive (AD/HU 369/34 Amdt 1) mandates inspection and modification of specified tail rotor hub assemblies and blade attachment bolts on 500 model 369H Series helicopters, by requiring compliance with Hughes Service Information Note HN-128.1.\n\nIt affects owners/operators of those helicopters listed in the SIN, who must follow the Hughes procedures (and bear associated costs/downtime) under the Commonwealth Part 39 airworthiness regime."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a narrow, technical safety directive focused on a specific helicopter model and component. It represents the original and continuing purpose of Airworthiness Directives — targeted mandatory maintenance actions in response to identified safety defects. No scope creep is evident."},"complexity_factors":["Extremely short document (under 200 words)","Only 1 defined applicability criterion (500 model 369H Series)","Single external reference to Hughes SIN No. HN-128.1 — actual technical requirements contained in separate manufacturer document","No conditional logic, exceptions, or nested provisions","No cross-references to other legislation or regulations beyond basic CASA authority citation","Standardised AD format with minimal variation"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific McDonnell Douglas (formerly Hughes) and Kawasaki 369 series helicopters to inspect and modify their **tail rotor hub assemblies**.\n\n**Who it affects:**\n- Owners and operators of **500 model 369H Series helicopters**\n- Specifically those with tail rotor hub assemblies and blade attachment bolts covered by **Hughes Service Information Notice (SIN) No. HN-128.1**\n\n**What it requires:**\n- Inspection and modification of the tail rotor hub (the part that holds the tail rotor blades)\n- Compliance must follow the procedures in the referenced Hughes document (HN-128.1)\n\n**Why it matters:**\nTail rotor failures can cause catastrophic loss of control in helicopters. This directive addresses a known safety issue with specific hardware configurations, ensuring potentially defective components are identified and fixed before they fail in flight."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hu-369-34-amdt-1-tail-rotor-hub-inspection-and-modification","history":"/api/acts/ad-hu-369-34-amdt-1-tail-rotor-hub-inspection-and-modification/history","analysis":"/api/acts/ad-hu-369-34-amdt-1-tail-rotor-hub-inspection-and-modification/analysis","conflicts":"/api/acts/ad-hu-369-34-amdt-1-tail-rotor-hub-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-hu-369-34-amdt-1-tail-rotor-hub-inspection-and-modification/important-cases","documents":"/api/acts/ad-hu-369-34-amdt-1-tail-rotor-hub-inspection-and-modification/documents"}}