{"id":"F2006B04323","name":"AD/BELL 204/16 Amdt 1 - Transmission Support Case - Inspection","slug":"ad-bell-204-16-amdt-1-transmission-support-case-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44138,"registerId":"commonwealth-F2006B04323-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 204/16 Amdt 1 - Transmission Support Case - 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)  Bell Helicopter Textron 204 Series Helicopters\n\n \n\nAD/BELL 204/16\n\nAmdt 1\n\n\nTransmission Support Case - Inspection NK\n\n \n\nApplicability: All model 204B.\n\n \n\nRequirement: Visually inspect the two lift link attachment lugs on the transmission main support case for cracking.\n\n \n\nCompliance: At intervals not exceeding 100 hours’ time in service after 17 July 1974.\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 mechanical inspection for a specific aircraft model. It has not expanded beyond its original purpose of ensuring structural integrity of transmission support cases on Bell 204B helicopters."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 1 defined term implicitly referenced ('time in service')","No cross-references to other legislation or regulations","Single, unambiguous requirement with clear applicability","Simple compliance condition (interval-based, no conditional logic)","No exceptions, exemptions, or nested provisions"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety notice issued by Australia's Civil Aviation Safety Authority (CASA) for specific helicopters.\n\n**What it does:**\nOrders owners and operators of **Bell 204B helicopters** to visually inspect two specific parts — the \"lift link attachment lugs\" on the transmission main support case — for cracks. These lugs are critical structural components that help hold the helicopter's transmission (the gearbox that transfers power from the engine to the rotor) in place.\n\n**Who it affects:**\nAnyone who owns, operates, or maintains a **Bell 204B helicopter** (a variant of the Bell 204 series, originally a military helicopter adapted for civilian use).\n\n**Why it matters:**\nCracks in these attachment lugs could lead to transmission failure or separation — which in a helicopter means potentially catastrophic loss of control. This AD mandates regular inspections (every 100 flight hours) to catch problems before they cause accidents.\n\n**Key details:**\n- **Compliance deadline:** Must be done every 100 hours of flight time\n- **Effective from:** 17 July 1974 (this is an old directive, amended once)\n- **Action required:** Visual inspection only — no disassembly needed unless cracks are found"},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"This document is labelled Amendment 1 to AD/BELL 204/16, indicating it amends a prior directive. The supplied text itself applies to all Bell 204B helicopters and prescribes the visual inspection and 100-hour interval (Applicability; Requirement; Compliance). The source does not include the original (pre-amendment) text, so the specific ways the scope or content were changed from the original AD cannot be determined from this document alone."},"complexity_factors":["Narrow technical scope: single aircraft type and two specific attachment lugs (Applicability; Requirement).","Simple inspection method: visual inspection only, no complex procedures specified (Requirement).","Clear periodicity: fixed interval (every 100 hours TIS) with a stated start-reference date (Compliance).","Lack of detail on follow-up actions or acceptance criteria increases implementation discretion for maintenance personnel (Requirement).","No reporting, repair, or enforcement procedures are included in the text supplied, requiring reliance on other maintenance/regulatory materials for those elements (Requirement)."],"plain_english_summary":"Owners/operators of Bell 204B helicopters must perform a recurring visual inspection of the two lift link attachment lugs on the transmission main support case for cracking, at intervals not exceeding 100 hours time-in-service (measured after 17 July 1974). The Civil Aviation Safety Authority issues the requirement; operators are responsible for scheduling inspections and any follow-up maintenance under existing maintenance rules to manage the safety risk."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-204-16-amdt-1-transmission-support-case-inspection","history":"/api/acts/ad-bell-204-16-amdt-1-transmission-support-case-inspection/history","analysis":"/api/acts/ad-bell-204-16-amdt-1-transmission-support-case-inspection/analysis","conflicts":"/api/acts/ad-bell-204-16-amdt-1-transmission-support-case-inspection/conflicts","importantCases":"/api/acts/ad-bell-204-16-amdt-1-transmission-support-case-inspection/important-cases","documents":"/api/acts/ad-bell-204-16-amdt-1-transmission-support-case-inspection/documents"}}