{"id":"F2006B04521","name":"AD/BELL 206/68 - Main Rotor Pillow Block Bushings - Replacement","slug":"ad-bell-206-68-main-rotor-pillow-block-bushings-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114229,"registerId":"commonwealth-F2006B04521-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 206/68 - Main Rotor Pillow Block Bushings - Replacement","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\nBell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters\n\n \n\nAD/BELL 206/68  Main Rotor Pillow Block Bushings - Replacement\n\n\n11/75\n\n \n\nApplicability: All models.\n\n \n\nDocument: 1. Bell SB No. 206-75-3; or\n\n \n\n2. FAA AD 75-18-07.\n\n \n\nNote: Agusta SB BT206-97 refers.\n\n \n\nCompliance: Within 600 hours time in service after 28 November 1975. Background: AD/Agusta 206/54 equivalent.\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 pillow block bushing replacement. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (approximately 150 words)","Only 2 defined compliance paths (Bell SB or FAA AD)","Single, clear deadline (600 hours time in service from fixed date)","No nested exceptions or conditional logic","No cross-references to other legislation beyond cited technical documents","Straightforward applicability (all models)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of certain Bell 206 helicopters to replace specific parts called \"main rotor pillow block bushings\" (metal sleeves that allow the main rotor to rotate smoothly).\n\n**Who it affects:**\n- Owners and operators of Bell 206 and Agusta Bell 206 series helicopters\n- All models of these helicopters are covered\n\n**What it requires:**\n- Replace the main rotor pillow block bushings within **600 hours of flight time** after 28 November 1975\n- Follow the procedures in Bell Service Bulletin 206-75-3 or FAA AD 75-18-07\n\n**Why it matters:**\nThese bushings are critical safety components. If they fail, the main rotor could malfunction, potentially causing catastrophic accidents. This directive ensures worn or defective parts are replaced before they become dangerous.\n\n**Key background:**\nThis Australian directive matches an earlier Agusta directive (AD/Agusta 206/54) and aligns with American safety standards (FAA AD 75-18-07)."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive maintains the original, narrow scope of requiring replacement of the main rotor pillow block bushings on Bell/Agusta 206 series helicopters. It applies to all models and references specific service documents for the work (Applicability: All models.; Document: Bell SB No. 206-75-3; or FAA AD 75-18-07.; Note: Agusta SB BT206-97 refers.; Background: AD/Agusta 206/54 equivalent.). There is no indication in the text supplied that the regulatory scope was broadened or narrowed from the original intent."},"complexity_factors":["Short, focused mandate limited to a single replacement task (Main rotor pillow block bushings) — low procedural breadth (Title/AD/BELL 206/68).","Clear applicability to all models reduces case-by-case complexity (Applicability: All models.).","Fixed compliance window (600 hours TIS after 28 November 1975) simplifies scheduling but requires accurate time-in-service tracking (Compliance: Within 600 hours time in service after 28 November 1975.).","Dependence on external technical documents (Bell SB No. 206-75-3; FAA AD 75-18-07; Agusta SB BT206-97) introduces moderate complexity because detailed procedures, parts and tolerances are not included in the directive text (Document: Bell SB No. 206-75-3; or FAA AD 75-18-07.; Note: Agusta SB BT206-97 refers.).","Regulatory enforcement under Civil Aviation Regulations Part 39 provides little discretionary relief; compliance is mandatory (PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY — Schedule of Airworthiness Directives).","Age and cross-referencing (dates and equivalence to previous Agusta AD) may complicate interpreting which technical revision applies if later amendments exist (11/75; Background: AD/Agusta 206/54 equivalent.)."],"plain_english_summary":"The directive mandates replacement of the main-rotor pillow block bushings on all Bell/Agusta 206 series helicopters, to be done within 600 hours time-in-service after 28 November 1975 using the procedures/parts in Bell SB No. 206-75-3 or FAA AD 75-18-07 (Agusta SB BT206-97 noted).  \n\nOwners/operators must fund and schedule the work; compliance is compulsory and will drive demand for parts and maintenance labour."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-206-68-main-rotor-pillow-block-bushings-replacement","history":"/api/acts/ad-bell-206-68-main-rotor-pillow-block-bushings-replacement/history","analysis":"/api/acts/ad-bell-206-68-main-rotor-pillow-block-bushings-replacement/analysis","conflicts":"/api/acts/ad-bell-206-68-main-rotor-pillow-block-bushings-replacement/conflicts","importantCases":"/api/acts/ad-bell-206-68-main-rotor-pillow-block-bushings-replacement/important-cases","documents":"/api/acts/ad-bell-206-68-main-rotor-pillow-block-bushings-replacement/documents"}}