{"id":"F2006B04342","name":"AD/BELL 204/39 - Pillow Block Bolts and Hardware","slug":"ad-bell-204-39-pillow-block-bolts-and-hardware","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44157,"registerId":"commonwealth-F2006B04342-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.","sortOrder":0},{"sectionNumber":"AD/BELL 204/39 Pillow Block Bolts and Ha","sectionType":"part","heading":"AD/BELL 204/39 Pillow Block Bolts and Hardware 8/2000","content":"# AD/BELL 204/39 Pillow Block Bolts and Hardware 8/2000\n\nApplicability: Model 204B.\n\nRequirement: Action in accordance with the technical requirements of FAA AD 92-23-01.\n\nCompliance: Before further flight after the effective date of this directive, thereafter at each:\n\n    each hub assembly,\n    overhaul,\n    change of a MR hub retention strap, or\n    whenever the bolts are removed for any reason.\n\nThis Airworthiness Directive becomes effective on 10 August 2000.\n\nBackground: This directive follows the detection of cracks in the pillow block bolts on Model 205 and 212 helicopters. Failure of all four bolts will permit main rotor separation. This directive also follows the re-introduction of the AD Series after sixteen years.\n\n![](image.003.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 6 July 2000\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 12 July 2000.","sortOrder":1}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The directive is applied to Model 204B (Applicability) even though the Background describes detected cracks on Models 205 and 212; the instrument re-introduces the AD series after 16 years, effectively extending or clarifying regulatory coverage to 204B operators who must now follow FAA AD 92-23-01 (Requirement; Background)."},"complexity_factors":["Cross-reference to an external FAA airworthiness directive for the required technical actions (Requirement).","Immediate mandatory compliance before further flight creates urgent operational impact (Compliance).","Recurring and conditional compliance triggers — at hub assembly, overhaul, MR hub-retention strap change, or any bolt removal — increase inspection frequency and record-keeping (Compliance).","Safety-critical consequence (main rotor separation) raises enforcement and liability stakes (Background).","Delegate-issued under CAR 1998 subregulation 39.1(1) embeds regulatory discretion in issuance and timing (preamble).","Re-introduction of the AD series after 16 years may affect legacy compliance records and prior applicability (Background)."],"plain_english_summary":"Requires operators of Model 204B helicopters to follow the technical requirements of FAA AD 92-23-01 covering pillow-block bolts and related hardware to address bolt cracking that can lead to main-rotor separation (Requirement; Applicability; Background). Compliance is mandatory before the next flight and at each hub assembly, overhaul, MR hub-retention strap change, or any time the bolts are removed, shifting inspection/repair costs and operational downtime to operators and maintenance providers (Compliance)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard airworthiness directive with narrow, specific scope addressing a known safety defect in a particular helicopter model. No scope creep detected."},"complexity_factors":["Very short document (under 300 words)","Only 1 defined applicability (Model 204B)","Single requirement referencing external technical standard (FAA AD 92-23-01)","Simple compliance structure with 4 clear triggering events","No nested exceptions or conditional logic","Minimal cross-referencing (only to CAR 1998 subregulation 39.1(1) and external FAA document)"],"plain_english_summary":"CASA has issued an emergency safety order for Bell Model 204B helicopters requiring inspection and replacement of pillow‑block bolts found to crack. Operators must follow FAA AD 92‑23‑01 and comply before any flight after 10 August 2000, repeating the action whenever the hub is worked on, after major overhaul, when a retention strap is changed, or bolts are removed.\n\nFailure of all four bolts can allow the main rotor to separate, causing catastrophic loss; the order was reinstated after 16 years following cracked‑bolt findings in Models 205/212."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-204-39-pillow-block-bolts-and-hardware","history":"/api/acts/ad-bell-204-39-pillow-block-bolts-and-hardware/history","analysis":"/api/acts/ad-bell-204-39-pillow-block-bolts-and-hardware/analysis","conflicts":"/api/acts/ad-bell-204-39-pillow-block-bolts-and-hardware/conflicts","importantCases":"/api/acts/ad-bell-204-39-pillow-block-bolts-and-hardware/important-cases","documents":"/api/acts/ad-bell-204-39-pillow-block-bolts-and-hardware/documents"}}