{"id":"F2008L01655","name":"AD/BELL 430/1 Amdt 4 - Tail Rotor Blade","slug":"ad-bell-430-1-amdt-4-tail-rotor-blade","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":73742,"registerId":"commonwealth-F2008L01655-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Bell Helicopter Textron Canada (BHTC) 43","sectionType":"division","heading":"Bell Helicopter Textron Canada (BHTC) 430 Series Helicopters","content":"### Bell Helicopter Textron Canada (BHTC) 430 Series Helicopters\n\n| AD/BELL 430/1 Amdt 4 | Tail Rotor Blade | 7/2008 DM |\n| -------------------- | ---------------- | --------- |\n\n| Applicability: | Model 430 helicopters.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Inspect the tail rotor blades in accordance with Part I of Bell Helicopter Textron Canada Alert Service Bulletin (ASB) 430-04-31 Revision B, or later Transport Canada approved revision.2. Inspect the tail rotor blades in accordance with Part II of ASB 430-04-31 Revision B, or later Transport Canada approved revision.3. Rework the affected tail rotor blades in accordance with Part III of ASB430-04-31 Revision B, or later Transport Canada approved revision.Note 1: Reworking the tail rotor blades in accordance with Requirement 3 eliminates the repetitive inspection requirements of this Directive.Note 2: Transport Canada AD CF-2004-21 R3 refers.                                                                   |\n| Compliance:    | 1. Unless the initial inspection is already accomplished, within 3 flight hours after1 June 2008, and thereafter at intervals not to exceed 3 flight hours.2. Unless the initial inspection is already accomplished, within 50 flight hours after 1 June 2008, and thereafter at intervals not to exceed 50 flight hours.3. Before 31 December 2008, unless already accomplished.This Directive shall be entered on the Maintenance Release as maintenance required. The Requirement 1 inspection may be performed and certified by the Pilot in Command who has been trained to do the inspection by an appropriately qualified person. In this case, a copy of the Requirement document and this Directive is to be carried on the aircraft. |\n|                | This Amendment becomes effective on 1 June 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n\n| Background: | Reports were received of three occurrences of cracked tail rotor blades; discovered during scheduled inspection. Two cracks initiated from the outboard bearing bore underneath the flanged sleeves. The third crack initiated from the inboard bearing bore. Corrosion and machining burrs are suspected as the crack initiators.Amendment 1 clarified applicability and allowed the pilot to accomplish Requirement 1 inspections.Amendment 2 expanded applicability but with no change to technical content.Amendment 3 introduced terminating action for the repetitive inspection requirements.Amendment 4 is issued in response to a revision of the related Transport Canada AD, which extends terminating action until 31 December 2008. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n19 May 2008","sortOrder":0},{"sectionNumber":"AD/BELL 430/1 Amdt 4","sectionType":"part","heading":"AD/BELL 430/1 Amdt 4","content":"## AD/BELL 430/1 Amdt 4","sortOrder":1},{"sectionNumber":"Tail Rotor Blade","sectionType":"part","heading":"Tail Rotor Blade","content":"## Tail Rotor Blade","sortOrder":2},{"sectionNumber":"7/2008 DM","sectionType":"part","heading":"7/2008 DM","content":"## 7/2008 DM","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"Scope has changed from the original: successive amendments clarified and expanded applicability, allowed pilots to perform/certify the initial inspection, introduced a terminating action (blade rework) for the repetitive inspections, and Amendment 4 extended the deadline for that terminating action until 31 December 2008. (See Background and Requirement/Compliance text.)"},"complexity_factors":["Multiple, very short recurring inspection intervals (initial inspections and repeat intervals at 3 flight hours and 50 flight hours respectively) — Compliance section","Terminating action (blade rework) that removes repetitive inspections and a firm deadline for that action (before 31 December 2008) — Requirement/Compliance","Cross-reference to manufacturer Alert Service Bulletin (ASB 430-04-31 Rev B or later) and Transport Canada AD CF-2004-21 R3, requiring alignment with external documents and approvals","Permission for a trained Pilot in Command to perform and certify Requirement 1, changing who may carry out and certify maintenance tasks — Compliance note","Mandatory entry on the aircraft Maintenance Release, creating administrative record-keeping and certification obligations","Amendment history (clarified applicability, expanded applicability, introduced and then extended terminating action) increases tracking and implementation complexity"],"plain_english_summary":"Requires Model 430 operators to inspect tail-rotor blades frequently and to rework affected blades in accordance with Bell ASB 430-04-31 (Rev B or later). Repetitive inspections must be carried out at very short intervals until the rework is completed, which removes the repeat-inspection requirement. A trained pilot-in-command may perform and certify the initial inspection; the action must be recorded on the maintenance release. The Directive is effective 1 June 2008 and the rework terminating action is extended to 31 December 2008."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is Amendment 4 to an existing Airworthiness Directive. The amendments have remained tightly focused on the original safety issue (tail rotor blade cracks in Bell 430 helicopters). Amendment 4 simply extends a compliance deadline for the terminating action; it does not expand the scope beyond the original tail rotor blade safety issue."},"complexity_factors":["Short, single-purpose document focused on one mechanical component","Clear three-part structure: applicability, requirements, compliance deadlines","Only 4 defined compliance periods with straightforward conditional logic ('unless already accomplished')","Cross-references to external technical document (Bell ASB 430-04-31) and Canadian aviation authority (Transport Canada AD CF-2004-21 R3) — requires external lookup for full implementation details","Minor administrative complexity in allowing pilot-performed inspections under specific conditions"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires owners/operators of Bell 430 helicopters to inspect tail rotor blades for cracks and to complete a specified rework as the permanent fix. It stems from cracks linked to corrosion and machining defects that could cause loss of control.\n\nThe AD (4th update) extends the deadline for the permanent repair, allows trained pilots to perform the initial check if documented, and sustains frequent inspections until rework is done."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-430-1-amdt-4-tail-rotor-blade","history":"/api/acts/ad-bell-430-1-amdt-4-tail-rotor-blade/history","analysis":"/api/acts/ad-bell-430-1-amdt-4-tail-rotor-blade/analysis","conflicts":"/api/acts/ad-bell-430-1-amdt-4-tail-rotor-blade/conflicts","importantCases":"/api/acts/ad-bell-430-1-amdt-4-tail-rotor-blade/important-cases","documents":"/api/acts/ad-bell-430-1-amdt-4-tail-rotor-blade/documents"}}