{"id":"F2006L03415","name":"AD/BELL 430/7 - Vertical Fin Attachment Bolts","slug":"ad-bell-430-7-vertical-fin-attachment-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":60870,"registerId":"commonwealth-F2006L03415-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 430/7 | Vertical Fin Attachment Bolts | 11/2006 |\n| ------------- | ----------------------------- | ------- |\n\n| Applicability: | Model 430 helicopters, serial numbers 49001 through 49036.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Check the torque of the vertical fin attachment bolts in accordance with Part 1 of BHTC Alert Service Bulletin (ASB) 430-98-5, or later Transport Canada approved revision.2. Modify the tailboom and vertical fin fitting attachment including replacement of hardware, in accordance with Part II of ASB 430-98-5, or later Transport Canada approved revision.3. Verify the correct torque of the attachment bolts in accordance with Part III, Special Inspections, of ASB 430-98-5, or later Transport Canada approved revision.Note: Transport Canada AD CF-98-23 refers. |\n| Compliance:    | 1. Unless already accomplished, within 25 hours time-in-service after the effective of this directive.2. Unless already accomplished, before 26 November 2006.3. Unless already accomplished, within 5 to 10 flight hours after incorporation of Requirement 2.                                                                                                                                                                                                                                                                                                                    |\n|                | This Airworthiness Directive becomes effective on 26 October 2006.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |\n| Background:    | A loss of torque of the vertical fin attachment bolts resulted in the fracture four of the eight attachment bolts on a Model 230 helicopter, which is of similar design to the Model 430.                                                                                                                                                                                                                                                                                                                                                                                          |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n13 September 2006","sortOrder":0},{"sectionNumber":"AD/BELL 430/7","sectionType":"part","heading":"AD/BELL 430/7","content":"## AD/BELL 430/7","sortOrder":1},{"sectionNumber":"Vertical Fin Attachment Bolts","sectionType":"part","heading":"Vertical Fin Attachment Bolts","content":"## Vertical Fin Attachment Bolts","sortOrder":2},{"sectionNumber":"11/2006","sectionType":"part","heading":"11/2006","content":"## 11/2006","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"The AD does not expand or narrow coverage beyond its stated aim: it targets specific Model 430 serial numbers and prescribes inspections and a modification to address bolt torque loss. It implements Bell ASB 430‑98‑5 (or later TC‑approved revisions) and references Transport Canada AD CF‑98‑23 rather than altering the scope of those documents."},"complexity_factors":["Multiple technical requirements: initial torque check, structural modification with hardware replacement, and follow‑up torque verification (Requirements 1–3).","Tiered and tight compliance deadlines (25 flight hours after effective date; before 26 Nov 2006; 5–10 flight hours after modification).","Limited applicability to a narrow serial‑number range (Model 430, S/N 49001–49036) which concentrates compliance on a subset of operators.","Dependence on external documents (BHTC ASB 430‑98‑5 and Transport Canada AD CF‑98‑23) and allowance for later Transport Canada‑approved revisions creates procedural dependency and potential change through those approvals.","Requires hands‑on maintenance work and replacement hardware — direct costs, scheduling with maintenance providers, and potential aircraft downtime.","Regulatory enforcement tied to an effective date (26 Oct 2006) and issued by CASA delegate, creating a fixed compliance trigger and administrative oversight.","Background link to a similar failure on Model 230 informs the corrective focus but does not itself specify additional measures."],"plain_english_summary":"This Airworthiness Directive orders owners/operators of Bell 430 helicopters serial numbers 49001–49036 to check and, if necessary, correct the torque on vertical fin attachment bolts, modify the tailboom/fin fitting and replace hardware, then re‑verify bolt torque, using Bell Alert Service Bulletin 430‑98‑5 or a later Transport Canada‑approved revision. Operators pay for inspections, parts and labour; the Civil Aviation Safety Authority delegate enforces deadlines (25 flight hours, before 26 Nov 2006, and 5–10 flight hours after modification) and the AD cross‑references Transport Canada AD CF‑98‑23."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific mechanical defect in a limited fleet of helicopters. The scope remains precisely focused on the original safety issue — preventing tail fin detachment due to bolt failure. No expansion beyond this original purpose."},"complexity_factors":["Single, specific mechanical issue (vertical fin bolts)","Only 36 aircraft affected (narrow serial number range)","Three sequential requirements with clear deadlines","References external technical document (service bulletin) but does not reproduce it","No defined terms section, no cross-references to other legislation","Background explanation is one sentence","Total length: approximately 250 words"],"plain_english_summary":"This CASA Airworthiness Directive orders urgent safety action on Bell 430 helicopters (S/N 49001–49036) because bolts securing the vertical fin may be under-torqued. It stems from bolt failures on a related model; vertical fin separation in flight could cause a crash.\n\nOwners/operators must follow Bell’s service bulletin (ASB 430-98-5) for inspection, modification and re-checks within the mandated timeframes to eliminate the hazard."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-430-7-vertical-fin-attachment-bolts","history":"/api/acts/ad-bell-430-7-vertical-fin-attachment-bolts/history","analysis":"/api/acts/ad-bell-430-7-vertical-fin-attachment-bolts/analysis","conflicts":"/api/acts/ad-bell-430-7-vertical-fin-attachment-bolts/conflicts","importantCases":"/api/acts/ad-bell-430-7-vertical-fin-attachment-bolts/important-cases","documents":"/api/acts/ad-bell-430-7-vertical-fin-attachment-bolts/documents"}}