{"id":"F2009L01645","name":"AD/BELL 427/10 - Anti-drive Link Assembly","slug":"ad-bell-427-10-anti-drive-link-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":78443,"registerId":"commonwealth-F2009L01645-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Bell Helicopter Textron 427 Series Helic","sectionType":"division","heading":"Bell Helicopter Textron 427 Series Helicopters","content":"### Bell Helicopter Textron 427 Series Helicopters\n\n| AD/BELL 427/10 | Anti-drive Link Assembly | 7/2009 TX |\n| -------------- | ------------------------ | --------- |\n\n| Applicability: | Bell Helicopter Textron Canada (BHTC) Helicopter Models 427 with anti-drive link assembly Part Number (P/N) 406-010-432-101 with a serial number (S/N) prefix TI or TIFS.Models affected: Model 427 - S/N 56001 through 56074, 58001 and 58002.                                                                                                                                        |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Perform a one time inspection and if required, rectification, of the anti-drive link assembly P/N 406-010-432-101 to ensure that bearing P/N 406-310-403-101 is correctly staked in the link assembly in accordance with BHTC Alert Service Bulletin 427-09-24 Rev A - dated 30 March 2009 or later approved revision.Note: Transport Canada AD CF-2009-14 dated 15 April 2009 refers. |\n| Compliance:    | Within the next 10 flight hours, but no later than 30 days from the effective day of this AD, unless already accomplished.                                                                                                                                                                                                                                                             |\n|                | This Airworthiness Directive becomes effective on 6 May 2009.                                                                                                                                                                                                                                                                                                                          |\n| Background:    | During a pre-flight check it was observed that the swash plate link assembly bearing P/N 406-310-403-101 had moved in the lever race making contact with the swash plate support. Further investigation has revealed that the bearing had not been staked correctly during manufacture.This situation, if not corrected, could lead to loss of control of the helicopter.              |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n30 April 2009","sortOrder":0},{"sectionNumber":"AD/BELL 427/10","sectionType":"part","heading":"AD/BELL 427/10","content":"## AD/BELL 427/10","sortOrder":1},{"sectionNumber":"Anti-drive Link Assembly","sectionType":"part","heading":"Anti-drive Link Assembly","content":"## Anti-drive Link Assembly","sortOrder":2},{"sectionNumber":"7/2009 TX","sectionType":"part","heading":"7/2009 TX","content":"## 7/2009 TX","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument sets a focused corrective action for a specific improperly staked bearing on listed helicopters. The text shows no expansion or narrowing beyond that initial corrective purpose; it prescribes a one-time inspection and rectification where required, consistent with the stated intent."},"complexity_factors":["Narrow technical scope: targets a single part (bearing P/N 406-310-403-101) and specific anti-drive link assembly P/N 406-010-432-101 (Applicability).","Serial-number specificity: only certain Bell 427 serial numbers are affected, requiring operators to verify airframe identity (Applicability).","Time-critical compliance: requires action within 10 flight hours or 30 days, creating scheduling pressure for operators (Compliance).","One-time inspection plus potential rectification: may require immediate maintenance resources and parts if a defect is found (Requirement; Background).","Dependence on manufacturer service bulletin for procedural detail (BHTC Alert Service Bulletin 427-09-24 Rev A cited in Requirement).","Safety-critical consequence: defect described as potentially leading to loss of control, increasing regulatory urgency and enforcement focus (Background).","Regulatory cross-reference: references Transport Canada AD CF-2009-14, indicating coordinated oversight and possible procedural alignment (Requirement note).","Limited administrative discretion: directive is prescriptive (who, what, and when), leaving little regulatory flexibility for operators (Requirement; Compliance)."],"plain_english_summary":"Mandates a one-time inspection (and repair if needed) of the anti-drive link assembly bearing P/N 406-310-403-101 on specified Bell 427 helicopters to confirm the bearing is correctly staked, following Bell Alert Service Bulletin 427-09-24 Rev A. Applies to listed Bell 427 serial numbers fitted with anti-drive link assembly P/N 406-010-432-101 and must be completed within 10 flight hours or 30 days of the AD (effective 6 May 2009). The action responds to an observed unstaked bearing that could lead to loss of control."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive addressing a specific manufacturing defect in a specific helicopter model. It has not expanded beyond its original safety purpose."},"complexity_factors":["Single, specific mechanical defect addressed with clear part numbers and serial number ranges","Straightforward one-time inspection requirement with no nested conditions or alternative compliance methods","Simple binary compliance timeline (10 flight hours OR 30 days)","No defined terms section, no cross-references to other legislation beyond a single reference to a Canadian Transport Canada AD","Single applicability criterion with explicit model and serial number identification","Background provides clear causal explanation without legal ambiguity"],"plain_english_summary":"This CASA emergency AD requires owners/operators of certain Bell 427 helicopters (S/N 56001–56074, 58001–58002) fitted with anti‑drive link P/N 406‑010‑432‑101 (S/Ns beginning “TI”/“TIFS”) to perform a one‑time inspection and, if the bearing is not properly staked, rectify it per the manufacturer within 10 flight hours or 30 days. Failure could lead to swashplate interference and loss of control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-427-10-anti-drive-link-assembly","history":"/api/acts/ad-bell-427-10-anti-drive-link-assembly/history","analysis":"/api/acts/ad-bell-427-10-anti-drive-link-assembly/analysis","conflicts":"/api/acts/ad-bell-427-10-anti-drive-link-assembly/conflicts","importantCases":"/api/acts/ad-bell-427-10-anti-drive-link-assembly/important-cases","documents":"/api/acts/ad-bell-427-10-anti-drive-link-assembly/documents"}}