{"id":"F2007L01250","name":"AD/BELL 206/166 Amdt 1 - Main Rotor Latch Bolts","slug":"ad-bell-206-166-amdt-1-main-rotor-latch-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":65384,"registerId":"commonwealth-F2007L01250-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Bell Helicopter Textron Canada (BHTC) 20","sectionType":"division","heading":"Bell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters","content":"### Bell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters\n\n| AD/BELL 206/166 Amdt 1 | Main Rotor Latch Bolts | 7/2007 DM |\n| ---------------------- | ---------------------- | --------- |\n\n| Applicability: | Model 206 A and Model 206 B helicopters, with serial numbers up to and including serial number 3216, with main rotor latch bolts, part numbers 206-010-169-001/-003 and 206-011-122-003, installed.                                                                                                                                                                                                                                      |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Remove from service the applicable main rotor latch bolts and replace with serviceable parts, in accordance with BHTC Alert Service Bulletin 206-06-109 original issue, or later Transport Canada approved revision.Note: Transport Canada AD CF-2006-23R1 refers.                                                                                                                                                                       |\n| Compliance:    | Unless already accomplished, at the next scheduled main rotor hub disassembly after 7 May 2007, but no later than 7 June 2007.                                                                                                                                                                                                                                                                                                           |\n|                | This Amendment becomes effective on 8 May 2007.                                                                                                                                                                                                                                                                                                                                                                                          |\n| Background:    | The manufacturer’s re-evaluation of the structural analysis indicates the need for the removal from service of the affected bolts in the main rotor latch application.Amendment 1 is issued in response to a revision of the related Transport Canada AD, which clarifies applicability for those Model 206 B helicopters that were converted from Model 206 A helicopters, and have serial numbers within the range of the Model 206 A. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n2 May 2007","sortOrder":0},{"sectionNumber":"AD/BELL 206/166 Amdt 1","sectionType":"part","heading":"AD/BELL 206/166 Amdt 1","content":"## AD/BELL 206/166 Amdt 1","sortOrder":1},{"sectionNumber":"Main Rotor Latch Bolts","sectionType":"part","heading":"Main Rotor Latch Bolts","content":"## Main Rotor Latch Bolts","sortOrder":2},{"sectionNumber":"7/2007 DM","sectionType":"part","heading":"7/2007 DM","content":"## 7/2007 DM","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 1 alters the instrument’s scope by clarifying applicability to include Model 206 B helicopters that were converted from Model 206 A and which have serial numbers within the Model 206 A range. The change (Background) follows a revision of the related Transport Canada AD and therefore widens and clarifies which airframes must comply with the bolt replacement requirement."},"complexity_factors":["Technical specificity: applicability depends on exact helicopter models, serial number range (up to and including 3216) and two precise part numbers (206-010-169-001/-003 and 206-011-122-003) (Applicability).","Cross-reference to external documents: compliance must follow BHTC Alert Service Bulletin 206-06-109 and refers to Transport Canada AD CF-2006-23R1, creating dependency on external approvals and revisions (Requirement / Note).","Timing constraint tied to maintenance cycle: compliance is required at the next scheduled main rotor hub disassembly after 7 May 2007, or by 7 June 2007, which mixes calendar and operational triggers and may complicate scheduling (Compliance).","Who bears cost and action: aircraft owners/operators must remove and replace bolts and obtain serviceable parts, creating direct parts and labour costs (Requirement).","Parts availability and definition risk: mandate to replace with ‘serviceable parts’ creates operational risk if approved replacement stocks are limited or if interpretation of 'serviceable' varies (Requirement).","Record‑keeping / traceability burden: Amendment 1’s clarification about Model 206 B helicopters converted from Model 206 A increases the need to verify conversion history and serial-number records (Background).","Limited regulatory discretion: the directive sets specific parts, timing and a prescribed service bulletin, leaving little operator discretion but relying on manufacturer/TC guidance for technical detail (Requirement / Note)."],"plain_english_summary":"This directive requires owners/operators of Bell 206 A and B helicopters (serial numbers up to 3216) fitted with certain main rotor latch bolts to remove and replace those bolts with serviceable parts per the manufacturer’s alert service bulletin, by the next main rotor hub disassembly after 7 May 2007 and no later than 7 June 2007. The action follows a manufacturer structural re‑evaluation; Amendment 1 clarifies that some Model 206 B helicopters converted from Model 206 A are included."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope of the airworthiness directive. Amendment 1 merely clarifies applicability for converted aircraft (Model 206B helicopters originally built as Model 206A) to ensure no affected aircraft slip through regulatory gaps. The core safety purpose — replacing potentially defective main rotor bolts — remains unchanged."},"complexity_factors":["Single, specific mechanical component targeted (main rotor latch bolts)","Limited applicability: only 2 helicopter models with serial number cutoff and specific part numbers","Straightforward compliance requirement: remove and replace per manufacturer bulletin","Simple deadline structure: next scheduled maintenance OR hard date, whichever comes first","No nested exceptions, conditional logic, or extensive cross-referencing to other legislation","Only references one external document (Transport Canada AD and manufacturer service bulletin)"],"plain_english_summary":"This AD mandates removal and replacement of specific main-rotor latch bolts (PNs 206-010-169-001/-003 and 206-011-122-003) on Bell 206A/B helicopters up to S/N 3216, following Bell ASB 206-06-109, by the next hub disassembly after 7 May 2007 and no later than 7 June 2007. It affects Australian owners, operators and maintenance organisations; Amendment 1 confirms converted 206B aircraft with retained 206A serials are included."},"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-206-166-amdt-1-main-rotor-latch-bolts","history":"/api/acts/ad-bell-206-166-amdt-1-main-rotor-latch-bolts/history","analysis":"/api/acts/ad-bell-206-166-amdt-1-main-rotor-latch-bolts/analysis","conflicts":"/api/acts/ad-bell-206-166-amdt-1-main-rotor-latch-bolts/conflicts","importantCases":"/api/acts/ad-bell-206-166-amdt-1-main-rotor-latch-bolts/important-cases","documents":"/api/acts/ad-bell-206-166-amdt-1-main-rotor-latch-bolts/documents"}}