{"id":"F2006B04470","name":"AD/BELL 206/156 - Tail Rotor Blade","slug":"ad-bell-206-156-tail-rotor-blade","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44307,"registerId":"commonwealth-F2006B04470-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# ![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\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 CASR 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.\n\n![](image.001.png)  \n\nBell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters","sortOrder":0},{"sectionNumber":"AD/BELL 206/156 Tail Rotor Blade 2/2005 ","sectionType":"part","heading":"AD/BELL 206/156 Tail Rotor Blade 2/2005 TX","content":"# AD/BELL 206/156 Tail Rotor Blade 2/2005 TX\n\nApplicability: Model 206A, 206B, and 206L helicopters equipped with tail rotor blade part number 206-016-201-131, serial numbers CS-4820 through CS-4845.\n\nRequirement: Part A. Identification of Affected Tail Rotor Blades\n\nVerify if the aircraft is equipped with tail rotor blades identified in the “Blades Affected” section of Bell Helicopter Alert Service Bulletin (ASB) 206-04-101 or 206L-04-131, as applicable. If the aircraft is equipped with an affected blade, enter the part number and serial number into the technical record. If not equipped, indicate in the record that the aircraft is not equipped with blades affected by this Directive.\n\nPart B. Check for Tail Rotor Doubler De-bonding\n\nUntil blade replacement, check the affected blades in accordance with Part I of ASB 206-04-101 or 206L-04-131, as applicable, or later Transport Canada approved revision.\n\nPart C. Replacement of the Blades\n\nReplace all affected blades in accordance with Part II of ASB 206-04-101 or 206L- 04-131, as applicable, or later Transport Canada approved revision.\n\nNote: Transport Canada AD CF-2004-25 refers.\n\nCompliance: For Part A:\n\nBefore further flight after 30 December 2004\\. For Part B:\n\nDaily, until blade replacement. For Part C:\n\nWithin 100 hours time in service after 30 December 2004, or before 31 January 2005, whichever occurs first.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The supplied text sets a clear, self‑contained applicability and corrective regime for specific tail‑rotor blades. There is no material in the text indicating the AD’s scope was expanded or narrowed from an earlier intent; the AD identifies affected serial numbers and prescribes identification, inspection and replacement obligations with fixed compliance deadlines (Applicability; Requirement Parts A–C; Compliance)."},"complexity_factors":["Narrow, serial‑number‑limited applicability reduces scope but requires checking records and physical verification (Applicability; Requirement Part A).","Multiple, time‑linked actions (identify, daily inspections, replace within 100 TAS hours or by a calendar date) create short compliance windows and scheduling pressure (Requirement Parts A–C; Compliance).","Mandatory record‑keeping of part and serial numbers imposes administrative compliance burden on operators/maintenance organisations (Requirement Part A).","Dependence on external technical documents (Bell Helicopter Alert Service Bulletin) and any later Transport Canada approved revisions creates ongoing reference and versioning obligations (Requirement Parts B–C).","Enforcement via CASR subregulation 39.1(1) places decision authority with the CASA delegate and makes timely action mandatory (preamble)."],"plain_english_summary":"This Airworthiness Directive requires operators of Bell 206A, 206B and 206L helicopters fitted with a specific tail‑rotor blade series (P/N 206‑016‑201‑131, S/N CS‑4820 to CS‑4845) to identify affected blades, perform repeated checks for tail‑rotor doubler de‑bonding, and replace any affected blades within short, specified timeframes. Operators must record part and serial numbers in the technical record, perform daily inspections until replacement, and meet hard deadlines enforced under CASR subregulation 39.1(1)."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific manufacturing defect in a limited batch of tail rotor blades. It has not expanded beyond its initial safety purpose."},"complexity_factors":["Short, single-purpose directive with clear sequential requirements (Part A, B, C)","Only 4 defined applicability criteria (3 models + specific part/serial numbers)","Heavy reliance on external technical documents (Bell ASBs and Transport Canada AD) — operators must source and interpret these separately","Simple conditional logic: 'if equipped, do X; if not, do Y'","Clear compliance deadlines with straightforward alternatives ('whichever occurs first')","No nested exceptions or complex cross-referencing within the instrument itself"],"plain_english_summary":"This AD mandates owners/operators of Bell 206A/B/L helicopters fitted with specific tail rotor blades (PN 206-016-201-131, SN CS-4820–CS-4845) to identify affected blades, perform daily checks for doubler de-bonding, and replace them within 100 flight hours or by 31 Jan 2005. It addresses a manufacturing defect that can cause tail rotor failure and loss of directional control, and requires following Bell/Transport Canada service instructions for compliance."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-206-156-tail-rotor-blade","history":"/api/acts/ad-bell-206-156-tail-rotor-blade/history","analysis":"/api/acts/ad-bell-206-156-tail-rotor-blade/analysis","conflicts":"/api/acts/ad-bell-206-156-tail-rotor-blade/conflicts","importantCases":"/api/acts/ad-bell-206-156-tail-rotor-blade/important-cases","documents":"/api/acts/ad-bell-206-156-tail-rotor-blade/documents"}}