{"id":"F2007L04229","name":"AD/BELL 206/158 Amdt 3 - Fuel Distribution System","slug":"ad-bell-206-158-amdt-3-fuel-distribution-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":70438,"registerId":"commonwealth-F2007L04229-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 206/158 Amdt 3 | Fuel Distribution System | 12/2007 |\n| ---------------------- | ------------------------ | ------- |\n\n| Applicability: | Bell Helicopter Textron Canada (BHTC), Model 206 series helicopters up to S/N 5305 inclusive. |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Inspect the grounding of the fuel pumps and solenoid valve, as per instructions provided in Part I of Alert Service Bulletin (ASB) 206-05-103, dated 11 February 2005, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada.2. Perform clamping of the purge hose and position the boost pumps as indicated, in accordance with Part II of ASB 206-05-103, Revision A dated 12 July 2006 or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada.3. Verify the installation of the restrictor as per the instructions provide in Part III of ASB 206-05-103, Revision A or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada.4. Verify the installation of a filter as per the instructions provide in Part IV of ASB 206-05-103, Revision A or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada.5. For helicopters requiring the filter, amend the maintenance program to require a recurring 24 month inspection and cleaning as indicated in Part IV, paragraph 2 of ASB 206-05-103 Revision A or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada.Note: Transport Canada AD CF-2005-10R3 refers. |\n| Compliance: | For Requirement 1 - Within the next 100 hours time in service, but no later than22 December 2007.For Requirement 2 - No later than 22 December 2007.For Requirements 3, 4 and 5 - At the next 100-hour inspection but no later than22 December 2007. |\n\n| | This Amendment becomes effective on 22 November 2007. |\n| ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Background: | Transport Canada has advised that inadequate electrical grounding of the fuel boost pump and the fuel drain solenoid valve, combined with fuel hoses contact, could cause arcing in the main fuel cell which may in turn cause an explosion and resultant fire.The original issue of this Directive required a one time inspection to ensure correct grounding and, if necessary the disconnection and stowage of the engine fuel purge hose.Since Canadian Airworthiness Directive CF-2005-10 was issued, Transport Canada has determined that the purge hose relocation as per instructions provided in Part II of ASB 206-05-103, could cause an engine flameout in a low fuel, boost pump off, condition. Amendment 1 revoked, Requirement 2 of the initial issue of this Directive and required the helicopter fuel purge hose to be returned to its previous configuration.Further investigation revealed that the engine flameout was caused by absence of restrictor, part number 206-061-637-001 or 206-061-655-001. Amendment 2 mandated purge hose installation and boost pump positioning in addition to verification of installation of a fuel restrictor and filter.Amendment 3 changes the applicability section of this Directive to list Model 206 helicopters by serial number range disregarding the suffix of “A” or “B”. This is due to some Model 206A helicopters being converted to Model 206B helicopters.The original issue of this Directive became effective on 16 June 2005.Amendment 1of this Directive became effective on 2 December 2005.Amendment 2 of this Directive became effective on 25 October 2006. |\n\n![](image.001.png) \nDavid Punshon \nDelegate of the Civil Aviation Safety Authority\n\n12 October 2007","sortOrder":0},{"sectionNumber":"AD/BELL 206/158 Amdt 3","sectionType":"part","heading":"AD/BELL 206/158 Amdt 3","content":"## AD/BELL 206/158 Amdt 3","sortOrder":1},{"sectionNumber":"Fuel Distribution System","sectionType":"part","heading":"Fuel Distribution System","content":"## Fuel Distribution System","sortOrder":2},{"sectionNumber":"12/2007","sectionType":"part","heading":"12/2007","content":"## 12/2007","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"The Directive has expanded beyond the original one‑time inspection intent. The original requirement was a single inspection for correct grounding and (if necessary) disconnection/stowage of the purge hose to prevent arcing. Subsequent amendments revoked and reinstated hose actions after discovering an engine flameout risk, then added mandatory verification/installation of a fuel restrictor and a fuel filter and introduced a recurring 24‑month maintenance requirement for the filter. Amendment 3 altered applicability (serial number listing ignoring A/B suffix). In sum, the instrument evolved from a single inspection to a package of one‑off hardware checks/installs plus a recurring maintenance obligation, so its practical scope and ongoing burden on operators increased from the original limited inspection."},"complexity_factors":["Five distinct mandatory actions (Requirements 1–5) with different timings (one‑off vs recurring).","Cross‑reference to a single ASB divided into Parts I–IV (ASB 206‑05‑103) and to later revisions approved by Transport Canada.","Multiple dated revisions of the ASB are referenced (original ASB dated 11 Feb 2005; Revision A dated 12 Jul 2006) creating version‑control complexity.","Applicability limited by serial number range (up to S/N 5305 inclusive) with explicit instruction to disregard A/B suffixes (adds identification complexity).","Several amendment steps in the directive’s history (original issue + Amendments 1–3) and a background narrative describing revocations and replacements of requirements.","Conditional compliance windows (within 100 flight hours OR by a calendar date), creating alternate compliance triggers.","Mandated change to an operator’s maintenance program (recurring 24‑month inspection), introducing an ongoing compliance obligation.","References to specific part numbers for restrictors (206‑061‑637‑001 or 206‑061‑655‑001) and to filters, which raises supply/parts management issues."],"plain_english_summary":"**What this directive does (mechanically)**\n\n- It orders owners/operators of Bell 206 series helicopters (serial numbers up to 5305 inclusive) to carry out specific inspections and modifications to the fuel distribution system, following the procedures in Alert Service Bulletin (ASB) 206-05-103 (Parts I–IV) or later ASB revisions approved by the Chief, Continuing Airworthiness, Transport Canada.\n- The mandated actions are: \n 1. Inspect the electrical grounding of the fuel boost pumps and the fuel drain solenoid valve (Part I of the ASB). \n 2. Clamp the engine purge hose and position the boost pumps as shown in the ASB (Part II). \n 3. Verify that a fuel restrictor (part number 206-061-637-001 or 206-061-655-001) is installed (Part III). \n 4. Verify that a fuel filter called for in the ASB is installed (Part IV). \n 5. If the filter is fitted, add a recurring 24‑month inspection/cleaning requirement into the helicopter’s maintenance program (Part IV, para 2).\n- Deadlines: Requirement 1 must be done within the next 100 flight hours or by 22 December 2007 (whichever is sooner). Requirement 2 by 22 December 2007. Requirements 3–5 at the next 100‑hour inspection or by 22 December 2007. The Amendment took effect on 22 November 2007.\n\n**Who this affects**\n\n- Helicopter owners and operators of Bell 206 series helicopters up to serial number 5305 inclusive (the directive explicitly disregards A/B suffixes because some aircraft have been converted). \n- Maintenance organisations and licensed engineers who must perform the inspections/modifications and record them in maintenance logs. \n- Operators pay for parts (restrictor, filter where required), labour and any additional downtime; regulators (CASA via the delegate) set enforcement and accept compliance evidence; the ASB instructions are issued by the manufacturer and accepted where approved by Transport Canada.\n\n**Why the directive exists (stated purpose) and what that implies in practice**\n\n- The stated safety risk: inadequate electrical grounding of the boost pump and fuel drain solenoid combined with fuel hose contact can produce electrical arcing inside the main fuel cell, which could lead to an explosion and fire. The directive therefore focuses on grounding, hose routing/retention, and the presence of a restrictor and filter to prevent conditions that previously allowed flameout or arcing.\n\n- Practically that means operators must: inspect electrical bonds and fix them if needed; install or verify mechanical items (clamps, hose positions, restrictor, filter); and, where filters are used, add a regular 24‑month cleaning cycle to the maintenance schedule.\n\n**Costs, incentives and trade‑offs**\n\n- Who pays: the helicopter owner/operator bears the direct costs (parts, labour, inspection time, potential downtime). \n- Concentration of costs/benefits: the cost is concentrated on the aircraft owner/operator; the safety benefit is shared (diffuse) among crew, passengers and third parties. \n- Compliance burden: multiple discrete actions are required, some one‑off (inspect/grind/fix, install restrictor/filter), and one recurring requirement (24‑month filter servicing where fitted). Maintenance programs must be updated and records kept. \n- Implementation risks and trade‑offs: prior amendments show a trade‑off between hose relocation (intended to reduce arcing risk) and unintended engine flameout in certain fuel conditions; that discovery led to the identification/mandating of a restricting part and filter. Incorrect installations or omission of the restrictor/filter may reintroduce either fire or flameout risks. \n- Supply and downtime risk: availability of the correct restrictor/filter parts and the time taken to perform modifications will affect operational availability and costs.\n\n**How compliance is enforced and what governs acceptable work**\n\n- The directive requires compliance in the stated timeframes and references the manufacturer ASB for the detailed procedures (ASB 206-05-103 and its revisions). The ASB revisions must be those approved by the Chief, Continuing Airworthiness, Transport Canada. The local regulator’s delegate published the amendment and enforces compliance.\n\n**Net practical effect**\n\n- Operators of affected Bell 206s must check and, if necessary, correct electrical grounding, adjust hose/clamping/boost pump position, verify/install a fuel restrictor and filter, and add a periodic maintenance task for filter cleaning. These measures are intended to reduce the combined risk of arcing-induced fire and engine flameout tied to purge‑hose configurations and missing parts (restrictor/filter)."},"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":4,"scope_assessment":{"changed":true,"description":"The original directive was a simple one-time grounding inspection and hose disconnection. Through three amendments, it has expanded into a comprehensive fuel system modification program involving: electrical inspections, mechanical repositioning, mandatory parts installation (restrictor and filter), and ongoing maintenance program amendments. The applicability was also broadened from specific model suffixes to a serial number range to capture converted aircraft."},"complexity_factors":["Multiple compliance deadlines with different triggering conditions (hours-based vs calendar-based)","References to external technical documents (Alert Service Bulletin 206-05-103 and its revisions) without reproducing their content","Conditional applicability based on serial number ranges and model conversions","Nested revision history requiring understanding of Amendments 1 and 2 to fully grasp Amendment 3's purpose","Cross-reference to Canadian aviation authority (Transport Canada AD CF-2005-10R3) for additional context","Five distinct technical requirements with different compliance methods and approved alternative standards"],"plain_english_summary":"This mandatory CASA Airworthiness Directive applies to Bell 206 helicopters (serial numbers up to 5305) and requires five fuel‑system safety modifications and related maintenance updates to prevent fuel‑tank arcing/explosion and fuel‑starvation engine flameout. It affects owners and operators and fixes grounding and hose‑contact risks while adding a fuel‑flow restrictor, filter, and recurring inspection to resolve a low‑fuel flameout issue. Compliance deadlines are set within upcoming 100‑hour checks or by 22 Dec 2007."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-206-158-amdt-3-fuel-distribution-system","history":"/api/acts/ad-bell-206-158-amdt-3-fuel-distribution-system/history","analysis":"/api/acts/ad-bell-206-158-amdt-3-fuel-distribution-system/analysis","conflicts":"/api/acts/ad-bell-206-158-amdt-3-fuel-distribution-system/conflicts","importantCases":"/api/acts/ad-bell-206-158-amdt-3-fuel-distribution-system/important-cases","documents":"/api/acts/ad-bell-206-158-amdt-3-fuel-distribution-system/documents"}}