{"id":"F2005L02845","name":"AD/BELL 430/5 - Never-Exceed Speed - Instrumentation Change","slug":"ad-bell-430-5-never-exceed-speed-instrumentation-change","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":37856,"registerId":"commonwealth-F2005L02845-current","compilationNumber":null,"startDate":"2026-04-01","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 430/5 | Never-Exceed Speed - Instrumentation Change | 11/2005 |\n| ------------- | ------------------------------------------- | ------- |\n\n| Applicability: | Bell Helicopter Textron Canada (BHTC) Model 430 helicopters as follows:                                                                                                                                                                                                                 |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|                | a. Serial Number (S/N) 49001 through 49103, equipped with Overspeed Warning Kit, Part Number (P/N) 430-706-004-101 or 430-706-004-103.                                                                                                                                                  |\n|                | b. S/N 49001 through 49100, equipped with Single Automatic Flight Control System (AFCS) with Flight Director Kit, P/N 430-705-009-103, -105, -109,-111, -115 or -117; or P/N 430-705-011-109, -111, -121 or -123.                                                                       |\n|                | c. S/N 49001 through 49100 equipped with Dual AFCS with Flight Director Kit, P/N 430-705-011-103, -105, -115, -117, -125, -127, -129, -133, -135 or-137.                                                                                                                                |\n| Requirement:   | Helicopters Equipped with Overspeed Warning Kit - Unless already accomplished, carry out the following in accordance with Part 1 of BHTC Alert Service Bulletin (ASB) 430-05-35 dated 21 June 2005 or later revision approved by the Chief, Continuing Airworthiness, Transport Canada: |\n|                | Replace the VNE Overspeed Warning Computer, the pilot and co-pilot Airspeed Indicator, and the VNE Converter, and                                                                                                                                                                       |\n|                | Remove the decal, P/N 430-075-070-103, from below the pilot and co-pilot Airspeed Indicators.                                                                                                                                                                                           |\n|                | Helicopters Equipped with Single or Dual AFCS with Flight Director Kit - Unless already accomplished, carry out the following in accordance with Part 2 of BHTC ASB 430-05-35 or later revision approved by the Chief, Continuing Airworthiness, Transport Canada:                      |\n|                | Replace the AFCS Air Data Computer Adapter module, and                                                                                                                                                                                                                                  |\n|                | Remove the decal, P/N 430-075-070-101, from above the pilot and co-pilot horizontal situation indicator (HSI) display.                                                                                                                                                                  |\n|                | Note: Transport Canada AD CF-2005-30 refers.                                                                                                                                                                                                                                            |\n\n| Compliance: | No later than 31 July 2007.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|             | This Airworthiness Directive becomes effective on 27 October 2005.                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |\n| Background: | Transport Canada has received advice from BHTC that following cold weather testing to establish VNE values at cold temperatures (-40°C) it was determined that modification to the helicopter’s instrumentation is required. This modification affects the software in the VNE Overspeed Warning Computer (required for certain operations) and in the AFCS Air Data Computer. The changes in the VNE Overspeed Warning Computer also necessitate the replacement of the pilot and co-pilot Airspeed Indicator and the VNE Converter. |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n16 September 2005","sortOrder":0},{"sectionNumber":"AD/BELL 430/5","sectionType":"part","heading":"AD/BELL 430/5","content":"## AD/BELL 430/5","sortOrder":1},{"sectionNumber":"Never-Exceed Speed - Instrumentation Cha","sectionType":"part","heading":"Never-Exceed Speed - Instrumentation Change","content":"## Never-Exceed Speed - Instrumentation Change","sortOrder":2},{"sectionNumber":"11/2005","sectionType":"part","heading":"11/2005","content":"## 11/2005","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — a targeted safety modification for specific Bell 430 helicopter configurations based on cold weather testing findings. The instrument replacement requirement remains precisely bounded by serial numbers and equipment types."},"complexity_factors":["Multiple applicability categories based on serial number ranges and installed equipment (3 distinct configurations)","Cross-reference to external technical document (Bell Helicopter Alert Service Bulletin 430-05-35)","Specific part numbers referenced throughout (approximately 15 distinct P/Ns)","Conditional compliance language ('Unless already accomplished')","Reference to Canadian aviation authority (Transport Canada AD CF-2005-30) indicating harmonised international regulation"],"plain_english_summary":"This CASA Airworthiness Directive mandates replacement of certain flight instruments and computers that calculate/display the helicopter's never-exceed speed (VNE) on specified Bell 430 helicopters, after -40°C testing showed they can give incorrect speed indications in extreme cold.  \n\nIt affects owners/operators of Bell 430s with the listed overspeed or automatic flight control system configurations and must be completed by 31 July 2007."},"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD stays within its original, narrowly defined airworthiness purpose: it mandates instrument and software changes identified by cold-temperature testing to ensure correct VNE/overspeed indications. It does not expand into other airworthiness areas, operational restrictions, or unrelated equipment requirements; it delegates technical method to the manufacturer’s ASB as is standard practice."},"complexity_factors":["Applicability subdivided into three groups by serial number ranges and multiple specific part numbers (moderate conditionality)","Two distinct sets of required work (Part 1 for Overspeed Warning Kit, Part 2 for AFCS Flight Director Kits)","References an external document for procedures (BHTC ASB 430-05-35) and requires regulator approval of later revisions (cross-reference/delegation)","Several specific part numbers to replace and two specific decal part numbers to remove (detail but not legal complexity)","Fixed compliance deadline and effective date (simple temporal requirement)","Reference to another regulator’s AD (Transport Canada AD CF-2005-30) – single additional cross-reference"],"plain_english_summary":"**What this instrument requires (mechanics first)**\n\n- This Airworthiness Directive (AD) applies to specific Bell 430 helicopters by serial number and by the fitted kits listed (see Applicability). It requires replacing or modifying certain instruments and avionics modules, and removing two decals, according to Bell Helicopter Textron Canada (BHTC) Alert Service Bulletin (ASB) 430-05-35 (Parts 1 and 2) or a later Transport Canada–approved revision. (Requirement)\n\n- For helicopters fitted with the Overspeed Warning Kit (specified part numbers), the AD requires:\n  - Replace the VNE Overspeed Warning Computer (software/hardware), the pilot and co‑pilot airspeed indicators, and the VNE converter; and\n  - Remove the decal P/N 430-075-070-103 that sits below the airspeed indicators. (Requirement: Overspeed Warning Kit)\n\n- For helicopters fitted with the Single or Dual Automatic Flight Control System (AFCS) with Flight Director Kits (specified part numbers), the AD requires:\n  - Replace the AFCS Air Data Computer adapter module; and\n  - Remove the decal P/N 430-075-070-101 that sits above the pilot and co‑pilot horizontal situation indicator (HSI) display. (Requirement: AFCS/Flight Director)\n\n- Compliance must be completed no later than 31 July 2007. The AD became effective 27 October 2005. (Compliance / Effective Date)\n\n**Who is affected and who pays**\n\n- Affected parties: Operators (owners and managers) of Bell Helicopter Textron Canada (BHTC) Model 430 helicopters with the serial numbers and kits listed in the Applicability section. The AD lists three applicability groups by serial number range and installed kit part numbers. (Applicability)\n\n- Who pays: The operator bears the cost of purchasing replacement parts, arranging and paying for the installation work, and any aircraft downtime while work is done. BHTC supplies the ASB that specifies approved parts and installation instructions. Transport Canada is cited as the approving authority for ASB revisions. (Requirement / Background)\n\n**Why the change was ordered (stated reason)**\n\n- Transport Canada and BHTC determined, after cold-temperature testing to establish VNE (never-exceed speed) at −40°C, that instrumentation and software modifications were required to ensure correct VNE indication and overspeed warnings in cold conditions. That meant updates to the VNE Overspeed Warning Computer and the AFCS Air Data Computer, and replacement of associated airspeed indicators and the VNE converter. (Background)\n\n**How it works in practice**\n\n- The AD does not supply step-by-step procedures itself; it mandates compliance with the procedures published in BHTC ASB 430-05-35 (Part 1 for Overspeed Kit changes; Part 2 for AFCS changes) or a later revision that Transport Canada approves. The ASB will specify exact part numbers, installation steps, and any necessary tests. (Requirement / ASB reference)\n\n**Practical effects and operational consequences**\n\n- Operators must schedule and pay for the retrofits or replacements and remove the specified decals. That can cause aircraft downtime until work is completed.\n\n- The modifications change software and hardware that feed speed and overspeed indications. That can affect cockpit indications and may require verification flights or bench tests per the ASB.\n\n- The AD references Transport Canada AD CF-2005-30, so operators and maintainers should track any related or follow‑on directives or approvals from regulators. (Note)\n\n**Costs, incentives and trade-offs (mechanisms — not value judgements)**\n\n- Direct costs: purchase of replacement computers, airspeed indicators, converter, adapter modules; labor to install; inspections and functional tests per the ASB. These costs fall on operators. (Requirement)\n\n- Benefit allocation: The immediate safety/airworthiness effect (ensuring accurate VNE and overspeed warnings at cold temperatures) accrues to pilots, operators and passengers via more reliable instrumentation. The concentrated beneficiaries include parts suppliers and maintenance providers who sell/fit the mandated items. (Background / Requirement)\n\n- Implementation risk and timing: Compliance is mandatory by a fixed date. If parts are scarce or workshops are fully booked, operators risk non‑compliance or grounded aircraft. The AD defers detailed procedures to the ASB and to Transport Canada's approval of any ASB revisions, which focuses discretion on the manufacturer and the national regulator to define how the work is done. (Requirement / ASB reference)\n\n- Operational substitution effects: Replacing equipment and software can change cockpit behaviour (different alarm thresholds, different indications). Operators may need to update flight manuals, checklists or pilot briefing material to reflect the changed instruments (this is a likely operational step though not spelled out in the AD itself). (Background / Requirement)\n\n**Where to look for the installation detail**\n\n- The AD mandates following BHTC ASB 430-05-35 (Part 1 and Part 2) or any later revision approved by Transport Canada’s Chief, Continuing Airworthiness. The ASB contains the technical steps, torque values, test procedures and post‑installation verification. (Requirement)\n\n**Key citations in the AD text**\n\n- Applicability: serial numbers S/N 49001–49103 and specific P/Ns for Overspeed Warning Kit and AFCS Flight Director Kits. (Applicability)\n- Required actions: replace specified computers/indicators/adapters and remove two decals (Requirement).\n- Compliance date: 31 July 2007; effective 27 October 2005. (Compliance / Effective Date).\n- Rationale: cold‑temperature VNE testing at −40°C indicated instrumentation/software changes were needed. (Background)\n\n**Bottom line**\n\nOperationally, affected Bell 430 operators must have specific avionics and indicators replaced and specific decals removed by the ASB procedures before the compliance date. The declared purpose is to ensure accurate never‑exceed speed and overspeed warnings at very low temperatures; the practical costs are parts, labour and aircraft downtime paid by the operators, while the detailed installation steps and final approval rest with the manufacturer’s ASB and Transport Canada."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-430-5-never-exceed-speed-instrumentation-change","history":"/api/acts/ad-bell-430-5-never-exceed-speed-instrumentation-change/history","analysis":"/api/acts/ad-bell-430-5-never-exceed-speed-instrumentation-change/analysis","conflicts":"/api/acts/ad-bell-430-5-never-exceed-speed-instrumentation-change/conflicts","importantCases":"/api/acts/ad-bell-430-5-never-exceed-speed-instrumentation-change/important-cases","documents":"/api/acts/ad-bell-430-5-never-exceed-speed-instrumentation-change/documents"}}