{"id":"F2005L01356","name":"AD/BELL 206/154 Amdt 1 - Freewheel Aft Bearing Cap","slug":"ad-bell-206-154-amdt-1-freewheel-aft-bearing-cap","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":35164,"registerId":"commonwealth-F2005L01356-current","compilationNumber":null,"startDate":"2026-04-01","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 206/154 Amdt 1 | Freewheel Aft Bearing Cap | 7/2005 |\n| ---------------------- | ------------------------- | ------ |\n\n| Applicability: | Bell Helicopter Textron Canada (BHTC) model 206L-4 helicopters fitted with freewheel aft bearing cap P/N 406-040-509-101, serial numbers A-1833 throughA-1912.                                                                                                                                                                                                                                                                                                                                                                    |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Identify the aft bearing cap serial numbers for applicability in accordance with Part I of BHTC Alert Service Bulletin (ASB) 206L-04-129 Revision A dated 01 December 2004 or later revision approved by Transport Canada.2. Depending on the average engine start cycle count, rework the affected freewheel aft bearing caps in accordance with Part II or Part III of the ASB.3. Rework the freewheel assembly in accordance with Part IV of the ASB.Note: Transport Canada AD CF-2004-17 R1 dated 11 February 2005 refers. |\n| Compliance:    | 1. Within 7 days after the effective date of this Directive.2. Unless previously accomplished, within 50 flight hours after the effective date of this directive.3. Unless previously accomplished, within 300 flight hours after the effective date of this directive, but no later than 30 September 2005.                                                                                                                                                                                                                      |\n|                | This Amendment becomes effective on 7 July 2005.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |\n| Background:    | Due to an oversight during manufacturing, a lubrication channel to allow oil flow has not been machined into an identifiable batch of aft bearing caps. Omission of the lubrication channel may cause lack of lubrication and reduced durability. As a result, the freewheel unit may cease to function.Amendment 1 is issued in response to a revision of the related Transport Canada AD which places an ultimate life on affected freewheel assembly components that have operated with a defective aft bearing cap.           |\n\n|     | The original issue of this Airworthiness Directive became effective on 23 December 2004. |\n| --- | ---------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n27 May 2005","sortOrder":0},{"sectionNumber":"AD/BELL 206/154 Amdt 1","sectionType":"part","heading":"AD/BELL 206/154 Amdt 1","content":"## AD/BELL 206/154 Amdt 1","sortOrder":1},{"sectionNumber":"Freewheel Aft Bearing Cap","sectionType":"part","heading":"Freewheel Aft Bearing Cap","content":"## Freewheel Aft Bearing Cap","sortOrder":2},{"sectionNumber":"7/2005","sectionType":"part","heading":"7/2005","content":"## 7/2005","sortOrder":3}],"analysis":{"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"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This amendment expands the original directive by incorporating a revision from the related Transport Canada AD that places an \"ultimate life\" (a firm operational life limit) on freewheel assembly components that have operated with the defective aft bearing cap. In other words, beyond mandating immediate inspection and rework, the amendment adds a prescriptive life-limit for affected components—broadening the directive from a corrective rework action to also include a definitive operational-lifespan restriction for parts that experienced the defect. (Background)"},"complexity_factors":["Short, single-issue directive limited to one part number and a specific serial-number range (A-1833 to A-1912)","Cross-reference to manufacturer Alert Service Bulletin (ASB 206L-04-129) with four Parts (I–IV) that contain the technical steps","Cross-reference to Transport Canada AD CF-2004-17 R1 for life-limit requirement","Conditional branching: rework path depends on average engine start cycle count (choice between Part II or Part III)","Multiple, time-staggered compliance windows (7 days, 50 flight hours, 300 flight hours / hard calendar date)","No extensive defined-term list in the text, but reliance on external documents increases interpretive steps for operators"],"plain_english_summary":"This directive orders owners/operators of Bell 206L‑4 helicopters with freewheel aft bearing caps serial A‑1833–A‑1912 to inspect and, if fitted with the defective caps (missing a lubrication channel), follow Bell ASB 206L‑04‑129 rework instructions within short flight‑hour and calendar windows. CASA enforces it; operators pay for inspection, rework or replacement and downtime. The action restores lubrication, limits life of affected parts, and reduces risk of freewheel failure."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment remains tightly scoped to its original purpose: addressing the specific manufacturing defect in freewheel aft bearing caps. Amendment 1 does not expand the scope — it merely refines the compliance requirements by adding a life limit for components that operated with the defective part, based on updated technical data from Transport Canada. The applicability (specific helicopter model and part serial numbers) remains unchanged from the original December 2004 directive."},"complexity_factors":["Short, single-purpose directive with clear sequential compliance deadlines","Only 4 specific serial number ranges affected (A-1833 through A-1912)","References external technical document (BHTC Alert Service Bulletin 206L-04-129) for detailed procedures — main text defers to this rather than reproducing complex instructions","Simple conditional logic: compliance path depends on engine start cycle count (two branches: Part II or Part III of ASB)","No nested definitions or interpretation sections — only one technical term defined by reference (P/N 406-040-509-101)","Clear effective date and amendment history (original + Amendment 1)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires specific maintenance actions on certain Bell 206L-4 helicopters to prevent mechanical failure.\n\n**What it does:**\n- **Targets:** Bell 206L-4 helicopters with a specific faulty part — the \"freewheel aft bearing cap\" (a component in the helicopter's transmission system that allows the rotor to spin freely when the engine is disengaged).\n- **The problem:** Some bearing caps were manufactured without a crucial oil channel. Without lubrication, the freewheel unit could seize up, potentially causing loss of rotor control.\n- **What must happen:**\n  1. **Within 7 days:** Check if your helicopter has the affected part (serial numbers A-1833 through A-1912).\n  2. **Within 50 flight hours:** Rework or replace the bearing cap depending on how many times the engine has been started.\n  3. **Within 300 flight hours (or by 30 September 2005, whichever comes first):** Rework the entire freewheel assembly.\n\n**Who it affects:**\n- Owners and operators of specific Bell 206L-4 helicopters in Australia.\n- Maintenance engineers working on these aircraft.\n\n**Why it matters:**\nThis is a **flight safety critical** issue. A seized freewheel unit could lead to catastrophic loss of control. The directive is legally binding — operators cannot fly these helicopters without complying. This version (Amendment 1) updates the original December 2004 order to add a \"life limit\" (maximum usage time) for parts that ran with the defective bearing cap, based on new information from Canadian aviation authorities."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-206-154-amdt-1-freewheel-aft-bearing-cap","history":"/api/acts/ad-bell-206-154-amdt-1-freewheel-aft-bearing-cap/history","analysis":"/api/acts/ad-bell-206-154-amdt-1-freewheel-aft-bearing-cap/analysis","conflicts":"/api/acts/ad-bell-206-154-amdt-1-freewheel-aft-bearing-cap/conflicts","importantCases":"/api/acts/ad-bell-206-154-amdt-1-freewheel-aft-bearing-cap/important-cases","documents":"/api/acts/ad-bell-206-154-amdt-1-freewheel-aft-bearing-cap/documents"}}