{"id":"F2007L03910","name":"AD/BELL 222/44 - Disc Assemblies - Tail Rotor Driveshaft","slug":"ad-bell-222-44-disc-assemblies-tail-rotor-driveshaft","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":70556,"registerId":"commonwealth-F2007L03910-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Bell Helicopter Textron Canada (BHTC) 22","sectionType":"division","heading":"Bell Helicopter Textron Canada (BHTC) 222 Series Helicopters","content":"### Bell Helicopter Textron Canada (BHTC) 222 Series Helicopters\n\n| AD/BELL 222/44 | Disc Assemblies - Tail Rotor Driveshaft | 12/2007 DM |\n| -------------- | --------------------------------------- | ---------- |\n\n```html\n

Applicability:

Bell Helicopter Textron Canada (BHTC) Model 230 helicopters S/N up to 23038 fitted with disc assemblies part number (P/N) 36300-1, 37855-1 and C048354-1.

Requirement:

1. Verify disc assemblies P/N 36300-1, 37855-1 and C048354-1 for manufacturing date, proper thickness and indexing, in accordance with the instructions provided in BHTC Alert Service Bulletin (ASB) ASB-230-07-37 dated 28 March 2007 or later approved revisions.

If disc assemblies, after verification in accordance with Requirement 1, do not require any further action, or if the manufacturing date is not between 01 November 2005 and 30 November 2006, make an appropriate log book entry to this effect. No further action is required.

2. Remove any disc assembly which is not within the required thickness as per table below:

Disc Assembly P/N

Total Thickness

Minimum

Maximum

36300-1

0.174 inch (4.42 mm)

0.186 inch (4.75 mm)

37855-1

0.126 inch (3.20 mm)

0.138 inch (3.50 mm)

C048354-1

0.046 inch (1.16 mm)

0.051 inch (1.29 mm)

3. Remove any disc assembly which is not properly indexed.

4. Do not install any of the disc assemblies P/N 36300-1, 37855-1 and C048354-1 into any helicopter unless it is compliant to the ASB-230-07-37 dated 28 March 2007 or later approved revisions.

Note: Transport Canada Airworthiness Directive CF-2007-15 dated 24 August 2007 refers.

\n```\n\n| Compliance: | 1. Unless already accomplished, no later than 25 flight hours or 30 days from the effective date of this directive, whichever comes first.2. Within 10 flight hours, after the completion of requirement 1.3. Within 300 flight hours or at next scheduled inspection, whichever comes first, after the completion of requirement 1.4. After the effective date of this Airworthiness Directive. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| | This Airworthiness Directive becomes effective on 3 October 2007. |\n| Background: | Transport Canada has determined that disc assemblies part number (P/N) 36300-1, 37855-1 and C048354-1 manufactured between 1 November 2005 and 30 November 2006, may have discs of improper thickness or discs may have been indexed incorrectly. |\n\n![](image.001.png) \nDavid Villiers \nDelegate of the Civil Aviation Safety Authority\n\n28 September 2007","sortOrder":0},{"sectionNumber":"AD/BELL 222/44","sectionType":"part","heading":"AD/BELL 222/44","content":"## AD/BELL 222/44","sortOrder":1},{"sectionNumber":"Disc Assemblies - Tail Rotor Driveshaft","sectionType":"part","heading":"Disc Assemblies - Tail Rotor Driveshaft","content":"## Disc Assemblies - Tail Rotor Driveshaft","sortOrder":2},{"sectionNumber":"12/2007 DM","sectionType":"part","heading":"12/2007 DM","content":"## 12/2007 DM","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive's scope aligns with the stated safety concern: it targets specific disc assembly part numbers manufactured within the stated date range and fitted to defined helicopter serial numbers. It does not broaden applicability beyond those parts, dates and airframes identified in the source text."},"complexity_factors":["Narrow applicability by helicopter serial number and three specific part numbers reduces scope complexity (Applicability).","Technical measurement tolerances for total thickness require precise measurement and judgement (Requirement 2; table of minimum/maximum values).","Indexing correctness is a qualitative check that can require interpretation by maintenance staff (Requirement 3).","Multiple, short compliance windows create operational scheduling pressure (Compliance: 25 flight hours/30 days; 10 flight hours; 300 flight hours/next inspection).","Dependence on an external service bulletin for inspection/verification procedure concentrates discretionary technical detail in the ASB (Requirement 1, ASB-230-07-37).","Mandatory logbook entries impose a traceability/administrative burden on operators (Requirement 1 note on log book entry)."],"plain_english_summary":"This directive requires operators of certain Bell 230-series helicopters (S/N up to 23038) to inspect specific tail-rotor driveshaft disc assemblies (P/N 36300-1, 37855-1, C048354-1) per BHTC ASB-230-07-37 for manufacturing date, thickness and correct indexing, and to remove or not re-install non-compliant discs. It sets short mandatory compliance windows and logbook-entry requirements.\n\nOperators pay inspection, removal and replacement costs; maintenance personnel follow the ASB to decide compliance; the rule adds targeted inspections and record-keeping, concentrating costs on affected helicopters and parts."},"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":3,"scope_assessment":{"changed":false,"description":"This is a standard airworthiness directive with a clear, narrow safety purpose. It addresses a specific manufacturing defect in specific helicopter models during a defined time period. The scope remains tightly focused on the identified safety risk without expansion into broader operational or maintenance requirements."},"complexity_factors":["Multiple conditional requirements (if/then logic) based on manufacturing date and inspection results","Nested compliance deadlines (different timeframes for different requirements, some triggered by completion of previous requirements)","Specific technical measurements with dual unit systems (imperial and metric)","Cross-reference to external technical document (Bell Alert Service Bulletin ASB-230-07-37) which contains the actual inspection procedures","Reference to corresponding Canadian aviation directive (CF-2007-15) indicating harmonised international regulation","Three distinct part numbers with different thickness specifications requiring individual assessment"],"plain_english_summary":"Owners and operators of Bell Helicopter Textron Canada Model 230 (S/N up to 23038) fitted with disc assemblies P/N 36300-1, 37855-1, or C048354-1 must inspect those tail-rotor driveshaft discs per Bell ASB‑230‑07‑37 and record results. Assemblies manufactured 1 Nov 2005–30 Nov 2006 may be wrong thickness or mis‑indexed, risking driveshaft failure and loss of control; defective or improperly indexed discs must be removed and non‑compliant installations are prohibited (compliance deadlines apply)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-222-44-disc-assemblies-tail-rotor-driveshaft","history":"/api/acts/ad-bell-222-44-disc-assemblies-tail-rotor-driveshaft/history","analysis":"/api/acts/ad-bell-222-44-disc-assemblies-tail-rotor-driveshaft/analysis","conflicts":"/api/acts/ad-bell-222-44-disc-assemblies-tail-rotor-driveshaft/conflicts","importantCases":"/api/acts/ad-bell-222-44-disc-assemblies-tail-rotor-driveshaft/important-cases","documents":"/api/acts/ad-bell-222-44-disc-assemblies-tail-rotor-driveshaft/documents"}}