{"id":"F2013L01470","name":"AD/BELL 204/6 Amdt 13 - Main Rotor Mast and Trunnion - Retirement Index Number (RIN) Recount/Inspection","slug":"ad-bell-204-6-amdt-13-main-rotor-mast-and-trunnion-retirement-index-number-rin-recount-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":91279,"registerId":"commonwealth-F2013L01470-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Bell Helicopter Textron 204 Series Helic","sectionType":"division","heading":"Bell Helicopter Textron 204 Series Helicopters","content":"### Bell Helicopter Textron 204 Series Helicopters\n\n| AD/BELL 204/6 Amdt 13 | Main Rotor Mast and Trunnion - Retirement Index Number (RIN) Recount / Inspection | 16/2013 |\n| --------------------- | --------------------------------------------------------------------------------- | ------- |\n\n| Applicability: | Model 204B helicopter, with main rotor mast, part number 204-011-450-001, -007,-105, -113, or -119, or main rotor trunnion, part number 204-011-105-001, or -103, installed.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | For the main rotor mast and trunnion, determine the accumulated Retirement Index Number (RIN), inspect, and action in accordance with the technical requirements of FAA Emergency Airworthiness Directive 2000-15-52, Amendment 39-12042.Bell Helicopter Textron Alert Service Bulletin 204-00-51, dated 8 April 2000 approved by the United States Federal Aviation Administration (FAA) as an Alternative Method of Compliance (AMOC) to FAA AD 2000-15-52, Amendment 39-12042 is considered acceptable for compliance with the equivalent Requirement of this AD.                                                                                                                                                                              |\n| Compliance:    | From the effective date of this directive.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |\n|                | This Amendment becomes effective on 2 August 2013.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n| Background:    | Amendment 13 removes the requirement for retiring bolts connecting the Drive Link to Rotating Swashplate at 500 hours Time in Service (TIS). Current TIS of 1000 hours per Bell Helicopter Textron Maintenance and Overhaul Manual BHT-204B-M&O-1 is considered adequate. This amendment also makes reference to FAA AD 2000-15-52, Amendment 39-12042 for inspection of main rotor mast and trunnion. This amendment also notates the acceptability of an FAA approved AMOC for compliance with the equivalent requirement of this AD.Amendment 12 of this AD became effective on 10 August 2000 and was issued to require a specific life limitation for bolts connecting main rotor swashplate outer ring trunnions to swashplate drive links. |\n\n![](image.001.png)  \nMike Higgins  \nDelegate of the Civil Aviation Safety Authority\n\n26 July 2013","sortOrder":0},{"sectionNumber":"AD/BELL 204/6 Amdt 13","sectionType":"part","heading":"AD/BELL 204/6 Amdt 13","content":"## AD/BELL 204/6 Amdt 13","sortOrder":1},{"sectionNumber":"Main Rotor Mast and Trunnion - Retiremen","sectionType":"part","heading":"Main Rotor Mast and Trunnion - Retirement Index Number (RIN) Recount / Inspection","content":"## Main Rotor Mast and Trunnion \\- Retirement Index Number (RIN) Recount / Inspection","sortOrder":2},{"sectionNumber":"16/2013","sectionType":"part","heading":"16/2013","content":"## 16/2013","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"Amendment 13 modifies prior scope by removing a 500‑hour bolt retirement requirement, adopting a 1000‑hour practice per Bell’s manual, and explicitly aligning inspection/compliance with FAA AD 2000‑15‑52 while accepting FAA‑approved AMOCs (Background / Requirement)."},"complexity_factors":["Cross-reference to an external FAA airworthiness directive (FAA AD 2000-15-52) as the technical requirement increases legal/technical linkage (Requirement).","Acceptance of FAA‑approved Alternative Methods of Compliance (AMOC) introduces regulatory discretion and dependency on foreign authority approvals (Requirement / Background).","Change to a component life limit (removal of 500‑hour bolt retirement and adoption of 1000‑hour practice) alters maintenance planning, asset life accounting, and costs for operators (Background).","Parts‑and‑model specificity (Model 204B and enumerated part numbers) requires narrow applicability checks and record verification (Applicability).","Immediate compliance from the effective date limits lead time for operators to implement recounts, inspections and any corrective actions (Compliance).","Record‑keeping and RIN recount procedures can be technically detailed and may require specialist inspection, raising implementation and labour costs (Requirement).","Amendment history and prior conflicting requirements (Amendment 12 vs Amendment 13) increase interpretive complexity for maintenance organisations (Background)."],"plain_english_summary":"Mechanically, this directive requires operators of Bell 204B helicopters with specified main rotor mast or trunnion parts to recount the accumulated Retirement Index Number (RIN), perform inspections and corrective actions per FAA AD 2000-15-52, and permits compliance via an FAA‑approved AMOC. It removes the prior 500‑hour bolt retirement requirement and recognises a 1000‑hour practice in Bell’s maintenance manual. Affected operators pay for the inspections and any repairs; the regulator accepts FAA‑approved alternatives and operators must update RIN records and maintenance schedules."},"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 amendment remains tightly focused on its original purpose: ensuring the airworthiness of main rotor mast and trunnion components on Bell 204B helicopters. While Amendment 13 removes a secondary requirement (bolt retirement) and updates references to current FAA standards, this represents refinement rather than scope creep. The directive has not expanded to cover additional aircraft types, components, or operational scenarios beyond the original safety intent."},"complexity_factors":["Short, single-purpose directive (approximately 300 words of substantive content)","Only 6 specific part numbers referenced in applicability","Single primary requirement with one acceptable alternative compliance method (AMOC)","No nested definitions or interpretation sections","Clear cross-reference to external FAA document rather than reproducing technical standards internally","Simple effective date compliance (no phased or conditional timelines)"],"plain_english_summary":"This AD mandates tracking fatigue life (RIN) and FAA-standard inspections of main rotor mast and trunnion parts on Bell 204B helicopters with the specified part numbers, requiring corrective action if defects are found. It affects owners, operators and maintenance organisations and preserves critical inspections for flight‑critical components. The amendment drops the obsolete 500‑hour bolt retirement rule, aligning bolt life with the manufacturer/FAA (1,000 hours) while maintaining mast/trunnion safety measures."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-204-6-amdt-13-main-rotor-mast-and-trunnion-retirement-index-number-rin-recount-inspection","history":"/api/acts/ad-bell-204-6-amdt-13-main-rotor-mast-and-trunnion-retirement-index-number-rin-recount-inspection/history","analysis":"/api/acts/ad-bell-204-6-amdt-13-main-rotor-mast-and-trunnion-retirement-index-number-rin-recount-inspection/analysis","conflicts":"/api/acts/ad-bell-204-6-amdt-13-main-rotor-mast-and-trunnion-retirement-index-number-rin-recount-inspection/conflicts","importantCases":"/api/acts/ad-bell-204-6-amdt-13-main-rotor-mast-and-trunnion-retirement-index-number-rin-recount-inspection/important-cases","documents":"/api/acts/ad-bell-204-6-amdt-13-main-rotor-mast-and-trunnion-retirement-index-number-rin-recount-inspection/documents"}}