{"id":"F2013L01472","name":"AD/BELL 205/1 Amdt 33 - Main Rotor Mast and Trunnion - Retirement Index Number (RIN) Recount/Inspection","slug":"ad-bell-205-1-amdt-33-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":91281,"registerId":"commonwealth-F2013L01472-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Bell Helicopter Textron 205 Series Helic","sectionType":"division","heading":"Bell Helicopter Textron 205 Series Helicopters","content":"### Bell Helicopter Textron 205 Series Helicopters\n\n| AD/BELL 205/1 Amdt 33 | Main Rotor Mast and Trunnion - Retirement Index Number (RIN) Recount / Inspection | 16/2013 |\n| --------------------- | --------------------------------------------------------------------------------- | ------- |\n\n| Applicability: | Model 205A, 205A-1, and 205B helicopters, with main rotor mast, part number204-011-450-001, -007, -105, -113, or -119, or main rotor trunnion, part number204-011-105-001, 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 205-00-76, 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:    | This Airworthiness Directive mandates life limits and inspections for critical components, to prevent their failure in service from metal fatigue. Amendment 33 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 Manual BHT-205A1-MM-1 is considered acceptable. This amendment also notates the acceptability of an FAA approved AMOC for compliance with the equivalent requirement of this AD.Amendment 32 became effective on 9 August 2000 and was issued in response to a new FAA AD which was prompted by a report of another cracked main rotor mast. Metallurgical inspection revealed that the mast cracked as a result of fatigue in snap ring groove radii that were smaller than the 0.020 inch minimum allowable dimension. The FAA has concluded that several corrections to the RIN counting procedure are required based on a review of the fatigue data and previously issued Directives. |\n\n|     | The original issue of this Airworthiness Directive became effective on5 September 1968. |\n| --- | --------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nMike Higgins  \nDelegate of the Civil Aviation Safety Authority\n\n26 July 2013","sortOrder":0},{"sectionNumber":"AD/BELL 205/1 Amdt 33","sectionType":"part","heading":"AD/BELL 205/1 Amdt 33","content":"## AD/BELL 205/1 Amdt 33","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":6,"scope_assessment":{"changed":true,"description":"Amendment 33 narrows one prior retirement obligation by removing the 500‑hour retirement requirement for Drive Link to rotating swashplate bolts and accepts the 1,000‑hour interval in the Bell maintenance manual as compliant (Requirement; Background). It also explicitly records that an FAA‑approved AMOC (Bell Alert Service Bulletin 205‑00‑76) is acceptable for compliance (Requirement). The amendment therefore adjusts component retirement timing and clarifies acceptable compliance documents and RIN counting procedures."},"complexity_factors":["Cross‑reference to external FAA Emergency Airworthiness Directive 2000‑15‑52 and Bell Helicopter Textron Alert Service Bulletin 205‑00‑76 as the technical compliance standard (Requirement).","Technical counting and measurement procedure: RIN recount and corrections to the RIN counting procedure based on fatigue data, including a dimensional fatigue issue (snap ring groove radii < 0.020 inch) (Background).","Specific part‑number applicability for multiple mast and trunnion parts, requiring accurate parts identification in maintenance records (Applicability).","Change to retirement intervals for a subset of components (removal of 500 TIS bolt retirement; acceptance of 1,000 TIS per maintenance manual), creating potential record‑keeping and life‑limit transition work (Requirement; Background).","Administrative compliance timing: directive effective from the stated date and immediate compliance obligation (Compliance).","Acceptance of FAA‑approved Alternative Method of Compliance (AMOC) introduces regulatory equivalence and potential discretion in accepted compliance routes (Requirement)."],"plain_english_summary":"This Airworthiness Directive applies to Bell 205A, 205A‑1 and 205B helicopters with specified main rotor mast and trunnion part numbers. It requires operators to recount the Retirement Index Number (RIN), inspect the main rotor mast and trunnion, and take the actions set out in the referenced FAA Emergency AD and Bell Alert Service Bulletin. Amendment 33 also removes a prior 500‑hour retirement for certain swashplate bolts and accepts a 1,000‑hour retirement interval under the Bell maintenance manual."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":true,"description":"The original 1968 directive established basic life limits for the main rotor mast. Over 45 years and 33 amendments, the scope has expanded significantly: it now covers trunnions (added later), incorporates complex fatigue calculation methodologies (RIN counting), references foreign (FAA) regulatory frameworks, and includes alternative compliance pathways. The current version manages multiple component lifecycles (mast, trunnion, and historically bolts) rather than the single component originally regulated. The amendment process has turned this into a living document that tracks evolving engineering understanding of metal fatigue in these components."},"complexity_factors":["Heavy reliance on external documents: compliance requires cross-referencing FAA Emergency AD 2000-15-52 and Bell Helicopter Service Bulletin 205-00-76, neither of which are reproduced in the text","Technical aviation terminology throughout (RIN, TIS, AMOC, trunnion, snap ring groove radii) without glossary or explanation","Multiple nested applicability conditions: specific helicopter models AND specific part numbers for two different components","Amendment structure creates historical layering: references to Amendment 32, original 1968 issue, and background explaining what changed versus what remains","Dual compliance pathways: direct compliance with FAA AD OR compliance via approved AMOC alternative"],"plain_english_summary":"This AD orders operators of specified Bell 205A/205A‑1/205B helicopters to calculate accumulated fatigue life (RINs) and inspect the main rotor mast and trunnion, taking actions if defects are found. It also relaxes a previous 500‑hour bolt retirement to 1,000 hours and accepts FAA‑approved alternative compliance.\n\nIt targets owners of these vintage helicopters because mast/trunnion fatigue led to an in‑service crack; the measures prevent catastrophic rotor failure while refining retirement timing."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-205-1-amdt-33-main-rotor-mast-and-trunnion-retirement-index-number-rin-recount-inspection","history":"/api/acts/ad-bell-205-1-amdt-33-main-rotor-mast-and-trunnion-retirement-index-number-rin-recount-inspection/history","analysis":"/api/acts/ad-bell-205-1-amdt-33-main-rotor-mast-and-trunnion-retirement-index-number-rin-recount-inspection/analysis","conflicts":"/api/acts/ad-bell-205-1-amdt-33-main-rotor-mast-and-trunnion-retirement-index-number-rin-recount-inspection/conflicts","importantCases":"/api/acts/ad-bell-205-1-amdt-33-main-rotor-mast-and-trunnion-retirement-index-number-rin-recount-inspection/important-cases","documents":"/api/acts/ad-bell-205-1-amdt-33-main-rotor-mast-and-trunnion-retirement-index-number-rin-recount-inspection/documents"}}