{"id":"F2007L01556","name":"AD/DAUPHIN/46 Amdt 2 - Main Rotor Gearbox Suspension Diagonal Cross-Member","slug":"ad-dauphin-46-amdt-2-main-rotor-gearbox-suspension-diagonal-cross-member","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":66049,"registerId":"commonwealth-F2007L01556-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Eurocopter SA 360 and SA 365 (Dauphin) S","sectionType":"division","heading":"Eurocopter SA 360 and SA 365 (Dauphin) Series Helicopters","content":"### Eurocopter SA 360 and SA 365 (Dauphin) Series Helicopters\n\n| AD/DAUPHIN/46 Amdt 2 | Main Rotor Gearbox SuspensionDiagonal Cross-Member | 7/2007 |\n| -------------------- | -------------------------------------------------- | ------ |\n\n| Applicability: | Model AS 365 N, N1, and N2 helicopters equipped with main rotor gearbox suspension diagonal cross-members, part number 365A38-3023-20, -21, -22, -23,and -24.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Action in accordance with paragraph 2.B of Eurocopter AS 365 N Alert Service Bulletin No. 05.00.37 Revision 2, or later EASA approved revision.If a crack is detected, before further flight, remove and replace the diagonal brace cross-member in accordance with paragraph 2.B.3.a of the Requirement document.If the complete failure of the diagonal cross-member is detected, before further flight, remove and replace the diagonal cross-member and perform the checks in accordance with paragraph 2.B.3.b of the Requirement document.Note: EASA AD 2007-0129 refers.                                                                                                                                                                                                                                                                                                                        |\n| Compliance:    | 1. Perform an initial check of the centre portion of the main rotor gearbox diagonal cross-member as specified in the Requirement document, unless already accomplished:a. Upon the accumulation of 15,000 flight cycles for AS 365 N and N1 helicopters, and upon the accumulation of 11,000 flight cycles for AS 365 N2 helicopters; or,b. Within 50 flight hours or 250 flight cycles after 16 July 2003, whichever occurs first; for cross-members that have logged more than 15,000 flight cycles on AS 365 N and N1 helicopters, and for cross-members that have logged more than 11,000 flight cycles on AS 365 N2 helicopters.2. Following the initial check performed at the times specified in Compliance 1, repeat thereafter at intervals not to exceed 50 flight hours or 250 flight cycles, whichever occurs first.The compliance times remain unchanged by this issue of the Directive. |\n|                | This Amendment becomes effective on 5 July 2007.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |\n\n| Background: | The manufacturer received a report of a cracked main rotor gearbox suspension diagonal cross-member.Amendment 1 introduced changes to compliance times.Amendment 2 is issued in response to a new EASA AD, which introduces certain check requirements when complete failure of the diagonal cross-member occurs. |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n16 May 2007","sortOrder":0},{"sectionNumber":"AD/DAUPHIN/46 Amdt 2","sectionType":"part","heading":"AD/DAUPHIN/46 Amdt 2","content":"## AD/DAUPHIN/46 Amdt 2","sortOrder":1},{"sectionNumber":"Main Rotor Gearbox SuspensionDiagonal Cr","sectionType":"part","heading":"Main Rotor Gearbox SuspensionDiagonal Cross-Member","content":"## Main Rotor Gearbox Suspension  \nDiagonal Cross-Member","sortOrder":2},{"sectionNumber":"7/2007","sectionType":"part","heading":"7/2007","content":"## 7/2007","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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific mechanical failure mode in a defined aircraft fleet. The amendment history shows incremental refinement (compliance time adjustments in Amendment 1, additional failure-mode procedures in Amendment 2) rather than scope creep. The directive remains tightly focused on the diagonal cross-member inspection and replacement requirements as originally intended."},"complexity_factors":["Multiple conditional compliance paths based on helicopter model (N/N1 vs N2) and accumulated flight cycles","Dual measurement units for recurring inspections (flight hours OR flight cycles, whichever occurs first)","Cross-reference to external technical document (Eurocopter Alert Service Bulletin 05.00.37 Rev 2) for actual inspection procedures","Nested conditional requirements: different actions required depending on whether crack vs complete failure is detected","Effective date and amendment history tracking (Amendment 2) with reference to previous amendments and European EASA AD","Specific part number applicability list (5 variants: -20 through -24)"],"plain_english_summary":"Owners and operators of Eurocopter Dauphin AS365 N/N1/N2 helicopters (with certain main rotor gearbox suspension cross-members) must perform recurrent inspections of the cross-member and replace it if cracked or failed.  \n\nThis mandatory CASA AD aims to prevent main-rotor separation after a manufacturer-reported crack and aligns with the related EASA directive, adding requirements for handling complete cross-member failures."},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"Amendment 2 extends the directive to incorporate check requirements and specific actions when complete failure of the diagonal cross-member occurs, citing a new EASA AD (Background; Requirement). It does not alter the recurring inspection intervals introduced earlier (Compliance)."},"complexity_factors":["Technical specificity: exact helicopter models and multiple part numbers listed (Applicability).","Conditional compliance timing: different initial thresholds by model (15,000 cycles for N/N1; 11,000 for N2) and an alternate short-term window tied to 16 July 2003 (Compliance).","Recurring inspection intervals with two metrics (50 flight hours or 250 flight cycles) create tracking and scheduling burdens (Compliance).","Safety-critical immediate actions: 'before further flight' mandatory removal and replacement if crack or complete failure is found, increasing operational disruption risk (Requirement).","Dependence on external documents: actions must follow Eurocopter Alert Service Bulletin Rev 2 or later EASA‑approved revision and refer to an EASA AD, adding coordination and version-control complexity (Requirement; Background).","Amendment history: prior amendment changed compliance times and this amendment adds checks for complete failure, requiring operators to track evolving directives (Background)."],"plain_english_summary":"Requires operators of AS 365 N, N1 and N2 helicopters fitted with diagonal cross-member part numbers 365A38-3023-20 to -24 to inspect the centre of the main-rotor gearbox diagonal cross-member at specified flight-cycle/hour intervals and to remove-and-replace it before further flight if cracked or if complete failure is detected (Requirement; Compliance). Issued by CASA referencing Eurocopter service information and an EASA AD, it imposes recurring inspection duties, immediate replacement obligations, and associated operator costs and aircraft downtime."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dauphin-46-amdt-2-main-rotor-gearbox-suspension-diagonal-cross-member","history":"/api/acts/ad-dauphin-46-amdt-2-main-rotor-gearbox-suspension-diagonal-cross-member/history","analysis":"/api/acts/ad-dauphin-46-amdt-2-main-rotor-gearbox-suspension-diagonal-cross-member/analysis","conflicts":"/api/acts/ad-dauphin-46-amdt-2-main-rotor-gearbox-suspension-diagonal-cross-member/conflicts","importantCases":"/api/acts/ad-dauphin-46-amdt-2-main-rotor-gearbox-suspension-diagonal-cross-member/important-cases","documents":"/api/acts/ad-dauphin-46-amdt-2-main-rotor-gearbox-suspension-diagonal-cross-member/documents"}}