{"id":"F2006L01164","name":"AD/DAUPHIN/84 - Main Rotor Hub-to-Main Rotor Mast Bolted Attachment","slug":"ad-dauphin-84-main-rotor-hub-to-main-rotor-mast-bolted-attachment","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":58568,"registerId":"commonwealth-F2006L01164-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/84 | Main Rotor Hub-to-Main RotorMast Bolted Attachment | 6/2006 TX |\n| ------------- | -------------------------------------------------- | --------- |\n\n| Applicability: | Model SA 365 N, and N1 helicopters, Model AS 365 N2 and N3 helicopters, and Model SA 365 C, C1, C2, and C3 helicopters; delivered before 27 March 2006, and equipped with a main rotor hub-to-main rotor mast (MRH/mast) bolted attachment assembled by Eurocopter.                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. On MRH/mast assemblies affected by Applicability section of this Directive, and having logged less than 280 flight hours:Check the tightening torque of the MRH/mast assembly attachment bolts, in accordance with paragraph 2.B. of Eurocopter AS 365N Alert Service Bulletin (ASB) No. 62.00.22, or SA 365 C ASB No. 65.44, as applicable.2. On MRH/mast assemblies affected by Applicability section of this Directive, and having logged more than 280 flight hours:Check the tightening torque of the MRH/mast assembly attachment bolts, in accordance with paragraph 2.B. of Eurocopter AS 365N ASB No. 62.00.22, or SA 365 C ASB No. 65.44, as applicable.Note: EASA Emergency AD 2006-0084-E refers. |\n| Compliance:    | 1. Within 300 flight hours after 13 April 2006.2. Within 20 flight hours after 13 April 2006.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |\n|                | This Airworthiness Directive becomes effective on 13 April 2006.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |\n| Background:    | Several reports were received of tightening torque loss detected on the main rotor hub-to-main rotor mast bolted attachment on Eurocopter assembled attachments with less than 300 operating hours. A loss of tightening torque can lead to deterioration of the MRH/mast attachment and possible loss of the main rotor.                                                                                                                                                                                                                                                                                                                                                                                        |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n12 April 2006","sortOrder":0},{"sectionNumber":"AD/DAUPHIN/84","sectionType":"part","heading":"AD/DAUPHIN/84","content":"## AD/DAUPHIN/84","sortOrder":1},{"sectionNumber":"Main Rotor Hub-to-Main RotorMast Bolted ","sectionType":"part","heading":"Main Rotor Hub-to-Main RotorMast Bolted Attachment","content":"## Main Rotor Hub-to-Main Rotor  \nMast Bolted Attachment","sortOrder":2},{"sectionNumber":"6/2006 TX","sectionType":"part","heading":"6/2006 TX","content":"## 6/2006 TX","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive applies to Eurocopter‑assembled MRH/mast bolted attachments on listed Dauphin models delivered before 27 March 2006 and mandates torque checks per the referenced Eurocopter ASBs. The text mirrors the emergency safety focus described and does not indicate any expansion or narrowing of scope beyond the specified models, delivery cutoff, and assembly origin."},"complexity_factors":["Applicability limited to multiple specific models and variants (identifying eligible airframes)","Delivery date cutoff (before 27 March 2006) narrows affected population","Two-tier compliance timing linked to logged flight hours (<280 vs >280) increases administrative tracking","Mandated use of specific Eurocopter Alert Service Bulletins for the inspection procedure","Cross-reference to an EASA Emergency AD (external regulatory source)","Technical requirement to measure tightening torque and record results (requires appropriate tools and maintenance competence)","Compliance deadlines tied to an effective date (13 April 2006) and expressed in flight hours, not calendar time"],"plain_english_summary":"Requires operators of specified Eurocopter Dauphin helicopters (SA 365 N/N1, AS 365 N2/N3, SA 365 C/C1/C2/C3) delivered before 27 March 2006 and fitted with Eurocopter‑assembled main rotor hub‑to‑mast bolted attachments to check the tightening torque of those attachment bolts. Checks must follow the named Eurocopter Alert Service Bulletins and be done within set flight‑hour windows (shorter window if the assembly has logged more than 280 hours) to address reported torque loss and reduce the risk of main rotor separation."},"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 AD maintains its original narrow scope — addressing a specific mechanical defect in specific helicopter models. It has not expanded beyond its original safety purpose of addressing the main rotor hub-to-mast bolt torque issue."},"complexity_factors":["Short, single-purpose document (approximately 300 words)","Only 2 main requirements with clear flight-hour thresholds","Simple conditional logic based on logged flight hours (280 hour threshold)","Cross-reference to external technical documents (Eurocopter Service Bulletins) rather than reproducing complex procedures in the AD itself","Minimal defined terms (only standard aviation terminology like 'MRH/mast')","Clear compliance deadlines with specific dates and flight hour limits","No nested exceptions or complex sub-clauses"],"plain_english_summary":"This AD orders urgent torque checks of the bolted main rotor hub-to-mast assembly on certain Eurocopter SA‑365 Dauphin helicopters delivered before 27 Mar 2006 with the original Eurocopter assembly, after reports bolts are losing preload and risking main rotor separation in flight.  \n\nChecks must be done promptly: within 300 flight hours for helicopters under 280 hours, and within 20 flight hours for those over 280 hours (from 13 Apr 2006)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dauphin-84-main-rotor-hub-to-main-rotor-mast-bolted-attachment","history":"/api/acts/ad-dauphin-84-main-rotor-hub-to-main-rotor-mast-bolted-attachment/history","analysis":"/api/acts/ad-dauphin-84-main-rotor-hub-to-main-rotor-mast-bolted-attachment/analysis","conflicts":"/api/acts/ad-dauphin-84-main-rotor-hub-to-main-rotor-mast-bolted-attachment/conflicts","importantCases":"/api/acts/ad-dauphin-84-main-rotor-hub-to-main-rotor-mast-bolted-attachment/important-cases","documents":"/api/acts/ad-dauphin-84-main-rotor-hub-to-main-rotor-mast-bolted-attachment/documents"}}