{"id":"F2006B08760","name":"AD/DAUPHIN/49 - MRH Spherical Thrust Bearings/Attach Beams Attachment Bolts","slug":"ad-dauphin-49-mrh-spherical-thrust-bearings-attach-beams-attachment-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52034,"registerId":"commonwealth-F2006B08760-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DAUPHIN/49 - MRH Spherical Thrust Bearings/Attach Beams Attachment Bolts","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nEurocopter SA 360 and SA 365 (Dauphin) Series Helicopters\n\nAD/DAUPHIN/49 MRH Spherical Thrust Bearings/Attach\n\nBeams Attachment Bolts\n\n  \n14/98\n\nApplicability: SA 365 helicopters, versions C, C1, C2, and C3, and AS 365 helicopters, versions N, N1, N2, and N3, fitted with main rotor head spherical thrust bearings/attach beam attachment bolts, all part numbers.\n\nRequirement: Check the tightening torque load of both the spherical thrust bearing/attach beam attachment bolts in accordance with the instructions specified in paragraph 2B of Eurocopter SA 365C Service Bulletin (SB) No. 05.22, or AS 365N SB No. 05.00.39, as applicable.\n\nIf the tightening torque is less than 12 m. daN:\n\nRemove the spherical thrust bearing and check for cracks. If a crack is found, replace the spherical thrust bearing.\n\nNote: DGAC AD 98-383-044(A) and AD 98-384-047(A) refer.\n\nCompliance: Initially, when the spherical thrust bearing attachment bolts are required to be removed, but at the latest before the accumulation of 550 flying hours after 31 December 1998; thereafter at intervals not to exceed 550 flying hours.\n\nThis Airworthiness Directive becomes effective on 31 December 1998.\n\nBackground: The DGAC requires the actions specified by this Directive in order to prevent the formation of cracks in the metal components of the spherical thrust bearings, due to increased stress resulting from possible loosening of the attachment bolts.","sortOrder":0}],"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 discrete, single-issue Airworthiness Directive addressing a specific mechanical defect (bolt torque and bearing cracks). It has not expanded beyond its original safety purpose."},"complexity_factors":["Short, single-purpose directive (approximately 200 words)","Only 4 defined/referenced documents (two service bulletins, two French DGAC ADs)","Simple conditional logic: one clear threshold (12 m.daN) with binary outcome","No nested exceptions or complex cross-referencing within the instrument itself","Technical terminology requires aviation engineering knowledge but is standard for the field","Compliance timeline uses straightforward 'whichever comes first' logic"],"plain_english_summary":"This Airworthiness Directive applies to certain Eurocopter Dauphin (SA/AS 365) helicopters and requires owners/operators to check the torque of two main-rotor-head bolts and inspect the associated spherical thrust bearings. Loose bolts can overstress bearings, causing cracks that could lead to catastrophic rotor failure. If torque is below the specified value, remove and inspect the bearing and replace if cracked. Initial and repeat inspections occur at specified maintenance intervals (550 flight hours)."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The Directive's scope aligns with its stated purpose: it limits obligations to specified Dauphin models fitted with the named attachment bolts and requires torque checks, conditional removal/inspection, and replacement where cracks are found. Compliance timing is explicitly prescribed (initial when bolts are removed or by 550 flying hours after 31 Dec 1998, then every 550 hours). No broader or additional airframe or system requirements are introduced beyond these checks and inspections."},"complexity_factors":["Technical measurement requirement: requires accurate torque checking to a numeric threshold (12 m.daN).","Conditional maintenance action: removal and crack inspection only if torque is below the threshold.","Recurring compliance schedule: initial check tied to bolt removal or a hard deadline (550 flying hours after 31 Dec 1998), then 550‑hour intervals.","Model-and-fitment specificity: applies only to SA 365 (C/C1/C2/C3) and AS 365 (N/N1/N2/N3) helicopters fitted with the specified bolts.","Reference to manufacturer service bulletins (paragraph 2B of Eurocopter SB No. 05.22 or SB No. 05.00.39) for procedural detail.","Cross-reference to foreign authority ADs (DGAC AD 98-383-044(A) and 98-384-047(A)) which informs the background and rationale."],"plain_english_summary":"This Airworthiness Directive requires operators of specified Eurocopter SA 365 and AS 365 Dauphin helicopters fitted with main-rotor spherical thrust bearing/attach beam attachment bolts to check the bolts' tightening torque and, if torque is under 12 m.daN, remove and inspect the spherical thrust bearing and replace it if cracked. The DGAC states the measure prevents cracking from bolt loosening. Operators pay for the torque checks, removals and any replacements; CASA fixes timing (initial when bolts are removed or by 550 flying hours after 31 Dec 1998, then every 550 hours)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dauphin-49-mrh-spherical-thrust-bearings-attach-beams-attachment-bolts","history":"/api/acts/ad-dauphin-49-mrh-spherical-thrust-bearings-attach-beams-attachment-bolts/history","analysis":"/api/acts/ad-dauphin-49-mrh-spherical-thrust-bearings-attach-beams-attachment-bolts/analysis","conflicts":"/api/acts/ad-dauphin-49-mrh-spherical-thrust-bearings-attach-beams-attachment-bolts/conflicts","importantCases":"/api/acts/ad-dauphin-49-mrh-spherical-thrust-bearings-attach-beams-attachment-bolts/important-cases","documents":"/api/acts/ad-dauphin-49-mrh-spherical-thrust-bearings-attach-beams-attachment-bolts/documents"}}