{"id":"F2006B10232","name":"AD/GAZELLE/13 - Main Gearbox Input Gear Slotted Nut - Inspection","slug":"ad-gazelle-13-main-gearbox-input-gear-slotted-nut-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55890,"registerId":"commonwealth-F2006B10232-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/GAZELLE/13 - Main Gearbox Input Gear Slotted Nut - Inspection","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Eurocopter SA341 and SA342 (Gazelle) Series Helicopters\n\n \n\nAD/GAZELLE/13 Main Gearbox Input Gear Slotted Nut - Inspection\n\n\n5/83\n\n \n\nApplicability: All SA 341 and SA 342 models fitted with main gearbox Part No. 341A 32.1000.01 through 06 with the embodiment of Modification A.M.S. 07.70.76/S.374.\n\n \n\nDocument: SA 341-342 Service Bulletin 65-24.\n\n \n\nNote: For gearboxes not modified as above refer to AD/GAZELLE/9 and Service Bulletin 65.19.\n\n \n\nCompliance: Within 100 hours time in service after 31st May 1983 carry out the inspection as per the requirement document.\n\n \n\nBackground: The manufacturer has introduced an inspection method to ensure that the correct torque load had been applied to the slotted nut which retains the input gear flange.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in a specific aircraft type. It has not expanded beyond its original purpose of ensuring proper torque on the gearbox input gear slotted nut."},"complexity_factors":["Single, specific technical requirement (one inspection task)","Limited applicability (specific helicopter models, specific gearbox part numbers, specific modification status)","Clear compliance deadline (100 hours time in service after fixed date)","Only one cross-reference (to alternative directive AD/GAZELLE/9 for unmodified gearboxes)","No defined terms section, no conditional logic, no nested exceptions","Total length: approximately 150 words of substantive content"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft operators.\n\n**What it does:**\nOrders owners and operators of specific Eurocopter Gazelle helicopters (SA341 and SA342 models) to inspect a critical component — the slotted nut that holds the main gearbox input gear in place.\n\n**Who it affects:**\nAnyone operating Gazelle helicopters with specific main gearbox part numbers (341A 32.1000.01 through 06) that have been modified in a particular way (Modification A.M.S. 07.70.76/S.374).\n\n**What must be done:**\nWithin 100 hours of flying time after 31 May 1983, operators must carry out an inspection following the manufacturer's Service Bulletin 65-24. This inspection checks that the slotted nut was tightened to the correct torque (tightness) specification.\n\n**Why it matters:**\nThe gearbox input gear is crucial for transferring power from the engine to the rotor blades. If the retaining nut is improperly tightened, it could loosen in flight, leading to catastrophic gearbox failure and potential loss of the aircraft.\n\n**Note:** If your helicopter has a different gearbox configuration, a different directive (AD/GAZELLE/9) applies instead."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The instrument imposes a targeted inspection obligation on operators of specified gearboxes; the text does not indicate an expansion or contraction of scope beyond introducing that inspection requirement and referencing the applicable service bulletin."},"complexity_factors":["Narrow technical applicability: specific helicopter models and gearbox part numbers (Applicability).","Single, time-bound action: inspection required within 100 hours after a specified date (Compliance).","Dependence on an external technical document for the required procedure: SA 341-342 Service Bulletin 65-24 (Document).","Cross-reference to other directives for gearboxes without the modification (Note: AD/GAZELLE/9 and Service Bulletin 65.19).","Safety-critical mechanical inspection (Background) which may require trained personnel and downtime for operators."],"plain_english_summary":"This airworthiness directive requires operators of Eurocopter SA341 and SA342 helicopters fitted with main gearbox Part No. 341A 32.1000.01–06 with Modification A.M.S. 07.70.76/S.374 to inspect the main gearbox input gear slotted nut using the method in Service Bulletin 65-24 within 100 hours’ time in service after 31 May 1983. The inspection checks that the slotted nut received the correct torque; operators pay for and must carry out the check following the manufacturer’s procedure as mandated by the regulator."}},"importantCases":[],"_links":{"self":"/api/acts/ad-gazelle-13-main-gearbox-input-gear-slotted-nut-inspection","history":"/api/acts/ad-gazelle-13-main-gearbox-input-gear-slotted-nut-inspection/history","analysis":"/api/acts/ad-gazelle-13-main-gearbox-input-gear-slotted-nut-inspection/analysis","conflicts":"/api/acts/ad-gazelle-13-main-gearbox-input-gear-slotted-nut-inspection/conflicts","importantCases":"/api/acts/ad-gazelle-13-main-gearbox-input-gear-slotted-nut-inspection/important-cases","documents":"/api/acts/ad-gazelle-13-main-gearbox-input-gear-slotted-nut-inspection/documents"}}