{"id":"F2005L03925","name":"AD/ECUREUIL/115 - Tail Rotor Drive Shaft Rivets","slug":"ad-ecureuil-115-tail-rotor-drive-shaft-rivets","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":39747,"registerId":"commonwealth-F2005L03925-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Eurocopter AS 350 (Ecureuil) Series Heli","sectionType":"division","heading":"Eurocopter AS 350 (Ecureuil) Series Helicopters","content":"### Eurocopter AS 350 (Ecureuil) Series Helicopters\n\n| AD/ECUREUIL/115 | Tail Rotor Drive Shaft Rivets | 1/2006 |\n| --------------- | ----------------------------- | ------ |\n\n| Applicability: | Eurocopter EC 130 B4 helicopters delivered before 1 January 2005.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Check that there are no cracks and no loose rivets in the tube-to-flange attachment of the tail rotor drive centre section shaft, and check the perpendicularity of bearing No. 1, in accordance with paragraph 2.B. of Eurocopter EC 130 Alert Service Bulletin (ASB) No. 65A002 dated16 November 2005 or later DGAC approved revisions.2. - If a crack or a loosened rivet is found, replace the tail rotor drive centre section shaft.- If the out-of-perpendicularity of the bearing is more than 0.1 mm, carry out the procedure described in paragraph 2.B.2. of ASB No. 65A002 or later DGAC approved revisions.Note: DGAC AD F-2005-190 EASA approval No. 2005-6410 dated 15 November 2005 refers. |\n| Compliance:    | 1. Within 50 flying hours or three months after the effective date of this AD, whichever occurs first.2. Before the next flight after the effective date of this AD.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |\n|                | This Airworthiness Directive becomes effective on 19 January 2006.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |\n| Background:    | There have been several cases of loosened rivets in the tube-to-flange attachment of the tail rotor drive centre section shaft. In one case, this loosening of rivets was associated with a crack in the tube which started from a loosened rivet hole. These occurrences can lead to failure of the tail rotor drive centre section shaft.                                                                                                                                                                                                                                                                                                                                                                   |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n30 November 2005","sortOrder":0},{"sectionNumber":"AD/ECUREUIL/115","sectionType":"part","heading":"AD/ECUREUIL/115","content":"## AD/ECUREUIL/115","sortOrder":1},{"sectionNumber":"Tail Rotor Drive Shaft Rivets","sectionType":"part","heading":"Tail Rotor Drive Shaft Rivets","content":"## Tail Rotor Drive Shaft Rivets","sortOrder":2},{"sectionNumber":"1/2006","sectionType":"part","heading":"1/2006","content":"## 1/2006","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD is narrowly focused on inspection and corrective action for loosened rivets and possible cracking at the tube-to-flange attachment of the tail rotor drive centre section shaft on EC 130 B4 helicopters delivered before 1 January 2005. It aligns with the stated original safety problem (loosened rivets leading to cracks and possible shaft failure) and does not expand the scope beyond that specific issue or affected fleet."},"complexity_factors":["Short document and narrowly targeted to one helicopter model and one component","Single referenced service bulletin (Eurocopter ASB No. 65A002) plus DGAC/EASA approvals — external cross-references but limited in number","Two simple conditional outcomes: (a) replace shaft if crack or loose rivet found; (b) carry out specified procedure if bearing perpendicularity > 0.1 mm","Two compliance timeframes (within 50 flying hours or 3 months; and a before‑next‑flight requirement), creating a small timing ambiguity that depends on reading the AD and ASB together","Technical measurement requirement (0.1 mm perpendicularity) requires precise measurement and introduces implementation nuance"],"plain_english_summary":"This AD requires owners/operators/maintenance organisations of Eurocopter EC130 B4 helicopters delivered before 1 Jan 2005 to inspect the tail-rotor drive centre section shaft (tube-to-flange rivets and bearing alignment) and to follow Eurocopter ASB No. 65A002 (or later DGAC-approved revisions). Cracked or loosened-rivet shafts must be replaced; bearing perpendicularity beyond 0.1 mm must be corrected per the ASB.\n\nInspections are mandated within 50 flight hours or three months (and with specified before-next-flight action). The aim is to prevent shaft failure and protect flight safety."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope. It targets a specific safety-critical defect in a specific helicopter model series with a defined manufacturing cutoff date. There is no evidence of scope creep; the directive remains tightly focused on the rivet and crack issue identified in the background."},"complexity_factors":["Single, specific mechanical component addressed (tail rotor drive shaft rivets)","Only one defined applicability criterion (delivery date before 1 January 2005)","Straightforward two-step compliance requirement with clear timeframes","Minimal cross-referencing (only to one manufacturer service bulletin and one French aviation authority document)","No nested exceptions or conditional logic beyond the standard 'if found, then repair/replace' structure","Short document (approximately 300 words of substantive content)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's aviation regulator (CASA) to fix a dangerous mechanical problem in specific helicopters.\n\n**What it does:**\nOrders owners and operators of **Eurocopter EC 130 B4 helicopters** (built before 1 January 2005) to urgently inspect the tail rotor drive shaft for cracks and loose rivets. The tail rotor is the small vertical rotor at the back of a helicopter that stops it from spinning in circles; if its drive shaft fails, the pilot loses control and the helicopter can crash.\n\n**Who must act:**\nAnyone who owns, operates, or maintains an affected EC 130 B4 helicopter.\n\n**What they must do:**\n- **Within 50 flying hours or 3 months** (whichever comes first): Inspect the tail rotor drive shaft's centre section for cracks and loose rivets, and check that a specific bearing is properly aligned.\n- **Immediately** (before next flight): If they find cracks, loose rivets, or misalignment beyond 0.1mm, they must either replace the shaft or follow specific repair procedures.\n\n**Why it matters:**\nSeveral helicopters had already experienced loose rivets in this part. In one case, a loose rivet led to a crack that could have caused the tail rotor to fail completely. This AD prevents potential catastrophic accidents by forcing inspections before the problem causes a crash.\n\n**Key terms explained:**\n- **Airworthiness Directive (AD):** A legally binding safety order from aviation regulators requiring specific maintenance actions.\n- **ASB (Alert Service Bulletin):** An urgent technical notice from the manufacturer describing a problem and how to fix it.\n- **DGAC:** The French aviation authority (Direction Générale de l'Aviation Civile), which approved the technical procedure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ecureuil-115-tail-rotor-drive-shaft-rivets","history":"/api/acts/ad-ecureuil-115-tail-rotor-drive-shaft-rivets/history","analysis":"/api/acts/ad-ecureuil-115-tail-rotor-drive-shaft-rivets/analysis","conflicts":"/api/acts/ad-ecureuil-115-tail-rotor-drive-shaft-rivets/conflicts","importantCases":"/api/acts/ad-ecureuil-115-tail-rotor-drive-shaft-rivets/important-cases","documents":"/api/acts/ad-ecureuil-115-tail-rotor-drive-shaft-rivets/documents"}}