{"id":"F2006B02445","name":"AD/ARRIEL/14 Amdt 1 - Centrifugal Impeller","slug":"ad-arriel-14-amdt-1-centrifugal-impeller","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41701,"registerId":"commonwealth-F2006B02445-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/ARRIEL/14 Amdt 1 - Centrifugal Impeller","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \n\nAIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/ARRIEL/14 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\nTurbomeca Turbine Engines \\- Arriel Series\n\nAD/ARRIEL/14\n\nAmdt 1\n\n  \nCentrifugal Impeller 6/2002\n\nApplicability: All Arriel 1D,1D1,1S, and 1S1 not incorporating Mod TU300 and Mod TU316A.\n\nRequirement: 1. Carry out Mod TU300; installation of a sleeve in the bleed valve boss as described in Turbomeca Service Bulletin (SB) No. 292 72 0261; and\n\n2. Carry out Mod TU316A; bonding of sleeve as described in Turbomeca SB No. 292 72 0275 Update 2\n\nNote: DGAC AD 2002-126(A) refers.\n\nCompliance: Unless previously accomplished; within 100 hours time in service or prior to 31 July 2002, whichever occurs first.\n\nThis amendment becomes effective on 13 June 2002.\n\nBackground: This Directive was originally issued to require the installation of a sleeve into the bleed valve boss. In service experience has shown the necessity to bond the sleeve in the bleed valve boss. This amendment mandates the incorporation of Mod TU316A to engines incorporating Mod TU300.\n\nThe original issue of this Airworthiness Directive became effective on 30 December 1999.\n\n![](image.002.png)  \n\nJames Coyne\n\nDelegate of the Civil Aviation Safety Authority 3 May 2002\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 22 May 2002.\n\n  \nPage 1 of 1","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment stays tightly within the original scope of the 1999 directive. It simply adds a second required modification (bonding the sleeve) based on in-service experience, without expanding to new engine models or creating new regulatory frameworks."},"complexity_factors":["Very short document (1 page)","Only 4 defined technical terms (Mod TU300, Mod TU316A, SB references, DGAC AD)","Simple conditional logic: applies only to engines without specific modifications","No nested exceptions or cross-references to other legislation","Clear, linear structure: Applicability → Requirement → Compliance → Background","Single compliance deadline with straightforward alternative ('whichever occurs first')"],"plain_english_summary":"This safety order updates a prior directive for Turbomeca Arriel helicopter engines, requiring owners/operators of Arriel 1D, 1D1, 1S or 1S1 engines (without TU300 or TU316A mods) to fit a metal sleeve in the bleed valve boss and bond it so it cannot work loose. The mandatory fix closes a known safety gap that could cause engine damage or failure and had to be completed within 100 flight hours or by 31 July 2002."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment expands the original AD's mechanics: the initial directive required installation of a sleeve (Mod TU300); this amendment additionally mandates bonding the sleeve (Mod TU316A). It therefore converts a single retrofit requirement into a two‑step mandatory modification for engines already incorporating Mod TU300 and for those still needing Mod TU300, within the stated compliance timeframe (100 hours TIS or by 31 July 2002)."},"complexity_factors":["Narrow technical scope — applies only to specific Turbomeca Arriel variants (1D, 1D1, 1S, 1S1)","Requires physical retrofit (installation and bonding) rather than paperwork or inspections","Relies on external technical documents (Turbomeca Service Bulletins No. 292 72 0261 and No. 292 72 0275 Update 2) for implementation details","Amendment changes prior directive (revokes and replaces AD/ARRIEL/14) — introduces interaction with earlier compliance actions","Time-limited compliance window (100 hours TIS or a calendar deadline) creates scheduling and operational constraints","Operational cost and downtime impact concentrated on affected engine owners/operators","Regulatory instruction issued by CASA delegate under CAR 1998 subregulation 39.1(1) — standard administrative process but with mandatory effect"],"plain_english_summary":"This Airworthiness Directive requires owners/operators of Turbomeca Arriel 1D/1D1/1S/1S1 engines (that do not already have Mod TU300 and Mod TU316A) to install a sleeve in the bleed‑valve boss (Mod TU300) and to bond that sleeve (Mod TU316A) following Turbomeca service bulletins. CASA issued the change after in‑service experience showed bonding was necessary. Affected operators must complete the work within 100 hours time in service or by 31 July 2002, whichever is sooner."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-arriel-14-amdt-1-centrifugal-impeller","history":"/api/acts/ad-arriel-14-amdt-1-centrifugal-impeller/history","analysis":"/api/acts/ad-arriel-14-amdt-1-centrifugal-impeller/analysis","conflicts":"/api/acts/ad-arriel-14-amdt-1-centrifugal-impeller/conflicts","importantCases":"/api/acts/ad-arriel-14-amdt-1-centrifugal-impeller/important-cases","documents":"/api/acts/ad-arriel-14-amdt-1-centrifugal-impeller/documents"}}