{"id":"F2007L02662","name":"AD/ARRIEL/25 Amdt 1 - Fuel Filter Drain Screw","slug":"ad-arriel-25-amdt-1-fuel-filter-drain-screw","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":68509,"registerId":"commonwealth-F2007L02662-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Turbomeca Turbine Engines - Arriel Serie","sectionType":"division","heading":"Turbomeca Turbine Engines - Arriel Series","content":"### Turbomeca Turbine Engines - Arriel Series\n\n| AD/ARRIEL/25 Amdt 1 | Fuel Filter Drain Screw | 10/2007 |\n| ------------------- | ----------------------- | ------- |\n\n| Applicability: | Turbomeca ARRIEL 2S1 and ARRIEL 2S2 turboshaft engines that have a Hydromechanical Unit (HMU) installed that was manufactured before8 December 2006 or repaired/overhauled by a Turbomeca approved repair centre before 8 December 2006.                                                                                                                                                                                                                      |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Replace the fuel filter drain screw with a new one and tighten to an effective torque of 6.5 Nm in accordance with Turbomeca Mandatory Service Bulletin 292 73 2824 or later approved revisions.Note: EASA AD 2007-0063 dated 08 March 2007 refers.                                                                                                                                                                                                           |\n| Compliance:    | Unless already accomplished, within 30 HMU operating hours after the effective date of this AD.                                                                                                                                                                                                                                                                                                                                                               |\n|                | This Amendment becomes effective on 27 September 2007.                                                                                                                                                                                                                                                                                                                                                                                                        |\n| Background:    | During assembly of the HMU it was discovered that the torque being applied to the screw was exceeding the material qualities of the screw. This could lead to failure of the screw allowing leakage of fuel potentially causing engine failure or fire.The current amendment of the AD corrects the EASA AD reference number only. The requirements and compliance schedule remain unchanged.The original issue of this AD became effective on 16 March 2007. |\n\n![](image.001.png)  \nCharles Lenarcic  \nDelegate of the Civil Aviation Safety Authority\n\n16 August 2007","sortOrder":0},{"sectionNumber":"AD/ARRIEL/25 Amdt 1","sectionType":"part","heading":"AD/ARRIEL/25 Amdt 1","content":"## AD/ARRIEL/25 Amdt 1","sortOrder":1},{"sectionNumber":"Fuel Filter Drain Screw","sectionType":"part","heading":"Fuel Filter Drain Screw","content":"## Fuel Filter Drain Screw","sortOrder":2},{"sectionNumber":"10/2007","sectionType":"part","heading":"10/2007","content":"## 10/2007","sortOrder":3}],"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The amendment does not change the substantive scope: it only corrects the EASA AD reference number. The AD's requirements (replace screw, torque to 6.5 Nm per Turbomeca service bulletin) and the compliance deadline (within 30 HMU operating hours) remain unchanged; the original AD was effective 16 March 2007 (Background)."},"complexity_factors":["Narrow applicability: applies only to ARRIEL 2S1 and 2S2 engines with HMUs manufactured or repaired before 8 December 2006 (Applicability).","Single, specific corrective action: replacement of the fuel filter drain screw and torque to 6.5 Nm (Requirement).","Dependence on a manufacturer document: compliance requires following Turbomeca Mandatory Service Bulletin 292 73 2824 or later revision (Requirement).","Short operational-time compliance window: must be done within 30 HMU operating hours after the AD's effective date (Compliance).","Safety rationale documented: risk of screw over-torque leading to material failure, fuel leakage, and potential engine failure or fire (Background).","Amendment limited to a reference correction: the amendment only corrects the EASA AD reference number; substantive requirements and timing remain unchanged (Background)."],"plain_english_summary":"This airworthiness directive requires replacing the fuel-filter drain screw on Turbomeca ARRIEL 2S1 and 2S2 engines whose Hydromechanical Units (HMUs) were manufactured or repaired before 8 December 2006, and tightening the new screw to 6.5 Nm in accordance with Turbomeca Mandatory Service Bulletin 292 73 2824. It seeks to prevent screw failure and fuel leakage that could cause engine failure or fire. Affected operators must complete the replacement within 30 HMU operating hours, incurring the parts, labour and operational time to do so."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a minor administrative amendment that corrects only the EASA AD reference number. The scope remains identical to the original March 2007 directive — it addresses the same safety issue, applies to the same engines, and maintains the same compliance requirements."},"complexity_factors":["Very short document (approximately 200 words)","Only 2 defined technical terms (HMU, Nm) with context provided","Single, unambiguous compliance requirement","No cross-references to other legislation beyond a single service bulletin reference","Simple conditional logic: only applies to engines with pre-December 2006 HMUs","No nested exceptions or sub-clauses"],"plain_english_summary":"This AD mandates replacing the fuel-filter drain screw on Turbomeca ARRIEL 2S1/2S2 engines with HMUs manufactured or repaired before 8 Dec 2006, tightening the new screw to 6.5 N·m per Turbomeca Service Bulletin 292 73 2824, within 30 operating hours from 27 Sep 2007. \n\nIt addresses overtightening that can damage the screw and cause fuel leaks, risking engine failure or fire. Amendment 1 only corrects a paperwork reference; the safety requirements remain unchanged."}},"importantCases":[],"_links":{"self":"/api/acts/ad-arriel-25-amdt-1-fuel-filter-drain-screw","history":"/api/acts/ad-arriel-25-amdt-1-fuel-filter-drain-screw/history","analysis":"/api/acts/ad-arriel-25-amdt-1-fuel-filter-drain-screw/analysis","conflicts":"/api/acts/ad-arriel-25-amdt-1-fuel-filter-drain-screw/conflicts","importantCases":"/api/acts/ad-arriel-25-amdt-1-fuel-filter-drain-screw/important-cases","documents":"/api/acts/ad-arriel-25-amdt-1-fuel-filter-drain-screw/documents"}}