{"id":"F2008L04479","name":"AD/ECUREUIL/119 Amdt 2 - Engine Controls - Twist Grip Assembly","slug":"ad-ecureuil-119-amdt-2-engine-controls-twist-grip-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":76499,"registerId":"commonwealth-F2008L04479-current","compilationNumber":null,"startDate":"2026-04-02","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/119 Amdt 2 | Engine Controls - Twist Grip Assembly | 13/2008 |\n| ---------------------- | ------------------------------------- | ------- |\n\n| Applicability: | EUROCOPTER EC 130 B4 helicopters, all serial numbers fitted with:- twist grip assemblies part numbers (P/N) 350A27520900, 350A27520901, 350A27520902 or 350A27520903 on the pilot's side with serial numbers (S/N) below 64.- twist grip assemblies P/N 350A27521201 on the co-pilot side with S/N below 11 and between 22 and 66 (inclusive).- twist grip assemblies P/N 350A27521201 on the co-pilot side with S/N from 11 to 21 (inclusive) and no letter “V” on the lever base.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Replace the drive tube in co-pilot twist grip assembly P/N 350A27521201 with S/N from 11 to 21 (inclusive) and no letter “V” on the lever base in accordance with paragraph 2.B. of EUROCOPTER EC 130 ASB No. 76A002.2. In autorotation training, the manoeuvre must be carried out until the helicopter touches down (full autorotation).3. Do not install a twist grip assembly P/N 350A27521201 with S/N from 11 to 21 (inclusive) and no letter “V” on the lever base on a helicopter, unless the drive tube has been replaced and the collective lever marked in accordance with paragraphs 2.B.2. and 2.B.3. of EUROCOPTER EC 130 ASB No. 76A002.4. Do not install twist grip assemblies P/N 350A27520900, 350A27520901, 350A27520902 and 350A27520903 with S/N below 64 on the pilot's side or twist grip assembly P/N 350A27521201 with S/N below 11 and between 22 and 66 (inclusive) on the co-pilot’s side, unless the bonding between the control pinion and the drive tube has been checked in accordance with paragraph 2.B.3. of EUROCOPTER EC 130 ASB No. 76A001 Revision 1 before installation on a helicopter.The use of later approved revisions of these documents is acceptable for compliance with the requirements of this AD.Note: EASA AD 2008-0184 dated 6 October 2008 refers. This AD supersedes EASA AD 2006-0079. |\n| Compliance:    | For Requirement 1 - Within 110 flight hours or 9 months after the effective date of this AD, whichever occurs first, unless previously accomplished.For Requirement 2 - Pending replacement of the twist grip drive tube as detailed in Requirement 1 of this AD.For Requirement 3 - After the effective date of this AD.For Requirement 4 - Before installation on a helicopter after the effective date of this AD.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n|                | This Amendment becomes effective on 18 December 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n| Background:    | This AD was issued following a case experienced during an autorotation training procedure during which the engine remained at idle rating although the twist grip had been turned back to the flight position.Analysis has revealed failure of the twist grip drive tube and control pinion bonded attachment due to non-compliant surface preparation.Amendment 1 corrected a typographical error in Requirement 3 of this AD. The statement should have read “paragraph 2.B.3” instead of “paragraph 2.8.3”. There were no changes to the compliance periods.This amendment requires the replacement of certain twist grips and to check other twist grips before installation.Amendment 1 of this AD became effective on 3 August 2006.The original issue of this AD became effective on 6 July 2006.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n6 November 2008","sortOrder":0},{"sectionNumber":"AD/ECUREUIL/119 Amdt 2","sectionType":"part","heading":"AD/ECUREUIL/119 Amdt 2","content":"## AD/ECUREUIL/119 Amdt 2","sortOrder":1},{"sectionNumber":"Engine Controls - Twist Grip Assembly","sectionType":"part","heading":"Engine Controls - Twist Grip Assembly","content":"## Engine Controls - Twist Grip Assembly","sortOrder":2},{"sectionNumber":"13/2008","sectionType":"part","heading":"13/2008","content":"## 13/2008","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"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This remains a targeted safety directive addressing a specific mechanical defect in helicopter engine controls. The amendment history shows only technical corrections (typo fixes) and clarifications of compliance requirements, not expansion into new operational areas or aircraft types."},"complexity_factors":["Multiple overlapping part number and serial number ranges creating four distinct applicability categories","Four separate requirements with different compliance timelines (flight hours vs. calendar time vs. 'pending' vs. 'before installation')","Cross-references to external technical documents (EUROCOPTER EC 130 ASB No. 76A002 and 76A001 Revision 1) without reproducing their content","Nested conditional logic in Requirement 4 ('unless the bonding...has been checked')","Amendment history references (Amendment 1, original issue) that contextualise but don't alter current obligations","Specific manufacturing detail ('no letter \"V\" on the lever base') as a distinguishing criterion"],"plain_english_summary":"This AD requires operators of Eurocopter EC130 B4 helicopters to address a manufacturing defect in the twist-grip drive tube that can prevent engine power recovery during autorotation. For certain co‑pilot grips (serials 11–21 without a \"V\" mark) the drive tube must be replaced within 110 flight hours or 9 months, and some other grips must be inspected before installation.\n\nUntil replacement, autorotation training must be flown to touchdown; affected parts may not be installed unless repaired and properly marked."},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"The amendment stays within the original safety objective (correcting a bonding failure in twist‑grip assemblies). Amendment 1 corrected a typographical error only. Amendment 2 imposes targeted replacements and installation/inspection requirements for specific part and serial‑number combinations; it clarifies and extends corrective actions but does not broaden the AD’s purpose beyond addressing the identified bonding defect and preventing recurrence."},"complexity_factors":["Multiple part numbers (P/Ns 350A27520900, 350A27520901, 350A27520902, 350A27520903, 350A27521201) to track","Several overlapping serial‑number ranges with conditional rules (e.g. S/N 11–21 with no letter “V”; S/N below 11; S/N between 22 and 66; S/N below 64)","Four distinct requirements with different triggers and compliance deadlines","Cross‑references to two Eurocopter ASBs (EC 130 ASB No. 76A002 and No. 76A001 Rev 1) for the technical procedures","Acceptance of later approved ASB revisions (adds versioning/approval dependency)","Operational proviso changing training practice (full autorotation until touchdown) while defect remains — mixes maintenance and operational requirements","Different compliance timing rules (110 flight hours or 9 months; immediate installation prohibition; before installation; pending condition)","Historical amendments (original AD, Amendment 1 typo correction, Amendment 2) create a short history that requires reading notes to understand changes"],"plain_english_summary":"**What this instrument does (plain English)**\n\n- This Airworthiness Directive (AD) orders specific inspections, checks, part replacements and installation restrictions for certain twist-grip assemblies (the throttle/collective twist control) fitted to EUROCOPTER EC 130 B4 helicopters. It is a safety directive: operators must correct or avoid particular suspect parts. (See Requirements 1–4.)\n\n**Who it affects**\n\n- Owners/operators of EUROCOPTER EC 130 B4 helicopters that have the listed twist-grip part numbers and serial-number ranges.\n- Maintenance organisations and parts suppliers who fit, check or replace those twist-grip assemblies.\n- Flight training organisations conducting autorotation training in affected helicopters while the defect is outstanding.\n\n**Mechanics — what you must do**\n\n- Requirement 1: Replace the drive tube in certain co‑pilot twist-grip assemblies (P/N 350A27521201 with S/N 11–21 that do not have a letter “V” on the lever base) in accordance with paragraph 2.B. of EUROCOPTER EC 130 Alert Service Bulletin (ASB) No. 76A002. (Compliance: within 110 flight hours or 9 months, whichever is first.)\n\n- Requirement 2: While the defective drive-tube condition remains uncorrected, autorotation training must be carried out to full touchdown (i.e. complete the autorotation to landing). (The AD treats this as a pending/temporary operational restriction until the replacement required in Requirement 1 is done.)\n\n- Requirement 3: You must not install a co‑pilot twist-grip assembly P/N 350A27521201 with S/N 11–21 and no “V” on the lever base on any helicopter unless the drive tube has been replaced and the collective lever has been marked as required by paragraphs 2.B.2 and 2.B.3 of ASB No. 76A002. (This restriction applies immediately after the AD’s effective date.)\n\n- Requirement 4: You must not install pilot-side twist-grip assemblies P/Ns 350A27520900/901/902/903 with S/Ns below 64, nor co‑pilot twist-grip P/N 350A27521201 with S/Ns below 11 or between 22 and 66 (inclusive), unless the bonding between the control pinion and drive tube has been checked as specified in paragraph 2.B.3 of EUROCOPTER EC 130 ASB No. 76A001 Revision 1. That check must be done before installation. (This is an installation‑time requirement.)\n\n- The AD accepts compliance using later approved revisions of the referenced ASBs.\n\n**Why it matters (source of the directive)**\n\n- The AD was issued after an autorotation‑training incident in which the engine stayed at idle even though the twist grip had been moved to the flight position. Investigation found failures in the bonded attachment between the drive tube and the control pinion caused by inadequate surface preparation during manufacture/repair. The AD aims to remove or inspect suspect parts and to place temporary operational limits until parts are corrected.\n\n**Who pays and who decides**\n\n- Operators/owners bear the direct costs (parts replacement, maintenance labour, downtime, and any training changes). Maintenance organisations do the work under the operator’s direction. CASA (via its Delegate) enforces compliance by issuing the AD; the work must be performed to the Eurocopter ASBs that the AD references.\n\n**Immediate incentives, costs and trade‑offs**\n\n- Incentives: operators are incentivised to replace or inspect suspect parts promptly to restore unrestricted operations and reduce training limitations.\n- Direct costs: parts procurement and maintenance labour, plus aircraft out‑of‑service time within the 110‑flight‑hour / 9‑month window (Requirement 1). If replacement parts are scarce, operators may face longer downtime or higher prices.\n- Administrative burden: identifying affected parts requires checking part numbers and serial numbers, recording the drive-tube replacement and marking the collective where required, and keeping the inspection records required by maintenance rules.\n- Market effects: maintenance shops and parts suppliers receive concentrated demand from affected operators. The AD reduces the pool of second‑hand twist‑grip assemblies that can be legally installed until they pass the specified checks, which may increase demand (and price) for inspected/modified units.\n\n**Implementation and compliance risk**\n\n- Availability risk: if replacement drive tubes or qualified maintenance slots are limited, operators may have to comply progressively within the time limit, potentially affecting scheduling.\n- Verification risk: effective compliance depends on correct execution of the ASB procedures (bonding checks, markings) and correct recording; the AD allows compliance via later approved ASB revisions, which reduces ambiguity but requires operators to ensure they use an approved revision.\n- Operational trade‑off: the temporary training requirement (full autorotation to touchdown during the defect window) changes training practice and may increase exposure to training risk or landing‑area constraints. The AD makes this a required operational mitigation until replacement is done.\n\n**Net effect on private choice and competition**\n\n- The AD constrains installation choices (certain serial‑numbered parts cannot be installed unless inspected/modified), which limits some aftermarket transactions until the parts are verified. It increases demand for compliant parts and for maintenance work but does not impose a permanent market restriction beyond the safety measures. The directive delegates the technical method of compliance to Eurocopter ASBs (so operators and MROs must follow manufacturer procedures).\n\n(References: Requirements 1–4 and compliance timing in the AD; inspection and replacement procedures referenced in EUROCOPTER EC 130 ASB Nos. 76A002 and 76A001 Rev 1.)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-ecureuil-119-amdt-2-engine-controls-twist-grip-assembly","history":"/api/acts/ad-ecureuil-119-amdt-2-engine-controls-twist-grip-assembly/history","analysis":"/api/acts/ad-ecureuil-119-amdt-2-engine-controls-twist-grip-assembly/analysis","conflicts":"/api/acts/ad-ecureuil-119-amdt-2-engine-controls-twist-grip-assembly/conflicts","importantCases":"/api/acts/ad-ecureuil-119-amdt-2-engine-controls-twist-grip-assembly/important-cases","documents":"/api/acts/ad-ecureuil-119-amdt-2-engine-controls-twist-grip-assembly/documents"}}