{"id":"F2006B09396","name":"AD/ECUREUIL/93 - Collective Lever Lock","slug":"ad-ecureuil-93-collective-lever-lock","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53735,"registerId":"commonwealth-F2006B09396-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)  \n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 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\n![](image.001.png)  \n\nEurocopter AS 350 (Ecureuil) Series Helicopters","sortOrder":0},{"sectionNumber":"AD/ECUREUIL/93 Collective Lever Lock 13/","sectionType":"part","heading":"AD/ECUREUIL/93 Collective Lever Lock 13/2003","content":"# AD/ECUREUIL/93 Collective Lever Lock 13/2003\n\nDM\n\nApplicability: Model AS 350 helicopter versions B, BA, BB, B1, B2, B3, and D; fitted with the pilot collective lever locking system: Locks part number 350A77.1309.xx and 350A27.3155.20.\n\nRequirement: Check for wear on the collective lever lock by measuring dimension “C” on the collective lever, in accordance with paragraph 2.B.2 of Eurocopter AS 350 Alert Service Bulletin No. 67.00.27.\n\nIf dimension “C” is:\n\n    \\- Greater than 0.7mm; no further action is required.\n\n    \\- Between 0.7mm and 0.5mm; replace or turn the lock in accordance with paragraph 2.B.3 of the Requirement document, within 100 flight hours after measurement.\n\n    \\- Less than 0.5mm; before further flight, replace or turn the lock in accordance with 2.B.3 of the Requirement document.\n\nNote: DGAC AD 2003-406(A) refers.\n\nCompliance: Within 50 flight hours after 5 November 2003.\n\nThis Airworthiness Directive becomes effective on 5 November 2003.\n\nBackground: The DGAC requires certain actions in response to an incident where the collective lever unlocked, which resulted in unintentional takeoff and overturn. Investigation revealed excessive wear on the collective lever lock.\n\n![Signature of David Villiers, Delegate of the Civil Aviation Safety Authority.](image.002.png)  \n\nDavid Villiers\n\n![](image.001.png)Delegate of the Civil Aviation Safety Authority 31 October 2003","sortOrder":1}],"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":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope. It addresses a specific mechanical wear issue on a specific helicopter model's collective lever locking system, exactly as intended when issued. There is no evidence of scope creep or expansion beyond the original safety purpose."},"complexity_factors":["Single, discrete safety issue addressed (collective lever lock wear)","Only 2 specific part numbers in applicability","Clear measurement threshold with three unambiguous outcomes","No nested exceptions or conditional logic beyond the wear measurement","Short document (under 300 words) with minimal cross-referencing (only one referenced service bulletin and one French DGAC directive)","No defined terms section"],"plain_english_summary":"This CASA safety order requires operators of certain Eurocopter AS350s fitted with specified collective-lock parts to inspect and measure wear on the pilot’s collective-locking mechanism and take action based on wear limits to prevent unexpected unlocking. It responds to a crash caused by an unlocked collective and imposes urgent compliance (50 flight hours from Nov 2003) because the defect poses a serious, immediate flight-safety risk."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD is narrowly targeted to correct a specific unsafe condition identified after an incident (collective lever unlocking due to excessive wear). It confines obligations to specified AS 350 variants and two lock part-number series, and requires a single inspection plus remedial actions tied to measured wear. There is no expansion beyond those parts/models or addition of unrelated obligations; the directive therefore does not materially change or broaden the scope beyond its original safety-focused purpose (Applicability; Requirement; Background)."},"complexity_factors":["Short, single-issue directive focused on one component (collective lever lock)","List of specific helicopter models and two lock part-number series in the Applicability section","Single measurement parameter (dimension \"C\") with three clear threshold bands (>0.7 mm; 0.5–0.7 mm; <0.5 mm) and distinct required responses","Cross-reference to Eurocopter AS 350 Alert Service Bulletin No. 67.00.27 for measurement and remedial procedure (external document dependency)","Compliance deadline (within 50 flight hours after a specified date) plus a secondary scheduling window for mid-range wear (within 100 flight hours) — two time constraints","Reference to a foreign airworthiness directive (DGAC AD 2003-406(A)) — minor coordination complexity","No extensive defined-terms section, no multiple nested exceptions, and no ongoing reporting or record-keeping obligations"],"plain_english_summary":"**What this directive does (mechanical effect)\n\n- Requires operators of certain Eurocopter AS 350 (Ecureuil) helicopter models to inspect the pilot collective lever locking device (specified part numbers) and measure a wear dimension called \"C\". (Applicability; Requirement)\n- Sets three clear outcomes based on the measured value of dimension \"C\":\n  - If C > 0.7 mm — no action required.\n  - If 0.5 mm ≤ C ≤ 0.7 mm — the lock must be either replaced or \"turned\" (a remedial action described by the manufacturer) within 100 flight hours after the measurement.\n  - If C < 0.5 mm — the lock must be replaced or turned before the next flight. (Requirement)\n- Tells operators to carry out the measurement in accordance with Eurocopter AS 350 Alert Service Bulletin No. 67.00.27 (the manufacturer’s detailed procedure) and to comply within 50 flight hours after 5 November 2003. (Requirement; Compliance)\n\n**Who is affected\n\n- Owners and operators of Eurocopter AS 350 B, BA, BB, B1, B2, B3 and D helicopters that are fitted with collective lever locks having part numbers 350A77.1309.xx or 350A27.3155.20. (Applicability)\n- Maintenance providers who perform the inspection, measurement and the remedial action (replacement or turning) must follow the manufacturer’s service bulletin. (Requirement)\n\n**Why it matters (official rationale and practical consequences)\n\n- The directive is issued in response to an incident in which a collective lever unlocked in flight, causing unintentional takeoff and overturn; investigation found excessive wear on the collective lever lock. The directive is therefore targeted at correcting an identified unsafe condition. (Background)\n\n- Practical effects on operators:\n  - Direct compliance cost: time and labour to inspect and to measure dimension \"C\", and the cost of either turning or replacing the lock if it falls below the thresholds. (Requirement)\n  - Operational disruption: if a lock measures < 0.5 mm, the helicopter is grounded until the remedial action is done (safety-first immediate action). If between 0.5 mm and 0.7 mm, the operator has up to 100 flight hours to schedule the work. (Requirement; Compliance)\n  - Reliance on the manufacturer’s service bulletin for the measurement technique and the remedial procedure creates an operational dependency on that document and on availability of approved parts or qualified maintenance. (Requirement)\n\n**Who pays and who decides\n\n- Operators/owners pay for inspections and any parts or labour for turning or replacing the lock. (Requirement)\n- The Civil Aviation Safety Authority (CASA) delegate issued the directive; operators must follow it to meet regulatory airworthiness obligations. (front matter; Compliance)\n\n**Trade-offs, incentives and implementation risks\n\n- Trade-offs: the directive forces near-term inspection and remediation (safety benefit) at the cost of maintenance expense and possible downtime. The 100-flight-hour allowance for the mid-range measurement balances safety and operational flexibility but delays full replacement.\n- Incentives: operators are incentivised to inspect promptly and either turn or replace worn locks to avoid grounding or incidents. Turning (rather than replacing) reduces immediate cash costs and may extend service life, but could defer a full replacement and potentially increase future maintenance needs.\n- Implementation risks and uncertainties:\n  - Accurate measurement of dimension \"C\" depends on using the manufacturer’s measurement method (cross-referenced service bulletin). Different maintenance shops might interpret or execute the measurement with varying precision. (Requirement)\n  - Availability of spare locks or authorised services could affect how quickly operators can comply, especially where immediate replacement is required (< 0.5 mm). (Requirement)\n  - The AD references the DGAC (French authority) AD 2003-406(A), so international coordination or differences in service guidance may be relevant for operators using overseas resources. (Note)\n\n**Concrete references to the directive text**\n- Applicability: models and affected part numbers listed under \"Applicability\".\n- Required action and measurement thresholds: in \"Requirement\" (dimension \"C\" >0.7 mm, 0.5–0.7 mm, <0.5 mm and corresponding actions).\n- Compliance timing: \"Within 50 flight hours after 5 November 2003.\" (Compliance)\n- Background: incident and reason given under \"Background\".\n\nOverall, the instrument imposes a short, targeted inspection and remedial regime on a well-specified set of helicopters and part numbers to address a particular unsafe condition. It delegates technical detail to the Eurocopter service bulletin, sets tight time-limited compliance windows, and shifts the direct costs to operators while prescribing when and how safety-critical remediation must be done."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ecureuil-93-collective-lever-lock","history":"/api/acts/ad-ecureuil-93-collective-lever-lock/history","analysis":"/api/acts/ad-ecureuil-93-collective-lever-lock/analysis","conflicts":"/api/acts/ad-ecureuil-93-collective-lever-lock/conflicts","importantCases":"/api/acts/ad-ecureuil-93-collective-lever-lock/important-cases","documents":"/api/acts/ad-ecureuil-93-collective-lever-lock/documents"}}