{"id":"F2006B09306","name":"AD/EC 120/10 Amdt 1 - Flight Control Stop Screws","slug":"ad-ec-120-10-amdt-1-flight-control-stop-screws","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53406,"registerId":"commonwealth-F2006B09306-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/EC 120/10 Amdt 1 - Flight Control Stop Screws","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nOn the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/EC 120/10 and issues the following 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 EC 120 Series Helicopters\n\nAD/EC 120/10\n\nAmdt 1\n\n  \nFlight Control Stop Screws 9/2004\n\nApplicability: Model EC 120 B helicopters; delivered before 30 June 2003.\n\nComponents affected: roll, pitch, and collective flight control stops.\n\nRequirement: 1. Action in accordance with paragraph 2.B.1. of Eurocopter Alert Service Bulletin EC 120 No. 67A010 R2.\n\n2. Action in accordance with paragraph 2.B.2. of Eurocopter Alert Service Bulletin EC 120 No. 67A010 R2.\n\nNote: DGAC AD F-2003-322 R1 refers.\n\nCompliance: 1. Within 100 flight hours after 30 October 2003, unless already accomplished.\n\n2. Within 500 flight hours or 1 year after 30 October 2003, whichever occurs first. The compliance time remains unchanged by this issue.\n\nThis Amendment becomes effective on 2 September 2004.\n\nBackground: A report was received of an incident during a ground run-up with a Model EC 120 helicopter, where it was possible to push the collective lever downward beyond it’s normal position. Investigation revealed that the locknut of the low pitch stop had come loose and that the stop was out of adjustment. The worst case scenario is that of collective low pitch stop maladjustment, which can result in rotor under-speed in an auto-rotation situation.\n\nAmendment 1 is issued in response to a revision of the related DGAC AD, which introduces a revised Requirement document with no change to the technical content.\n\nEurocopter EC 120 Series Helicopters\n\nAD/EC 120/10 Amdt 1 (continued)\n\nThe original issue of this Airworthiness Directive became effective on 30 October 2003.\n\n![Signature of David Villiers, Delegate of the Civil Aviation Safety Authority.](image.002.png)  \n\nDavid Villiers\n\nDelegate of the Civil Aviation Safety Authority 13 July 2004\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 11 August 2004.","sortOrder":0}],"analysis":{"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 amendment explicitly states it introduces 'no change to the technical content' from the original 2003 directive. The scope remains precisely targeted at EC 120 B helicopters with specific delivery dates and specific flight control components. The amendment serves purely administrative harmonisation with the French DGAC directive revision."},"complexity_factors":["Very short document (approximately 400 words)","Only 3 defined structural sections (Applicability, Requirement, Compliance)","Single cross-reference to external technical document (Eurocopter Service Bulletin)","Simple conditional logic: two sequential actions with clear time-based triggers","No nested exceptions or sub-delegations","Straightforward amendment structure — explicitly states no technical change from original"],"plain_english_summary":"This AD mandates inspections and corrective action on flight control stop screws for Eurocopter EC120 B helicopters delivered before 30 June 2003, after a loose locknut allowed excessive collective down travel that could reduce rotor RPM during autorotation and cause loss of control. Amendment 1 (effective 2 Sept 2004) makes no technical changes—it merely aligns the AD with the revised French DGAC notice; the original compliance deadlines remain unchanged."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Amendment 1 does not broaden or narrow the set of helicopters or the technical requirements. The AD text states that the amendment was issued to align with a revised DGAC AD and that the revised Requirement document contains no change to the technical content. Compliance times, applicability and the actions to be performed remain the same as the original AD (original effective date 30 October 2003; this Amendment effective 2 September 2004)."},"complexity_factors":["Short, single-issue AD focused on flight control stop screws","One clear applicability condition: Model EC 120 B helicopters delivered before 30 June 2003","Three components listed (roll, pitch, collective) but treated together","Two compliance actions with two different deadlines (100 flight hours; 500 flight hours or 1 year)","Cross-reference to an external technical document (Eurocopter ASB EC 120 No. 67A010 R2) for procedural detail","Cross-reference to a foreign authority AD (DGAC AD F-2003-322 R1)","Amendment revokes previous AD and replaces the Requirement document, but states no change to technical content (adds a layer of administrative history)"],"plain_english_summary":"**What this instrument does, in plain terms**\n\n- This Airworthiness Directive (AD) requires owners/operators of certain helicopters to inspect and, if necessary, adjust the flight control stop screws (the limiters that stop roll, pitch and collective motion) on Eurocopter Model EC 120 B helicopters that were delivered before 30 June 2003 (see \"Applicability\" and \"Components affected\").\n\n- The AD tells operators to carry out the specific inspection and adjustment steps described in the manufacturer’s document: Eurocopter Alert Service Bulletin EC 120 No. 67A010 R2, paragraphs 2.B.1 and 2.B.2 (see \"Requirement\"). In other words, CASA does not set the technical steps itself — it makes compliance with the Eurocopter instructions mandatory.\n\n- Timing (\"Compliance\"): one set of actions must be done within 100 flight hours after 30 October 2003; the other set within 500 flight hours or 1 year after 30 October 2003, whichever is earlier. Those times were carried over unchanged by this amendment.\n\n- This Amendment (Amdt 1) revokes the earlier AD/EC 120/10 and issues the revised AD; the amendment states it incorporates a revised DGAC (French authority) AD document but does not change the technical requirements.\n\n**Why the AD was issued (background and safety rationale)**\n\n- The AD follows a report in which, during a ground run-up, the collective lever on an EC 120 could be pushed beyond its normal limit. Investigation showed a loosened locknut on the low-pitch stop and an out-of-adjustment stop.\n\n- The safety concern is that if the collective low-pitch stop is maladjusted, in an autorotation (engine-off descent) the rotor could under-speed, which is a hazardous condition for safe landing.\n\n**Who is affected and who pays**\n\n- Affected: owners/operators and maintenance organisations responsible for EC 120 B helicopters delivered before 30 June 2003 (Applicability).\n\n- Who pays: the operator/owner pays for labour, parts and downtime necessary to carry out the inspections/adjustments required by the Eurocopter service bulletin that the AD makes mandatory. If a maintenance organisation performs the work, its costs will be billed to the operator under normal maintenance contracting.\n\n**Who decides and what instructions apply**\n\n- CASA (through its delegate) issues and enforces the AD (signature block). The AD mandates compliance with the manufacturer’s Alert Service Bulletin (ASB) paragraphs specified; the ASB contains the detailed technical steps.\n\n**Practical effects and compliance burden**\n\n- Operators must obtain Eurocopter ASB EC 120 No. 67A010 R2, follow the paragraphs referenced, schedule maintenance within the stated flight-hour/time windows, and record compliance in the aircraft’s maintenance log.\n\n- The burden is the time to inspect and adjust three types of stops (roll, pitch, collective), any parts or replacement hardware needed (e.g. locknuts), and potential aircraft downtime while work is done.\n\n**Implementation risks and notes**\n\n- The AD relies on the ASB for technical content; operators need access to that document and to personnel trained to perform the work.\n\n- The AD cross-references a related DGAC AD (F-2003-322 R1). Amendment 1 states it adopted a revised Requirement document to align with the DGAC AD but did not change technical content, so operators should follow the latest ASB/AD version cited.\n\n**Mechanisms and incentives**\n\n- CASA uses regulatory force (an AD) to convert the manufacturer’s recommended actions into mandatory actions for the affected fleet. That shifts the cost of the corrective action to aircraft owners/operators and creates a compliance requirement enforced through maintenance records and continued airworthiness oversight.\n\n**Where to look in the AD for the mechanics**\n\n- Applicability: which helicopters are covered.\n- Components affected: roll, pitch and collective stops.\n- Requirement: references to Eurocopter ASB EC 120 No. 67A010 R2 (paragraphs 2.B.1 and 2.B.2).\n- Compliance: the two specific compliance windows (100 FH; 500 FH or 1 year).\n- Background: the incident and safety rationale.\n\n(Technical terms: \"AD\" = Airworthiness Directive, a mandatory safety order for aircraft; \"ASB\" = Alert Service Bulletin, a manufacturer’s technical instruction.)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-ec-120-10-amdt-1-flight-control-stop-screws","history":"/api/acts/ad-ec-120-10-amdt-1-flight-control-stop-screws/history","analysis":"/api/acts/ad-ec-120-10-amdt-1-flight-control-stop-screws/analysis","conflicts":"/api/acts/ad-ec-120-10-amdt-1-flight-control-stop-screws/conflicts","importantCases":"/api/acts/ad-ec-120-10-amdt-1-flight-control-stop-screws/important-cases","documents":"/api/acts/ad-ec-120-10-amdt-1-flight-control-stop-screws/documents"}}