{"id":"F2007L01400","name":"AD/DAUPHIN/91 - Main and Tail Rotors - Servo Controls","slug":"ad-dauphin-91-main-and-tail-rotors-servo-controls","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":65755,"registerId":"commonwealth-F2007L01400-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Eurocopter SA 360 and SA 365 (Dauphin) S","sectionType":"division","heading":"Eurocopter SA 360 and SA 365 (Dauphin) Series Helicopters","content":"### Eurocopter SA 360 and SA 365 (Dauphin) Series Helicopters\n\n| AD/DAUPHIN/91 | Main and Tail Rotors - Servo Controls | 6/2007 |\n| ------------- | ------------------------------------- | ------ |\n\n| Applicability: | Eurocopter SA 365 N and N1, AS 365 N2 and N3 helicopters that are fitted with GOODRICH main and tail rotor servo-controls without the letter “R” marked in the inspection box of the servo-control identification plate, and whose Part Number (P/N) and Serial Number (S/N) are listed in paragraph 1.A of Eurocopter Alert Service Bulletin (ASB) AS 365 No. 67.00.13.                                                                                                                                                                                                                                                                                                    |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Check for identification of the P/N and S/N of the servo-controls installed on helicopters and on the shelves listed in paragraph 1.A of Eurocopter ASB AS 332 No. 67.00.37 or later approved revisions.2. Remove from service those servo-controls identified as having P/N and S/N listed in paragraph 1.A of Eurocopter ASB AS 365 No. 67.00.13 or later approved revisions.3. Do not install servo-controls with P/N and S/N as listed in paragraph 1.A Eurocopter ASB AS 365 No. 67.00.13 unless they have returned to conformity as detailed in Eurocopter ASB AS 365 No. 67.00.13 or later approved revisions.Note: EASA AD 2007-0099 dated 11 April 2007 refers. |\n| Compliance:    | 1. Within 2 months from the effective date of this AD.2. Within 2 years from the effective date of this AD.3. From the effective date of this AD.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |\n|                | This Airworthiness Directive becomes effective on 7 June 2007.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n\n| Background: | This AD is in response to a manufacturing non-conformity found on one batch of servo-control cap P/N 800137. A defective servo-control may not stop the rotation of the distributor sleeve which could cause untimely movements of the servo-controls which are used on the main and anti-torque rotors. This can lead to loss of control of the helicopter. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n\n![](image.001.png)  \nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n26 April 2007","sortOrder":0},{"sectionNumber":"AD/DAUPHIN/91","sectionType":"part","heading":"AD/DAUPHIN/91","content":"## AD/DAUPHIN/91","sortOrder":1},{"sectionNumber":"Main and Tail Rotors - Servo Controls","sectionType":"part","heading":"Main and Tail Rotors - Servo Controls","content":"## Main and Tail Rotors - Servo Controls","sortOrder":2},{"sectionNumber":"6/2007","sectionType":"part","heading":"6/2007","content":"## 6/2007","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD is narrowly targeted at a specific manufacturing non-conformity in a batch of servo-control caps and limits action to servo-controls with the listed P/N and S/N and lacking a marking (the letter “R”). It enforces identification, removal from service and a prohibition on re-installation unless returned to conformity. These measures are consistent with the AD's stated safety purpose and do not expand the scope beyond correcting the identified defect."},"complexity_factors":["Short, focused AD with three discrete mandatory actions (identify, remove, prohibit installation)","Small number of concrete compliance times (2 months, 2 years, immediate ban)","Reliance on external documents (Eurocopter ASB AS 365 No. 67.00.13 and a shelf-inventory ASB reference), increasing cross-document checking","Identification rule depends on physical marking (absence of letter “R” in inspection box) plus matching P/N and S/N lists","Potential typographical or cross-reference ambiguity (Requirement 1 references AS 332 No. 67.00.37 for shelf lists while applicability calls up AS 365 No. 67.00.13)","No extensive conditional logic or multiple nested exceptions","Safety-critical technical detail inside the ASB (return-to-conformity instructions) not reproduced in the AD, requiring operators to consult the ASB"],"plain_english_summary":"**What this Airworthiness Directive (AD) does — the mechanics**\n\n- It requires operators, maintainers and parts holders of certain Eurocopter Dauphin helicopters to identify whether specific GOODRICH servo-controls (the hydraulic devices that move the main and tail rotor control surfaces) are installed or held in stock, and to remove the affected units from service. (Requirements 1–2)\n- It bans installing any servo-control listed in the referenced Eurocopter Alert Service Bulletin (ASB) unless that unit has been returned to conformity according to the ASB. (Requirement 3)\n\n**Who is affected**\n\n- Owners and operators of Eurocopter SA 365 N and N1, and AS 365 N2 and N3 helicopters that are fitted with GOODRICH main and tail rotor servo-controls that: (a) do not have the letter “R” marked in the inspection box on the servo-control identification plate, and (b) have Part Numbers (P/N) and Serial Numbers (S/N) listed in paragraph 1.A of Eurocopter ASB AS 365 No. 67.00.13. (Applicability)\n- Maintenance organisations, parts stores and anyone holding spare servo-controls on shelves must also check their inventory against the ASB lists. (Requirement 1)\n\n**Deadlines / compliance timing**\n\n- Identify and check installed units and shelf stock within 2 months of the AD’s effective date. (Compliance 1)\n- Remove affected servo-controls from service within 2 years of the AD’s effective date. (Compliance 2)\n- The prohibition on installing listed servo-controls (unless returned to conformity) applies immediately from the effective date. (Compliance 3)\n\n**Official reason (what the regulator says)**\n\n- A manufacturing non-conformity was found in a batch of servo-control cap P/N 800137. A defective servo-control may fail to stop the rotation of the distributor sleeve, which can produce untimely or unintended movements of the servo-control. Because those servo-controls operate main and anti-torque (tail) rotors, such untimely movements could lead to a loss of control of the helicopter. (Background)\n\n**Who pays, who decides, and what behaviour changes**\n\n- Operators and parts-holders pay: they must inspect helicopters and inventories, remove and replace affected parts, and arrange any required repair or return-to-conformity actions per Eurocopter ASB. (Requirements 1–3)\n- The regulator (Civil Aviation Safety Authority, via the AD) decides the mandatory action and timings; Eurocopter ASB provides the technical means (lists and repair/return instructions). (AD text + ASB references)\n- Behaviour changes: airlines/owners must ground or withdraw affected components from service once identified (subject to the 2-year removal window), must not install listed servo-controls unless they are repaired/returned to conformity, and must track and reconcile serial numbers on-service and in stock. (Requirements and Compliance)\n\n**Costs, incentives, trade-offs, and implementation risks**\n\n- Direct costs: inspection labour, possible helicopter downtime, cost of replacement servo-controls or repair work to return units to conformity, and administrative effort to check and document serial-number lists. (Requirements 1–3)\n- Incentives: operators have an incentive to prioritise checks on aircraft or spares that have the listed P/N/S/N to avoid unplanned in-service events and regulatory non-compliance. Suppliers/repair stations have an incentive to provide timely return-to-conformity work if they are authorised to do so.\n- Trade-offs and opportunity costs: scheduling inspections and replacements may displace other maintenance work and temporarily reduce fleet availability; operators holding affected spares may face immediate stock write-downs or repair costs.\n- Implementation risk depends on traceability: the AD relies on readable identification plates (the presence/absence of letter “R” in an inspection box) and accurate P/N/S/N lists in the Eurocopter ASB. If identification plates are worn or records are incomplete, the inspection and inventory reconciliation workload will increase and there is a risk of missed affected units.\n- Administrative risk / ambiguity: the AD cross-references specific Eurocopter ASBs for the lists and for the return-to-conformity procedure. Any discrepancies between the AD and the ASB lists, or typographical cross-references (see note below), can create confusion about which parts are subject to action and which ASB to consult.\n\n**Operational note / practical steps for operators**\n\n1. Obtain Eurocopter ASB AS 365 No. 67.00.13 (and any later approved revisions) and check paragraph 1.A for the exact P/N and S/N lists.\n2. Inspect aircraft servo-control identification plates for the listed P/N/S/N and for the absence of the letter “R” in the inspection box.\n3. Inspect spare parts inventories (shelves) against the ASB lists. The AD also references an ASB for shelf lists (see Requirement 1); operators should confirm the correct Eurocopter ASB number with the manufacturer if unclear.\n4. Remove affected units from service or arrange return-to-conformity per the ASB before any re-installation. (Requirements 2–3)\n\nNote: the AD refers to Eurocopter ASBs and lists, and also references an EASA AD for the related action. Operators should use the ASB lists and the approved return-to-conformity procedure to determine which specific serial numbers are affected and how to fix them."},"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":3,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific manufacturing defect in a specific batch of servo-controls on specific helicopter models. The reference to both AS 365 and AS 332 service bulletins appears to be a minor cross-reference error in the text (AS 332 is the Super Puma, not the Dauphin), but this does not expand the substantive scope beyond the stated Dauphin models."},"complexity_factors":["Single, specific technical subject matter (servo-control defect)","Clear three-step compliance requirement structure","Heavy reliance on external technical documents (Eurocopter Alert Service Bulletins AS 365 No. 67.00.13 and AS 332 No. 67.00.37) for part identification — operators must cross-reference these separately","Precise applicability criteria requiring visual inspection (absence of 'R' marking) and serial number matching","Multiple compliance timeframes (2 months, 2 years, immediate) creating conditional obligations","No defined terms section — assumes technical aviation knowledge","Short document length (approximately 300 words of substantive content)"],"plain_english_summary":"This AD requires owners/operators of Eurocopter SA365 N/N1/N2/N3 helicopters to identify, remove and replace certain GOODRICH main and tail rotor servo-controls (those lacking an “R” on the ID plate and matching parts/serials in the service bulletin). A batch defect can let the servo cap fail to stop rotating, risking sudden uncontrolled rotor movements and loss of control. Inspections and removals must meet specified deadlines (inspect within 2 months; remove within 2 years)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dauphin-91-main-and-tail-rotors-servo-controls","history":"/api/acts/ad-dauphin-91-main-and-tail-rotors-servo-controls/history","analysis":"/api/acts/ad-dauphin-91-main-and-tail-rotors-servo-controls/analysis","conflicts":"/api/acts/ad-dauphin-91-main-and-tail-rotors-servo-controls/conflicts","importantCases":"/api/acts/ad-dauphin-91-main-and-tail-rotors-servo-controls/important-cases","documents":"/api/acts/ad-dauphin-91-main-and-tail-rotors-servo-controls/documents"}}