{"id":"F2005L01738","name":"AD/A330/20 Amdt 1 - Leading Edge Slat Type A Actuators","slug":"ad-a330-20-amdt-1-leading-edge-slat-type-a-actuators","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":35813,"registerId":"commonwealth-F2005L01738-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Airbus Industrie A330 Series Aeroplanes","sectionType":"division","heading":"Airbus Industrie A330 Series Aeroplanes","content":"### Airbus Industrie A330 Series Aeroplanes\n\n| AD/A330/20 Amdt 1 | Leading Edge Slat Type A Actuators | 8/2005 |\n| ----------------- | ---------------------------------- | ------ |\n\n| Applicability: | Airbus A330 series aeroplanes with leading edge slat rotary actuator Type A installed with Part Numbers (PN) 954A0000-01 or PN 954A0000-02 or PN 954B0000-01, but excluding Airbus A330 series aeroplanes on which Airbus modification 50138 or Service Bulletin (SB) A330-27-3100 or SB A330-27-3105 has been embodied.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | 1. With the exception of leading edge slat rotary actuators Type A that have not been subjected to Maintenance Review Board (MRB) task 27.80.00-07 “Lubrication of Slats Rotary Actuators”, carry out an inspection of the torque limiter assembly for grease contamination in accordance with the instructions of Airbus SB A330-27-3104 Revision 1; anda. should grease be found in the torque limiter during inspection, replace the rotary actuator; andb. should no grease be found in the torque limiter during inspection, repeat the inspection for grease contamination in accordance with the instructions of Airbus SB A330-27-3104 Revision 1.2. Should grease be found in the torque limiter during one of the repetitive inspections required by Requirement 1(b), replace the rotary actuator in accordance with the instructions of Airbus SB A330-27-3104 Revision 1.3. Discontinue use of MRB task 27.80.00-07 repetitive lubrication of rotary actuators Type A, Part Numbers (PN) 954A0000-01 or PN 954A0000-02 or PN 954B0000-01 in leading edge slat No.1 and remove that task from the aeroplane maintenance programme (AMM 12.22.27).4. Remove from service rotary actuators Type A PN 954A0000-01 or PN 954A0000-02 or PN 954B0000-01 and replace them with modified rotary actuators in accordance with SB A330-27-3100.The incorporation of SB A330-27-3105 is an acceptable means of compliance for the replacement of rotary actuators Type A PN 954B0000-01. |\n\n|             | Note 1. The inspection required by Requirement 1 only applies to Type A actuators that have been subjected to the referenced MRB task since aeroplane delivery. This MRB lubrication task is only scheduled from 5 years.Note 2: Rotary actuators Type B in leading edge slats are not affected by the deletion of this MRB repetitive lubrication task contained in Requirement 3.Note 3: DGAC AD F-2005-067 EASA approval No.3629 dated 20 April 2005 refers. This directive supersedes DGAC AD 2003-121(B).                                                                                                                                                                                          |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Compliance: | For Requirement 1, excluding 1(a) & (b): Remains unchanged as detailed in the original issue of this Directive as; unless previously accomplished, carry out within 1,000 flight hours after 7 August 2003. (The effective date of the original issue of this Directive.)For Requirement 1(a): Remains unchanged as detailed in the original issue of this Directive as, within 7,500 flight hours after 7 August 2003.For Requirement 1(b): At intervals not exceeding 7,500 flight hours.For Requirement 2: Not later than 2,500 flight hours after the required repetitive inspection.For Requirement 3: From the effective date of this Directive.For Requirement 4: At the latest by 30 June 2008. |\n|             | This Amendment becomes effective on 4 August 2005.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |\n| Background: | During a scheduled check on an A340 an excessive leak at the torque limiter output shaft seal of the rotary actuator Type A of leading edge slat No.1 was reported. Investigations by the supplier of the actuator found that parts of the torque limiter were totally contaminated with grease that had migrated from the power gear stage after re-greasing. Such contamination could cause the linkage drive to jam and lead to structural damage with a potential for loss of slat No1 leading edge. This AD is intended to prevent the possible loss of slat No1 leading edge.This amendment introduces a requirement to replace certain actuators with no change to the previous requirements.    |\n\n|     | The original issue of this AD became effective on 7 August 2003. |\n| --- | ---------------------------------------------------------------- |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n24 June 2005","sortOrder":0},{"sectionNumber":"AD/A330/20 Amdt 1","sectionType":"part","heading":"AD/A330/20 Amdt 1","content":"## AD/A330/20 Amdt 1","sortOrder":1},{"sectionNumber":"Leading Edge Slat Type A Actuators","sectionType":"part","heading":"Leading Edge Slat Type A Actuators","content":"## Leading Edge Slat Type A Actuators","sortOrder":2},{"sectionNumber":"8/2005","sectionType":"part","heading":"8/2005","content":"## 8/2005","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This amendment expands the original directive by adding a mandatory fleet modification requirement (Requirement 4) to remove and replace specified Type A rotary actuators with modified units by a fixed calendar deadline (30 June 2008). The original AD focused on inspection, repetitive inspections and stopping a lubrication MRB task; the amendment keeps those requirements and adds the longer‑term replacement obligation, thereby increasing the scope from inspection/maintenance changes to a fleet retrofit mandate. This change shifts some costs from recurring inspection/lubrication to a one‑off replacement programme and creates a firm compliance deadline for operators."},"complexity_factors":["Cross-references to three Airbus service bulletins (SB A330-27-3104 Rev 1, SB A330-27-3100, SB A330-27-3105) for procedures and acceptable means of compliance","Multiple conditional requirements (initial inspection, repeat inspections, replacement if grease found, discontinuation of MRB task, and eventual mandatory replacement of actuators)","Different compliance windows and intervals (1,000 fh, 2,500 fh, 7,500 fh, and a calendar deadline of 30 June 2008) creating layered timing rules","Applicability exclusions (aircraft with modification 50138 or specific SBs embodied are exempted)","Specificity of affected parts (three part numbers listed) requiring fleet-level parts tracking","Notes that limit the inspection requirement to actuators that have undergone a particular MRB task since delivery (adds an eligibility filter)","Amendment introduces an additional mandatory replacement requirement (new obligation layered onto existing AD text)"],"plain_english_summary":"**What this instrument does (mechanics)\n\n- Requires visual inspections of certain leading edge slat rotary actuators (Type A) on Airbus A330 aeroplanes for grease contamination in the torque limiter assembly, following the procedures in Airbus Service Bulletin (SB) A330-27-3104 Revision 1.\n- If grease is found in an inspected torque limiter, the actuator must be replaced. If no grease is found, the inspection must be repeated at the intervals specified (see timings below).\n- Stops (removes) a specific repetitive lubrication task (Maintenance Review Board task 27.80.00-07) from the aircraft maintenance programme for affected Type A actuators on leading edge slat No.1.\n- Requires permanent removal from service and replacement of specified Type A actuators (PN 954A0000-01, 954A0000-02, 954B0000-01) with modified actuators in accordance with SB A330-27-3100. SB A330-27-3105 is an acceptable alternative means of compliance for PN 954B0000-01.\n- Applies only to Airbus A330 series aeroplanes that have the specified Type A actuators installed, excluding aeroplanes that have already embodied Airbus modification 50138, SB A330-27-3100 or SB A330-27-3105.\n\n**Who is affected\n\n- Airline operators and maintenance organisations that operate Airbus A330 series aeroplanes with the listed Type A slat rotary actuator part numbers installed, unless the aeroplane already has the stated modification or service bulletin embodied.\n- Maintenance planners and engineers responsible for the aeroplane maintenance programme (AMM) and for compliance with airworthiness directives.\n\n**Key compliance timings (mechanical summary)\n\n- Initial inspection (Requirement 1 except 1(a) & 1(b)): within 1,000 flight hours after 7 August 2003 unless already done.\n- If grease is found and replacement is required under Requirement 1(a): replacement to be done within 7,500 flight hours after 7 August 2003.\n- Repetitive inspections (Requirement 1(b)): at intervals not exceeding 7,500 flight hours.\n- If replacement follows a repetitive inspection (Requirement 2): replacement not later than 2,500 flight hours after the repetitive inspection that triggered it.\n- The requirement to discontinue the MRB lubrication task (Requirement 3) takes effect from this Directive's effective date (4 August 2005).\n- Full replacement of the listed actuators with modified units (Requirement 4) must be completed by 30 June 2008.\n\n**Stated purpose and an operational test of that claim\n\n- The directive states its purpose is to prevent grease migration into the torque limiter of the actuator, which could jam the linkage and lead to structural damage or loss of the leading edge slat (source: background paragraph).\n- Costs and incentives: operators bear the direct costs (inspections, labour, parts, downtime) and must alter maintenance scheduling and the AMM (who pays: the operator; who decides how to schedule: the operator/maintenance organisation, subject to the AD and the referenced SB procedures).\n- Trade-offs and opportunity costs: removing a repetitive lubrication task reduces recurring maintenance actions but replaces that recurring cost with inspection costs and, ultimately, one-off actuator replacements for affected part numbers. If modified actuators are scarce or expensive, operators may face higher near-term costs and aircraft ground time.\n- Implementation risk: compliance depends on availability of replacement/modification parts and correct embodiment of the referenced SBs; clarity is required about which actuators have been ‘‘subjected to MRB task 27.80.00-07 since delivery’’ (the AD notes that this MRB task is scheduled from 5 years after delivery).\n- Compliance burden and discretion: maintenance organisations must follow Airbus SB A330-27-3104 Rev 1 for inspections and SB A330-27-3100 (or SB A330-27-3105 for one PN) for replacements. CASA (the regulator) enforces the AD; operators must record AMM changes and ensure inspections/replacements occur within the stated flight-hour limits.\n\n**Behavioural effects and distribution of costs/benefits\n\n- Behaviour change: stop periodic re-greasing (for the affected MRB task) on listed Type A actuators in slat No.1; add initial and repetitive inspections; replace contaminated actuators; and complete fleet modification by the deadline.\n- Concentration of effects: safety benefit is focused on preventing slat No.1 loss on affected aeroplanes (concentrated safety outcome); costs are concentrated on operators of affected A330s and potentially on third-party MROs performing the work.\n- Substitution and compliance options: incorporation of SB A330-27-3105 is explicitly accepted as an alternative for PN 954B0000-01; otherwise operators must follow the specified SBs and remove the MRB task from their AMM.\n\n**Practical points for operators (how to act)\n\n- Identify aircraft in fleet with the listed actuator PNs and whether modification 50138 or the listed SBs are already embodied.\n- Implement the inspection regime per SB A330-27-3104 Rev 1 within the specified flight-hour windows and record outcomes.\n- If grease contamination is found, replace the actuator per the relevant SB and log the work; if not found, continue repetitive inspections at or below the maximum interval.\n- Remove MRB task 27.80.00-07 from the AMM for affected Type A actuators on slat No.1.\n- Plan procurement and scheduling to meet the final replacement deadline (30 June 2008) for retrofit with the modified actuators.\n\n(References in requirements are to the Airbus service bulletins cited in the AD and to MRB task 27.80.00-07 as described.)"},"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 is an amendment to an existing Airworthiness Directive. The background states the amendment 'introduces a requirement to replace certain actuators with no change to the previous requirements.' The scope remains tightly focused on the specific mechanical fault in leading edge slat Type A actuators. It does not expand beyond the original safety purpose of preventing slat loss due to grease contamination."},"complexity_factors":["Multiple nested conditional requirements (Requirements 1, 1(a), 1(b), 2, 3, 4 with interdependencies)","Specific part number exclusions and inclusions (three PNs listed, plus two SBs and one modification as exclusions)","Cross-references to external Airbus Service Bulletins (SB A330-27-3104 Rev 1, SB A330-27-3100, SB A330-27-3105) and MRB task 27.80.00-07","Multiple compliance deadlines with different triggers (flight hours from specific dates, repetitive intervals, calendar date)","Exception to exception logic: Requirement 1 excludes actuators 'not subjected to' MRB task, creating a negative condition within a condition","Acceptable means of compliance alternative (SB A330-27-3105 for one specific PN only)"],"plain_english_summary":"This AD orders Australian operators of Airbus A330s with specified leading-edge slat rotary actuators (parts 954A0000-01, -02, or 954B0000-01) to address grease contamination that can jam the slat mechanism and risk structural failure. It applies unless the Airbus-approved modification/service bulletin is already installed.\n\nOperators must inspect the torque limiter for grease, immediately replace contaminated actuators, continue inspections every 7,500 flight hours if clean, cease the specified lubrication task, and replace all affected actuators by 30 June 2008."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a330-20-amdt-1-leading-edge-slat-type-a-actuators","history":"/api/acts/ad-a330-20-amdt-1-leading-edge-slat-type-a-actuators/history","analysis":"/api/acts/ad-a330-20-amdt-1-leading-edge-slat-type-a-actuators/analysis","conflicts":"/api/acts/ad-a330-20-amdt-1-leading-edge-slat-type-a-actuators/conflicts","importantCases":"/api/acts/ad-a330-20-amdt-1-leading-edge-slat-type-a-actuators/important-cases","documents":"/api/acts/ad-a330-20-amdt-1-leading-edge-slat-type-a-actuators/documents"}}