{"id":"F2007L01430","name":"AD/AS 355/94 - Load Compensator Levers","slug":"ad-as-355-94-load-compensator-levers","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":65815,"registerId":"commonwealth-F2007L01430-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Eurocopter AS 355 (Twin Ecureuil) Series","sectionType":"division","heading":"Eurocopter AS 355 (Twin Ecureuil) Series Helicopters","content":"### Eurocopter AS 355 (Twin Ecureuil) Series Helicopters\n\n| AD/AS 355/94 | Load Compensator Levers | 7/2007 TX |\n| ------------ | ----------------------- | --------- |\n\n| Applicability: | AS 355 N and AS 355 F2 helicopters. |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Verify the part number (P/N) of the load compensator lever installed on the rotorcraft together with the P/N of the hydraulic actuator assembly as detailed in the accomplishment instructions of EUROCOPTER AS 355 Alert Service Bulletin (ASB) No. 67.00.29 revision 1, dated 27 April 2007 or later NAA approved revision.Note 1: Instead of inspecting the rotorcraft, a review of the helicopter maintenance records along with any other applicable data (rotorcraft logbook, Components list, etc...) is acceptable if each P/N can be positively determined from that review.2. When a P/N cannot be identified, do all actions as detailed in paragraph 2.B.2.of the accomplishment instructions of AS 355 ASB No. 67.00.29 revision 1 or later NAA approved revision to determine the relevant part numbers.3. For helicopters Pre-MOD 072065 (i.e. with hydraulic actuator assembly355A75-1370-01 or 355A75-1370-03) on which a compensator lever P/N 355A27-0082-00 is found.a. Provided the rotorcraft has not been operated with the lever P/N355A27-0082-00 installed, replace the lever with a lever P/N355A27-0072-00 as instructed in paragraph 2.B.3.a. of the accomplishment instructions of ASB No. 67.00.29 revision 1 or later NAA revision.b. If the rotorcraft has been operated with the lever P/N 355A27-0082-00 installed, do all actions as instructed in paragraph 2.B.3.b. of the accomplishment instructions of ASB No. 67.00.29 revision 1 or later NAA revision.4. For helicopters Post-MOD 072065 (i.e. with hydraulic actuator assembly 355A75-1370-02 or 355A75-1370-04) on which a compensator lever P/N 355A27-0072-00 is found. |\n\n| | a. Provided the rotorcraft has not been operated with the lever P/N355A27-0072-00 installed, replace the lever with a lever P/N355A27-0082-00 as instructed in paragraph 2.B.3.a. of the accomplishment instructions of ASB No. 67.00.29 revision 1 or later NAA revision.b. If the rotorcraft has been operated with the lever P/N 355A27-0072-00 installed, do all actions as instructed in paragraph 2.B.3.b. of the accomplishment instructions of ASB No. 67.00.29 revision 1 or later NAA revision.5. Do not install:- Load compensator lever P/N 355A27-0082-00 on any AS 355 N and F2 helicopters Pre-MOD 072065.(i.e. with hydraulic actuator assembly355A75-1370-01 or 355A75-1370-03 installed); or- Load compensator lever P/N 355A27-0072-00 on any AS 355 N and F2 helicopters Post-MOD 072065 (i.e. with hydraulic actuator assembly 355A75-1370-02 or 355A75-1370-04 installed).Note 2: EASA AD 2007-0131-E dated 11 May 2007 refers. |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Compliance: | 1. Before further flight, after the effective date of this AD.2. Before further flight, after the effective date of this AD.3. a. Before further flight, after the effective date of this AD.b. Within 10 flight hours after the effective date of this AD.4. a. Before further flight, after the effective date of this AD.b. Within 10 flight hours after the effective date of this AD.5. From the effective date of this AD. |\n| | This Airworthiness Directive becomes effective on 18 May 2007. |\n\n| Background: | This emergency AD is issued following a report of yaw control restricted travel in operation following the replacement of the load compensator. If not corrected, this condition could lead to the loss of control of the helicopter. Investigation revealed that the load compensator lever was incorrectly referenced in the Illustrated Parts Catalogue (IPC). Levers on helicopters Post-MOD 072065 (replacement of the load compensator hydraulic actuator) should be Part Number (P/N) 355A27-0082-00 and levers on helicopters Pre-MOD 072065 should be P/N 355A27-0072-00. This AD mandates inspection to identify the load compensator lever and the hydraulic actuator assembly installed on helicopters, to verify their compatibility and replacement of improper P/Ns when an incompatibility is found. |\n| ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png) \nCharles Lenarcic \nDelegate of the Civil Aviation Safety Authority\n\n15 May 2007","sortOrder":0},{"sectionNumber":"AD/AS 355/94","sectionType":"part","heading":"AD/AS 355/94","content":"## AD/AS 355/94","sortOrder":1},{"sectionNumber":"Load Compensator Levers","sectionType":"part","heading":"Load Compensator Levers","content":"## Load Compensator Levers","sortOrder":2},{"sectionNumber":"7/2007 TX","sectionType":"part","heading":"7/2007 TX","content":"## 7/2007 TX","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":6,"scope_assessment":{"changed":false,"description":"This AD remains tightly focused on its original emergency safety purpose: correcting a specific parts catalogue error affecting load compensator lever compatibility on AS 355 helicopters. The scope has not expanded beyond the immediate safety issue of ensuring correct part pairing to prevent yaw control failure."},"complexity_factors":["Multiple conditional branches based on modification status (Pre-MOD 072065 vs Post-MOD 072065)","Cross-referencing to external technical document (Eurocopter ASB No. 67.00.29 revision 1) for detailed accomplishment instructions","Nested conditional logic: different actions required depending on (a) modification status, (b) part number found, and (c) whether the helicopter has been operated with the incorrect part","Specific part number dependencies: four different hydraulic actuator P/Ns and two different lever P/Ns must be correctly matched","Alternative compliance method allowed (maintenance records review vs physical inspection) with qualification that part numbers must be 'positively determined'","Multiple compliance timeframes: 'before further flight' vs 'within 10 flight hours' depending on specific scenario","Prohibitive requirements (do not install) with effective date trigger","Reference to parallel European regulation (EASA AD 2007-0131-E) creating potential jurisdictional cross-check requirement"],"plain_english_summary":"This AD orders operators of Eurocopter AS 355 N and F2 helicopters to immediately verify the load compensator lever and hydraulic actuator part numbers and replace any incompatible combination. A parts-catalogue error led to a wrong lever possibly paired with a modified actuator, which can restrict yaw control and risk a crash. Affected operators must inspect records or the aircraft and correct mismatches before further flight."},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"The AD stays within the original safety purpose: to identify and correct an incompatibility between load compensator levers and hydraulic actuator assemblies that was caused by an incorrect parts reference in the Illustrated Parts Catalogue. It does not add unrelated requirements or expand to other models or systems beyond the lever/actuator compatibility and installation prohibitions tied to MOD 072065."},"complexity_factors":["Two helicopter models covered (AS 355 N and AS 355 F2) with discrete applicability","Four specific part numbers to cross‑check (lever P/Ns 355A27‑0072‑00 and 355A27‑0082‑00; actuator P/Ns 355A75‑1370‑01, ‑02, ‑03, ‑04)","Conditional logic based on modification status (Pre‑MOD 072065 vs Post‑MOD 072065)","Further conditional branches depending on whether the helicopter has been operated with the suspect lever installed","Deadlines vary by branch (some actions required before further flight, others within 10 flight hours)","Mandatory cross‑reference to an external document (Eurocopter ASB No. 67.00.29 Revision 1 or later NAA‑approved revision) for procedural detail","Alternative compliance route allowed (record review instead of physical inspection) which introduces evidentiary requirements","Prohibition on future installations adds a continuing operational constraint","Safety rationale and related EASA AD cross‑reference add external regulatory linkages"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Requires owners/operators of Eurocopter AS 355 N and AS 355 F2 helicopters to identify the part numbers (P/Ns) of the load compensator lever and the load compensator hydraulic actuator installed on each helicopter, and to ensure those two parts are compatible with each other.\n- If incompatible or uncertain, mandates specific actions: either immediate replacement of the lever with the correct P/N or further inspections/tests as set out in the referenced Eurocopter Alert Service Bulletin (ASB) No. 67.00.29 (Revision 1 or later NAA‑approved revision).\n- Prohibits installing the wrong lever on a helicopter that has (or has not) had the hydraulic actuator upgraded (the AD distinguishes helicopters Pre‑MOD 072065 and Post‑MOD 072065).\n\n**Who is affected**\n\n- Owners, operators and maintenance organisations responsible for Eurocopter AS 355 N and AS 355 F2 helicopters.\n\n**Why it matters (stated safety reason)**\n\n- The AD follows reports that placing an incorrect load compensator lever on some helicopters caused restricted yaw control (limited tail/rotation control). The condition, if not corrected, could lead to loss of control. Investigation showed the Illustrated Parts Catalogue listed the lever P/Ns incorrectly relative to a prior actuator modification (MOD 072065).\n\n**How it works in practice (steps and timing)**\n\n- Step 1: Identify the lever and hydraulic actuator P/Ns on each helicopter. You may either physically inspect the components or review maintenance records/logbooks where P/Ns can be positively determined. (Requirement 1; Compliance: before further flight after the effective date.)\n- Step 2: If a P/N cannot be determined from inspection/records, follow the ASB’s procedure to determine the correct P/Ns. (Requirement 2.)\n- Step 3: For helicopters Pre‑MOD 072065 (actuators P/N 355A75‑1370‑01 or 355A75‑1370‑03):\n - If you find lever P/N 355A27‑0082‑00 but the helicopter has not been operated with that lever installed, replace it with lever P/N 355A27‑0072‑00 before further flight.\n - If the helicopter has been operated with lever P/N 355A27‑0082‑00, carry out the additional actions in the ASB within 10 flight hours. (Requirement 3; timing: before further flight for non‑operated case; within 10 flight hours for operated case.)\n- Step 4: For helicopters Post‑MOD 072065 (actuators P/N 355A75‑1370‑02 or 355A75‑1370‑04):\n - If you find lever P/N 355A27‑0072‑00 but the helicopter has not been operated with that lever installed, replace it with lever P/N 355A27‑0082‑00 before further flight.\n - If the helicopter has been operated with lever P/N 355A27‑0072‑00, carry out the additional actions in the ASB within 10 flight hours. (Requirement 4; same timing structure.)\n- Step 5: From the effective date, do not install lever P/N 355A27‑0082‑00 on Pre‑MOD 072065 helicopters, and do not install lever P/N 355A27‑0072‑00 on Post‑MOD 072065 helicopters. (Requirement 5; prohibition effective immediately.)\n\n- The AD relies on Eurocopter ASB No. 67.00.29 (Revision 1 or later NAA‑approved revision) for the detailed inspection and corrective procedures; the AD makes following that ASB mandatory for compliance.\n\n**Who pays, who decides, and what behaviour changes**\n\n- Who pays: The direct costs fall on the helicopter owners/operators and maintenance organisations — costs include labour to inspect or review records, possible part replacement costs, parts logistics and helicopter downtime.\n- Who decides: The operator (or their maintenance organisation) must decide whether the P/Ns are identifiable from records or require physical inspection; maintenance personnel must carry out replacements or follow the ASB procedures. The regulator enforces compliance with the AD; the ASB (and any later NAA‑approved revisions) prescribes technical steps.\n- Behaviour changes: Operators must inspect or verify records before next flight, replace mismatched levers before flight (or within 10 flight hours in the specified cases), and stop installing the incompatible lever/actuator combinations in future maintenance.\n\n**Costs, trade‑offs and implementation risks**\n\n- Direct costs: parts and maintenance labour; potential short‑term grounding or restricted use until compliance is achieved.\n- Supply risk: if the correct lever P/N is not readily available, operators face delayed return‑to‑service or may need to source parts quickly (which affects scheduling and costs).\n- Record‑reliance trade‑off: the AD allows reliance on maintenance records instead of physical inspection when records positively identify P/Ns; this lowers inspection costs for well‑documented helicopters but increases risk where records are incomplete or inaccurate.\n- Operational risk reduction vs. downtime: the AD prioritises immediate safety (inspect/replace before further flight in many cases) at the expense of possible operational disruption and repair costs.\n- Implementation detail dependence: the AD cross‑references the Eurocopter ASB for procedural detail; operators must follow that ASB revision or later NAA‑approved revisions, so timely access to the correct ASB revision and any NAA approvals is necessary.\n\n**References/links in the instrument**\n\n- Refers to Eurocopter ASB No. 67.00.29 Revision 1 (dated 27 April 2007) or later NAA‑approved revisions and notes EASA AD 2007‑0131‑E as related material.\n"},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-as-355-94-load-compensator-levers","history":"/api/acts/ad-as-355-94-load-compensator-levers/history","analysis":"/api/acts/ad-as-355-94-load-compensator-levers/analysis","conflicts":"/api/acts/ad-as-355-94-load-compensator-levers/conflicts","importantCases":"/api/acts/ad-as-355-94-load-compensator-levers/important-cases","documents":"/api/acts/ad-as-355-94-load-compensator-levers/documents"}}