{"id":"F2006B09380","name":"AD/ECUREUIL/77 Amdt 1 - Horizontal Situation Indicator","slug":"ad-ecureuil-77-amdt-1-horizontal-situation-indicator","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53683,"registerId":"commonwealth-F2006B09380-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/ECUREUIL/77 Amdt 1 - Horizontal Situation Indicator","content":"![](image.001.png)\n\nAIRWORTHINESS DIRECTIVE\n\n![](image.001.png)  \n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/ECUREUIL/77 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 AS 350 (Ecureuil) Series Helicopters\n\nAD/ECUREUIL/77\n\nAmdt 1\n\n  \nHorizontal Situation Indicator 5/2004\n\nApplicability: AS 350 helicopters Versions B, BA, B1, B2, B3, BB and D equipped with Bendix/King KI 525A Horizontal Situation Indicator (HSI).\n\nRequirement: 1. Check the part number (P/N) of the KI 525A HSI installed on the helicopter.\n\nInitially, no further action is necessary if the P/N is not 066-3046-07.\n\n    2. If the P/N is 066-3046-07, modify the HSI installation in accordance with Eurocopter Alert Telex 34.00.13 paragraph 2.A.1, for helicopters with the HSI connected to a single navigation system, or paragraph 2.A.2, for helicopters with the HSI connected to at least two navigation systems.\n\nNote 1: Modification in accordance with Eurocopter Alert Service Bulletin (ASB)\n\n34.00.13 is considered acceptable for compliance with Requirement 2.\n\n    3. Before installing a KI 525A HSI P/N 066-3046-07 in place of a KI 525A HSI with P/Ns 066-3046-00, -01, -04 or -05 ensure that the HSI installation is modified in accordance with Requirement 2.\n\nNote 2: DGAC AD F-2002-281-091 R1 refers.\n\nCompliance: For Requirement 1 \\- Remains unchanged as ‘Either within 100 hours time in service after the effective date of the original issue of this Directive or before 10 August 2003, whichever occurs first’.\n\nFor Requirement 2 \\- Before further flight after the Requirement 1 check. For Requirement 3 - As of the effective date of this Amendment.\n\nThis Amendment becomes effective on 13 May 2004.\n\nBackground: Eurocopter has advised the French Direction Générale de l’Aviation Civile that KI 525A HSIs P/N 066-3046-07 may have been incorrectly installed on some helicopters. The incorrect installation may result in navigation errors.\n\nThe original issue of this Directive introduced measures to ensure that the affected HSIs were correctly installed.\n\nEurocopter AS 350 (Ecureuil) Series Helicopters\n\nAD/ECUREUIL/77 Amdt 1 (continued)\n\nThis Amendment contains some minor editorial amendments, together with allowing credit for modifications carried out in accordance with the ASB and introduces measures to ensure that the helicopter is modified prior to the installation of a\n\nKI 525A HSI P/N 066-3046-07.\n\nThe original issue of this Airworthiness Directive became effective on 5 June 2002.\n\n![Signature of James Coyne, Delegate of the Civil Aviation Safety Authority.](image.002.png)  \n\nJames Coyne\n\nDelegate of the Civil Aviation Safety Authority 2 April 2004\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 21 April 2004.","sortOrder":0}],"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"},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"This Amendment makes limited scope changes to the original AD rather than a broad re‑purposing. It (a) allows formal credit for modifications carried out using Eurocopter ASB 34.00.13 (so operators who followed that ASB are expressly covered), (b) adds an explicit requirement that a KI 525A HSI with P/N 066-3046-07 must not be installed unless the installation has already been modified (pre-installation restriction), and (c) includes minor editorial updates. Those changes tighten installation controls and clarify acceptable compliance methods compared with the original issue."},"complexity_factors":["Narrow applicability: only Eurocopter AS350 variants B, BA, B1, B2, B3, BB and D with Bendix/King KI 525A HSI","Single core conditional pathway: check P/N (Requirement 1) then, if P/N = 066-3046-07, perform modification (Requirement 2); otherwise no action","One further condition for future installations (Requirement 3) — must be pre-modified before installing P/N 066-3046-07","Cross-references to external manufacturer documents (Eurocopter Alert Telex 34.00.13 and ASB 34.00.13) for the actual modification procedure","Short document with few defined terms and minimal nested exceptions","Compliance timing references legacy dates from the original AD which can cause interpretive uncertainty about historical vs current obligations"],"plain_english_summary":"**What this AD does (mechanical changes first)**\n\n- **Check the HSI part number.** Operators of Eurocopter AS350 (Ecureuil) B, BA, B1, B2, B3, BB and D helicopters must check the part number (P/N) of any Bendix/King KI 525A Horizontal Situation Indicator (HSI) fitted to the aircraft (Applicability; Requirement 1).\n\n- **If the HSI is P/N 066-3046-07, modify the installation before further flight.** If the installed HSI is P/N 066-3046-07, the HSI installation must be modified in accordance with Eurocopter Alert Telex 34.00.13: use paragraph 2.A.1 when the HSI is connected to a single navigation system, or paragraph 2.A.2 when it is connected to two or more navigation systems (Requirement 2; Compliance).\n\n- **If you want to fit a P/N 066-3046-07 HSI later, modify first.** Before installing a KI 525A HSI with P/N 066-3046-07 as a replacement for units with P/N 066-3046-00, -01, -04 or -05, the installation must already be modified as required in Requirement 2 (Requirement 3).\n\n- **Compliance timing.** The initial P/N check was originally to be done either within 100 hours time-in-service after the original AD or before 10 August 2003 (Requirement 1). Any required modification (Requirement 2) must be done before further flight after that check. The requirement to ensure modification before installing a P/N 066-3046-07 HSI applies as of this Amendment's effective date (Compliance).\n\n- **Approved compliance method.** Work done in accordance with Eurocopter Alert Service Bulletin (ASB) 34.00.13 is explicitly accepted as compliance with Requirement 2 (Note 1).\n\n**Why the AD was issued (stated reason)**\n\n- Eurocopter told the French regulator that some KI 525A HSIs stamped P/N 066-3046-07 may have been installed incorrectly. The incorrect installation can lead to navigation errors (Background). The AD therefore requires identification and correction of any incorrect installations.\n\n**Who is affected and who pays**\n\n- Affected: Owners/operators of Eurocopter AS350 B/BA/B1/B2/B3/BB/D helicopters fitted with a Bendix/King KI 525A HSI.\n- Pays: The aircraft owner/operator pays for inspection, any labour and parts required for the modification, and any downtime while the helicopter is grounded for the corrective work.\n\n**Who decides and who carries out the work**\n\n- Regulatory decision: The Civil Aviation Safety Authority (CASA) delegate issued the AD under CASR powers (preamble). Practical instructions for the modification come from Eurocopter Alert Telex 34.00.13 (and ASB 34.00.13 is accepted as an alternative compliance method).\n- Carried out by: maintenance organisations or approved engineers who can perform the modification to the aircraft installation per the Eurocopter instructions.\n\n**Effects on operators, maintenance providers and market choices**\n\n- Immediate compliance actions (inspection and, where needed, modification before next flight) impose a direct operating cost and potential short groundings for affected helicopters.\n- Allowing credit for work done to Eurocopter ASB 34.00.13 reduces duplicate work and lets authorised maintenance organisations follow existing manufacturer instructions, which concentrates demand on technicians familiar with the ASB.\n- The AD does not change ownership, aircraft configuration rules beyond the HSI installation requirement, or market entry rules; it constrains operators' installation choices for that specific HSI part number (you cannot install P/N 066-3046-07 unless the installation is modified first).\n\n**Implementation and compliance risks / practical points**\n\n- The AD cross-references external manufacturer documents (Alert Telex and ASB). Effective compliance depends on access to and correct application of those documents.\n- The AD distinguishes installation procedures depending on whether the HSI is tied to one or multiple navigation systems. Incorrect application of the wrong paragraph could leave a safety issue unresolved.\n- Dates in the Compliance section refer back to the original AD’s effective window; operators should check maintenance records to ensure the required inspections/modifications were done in the timeframe specified or have since been rectified.\n\n**Summary sentence**\n\nThis AD requires operators of specified AS350 helicopters to identify any KI 525A HSI with P/N 066-3046-07 and, if present, to modify the HSI installation per Eurocopter instructions before further flight (and to ensure modification before installing that part number in the future). The stated purpose is to correct incorrect installations that can cause navigation errors. "},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment stays within the original scope of addressing incorrect HSI installations. It adds minor procedural refinements (giving credit for ASB compliance and adding a pre-installation requirement) but does not expand beyond the original safety purpose of ensuring correct HSI installation on affected helicopters."},"complexity_factors":["Short, single-purpose document (3 requirements only)","Minimal defined terms (only standard aviation abbreviations like P/N, HSI, ASB)","Clear conditional logic (if P/N is X, do Y; otherwise no action)","Simple cross-reference to manufacturer document (Eurocopter Alert Telex 34.00.13)","Straightforward compliance timeline (immediate or within 100 hours)","No nested exceptions or complex legal drafting"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires owners/operators of Eurocopter AS350 (B, BA, B1, B2, B3, BB, D) helicopters fitted with Bendix/King KI 525A HSIs (PN 066‑3046‑07) to inspect and, if necessary, modify the HSI installation to correct incorrect fittings that can cause hazardous navigation errors. It prevents installation of unmodified replacement units and (in this Amendment 1) grants credit for earlier repairs done per the manufacturer and clarifies the modification-before-installation requirement."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ecureuil-77-amdt-1-horizontal-situation-indicator","history":"/api/acts/ad-ecureuil-77-amdt-1-horizontal-situation-indicator/history","analysis":"/api/acts/ad-ecureuil-77-amdt-1-horizontal-situation-indicator/analysis","conflicts":"/api/acts/ad-ecureuil-77-amdt-1-horizontal-situation-indicator/conflicts","importantCases":"/api/acts/ad-ecureuil-77-amdt-1-horizontal-situation-indicator/important-cases","documents":"/api/acts/ad-ecureuil-77-amdt-1-horizontal-situation-indicator/documents"}}