AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/EC 120/7 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. Eurocopter EC 120 Series Helicopters AD/EC 120/7 Amdt 1 Horizontal Situation Indicator 5/2004 Applicability: EC 120 Versions B helicopters equipped with Bendix/King KI 525A Horizontal Situation Indicator (HSI). Requirement: 1. Check the part number (P/N) of the KI 525A HSI installed on the helicopter. Initially, no further action is necessary if the P/N is not 066-3046-07. 2. If the P/N is 066-3046-07, modify the HSI installation in accordance with Eurocopter Alert Telex 34A006 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. Note 1: Modification in accordance with Eurocopter Alert Service Bulletin (ASB) 34A006 is considered acceptable for compliance with Requirement 2. 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. Note 2: DGAC AD F-2002-282-009 R1 refers. Compliance: 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'. For Requirement 2 - Before further flight after the Requirement 1 check. For Requirement 3 - As of the effective date of this Amendment. This Amendment becomes effective on 13 May 2004. Background: 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. The original issue of this Directive introduced measures to ensure that the affected HSIs were correctly installed. Eurocopter EC 120 Series Helicopters AD/EC 120/7 Amdt 1 (continued) This 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 KI 525A HSI P/N 066-3046-07. The original issue of this Airworthiness Directive became effective on 5 June 2002. James Coyne Delegate of the Civil Aviation Safety Authority 2 April 2004 The above AD is notified in the Commonwealth of Australia Gazette on 21 April 2004.