COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 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. Radio Communication and Navigation Equipment AD/RAD/71 Chelton VOR/LOC High Pass Filter Type 7-429/1 8/2001 Applicability: Chelton (Electrostatics) Limited VOR/LOC high pass filter unit Part Number (P/N) 7-429/1. Requirement: Check any installation of Chelton high pass filters P/N 7-429/1 in accordance with Chelton (Electrostatics) Service Bulletin No CEL 01/2001 dated 1 May 2001. Note: CAA(UK) AD 001-05-2001 refers. Compliance: Before 1 November 2001. This Airworthiness Directive becomes effective on 9 August 2001. Background: These filters may have been installed in some aeroplanes to provide the VOR/LOC system with immunity to interference from commercial FM broadcasts. Chelton has advised that some filters may have been incorrectly installed with incompatible radios or in a dual radio installation with only one filter. Eugene Paul Holzapfel Delegate of the Civil Aviation Safety Authority 29 June 2001 The above AD is notified in the Commonwealth of Australia Gazette on 11 July 2001. Page 1 of 1