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 39.001(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. Gulfstream (Grumman) G1159 and G-IV Series Aeroplanes AD/G1159/52 Avionics Standard Communication Bus 7/2011 Applicability: Model GV-SP with serial number in the range 5001 through 5062 inclusive. Requirement: Actions specified in FAA Airworthiness Directive 2005-04-06 (Amendment 39-13978). Compliance: Unless already accomplished, perform initial inspection before issue of certificate of airworthiness. Unless terminating action has been accomplished, perform repetitive inspections at intervals not exceeding 60 days. This Airworthiness Directive becomes effective on 30 March 2011. Background: The FAA issued 2005-04-06 after receiving a report that all four cockpit flight panel displays went blank simultaneously. Charles Lenarcic Delegate of the Civil Aviation Safety Authority 24 March 2011