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. Dornier 328 Series Aeroplanes AD/DO 328/22 Ground Spoiler Valve Block 1/2006 Applicability: Dornier 328-100 aeroplanes, Serial Number: 3016, 3024, 3026, 3027, 3031, 3034, 3042, 3046, 3049, 3054, 3062, 3066, 3067, 3069, 3071, 3074, 3078, 3079, 3080, 3081, 3082, 3083, 3085, 3086, 3090, 3091, 3092, 3093, 3094 and 3095 if equipped with "active ground spoiler" (Option 040-001). Requirement: Unless previously accomplished, replace the ground spoiler valve block with valve block P/N 1060A0000-06 in accordance with Dornier 328 Service Bulletin No. 328-27-228 Revision 1 dated 18 December 1997. Note: LBA AD 1997-331/2 refers. Compliance: Prior to the issue of a Certificate of Airworthiness. This Airworthiness Directive becomes effective on 19 January 2006. Background: Failure analysis has shown elevated pressure in return lines under certain conditions can cause unwanted unlocking of the ground spoilers. James Coyne Delegate of the Civil Aviation Safety Authority 29 November 2005