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 328/23 Roll Spoiler Double Shuttle Valve 1/2006 Applicability: Dornier 328-100 aeroplanes serial number 3005 through 3119 inclusive. Requirement: Unless previously accomplished, replace the roll spoiler double shuttle valve in accordance with Dornier 328 Alert Service Bulletin No. SB-328-27-310 dated 10 June 2000. Note: LBA AD 1998-479/3 refers. Compliance: Within 30 days after the effective date of this AD. This Airworthiness Directive becomes effective on 19 January 2006. Background: Leakage was found from a roll spoiler actuator housing. Further investigation showed that the piston of the double shuttle valve had temporarily remained in the middle position allowing high pressure to reach the low pressure side of the roll spoiler actuator; this resulted in deformation of the housing cap and subsequent hydraulic fluid loss. This AD requires the replacement of the double shuttle valve to prevent hydraulic fluid loss. James Coyne Delegate of the Civil Aviation Safety Authority 29 November 2005