AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/HS 748/31 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. British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes AD/HS 748/31 Amdt 1 Gust Lock Baulking Actuator 1/2004 Applicability: All HS748 aeroplanes. Requirement: 1. Modify the aeroplane's gust lock system (Modification No 7673) in accordance with Parts 1 and 2 of BAe Systems Service Bulletin (SB) HS748-27-135 Revision 1 dated 10 December 2002. 2. Conduct an inspection of the baulk lever in accordance with Appendix 2 of SB HS748-27-135 Revision 1 or Revision 2 dated 2 October 2003. 3. Rework the Requirement 1 modification to the gust lock system in accordance with SB HS748-27-135 Revision 2. Note 1: CAA(UK) AD 003-12-2002 refers. Compliance: For Requirement 1 - Remains unchanged as 'Before 1 September 2003'. For Requirement 2 - Remains unchanged as 'Initially within 750 hours time in service (TIS) or 240 days, whichever occurs first, after the installation of the baulking actuator and thereafter, repeat the inspection at intervals of 750 hours TIS or 240 days, whichever occurs first'. Note 2: 750 hours TIS or 240 days is the 'C' Check interval. For Requirement 3 - Before 29 February 2004. This Amendment becomes effective on 22 January 2004. Background: BAe advises that there have been two incidents where re-engagement of the elevator gust-lock may have caused a flying control restriction. The original issue of this Directive required the installation of a rotary actuator at the elevator gust lock that will baulk the mechanism after gust-lock withdrawal so that an uncommanded re- engagement cannot occur. This Amendment revises the wiring of the gust lock actuator to ensure correct operation. British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes AD/HS 748/31 Amdt 1 (continued) The original issue of this Airworthiness Directive became effective on 20 March 2003. Jim Coyne Delegate of the Civil Aviation Safety Authority 4 December 2003 The above AD is notified in the Commonwealth of Australia Gazette on 24 December 2003.