AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B737/145 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. Boeing 737 Series Aeroplanes AD/B737/145 Amdt 1 Flightcrew Seat Locks and Seat Tracks 5/2004 Applicability: Model 737-300, -400, and -500 series aircraft, equipped with IPECO flightcrew seats; as listed in Boeing Alert Service Bulletin ASB 737-25A1363 Revision 1, dated 28 March 2002. Requirement: Inspect in accordance with the technical requirements of FAA AD 2004-04-03 Amdt 39-13483. Compliance: For Group 1 aircraft listed in ASB 737-25A1363 Revision 1: Before 10 November 2000; in accordance with ASB 737-25A1363. For Group 2 aircraft listed in ASB 737-25A1363 Revision 1: Within 90 days after 13 May 2004; in accordance with ASB 737-25A1363 Revision 1. The compliance time remains unchanged for Group 1 aircraft. This Amendment becomes effective on 13 May 2004. Background: The FAA received reports of instances of the pilot seat sliding to the aft-most position during acceleration and take-off on certain Model 737 series aircraft. Investigation revealed that the screws attaching the rear tracklock bracket to the seat track had broken, allowing excessive lateral movement and disengagement of the locking pin from the floor-mounted seat track. Boeing 737 Series Aeroplanes AD/B737/145 Amdt 1 (continued) Amendment 1 is issued in response to a new FAA AD, which revises applicability of the existing AD by adding aircraft with the introduction of Revision 1 of the related service bulletin. David Villiers Delegate of the Civil Aviation Safety Authority 2 April 2004 The above AD is notified in the Commonwealth of Australia Gazette on 21 April 2004.