AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/A320/122 and issues the following AD under subregulation 39.1 (1) of CAR 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. Airbus Industrie A319, A320 and A321 Series Aeroplanes AD/A320/122 Amdt 1 Crew Oxygen Supply 10/2001 Applicability: All A319, A320 or A321 series aeroplanes, without either Airbus Industrie Modification 21946 or 21999 embodied during production or Airbus Industrie Service Bulletin (SB) A320-35-1003 dated 26 August 1991 or Revision 1 dated 28 January 1993 incorporated whilst in service. Requirement: Replace the low pressure oxygen valve Part Number (P/N) DVE90-04 by a new modified valve P/N DVE90-05 or DVE90-06 in accordance with SB A320-35-1003, A320-35-1003 Revision 1 and/or SB A320-35-1016 dated 31 July 1996. Note: DGAC AD 2001-237(B) R1 refers. Compliance: Before 31 October 2002. This Amendment becomes effective on 4 October 2001. Background: The Direction Générale de L'Aviation Civile of France has advised that, following an inflight test, crew oxygen was not available. Investigation revealed that there was a discrepancy between the position of the solenoid operated low-pressure valve and the controlling push button switch. Several reset actions of the push button were required before oxygen became available. This condition could, in the event of rapid decompression or smoke in the cockpit, prevent the crew correctly responding to an emergency. This original issue of this Directive required the replacement of the solenoid operated oxygen low pressure valve. This Amendment identifies an additional modification that, if embodied during production, nullifies the requirement to replace the solenoid operated oxygen low pressure valve Airbus Industrie A319, A320 and A321 Series Aeroplanes AD/A320/122 Amdt 1 (Continued) The original issue of this directive became effective 6 September 2001. Eugene Paul Holzapfel Delegate of the Civil Aviation Safety Authority 13 August 2001 The above AD is notified in the Commonwealth of Australia Gazette on 12 September 2001.