COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Bombardier (Canadair) CL-600 (Challenger) Series Aeroplanes AD/CL-600/19 Fire Extinguishing Bottle Squib Wiring 13/89 Applicability: All CL 600-1A11 aircraft serial No 1004 through 1085. Requirement: 1. Perform a special check of the fire extinguisher system wiring in accordance with Canadair SB A600-0581. 2. Modify the fire extinguisher system in accordance with Canadair SB A600-0581. Compliance: Requirement 1: Within 50 hours time in service after 28 December 1989. Requirement 2: Within 100 hours time in service after 28 December 1989. Background: The current aircraft wiring configuration allows inadvertent cross connection of the fire extinguisher squibs during maintenance. This could result in extinguishing agent being directed to the wrong engine in the event of a fire. Compliance with Requirement 1 will validate the current aircraft configuration, whilst compliance with Requirement 2 will eliminate the possibility of any future cross connections.