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-600/31 Fuel Tank Arcing Prevention 6/97 Applicability: 1. Canadair CL-600-1A11 serial numbers 1004 to 1085. 2. Canadair CL-600-2A12 serial numbers 3001 to 3025 inclusive, 3035 to 3039 inclusive, 3041, 3042, 3044 to 3048 inclusive and 3050 to 3052 inclusive. 3. CL-600 fuel pumps Part Number 600-62966-25 and -27 held as spares, fitted with anti-noise filter Part Number 160-151501. Requirement: 1. For Canadair CL-600-1A11 aircraft replace electromagnetic interference (EMI) filter in accordance with Part B of Canadair Alert Service Bulletin (ASB) A600- 0644 Revision 1 dated 31 March 1995. 2. For Canadair CL-600-2A12 aircraft replace EMI filter in accordance with Part B of Canadair ASB A601-0441 Revision 1 dated 31 March 1995. 3. For uninstalled CL-600 fuel pumps, replace the existing EMI filter with a new item, Part Number 160-151501 (stamped with "Revision H" or subsequent revisions) following the procedures given in Part B of Canadair ASB A600-0644, Rev 1, (Items 11 to 13) , or ASB A601-0441, Rev 1, (Items 10 to 12). Note: Transport Canada AD CF-97-02 refers. Compliance: Requirements 1 and 2. Unless previously incorporated compliance is to be within next 100 hours time in service but no later than 31 December 1997. Requirement 3. Incorporate prior to installation. This Airworthiness Directive becomes effective on 22 May 1997. Background: Transport Canada has reported an incident where the EMI filter associated with the fuel pump had had a hole burnt through its casing due to arcing between internal wiring and the case. This directive is intended to minimise the possibility of arcing occurring within the fuel tank.