AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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. Bombardier (Canadair) CL-600 (Challenger) Series Aeroplanes AD/CL-600/47 Center Tank Fuel Transfer Shutoff Valve 2/2002 TX Applicability: CL-600-2B19 "Regional Jet" aircraft, serial numbers 7003 and subsequent. Requirement: Applicable to all affected aircraft. 1. Open and install a lock ring on applicable circuit breakers in accordance with the Accomplishment Instructions of the Bombardier Alert Service Bulletin (ASB) A601R-28-045, Revision A, dated 7 December 2001. 2. Disconnect and stow the electrical wires from the circuit breakers opened per Requirement 1, in accordance with the Accomplishment Instructions of ASB A601R-28-045, Revision A. 3. Determine the part number (P/N) of the fuel transfer shutoff valves installed in the center fuel tank. Replace any valve P/N 601R62256-5 with a valve P/N 601R62256-3. 4. If, as a result of Requirement 3, it has been verified that only valves with P/N 601R62256-3 are installed, reconnect the circuit breaker wires that have been disconnected and stowed in accordance with Requirement 2, remove lock rings and reset the associated circuit breakers. 5. Dispatch of aircraft with inoperative fuel transfer shutoff valves: Operation of the affected aircraft is permitted with the center fuel tank full and with both fuel transfer shutoff valves inoperative (applicable circuit breakers opened in accordance with Requirement 1), subject to the restrictions imposed in Requirement 6, if applicable. The Flight Crew must be briefed that the wing tanks will indicate full until the center tank is empty. An Engine Indicating and Crew Alerting System LR XFER SOV message will be indicated on the ground. This message may disappear during climb but will remain on during the remainder of the flight. This may be accomplished by inserting a copy of this Directive into the Aircraft Operations Manual. Bombardier (Canadair) CL-600 (Challenger) Series Aeroplanes AD/CL-600/47 (continued) Applicable to aircraft with serial numbers 7003 through 7109. 6. Determine whether the fuel vent system has been modified in accordance with the requirements of Bombardier Service Bulletin 601R-28-024, Revision A, dated 11 November 1998). Aircraft, which have not incorporated the fuel vent system modification, must operate with less than 200 pounds of fuel in the center fuel tank. Amend the limitation section of the Aircraft Flight Manual (AFM) to reflect this limit. This amendment may be accomplished by inserting a copy of this Directive into the AFM limitation section. Note: Transport Canada CF-2001-47 refers. Compliance: For Requirement 1 - Within one day after the effective date of this Directive. For Requirement 2 - Within four days after the effective date of this Directive. For Requirement 3 - Within 45 days after the effective date of this Directive For Requirement 4 - Concurrent with Requirement 3. For Requirement 5 - As of the effective date of this Directive until Requirement 4 is accomplished. For Requirement 6 - Within one day after the effective date of this Directive, until Requirement 4 is accomplished. This Airworthiness Directive becomes effective on 19 December 2001. Background: Transport Canada has advised that during bench testing of the center tank fuel transfer shutoff valve, it was found that, if the valve fails, it could overheat to a temperature that exceeds the fuel hot surface ignition point. Eugene Paul Holzapfel Delegate of the Civil Aviation Safety Authority 17 December 2001 The above AD is notified in the Commonwealth of Australia Gazette on 19 December 2001.