What was found
(CAN) CREW REPORTED NR 1 ENGINE FLAMED OUT DURING THE CLIMB OUT OF YYZ. THE AIRCRAFT RETURNED TO YYZ WITHOUT INCIDENT. UPON MAINTENANCE INVESTIGATION THE NR 1 OIL TANK CHIP DETECTOR WAS FOUND FLAGGED. MAINTENANCE PROCEEDED TO INSPECT THE ACCESSORY DRIVE AND FOUND THE SPUR GEAR (P/N 3121372-01) FOR THE FUEL PUMP HAD ALL THE TEETH SHEARED OFF. THE NR 1 ENGINE WAS REPLACED (TURBO MACHINERY AND REDUCTION GEAR BOX) ALONG WITH THE AC GENERATOR, OIL COOLER AND PROP ACTUATOR FOR POSSIBLE OIL CONTAMINATION.