What was found
ON DEPARTURE THE NR 6 L/E FAILED TO RETRACT, COMPLIED WITH COM PROCEDURE 2.27.12 SLAT WAS STILL EXTENDED. CONFERRED WITH DISPATCH/MDC, DECLARED AN EMERGENCY. COMPLIED WITH COM PROCEDURE 2.28.4 AND DUMPED APPROXIMATELY 23K LBS FUEL BEFORE RETURN TO STL. REMOVED AND REPLACED NR 6 L/E SLAT ACTUATOR IAW 27-81-32, ALL OPS NORMAL IAW 27-81-00. SERVICED HYDRAULICS TO FULL IAW 12-12-00.