What was found
FLT 649 - AIR RETURN TO OMA, ON CLIMB-OUT AT 1000 FEET AGL FLAPS 2 DEGREES WERE SELECTED AND A SPLIT FLAP CONDITION OCCURRED. SMOKE BEGAN TO FILL THE COCKPIT, AND EMERGENCY WAS DECLARED AND AN IMMEDIATE RETURN INITIATED. INSPECTED NR 1 AND NR 3 PRECOOLER REGULATOR AIR FLOW VALVES, FOUND NR 3 VALVE BROKEN. REPLACED NR 3 PRECOOLER MODULATING VALVE. (M)