What was found
ON DEPARTURE FROM STL, WHEN FLAPS WERE RETRACTED FROM 5 DEGREES TO UP, OUTBOARD AND INBOARD FLAPS STOPPED AT THE 2.5 TO 3 DEGREE RANGE. LE FLAPS REMAINED FULLY EXTENDED. AIRCRAFT RETURNED TO STL AND MADE AN UNEVENTFUL LANDING. REMOVED AND REPLACED FLAP CONTROL VALVE RETURN SPRING, IW B727 MM 27-51-51. FLAPS FUNCTIONALLY TESTED NORMAL ON GROUND. AIRCRAFT RETURNED TO SERVICE. (M)