What was found
ON DEPARTURE FROM "STL" PILOTS REPORTED THAT WHILE FLYING LEVEL AT 7000, AS PILOTS ACCELERATED THROUGH 200KIAS, LT ENG TORQUE BEGAN TO FLUTTER CONSTANTLY 50FT/LBS AND EXPERIENCED MULTIPLE DROPS OF +/-100 FT/LBS. ALL OTHER ENG INDICATIONS NORMAL, +300 FT LB SURGE EXPERIENCED ON SHORT FINAL. MAINTENANCE REMOVED, INSPECTED, RE-INSTALLED THE COMPRESSOR BLEED VALVE IAW P&W MM 75-30-00. OPERATIONAL CHECKS GOOD ON GROUND RUN.