What was found
DURING DESCENT AND APPROACH OF FLIGHT #3154 INTO MSP, LEFT ENGINE WOULD SURGEWHEN THE POWER LEVER WAS MOVED IN THE RANGE OF 50% TO 35% TORQUE. OK ABOVE OR BELOW THIS RANGE-CTOT WAS SELECTED OFF. ALSO THE POWER LEVER IS ON THE 64 DEGREE MARK WHEN THIS HAPPENED. MAINTENANCE CND PROBLEM, FOR TROUBLESHOOTING PURPOSES REMOVED CTOT PANEL PN 7239060-503, SN/OFF 229055, INSTALLED SERVICEABLE PANEL PN 7239060-503 SN/ON 845759, CTOT PANEL OPS CHECKS GOOD PER SAAB MM 71-00-00 TEST. NO TORQUE SURGES NOTED.