What was found
DURING TAKEOFF ROLL, FLIGHT CREW NOTED NR 1 ENGINE WOULDNOT PRODUCE REQUESTED POWER (62,000 LB). ALL OTHER ENGINE PARAMETERS WERENORMAL. FLIGHT CREW CONTINUED TAKEOFF. HOWEVER, AT PIC'S OPTION, AIRCRAFTRETURNED TO POINT OF DEPARTURE (AIR TURN-BACK). AIRCRAFT RETURNED WITHOUTINCIDENT. UPON INVESTIGATION, MX NOTED THE NR 1 ENGINE HAD ELECTRONICENGINE CONTROL DATA PLUG INSTALLED (60,000 LBS THRUST LIMIT). AIRCRFTRETURNED TO SERVICE (ALL ENGINES RESTRICTED TO 60,000 LB THRUST LIMIT).(M)