What was found
FAN BLADES REMOVED FROM ENGINE DUE TO EXCESSIVE AMOUNTS OF THRUST (FN) FOLLOWING COMPRESSOR CORE ZONE INSPECTION (CZI). FAN BLADES (30 EACH), PN 3072613-1 WERE REMOVED AND SENT FOR THRUST REDUCTION. MECHANICAL BEND TO REDUCE THRUST, PENETRANT INSP ONLY. UPON RETURN, BLADES WERE INSTALLED AND ENGINE RUN IN TEST CELL. UNABLE TO ADVANCE POWER LEVER MUCH BEYOND IDLE DUE TO A SEVERED FAN VIBRATION >1.0 INCH PER SECOND (IPS). FAN ASSY REMOVED AND A VECTOR SUMMATION BALANCE ACCOMPLISHED PER 72-IR-02 INSP REPAIR MANUAL. FAN REINSTALLED ON ENG WITH SAME SEVERE FAN VIBRATION. FAN REBLADED WITH A DIFFERENT (NOT REWORKED) SET OF BLADES. ENG WAS RUN IN TEST CELL. FAN RAN SMOOTH AND QUIET. REF: W.O. GR2323.