What was found
2ND STAGE COMPRESSOR DISK (PN 670802, SN H63817) WAS FOUND CRACKED DURING OVERHAUL INSPECTION. COMPRESSOR (SN 672571) WAS REMOVED FROM SERVICE DUE TO REACHING ITS O/H INTERVAL, HAVING A TSO OF 2987.9 HOURS AND A TT OF 5978.0 HOURS. DURING O/H INSPECTION, FIVE CRACKS WERE DETECTED BY EDDY CURRENT INSPECTION. CRACK LOCATIONS DETECTED BY EDDY CURRENT WERE IN THE CENTER RING OF DISK EXTENDING FROM BLADE PIN HOLES AT APPROXIMATELY A 45 DEGREE ANGLE. CRACKS WERE NOT DETECTABLE BY FLUORESCENT PENETRANT INSPECTION, THUS CRACK LENGTHS WERE NOT MEASURABLE.