What was found
(CAN) ENG REQUIRED REPLACEMENT OF CT DISK DUE TO EXCESS CT TIP CLEARANCES AND BURNED CT BLADES TIPS. NEW CT DISK ASSY, WITH QTY 8 NEW & QTY 35 OH CT BLADES WERE INSTALLED. 8 NEW BLADES NOTED TO HAVE A BLADE STEP AT INTERFACE BETWEEN CT BLADE PLATFORM & FIR TREE ROOT. CT DISK ASSY INSTALLED IAW MM, USUAL FIELD MAINT PERFORMED & ENG REASSEMBLED. GROUND RUN PERFORMANCE INDICATED ENG PERFORMANCE NOT AS EXPECTED. UPON SPLITTING ENG, RUB CONTACT BETWEEN CT DISK & CT AIR BAFFLE DISCOVERED. CT DISK REMOVED FOR INSP AND NOTED A SEVERE RUB OCCURRED ON L/E OF CT DISK PLATFORM FACE TO CT STATOR AIR SEAL. RUB ORIGINATED AT POSITION OF QTY 4 OF 8 NEW CT BLADES, INSTALLED IN DISK ASSY AT BUILD.