As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING THE PROACTIVE O/H OF ESN 892844, THE HIGH PRESSURE TURBINE ROTOR BLADES WERE FLORESCENT PENETRANT INSPECTED. IT WAS DISCOVERED THAT QTY 7 BLADES EXHIBITED TRANSITION ZONE FWD COOLING CIRCUIT CRACKS. AN ADDITIONAL 15 BLADES EXHIBITED CRACKING AT THE MINIMUM NECK ON THE FIRTREE AT THE CONVEX SIDE.