As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RT ENGINE WAS UNABLE TO REACH TAKEOFF TARGET TORQUE. ENGINE WAS REMOVED AS A PRECAUTION AND SENT FOR TEARDOWN. ENGINEERING HAS DETERMINED CAUSE TO BE A CRACKED SECOND STAGE IMPELLER RESULTING FROM CYCLIC FATIGUE. THIS IS A FOLLOW UP REPORT AND IS NOW CLOSED. (K)