As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 720 - NR 1 ENGINE HAD 1 QUICK LOUD BANG ON TRIP FROM DTW TO IND. NOTICED OIL TEMP/PRESSURE WERE FINE. WITH N1 MATCHED N2, FUEL FLOW AND EGT VERY HIGH. ABOVE IDLE AND BELOW 70 PERCENT N1 ENGINE HAS VIBRATION. SMOOTHES OUT ABOVE N1 BUT TEMPERATURE GETS TO RED LINE. REMOVED AND REPLACED NR 1 ENGINE DUE TO TURBINE DAMAGE. (M)