As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 2 ENGINE VIBRATION NOTICED WHEN REDUCING POWER FOR DESCENT, LOUDER AT LOWER N1'S. ALL ENGINE INSTRUMENTS NORMAL. *S/D* ONE T-4 BLADE FAILED AT THE AIRFOIL MID-SPAN. EXAMINATION SHOWS FAILURE MODE TO BE THAT OF STRESS RUPTURE DUE TO BLADE CREEP WHICH RESULTED FROM OVER TEMPERATURE. THE BLADES ON EITHER SIDE OF FAILED BLADE HAD MISSING SHROUDS BUT DID NOT INDICATE OVER TEMPERATURE. REPLACED N1 TURBINE ASSEMBLY.