What was found
(CAN) FLIGHT CREW ENCOUNTERED A NR 2 ENGINE CHIP WARNING LIGHT FOLLOWED BY COMPLETE ENGINE FAILURE WITHIN 1 MIN EMERGENCY LANDING EXECUTED. NR 2 ENGINE AND OIL COOLER REPLACED, A/C RETURNED TO SERVICE. SUBSEQUENT INVESTIGATION CARRIED OUT AT AMO REVEALED FAILURE OF THE NR 5 BEARING. THE BEARING FAILURE CAUSED POWER TURBINE ROTOR VIBRATION AND OSCILLATION RESULTING IN SUBSEQUENT DAMAGE AND DECOUPLING OF TURBINE TO COMPRESSOR (N1) COUPLING. THE GAS GENERATOR TURBINE ENTERED OVER-SPEED OF UNKNOWN VALUE. THE GP TURBINE OVER SPEED CAUSED NR 2 TURBINE BLADES TO PROGRESSIVELY SEPARATE FROM THE DISK. THE NR 5 BEARING HAD BEEN OVERHAUL INSPECTED BY THIS AMO APPROXIMATELY 757.9 HRS PRIOR TO FAILURE AND RE-INSTALLED AS (SERVICEABLE). THE BEARING HAS ACCUMULATED AT LEAST 3576 HRS. POSSIBLY AS MUCH AS 7040.4 HRS. (ON CONDITION PART). (TC NR 20070905001)