What was found
AT FL320, NR 3 ENG HIGH EGT, HIGH VIBES AND HIGH OIL PRESS PER CREW. EGT REACHED 670C. AFTER SHUTDOWN, ENG WINDMILLING, VIBES FELT IN AIRFRAME AND OIL PRESS INDICATES ZERO. SHOP TEARDOWN SHOWED THE ROOT CAUSE TO BE FAILURE OF A STAGE-2 HIGH PRESSURE TURBINE BLADE. THE BLADE HAD FAILED UNDER THE PLATFORM DUE TO STRESS CORROSION CRACKING (SCC). FOUR ADJACENT BLADES SUBSEQUENTLY FRACTURED AT THE PLATFORM CAUSING THE HEAVY VIBRATION. THE STAGE-1 HUB, BLADES, AND ROTATING AIRSEAL HAD TO BE SCRAPPED DUE TO HEAVY RUB. THE SCC FAILED BLADE HAD 19733 HOURS SINCE NEW. INCORPORATING PRATT & WHITNEY SERVICE BULLETIN PW4ENG 712-263.