What was found
LT ENG FIRE LOOP AND LT ENG OVERHT DETECT EICAS MESSAGES. OIL QTY AND OIL PRESSURE DROPPED. ENGINE SHUTDOWN. EMERGENCY DECLARED. ENGINE REPLACED. FOUND ONE HPT STG-2 BLADE FAILED AT AIRFOIL MID-SPAN AS A RESULT OF INTERNAL SULFIDATION. ANOTHER BLADE FAILED NEAR THE AIRFOIL PLATFORM, AS A RESULT OF CONTACT WITH DEBRIS FROM 1ST BLADE. RESULTED IN VIBRATION. OVER TIME, CAUSED FAILURE OF THE FIRE/OVERHEAT LOOPS, & RESULTED IN CRACKING OF OIL PRESSURE LINE BETWEEN SERVO FUEL HEATER & AIR OIL HEAT EXCHANGER. CAUSE OF BLADE SULFIDATION CONTAMINATION OF COOLING PASSAGES WITH TURBO-TIP COATING. PWA HAS CHANGED COATING PROCESS TO PRECLUDE FUTURE CONTAMINATION.