What was found
CLIMBING THROUGH 12,000 FEET A LOUD BOOM WAS HEARD FROM THE LT ENGINE. THERE WAS NO THROTTLE RESPONSE. SHUT DOWN THE ENGINE AND RETURNED TO SEA. FOUND SIGNIFICANT DAMAGE TO THE COMPRESSOR AND TURBINE. CHANGED THE ENGINE. CHECK-C 12-15-98 STL. *S/D* FOUND A FOURTH STAGE TURBINE BLADE FRACTURED DUE TO FATIGUE AND BLADE TIP RUB, CAUSING THE FRACTURE OF ALL OTHER FOURTH STAGE BLADES AND DAMAGE TO THIRD AND SECOND STAGE INNER SHROUDS.