What was found
ENGINE REMOVED DUE TO LOUD GRINDING NOISE, HIGH PITCH SQUEAL ACCOMPANIED BY TORQUE FLUCTUATIONS. UPON INSPECTION OF TURBINE PARTS NOTED THE FOLLOWING: RIM BREAKOUT OF 1 1/2" AND 1/4" OF TWO EACH BLADES ON 3RD STAGE WHEEL. SUSPECT CAUSE OF FAILURE TO BE A STRESS CRACK ORIGINATING ON THE LEADING EDGE SIDE OF BREAKOUT IN REFERENCE TO DIRECTION OF ROTATION, ON THE TRAILING EDGE OF RIM SHROUD AND PROGRESSED APPROXIMATELY 1/2 OF CHORDAL LENGTH UNTIL OVERLOAD. SECONDARY DAMAGE - P.T.SECTION EXHIBITS EXCESSIVE KNIFE AND SEAL CONTACT AND BEARING AREA DAMAGE.