What was found
ENGINE FAILED IN CRUISE. INVESTIGATION REVEALED THE FRACTURE OF THE RGB 1ST STAGE SUN GEAR FAILED DUE TO FATIGUE. THE ORIGINAL CAUSE OF THE FATIGUE COULD NOT BE DETERMINED. THE RGB DECOUPLING WAS CAUSED BY AN OVERSPEED CONDITION OF PT ROTOR RESULTING IN LIBERATION OF THE PT BLADES DUE TO TENSILE OVERLOAD. THE ENGINE WAS OVERHAULED AND RELEASED ON THE AUGUST 6, 1996 AND FAILED AT TSO 409 HOURS/1623 CSO.