Incident Overview
During climb after takeoff, at approximately 3,000 feet, the flight crew observed a drop in #2 engine pressure ratio (EPR) from about 1.82 to 1.74 EPR. Shortly thereafter, the first officer noted that the engine vibration monitor (AVM) for the #2 engine indicated maximum. At around 4,000 feet, a loud explosive noise emanated from the rear of the aircraft as the right engine lost power. The crew secured the right engine, returned to Tampa, and landed without further incident.
Examination Findings
Visual inspection revealed that turbine blades had exited the side of the engine tailpipe. A teardown examination was conducted to determine the cause of the failure.
Teardown Analysis
Examination of the high-pressure compressor center tube sealing ring found an approximately 1-inch (circumferential) piece of hard surface plating missing from the outside diameter sealing surface. This failure was in axial alignment with a gap in the rear piston ring. Neither the sealing ring nor the piston ring conformed to design specifications.
Evidence indicated that hot air caused coking of the oil. The turbine shaft had failed approximately 13 inches forward of the 4-1/2 bearing. The 4-1/2 bearing seals were damaged, and seven of them displayed coke deposits. The low-pressure turbine moved aft, intermeshing blades and stators.