Flight Crew Instrument; Flight Crew Commercial; Flight Crew Multiengine
Flight Crew Last 90 Days 320; Flight Crew Total 1500; Flight Crew Type 320
Aircraft Equipment Problem Critical
Aircraft Aircraft Damaged; Flight Crew Inflight Shutdown; Flight Crew Returned To Departure Airport; Flight Crew Landed in Emergency Condition; General Declared Emergency
Aircraft
I began the morning with a thorough preflight inspection of the Cessna 208 Caravan I would be flying that day to perform parachute operations. I verified that the engine oil was in the normal operating range. I departed on the first flight of the day. Upon climbout; I performed my daily routine engine checks at 6;000 FT MSL. The ITT; NG; fuel flow; propeller RPM; torque; oil pressure; and oil temperature were all within normal range. At 11;000 FT MSL; there was a loud 'bang' from the engine compartment followed by a residual 'screeching' noise. I began an emergency descent back into the airport. The fuel flow; oil pressure; and torque indicated '0;' so I began the standard emergency procedure for in-flight engine failure. I pitched for 80 KTS; turned the fuel selectors; fuel cutoff; and fuel condition to 'off;' and feathered the propeller. I landed the plane safely. Upon examination of the engine compartment; the Mechanic and I saw no evidence of engine oil or external damage to the engine. The fuel gauges were indicating approximately 500 LBS of fuel. There was no damage the airframe. Upon disassembly of the engine; the Mechanic found substantial amounts of metal shavings in the engine oil and significant damage to the free turbine. He stated; 'The problem was caused due to a catastrophic failure of the free turbine.' It was also noted that there was no chip detector installed on this PT6-A engine.
C208 Caravan pilot reported catastrophic engine failure that was later traced to the free turbine. He returned for a safe landing at departure airport.