C208 caravan pilot reported catastrophic engine failure that was later traced to the free turbine. H...

Narrative:

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 pounds 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.

Original NASA ASRS Text

Title: C208 Caravan pilot reported catastrophic engine failure that was later traced to the free turbine. He returned for a safe landing at departure airport.

Narrative: 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.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1025319
Time
Date	201207
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Caravan Undifferentiated
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Visual Approach
Flight Plan	None
Component
Aircraft Component	Turbine Engine
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Instrument Flight Crew Commercial Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 320 Flight Crew Total 1500 Flight Crew Type 320
Events
Anomaly	Aircraft Equipment Problem Critical

C208 caravan pilot reported catastrophic engine failure that was later traced to the free turbine. He returned for a safe landing at departure airport.