What happened
On July 16, 2006, a Cessna 208B (Caravan), registration PH-JMP, was conducting a parachute jump operation from Teuge Airport (EHTE). While climbing at an altitude of approximately 8,000 feet, the pilot heard a grinding noise followed by an audible bang. Immediately after this, the engine power dropped to zero. The aircraft was roughly 4.5 nautical miles from the airfield at the time of the failure.
The pilot initiated emergency procedures, broadcasting a "mayday" call to Teuge Radio. During the emergency, the seventeen passengers exited the aircraft via parachute. The pilot then proceeded to perform an emergency landing on the grass runway 0 and successfully landed the aircraft without injury to any person or damage to the airframe.
The investigation
Because no investigators from the Dutch Safety Board were present at the scene, the investigation relied on data provided by the pilot, airport authorities, and the maintenance facility responsible for the aircraft. The engine, a Pratt & Whitney Canada PT6A-114A turboprop, was inspected by maintenance personnel, who discovered that the low-pressure compressor was difficult to rotate. Metal debris was found in the magnetic chip detectors of both the accessory and reduction gearboxes, and damage was noted on the power turbine rotors and stators.
The engine was subsequently sent to the Pratt & Whitney Canada Customer Service Centre Europe in Germany for disassembly. Further analysis by the manufacturer in Canada focused on the failure of the compressor-turbine blades.
Findings
Technical analysis determined that the primary cause of the engine failure was the separation of compressor-turbine blades. The manufacturer identified creep—a process of slow, continuous plastic deformation caused by prolonged tensile stress at high temperatures—as the reason the blades failed.
While the specific trigger for the creep was not definitively established, the investigation noted that the compressor-turbine blades were well within their inspection interval, having flown only 712 hours since the last overhaul. However, it was noted that operating engines outside of specified temperature or torque limits can lead to creep and reduced component lifespan.