Accident Sequence
The flight, which was loaded with fertilizer, took off and experienced a loss of engine power. The pilot performed a forced landing, during which the airplane's landing gear entered a ditch and separated from the aircraft.
Pilot Report
The pilot reported that earlier takeoffs under similar load conditions had been completed without incident. During the accident flight, the pilot stated that initially the aircraft accelerated normally during the takeoff roll. However, immediately after breaking ground, during the initial climbout, the engine began to lose power, and the aircraft began to lose lift. The airplane continued to sink with partial power until impact.
Engine Examination
Examination of the engine revealed no exterior damage. Subsequent teardown of the engine disclosed that improper atomization of the fuel resulted in a non-atomized fuel stream at the first-stage turbine rotor. Subsequent atomization and ignition of this fuel caused a localized area of increased temperature and non-uniform thermal damage to the second- and third-stage turbine stators.
Findings
The localized area of increased temperature led to thermal damage to the second- and third-stage turbine rotors and increased second- and third-stage turbine rotor blade tip clearance. This condition rendered the engine incapable of producing full power. There was no evidence that the engine control system components contributed to the loss of engine power reported during the accident flight.