Accident Summary
According to the pilot, the aircraft had 90 gallons of fuel at departure, and he reported hearing no unusual engine sounds during the loss of engine power. The pilot had finished a spraying run and was returning to his airstrip for another load, flying at 150 feet above ground level, when the engine torque indication decreased to 30 percent. As he tried to increase power, the engine stopped, and the pilot executed an emergency landing in a muddy field.
Engine Examination
Post-accident inspection revealed that the compressor, turbine, accessory gear box, and reduction gear box all rotated freely. The chip detector was free of contaminants. The fuel lines to the engine, the fuel filter, and its bowl were unobstructed. No external contaminants were observed on the igniter. The engine pneumatic lines were intact and showed no signs of leakage. One blade of the first stage turbine rotor and two blades of the power turbine were found fractured. The compressor and turbine housing exhibited twisting without any localized outward deformations or punctures.
Fuel System Examination
The fuel-oil heater was intact; internal examination estimated a 50/50 ratio of fuel to water. The high pressure fuel pump and fuel control units were examined by Pratt & Whitney under the supervision of the Transportation Safety Board of Canada (TSB) and no anomalies were noted. The TSB concurred with the report that dynamic tests to the Fuel Control did not identify any indications that would have precluded appropriate engine performance. The gear stage was observed to be in good condition when ignoring damage created during the suspected field inspection of the pump. Metallic debris found in the field inspection of the high pressure fuel filter bowl was considered normal in that area.