Incident
While conducting fire suppression operations, an airplane experienced a loss of engine power during a normal application run over the fire. The pilot reported that the engine power was lost, and due to unsuitable terrain for an emergency landing, the pilot ditched the airplane into a nearby river. The airplane sustained substantial damage as a result of the forced landing.
Post-Accident Examination
A post-accident inspection of the turbine engine was conducted. The examination revealed that a compressor turbine blade was fractured in the first serration of the fir-tree root. Personnel from the Materials Laboratory examined the fracture face of the affected turbine blade and reported that the fracture surface appeared smooth with a curving boundary, typical of fatigue. Fatigue striations and ratchet marks, typical of high-cycle fatigue propagation, were observed. Near the fatigue origin, no surface damage was observed, and no material anomalies were visible on the fracture surface.