The Transportation Safety Board of Canada says investigators have not been able to determine why a crop-dusting plane stalled just before a fiery crash in Saskatchewan last summer that killed the pilot.
The board has released its report on the accident that happened on the evening of July 12 near Arborfield, about 260 kilometres northeast of Saskatoon.
The pilot of the single-engine Cessna AGtruck, operated by Clayton Air Service, had just finished spraying a field near Carrot River when he went down in some trees.
Investigators say he was an experienced aviator, the plane had fuel and had been properly maintained, and the weather was not a factor.
They determined that the shallow angle of the impact, little forward speed and no wreckage trail indicated an aerodynamic stall.
But their report concludes that the reason for the stall could not be found because of the mangled and burned wreckage, lack of witnesses and no flight data information.
The TSB said the pilot, whose name was not released by authorities, texted the company to notify them that he had completed his spraying job and was returning to Arborfield.
Soon after, a bystander heard a loud aircraft engine noise, followed by an explosion and smoke. A second explosion occurred and the bystander called emergency services after a quick survey of the crash scene.
The plane's emergency locator transmitter did not activate because it had been severely damaged by the impact and fire.
The crash was the third on the Prairies in about a week involving crop-dusting operations.
Two days before the Arborfield accident, a pilot was injured when the helicopter he was using to spray a field struck a power line and went down in the Rural Municipality of Eye Hill in western Saskatchewan.
Prior to that, a pilot suffered minor injuries when his aircraft plunged into a swamp after encountering strong winds while trying to land at the airport in Russell, Man.
