Weather conditions appeared to be perfect with blue skies posing no visibility problems.
But for some reason the single-seat autonomous glider plummeted into a field near a farm close to Romont.
The pilot, a Swiss man living in Bern, was killed upon impact, Fribourg cantonal police said.
The plane he was flying would have been normally capable of gliding without the use of an engine.
A neighbour noticed the aircraft appeared to be in difficulty, Le Matin newspaper reported.
“At first I believed he was going to end his flight on the roof of the tennis club,” he said.
But then the plane disappeared from view.
Police said there were no other injuries.
Fire fighters from Romont arrived at the scene to prevent fuel aboard the aircraft from contaminating the soil.
The plane was flying from Romont in the direction of Fribourg, police said.
The Swiss accident investigation service (SESA) is looking into the causes of the crash.