The plane suffered a malfunction and “fell almost vertically” soon after taking off from the Nancy-Essey airfield on the outskirts of the city of Nancy, the region’s prefect, Yves Séguy, said.…
On another site I read a comment: "Look at the elevator trim tabs. They are full nose up. This is a known issue with the PC6 in jump operations. You need full up nose trim to land it empty. On the next takeoff with a load of jumpers, you have to reset the trim before takeoff." No idea if that is a possibility, nor have seen the picture.