Abstract: Method for producing a semi-finished product for a wing-shaped element having, a front and rear edge, an arched bottom and a top wall that extends some distance apart between the front edge and the rear edge, includes: bending the sheet by forming two panels (3, 4) and a curved region which the panels adjoin, placing a former in the bent sheet with the front edge of the former positioned in the curved region, forcing a pressure member towards a rubber cushion with the bent sheet enclosed therebetween and deforming the sheet, placing the shaped sheet in a rubber press including a bottom block having a cavity with a shape approximately corresponding to the of one of the walls of the shaped sheet, pressing the shaped sheet with former between the bottom block and a rubber mat, removing the semi-finished product from the rubber press.